Sperm whales have their own unique cultures, accents, and potentially a phonetic alphabet. A team from MIT’s Computer Science & Artificial Intelligence Laboratory (CSAIL) and Project CETI (Cetacean Translation Initiative) may have decoded this phonetic alphabet that reveals sophisticated structures within sperm whale communication that could be similar to human phonetics and other animal linguistic systems. 

“Sperm whale calls are, in principle, capable of expressing a wider space of meanings than we previously thought!” MIT computer science graduate student Pratyusha Sharma tells PopSci. Sharma is a co-author of a new study published May 7 in the journal Nature Communications that describes these findings. 

Sperm whale ABCs

With some of the largest brains of any species on Earth, sperm whales have complex social behaviors. They travel in pods and have various cultural groups that dive and hunt together and even take turns looking after younger whales. They do this all in almost complete darkness, so they need strong communication to coordinate their lives in the ocean’s deepest depths.

[Related: Science Says Sperm Whales Could Really Wreck Ships.]

Sperm whales use a complex system of codas–short bursts of clicks–to communicate. In this study, the team collected 9,000 codas from sperm whale families in the Eastern Caribbean sperm observed by The Dominica Sperm Whale Project. They used acoustic biologging tags, called D-tags that were deployed on whales. The D-tags captured details of the whales’ vocal patterns. 

The team found that these short groups of clicks vary in structure depending on the conversational context. With this data in hand, they used a mix of algorithms for pattern recognition and classification, and on-body recording equipment. It revealed that the communications were not random or simple, but more structured and complex. 

The sperm whale’s essentially have their own phonetic alphabet. Various auditory elements that the team call rhythm, tempo, rubato, and ornamentation work together to form a large array of distinguishable codas. Depending on the context of the conversation, the whales can systematically modulate certain aspects of their codas. They may smoothly vary the duration of the calls–rubato–or add in some extra ornamental clicks. The team also found that the building blocks of these codas could be combined in various ways. The whales can then build many distinct vocalizations from these combinations. 

“The sperm whale communication system is a combinatorial coding system,” says Sharma. “Looking at a wider communicative context allowed us to discover that there is fine-grained variation in the structure of the calls of sperm whales that are both perceived and imitated in the course of their exchange.”

Using AI

The team developed new visualization and data analysis techniques that found individual sperm whales could emit various coda patterns in long exchanges. Using machine learning is important for pinpointing the specifics of their communications and predicting what they may say next. 

[Related: How bomb detectors discovered a hidden pod of singing blue whales.]

Scientists are interested in determining if these signals vary depending on the ecological context they are given in and how much the signals follow any potential rules similar to grammar that the listeners recognize. 

“The problem is particularly challenging in the case of marine mammals, because scientists usually cannot see their subjects or identify in complete detail the context of communication,” University of Pennsylvania Psychology Professor Emeritus Robert Seyfarth said in a statement. “Nonetheless, this paper offers new, tantalizing details of call combinations and the rules that underlie them in sperm whales.” Seyfarth was not involved in this study.

Alien communication on Earth

In future studies, CETI hopes to figure out whether elements like rhythm, tempo, ornamentation, and rubato carry specific intentions when communicated. This could provide insight into a specific linguistic phenomenon where simple elements are combined to present complex meanings. This “duality of patterning” was previously thought to be unique to human language. 

Research like this also parallels hypothetical scenarios in which humans contact alien species and need to communicate. 

“It’s about understanding a species with a completely different environment and communication protocols, where their interactions are distinctly different from human norms,” says Sharma. “Essentially, our work could lay the groundwork for deciphering how an ‘alien civilization’ might communicate, providing insights into creating algorithms or systems to understand entirely unfamiliar forms of communication.”

The post Sperm whales may have their own ‘alphabet’ appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Despite the reputation for being the trash pandas of the bird world, seagulls are kind of the masters of evolution. They can survive and thrive alongside humans, have a remarkable memory, and some have been observed using pieces of food to bait fish the way primates use tools. The seagull species that have bigger brains that are also more likely to nest on coastal cliffs may also be better adapted to breed in urban environments. 

A study published April 25 in the journal Frontiers in Ecology and Evolution found that more than half of cliff-nesting gull species that also nest in cities and towns have bigger brains. Species such as the Herring Gull, the Lesser Black-backed Gull, and the Black-legged Kittiwake potentially have a behavioral flexibility that allows them to nest in more challenging locations like rooftops.

“Many people will be familiar with gulls nesting and foraging in urban areas,” Madeleine Goumas, study co-author and a postdoctoral researcher specializing in herring gulls at the University of Exeter in England, said in a statement. “It’s not something you might expect from a seabird, so we wanted to try to understand why they do it.”

[Related: Seagulls hunger for food touched by human hands.]

In the study, the team combed through various research databases to find records of urban breeding and foraging among gulls and data on brain size by species. They then mapped a range of the different species present. 

Out of 50 gull species, 13 were recorded as using urban areas to breed, while 13 were recorded using urban areas to forage for food. Nine species bred and fed in more building-heavy environments. 

When they compared the figures for breeding with the birds’ known habits and brain size, they found that 10 out of the 19 cliff-nesting gull species (53 percent) also nested in urban areas. Only three out of 28 (11 percent) of generally non-cliff-nesting species nested in both spaces. 

[Related: The birds of summer patrolling Ocean City’s boardwalk.]

“We found that gull species with larger brains are more likely to be cliff-nesters, and cliff-nesting species are more likely to breed in urban areas,” study co-author and University of Exeter evolutionary biologist Neeltje Boogert said in a statement. “We also found that cliff-nesting is probably not something that was shared by the ancestor of gulls, so it is a relatively recent adaptation.”

They also point out that this is not a fixed or instinctive behavior in most gulls. The non-cliff-nesting gull species nest exclusively on the ground, most most traditionally cliff-nesting species can nest in both spaces. 

“This suggests that bigger brains enable these gull species to be flexible with regard to where they choose to nest, and this allows them to use unconventional sites, like buildings, for raising their young,” said Goumas.

[Related: Piping plovers are in trouble, but there’s some good news.]

In terms of foraging, the researchers found that neither brain size nor the shape of their wing were good indicators of seagull behavior in urban environments. The team also looked at the status of the gulls on the International Union on Conservation of Nature’s Red List. The gulls with stable or increasing populations were more than twice as likely to be observed using urban habitats than the species that are decreasing. Of the 10 Threatened or Near Threatened species, only the Black-legged Kittiwake was known to use urban spaces.

Observing how gull species function in populated areas with humans and buildings is important for conservation. Seeing what factors allow some to survive and thrive while others do not can inform why some aren’t faring as well. 

“Urbanization is a major problem for a lot of animals,” said Goumas. “It looks like some gull species have managed to overcome some of the challenges that prevent other animals from using urban areas, but we need more long-term studies as well as comparative studies on other taxa to fully understand the impacts of urban living.”

The post Bigger-brained gull species thrive in urban spaces appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Observers have documented multiple animal species using plants for self-medicinal purposes, such as great apes eating plants that treat parasitic infections or rubbing vegetation on sore muscles. But a wild orangutan recently displayed something never observed before—he treated his own open wound by activating a plant’s medical properties using his own spit. As detailed in a study published May 2 in Scientific Reports, evolutionary biologists believe the behavior could point toward a common ancestor shared with humans.

The discovery occurred within a protected Indonesian rainforest at the Suaq Balimbing research site. This region, currently home to roughly 150 critically endangered Sumatran orangutans, is utilized by an international team of researchers from the Max Planck Institute of Animal Behavior to monitor the apes’ behavior and wellbeing. During their daily observations, cognitive and evolutionary biologists noticed a sizable injury on the face of one of the local males named Rakus. Such wounds are unsurprising among the primates, since they frequently spar with one another—but then Rakus did something three days later that the team didn’t expect.

After picking leaves off of a native plant known as an Akar Kuning (Fibraurea tinctoria), well-known for its anti-inflammatory, anti-fungal, and antioxidant properties, as well as its use in traditional malaria medicines, Rakus began to chew the plant into a paste. He then rubbed it directly on his facial injury for several minutes before covering it entirely with the mixture. Over the next few days, researchers noted the self-applied natural bandage kept the wound from showing signs of infection or exacerbation. Within five days, the injury scabbed over before healing entirely.

Such striking behavior raises a number of questions, particularly how Rakus first learned to treat his face using the plant. According to study senior author Caroline Schuppli, one possibility is that it simply comes down to “individual innovation.”

“Orangutans at [Suaq] rarely eat the plant,” she said in an announcement. “However, individuals may accidentally touch their wounds while feeding on this plant and thus unintentionally apply the plant’s juice to their wounds. As Fibraurea tinctoria has potent analgesic effects, individuals may feel an immediate pain release, causing them to repeat the behavior several times.”

[Related: Gorillas like to scramble their brains by spinning around really fast.]

If this were the case, it could be that Rakus is one of the few orangutans to have discovered the benefits of Fibraurea tinctoria. At the same time, adult orangutan males never live where they were born—they migrate sizable distances either during or after puberty to establish new homes. So it’s also possible Rakus may have learned this behavior from his relatives, but given observers don’t know where he is originally from, it’s difficult to follow up on that theory just yet.

Still, Schuppli says other “active wound treatment” methods have been noted in other African and Asian great apes, even when they aren’t used to disinfect or help heal an open wound. Knowing that, “it is possible that there exists a common underlying mechanism for the recognition and application of substances with medical or functional properties to wounds and that our last common ancestor already showed similar forms of ointment behavior.”

Given how much humans already have in common with their great ape relatives, it’s easy to see how this could be a likely explanation. But regardless of how Rakus knew how to utilize the medicinal plant, if he ever ends up scrapping with another male orangutan again, he’ll at least know how to fix himself up afterwards.

The post Orangutan observed using a plant to treat an open wound appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

The saber-toothed cats that once prowled modern day California had more distinct dental features than even their sabers would suggest. Some of the complete skulls had a tooth socket occupied by two teeth–a permanent saber tooth and a baby tooth that would eventually fall out. These double-toothed sockets may have helped stabilize their signature front fangs and keep them from breaking off. The findings are described in a study published April 8 in the journal The Anatomical Record. 

Sharp, but easily lost teeth

The study looked at saber-toothed cat fossils found in the La Brea Tar Pits in Los Angeles. There are at least five separate lineages of saber-toothed animals that have evolved around the world. The species Smilodon fatalis roamed widely across North America and into Central America, before going extinct about 10,000 years ago.

Paleontologists studying these fossils have been stumped by why the adult animals with two canines that are more like thin-bladed knives avoided breaking them. During periods of food scarcity, saber-toothed cats broke their teeth more often than they did during times of plenty, potentially due to altered feeding strategies and eating rocks. Paleontologists also still do not know how saber-toothed animals hunted prey without completely breaking these unwieldy teeth. 

In an earlier study, a team from the University of California, Berkeley speculated that a baby tooth helped stabilize the permanent tooth against sideways breakage as it emerged from the gums. The baby tooth–also called a milk canine–are the types of teeth that all mammals grow and lose sometime before adulthood. The growth data seemed to imply that the two teeth sat there together for up to 30 months into the animal’s adolescence. 

[Related: Mighty sabertooth tigers may have purred like kittens.]

To investigate this tooth stabilization theory for the new study, the team used computer models that simulate a saber-tooth’s strength and stiffness against the sideways bending that happens when the saber tooth grows outwards. They also tested and bent plastic models of saber teeth. They found evidence that while fearsome, the saber tooth would have been increasingly vulnerable to breaking off as they emerged from the gums. Having the baby or milk tooth behind it would have worked like a buttress to make it significantly more stable. 

The temporary baby milk canine remaining behind long after the permanent saber tooth erupted indicates that it would have stayed in until the maturing cats learned how to hunt without damaging them. 

“The double-fang stage is probably worth a rethinking now that I’ve shown there’s this potential insurance policy, this larger range of protection,” study co-author and Cal Berkley paleontologist Jack Tseng said in a statement. “It allows the equivalent of our teenagers to experiment, to take risks, essentially to learn how to be a full-grown, fully fledged predator. I think that this refines, though it doesn’t solve, thinking about the growth of saber tooth use and hunting through a mechanical lens.”

Applying some beam theory

Some of the double-fanged specimens found from the La Brea tar pits are considered rare cases of animals with a delayed loss of a baby tooth. This gave Tseng the idea that maybe they had an evolutionary purpose. He used  the beam theory engineering analysis to model real saber teeth.

“According to beam theory, when you bend a blade-like structure laterally sideways in the direction of their narrower dimension, they are quite a lot weaker compared to the main direction of strength,” said Tseng. “Prior interpretations of how saber tooths may have hunted use this as a constraint. No matter how they use their teeth, they could not have bent them a lot in a lateral direction.”

The beam theory combined with computer models that simulated the sideways forces of a saber tooth could withstand before breaking. As the tooth got longer, it became easier to bend, increasing the chance of breakage.

[Related: This tiger-sized, saber-toothed, rhino-skinned predator thrived before the ‘Great Dying.’]

When a supportive baby tooth was added to the beam theory model, the stiffness of the permanent saber kept pace with the bending strength. This baby tooth essentially reduced its chance of breakage. 

The study has implications for how saber-toothed cats and other saber-toothed animals like Africa’s Inostrancevia africana may have hunted as adults. They likely used their predatory skills and strong muscles to compensate for the more vulnerable canines. 

The post How saber-toothed cats’ baby teeth kept their adult fangs from breaking appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

New research is throwing some cold water on the idea that the fearsome Tyrannosaurus rex was as smart as a primate. These possibly scaly-lipped theropods were about as smart as living reptiles like crocodiles, but not quite as intelligent as monkeys. The findings are detailed in a study published April 26 in the journal The Anatomical Record 

How smart was the T. rex?

In 2023, a study from Vanderbilt University neuroscientist Suzana Herculano-Houzel set off a dinosaur-sized debate. Herculano-Houzel proposed that dinosaurs like T. rex had an exceptionally high number of neurons–over 3 billion of them, or more than a baboon. This higher number of neurons could mean that they were more intelligent than assumed. 

The paper theorized that these high neuron counts could inform their intelligence, metabolism, and even give them some more monkey-like habits. They could have used tools and transmitted knowledge culturally like modern day primates, according to Herculano-Houzel’s study.

These bold claims that such a large and powerful reptilian carnivore could have been intelligent enough to sharpen tools and transmit knowledge shook the paleontology world.

[Related: Is T. rex really three royal species? Paleontologists cast doubt over new claims.]

Taking another look

In this new study, an international team of paleontologists, neuroscientists, and behavioral scientists argues that researchers should look at multiple lines of evidence when reconstructing long-extinct species. These include skeletal anatomy, bone composition, trace fossils that show movement, and the behaviors of their living relatives.

“Determining the intelligence of dinosaurs and other extinct animals is best done using many lines of evidence ranging from gross anatomy to fossil footprints instead of relying on neuron number estimates alone,” study co-author and University of Bristol paleontologist Hady George said in a statement.

The study reexamined the techniques that were used to predict both number of neurons and brain size in dinosaurs as well as decades of previous research. They found that the assumptions made about brain cavity size and corresponding neuron counts were unreliable. 

“Neuron counts are not good predictors of cognitive performance, and using them to predict intelligence in long-extinct species can lead to highly misleading interpretations,” Ornella Bertrand, a study co-author and mammalian paleontologist at the Institut Català de Paleontologia Miquel Crusafont said in a statement.

Despite being very similar to big birds, dinosaurs were reptiles. As reptiles, they have very different brains than birds or mammals, but brain tissue does not fossilize. To study what their brains must have been like, scientists look to their skulls for clues. Reptile brains typically don’t fill up their skull cavity and they also tend to have a lot of cerebrospinal fluid taking up space. 

“The first time I dissected an alligator brain, I took the top of the skull off and I went, ‘Where is the brain?’ Because there is this big space in there,” study co-author and University of Alberta neurophysiologist Doug Wylie said in a statement.

Reptile brains are also packed more loosely with neurons than bird or mammalian brains. They also don’t have the same kinds of connections and circuits in their brains, which would have limited the complexity of their social behaviors.

Neurons scale up

The size of the animal is also a major factor. An adult male baboon can range from 30 to 88 pounds, while a T. rex could be over 15,000 pounds. Number of neurons typically scales to body size, according to the team.

“We don’t know why it’s true, but it is true,” said study co-author and University of Alberta comparative neurobiologist Cristian Gutierrez-Ibanez said in a statement. “A larger animal needs more neurons.”

[Related: Giganotosaurus vs. T. rex: Who would win in a battle of the big dinosaurs?]

The team believes that the T. rex needed a huge number of neurons for just maintaining basic biological functions with such a large body and wouldn’t have had any leftover for things like cultural knowledge transmission or tool usage. 

The study also found that their brain size had been overestimated, particularly the forebrain. The neuron counts could have also been overestimated and the neuron count estimates are not a reliable guide to intelligence.

“The possibility that T. rex might have been as intelligent as a baboon is fascinating and terrifying, with the potential to reinvent our view of the past,” study co-author and University of Southampton palaeozoologist Darren Naish said in a statement. “But our study shows how all the data we have is against this idea. They were more like smart giant crocodiles, and that’s just as fascinating.”

In response to this new study re-examining her work, Herculano-Houzel told the Los Angeles Times, “I am delighted to see that my simple study using solid data published by paleontologists opened the way for new studies. Readers should analyze the evidence and draw their own conclusions. That’s what science is about!”

The post T. rex was probably about as intelligent as a crocodile appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Red squirrels living in Canada’s Yukon territory can have a pretty hard knock life. Bitterly cold winters, resource scarcity, intense competition for habitat, threats from large predators like the Canada lynx, and even take big reproductive risks for their genetic fitness. All of these stressors take their toll on these resilient rodents. Their early life struggles can also leave a lasting mark. The more challenges young red squirrels face in the year they’re born, the shorter their adult lifespan. The findings are detailed in a study published April 24 in the journal Proceedings of the Royal Society B: Biological Sciences and could have some implications for humans. 

Food booms

Red squirrels are about 11 inches long and weigh just over half a pound on average. They are known for their rust colored fur and “scolding chatter” above the trees. The new study uses data collected by the Kluane Red Squirrel Project, a multi-university long-term field study. The project has tracked and studied thousands of wild North American red squirrels in the southwestern region of the Yukon for more than 30 years that individually tags and tracks individual red squirrels to learn how they deal with all that’s thrown at them  . 

The new study analyzing the observations found that red squirrels that survive past their first year go on to live about 3.5 years on average. However, early life adversity like food scarcity can cut their life expectancy by at least 14 percent.

[Related: A Medieval strain of leprosy is infecting squirrels in the UK.]

“The ecosystem red squirrels inhabit in this region is unique,” study co-author and University of Arizona ecologist and evolutionary biologist Lauren Petrullo said in a statement. “Every three to seven years, their favorite food–seed from cones of white spruce trees–is produced in superabundance during what we call a food boom.”

The team found that even though these food booms are rare, they can interrupt some biological processes for the squirrels and help shape their lifespans.

“If a squirrel had a harsh first year of life, if they were lucky enough to experience a food boom in their second year of life, they lived just as long–if not longer–in spite of early-life adversity,” said Petrullo.

Rodents as proxies

Rodents like squirrels, rice, and mats, are often used as models for humans in a lab setting. However, the laboratory environment often has limited relevance to the bigger pictures of what is going on at an ecological and evolutionary level. 

“It can be hard to really replicate the ecological challenges that animals have evolved to cope with in a lab setting,” said Petrullo. 

Wild red squirrels can offer scientists a chance to better study the role that early-life environment plays. Petrullo and her colleagues hope that continued observations in the wild can help them learn more about the biological mechanisms that link squirrels’ early developmental conditions with their later-life survival. This could have some insights into our understanding of human resilience. 

[Related: Nature wasn’t healing: What really happened with wildlife during pandemic lockdowns.]

“Our findings in red squirrels echo what we know about how early-life adversity can shorten adult lifespan in humans and other primates,” Petrullo said. “Humans vary widely in how vulnerable or resilient they are to challenges faced during early development. Our study demonstrates that future environmental quality might be an important factor that can explain why some individuals appear to be more, or less, susceptible to the consequences of early-life adversity.” 

‘Born with a silver spoon’

While growing up as a young red squirrel in the Yukon can be quite difficult, there are some things that can go right. 

“Some red squirrels have the luck of being born into gentler early environments, akin to being born with a silver spoon,” Petrullo said. “Because of this, we’ve got this really nice individual variation in early-life environmental quality across a natural ecological environment.”
However, as global temperatures continue to climb, this environment is expected to see a good deal of change. It’s possible that food booms and other ecological patterns could change right alongside the climate and the connections between early-life experiences and lifespan could also shift. According to Petrullo, these changes could offer more insight into how animals may continue to adapt to environments that are only getting more challenging to survive in. Future study could also help scientists learn more about what environmental factors can buffer these squirrels from ongoing environmental threats.

The post Early trauma can shorten a red squirrel’s lifespan appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Many marine organisms–including sea worms, some jellyfish, sea pickles, and more–can emit ethereal glow through a process called bioluminescence. The evolutionary origins of this light production remain a mystery, but an international team of scientists have found that bioluminescence may have first evolved in a group of marine invertebrates called octocorals at least 540 million years ago–nearly 300 million years earlier than they previously believed. This new timeline could help scientists unravel bioluminescence’s origin story. The findings are detailed in a study published April 23 in the journal Proceedings of the Royal Society B.

What is bioluminescence? 

Bioluminescent organisms produce light via chemical reactions. This ability has independently evolved at least 94 times in nature. Bioluminescence is involved in multiple animal behaviors including communication, courtship, camouflage, and hunting. Fireflies, glowworms, and even some species of fungi on land are also considered bioluminescent organisms. 

“Nobody quite knows why it first evolved in animals,” Andrea Quattrini, a study co-author and the Smithsonian Museum of Natural History’s curator of corals, said in a statement. 

The earliest dated example of bioluminescence in animals was believed to be roughly 267 million years ago in small marine crustaceans known for a mucus-filled synchronized mating dance called ostracods, until this new research turned back the clock. 

An octocoral evolutionary tree

In the study, the team looked back into the evolutionary history of octocorals to search for clues to when it first appeared in animals. Octocorals are an ancient and frequently bioluminescent group of living animals that includes sea fans, sea pens, and soft corals. Just like hard corals, octocorals are tiny colonial polyps that build up a reef structure, but they are primarily soft bodied and not stony. The octocorals that glow generally light up when they are bumped or otherwise disturbed. According to the team, this makes the precise function of their ability to produce light a bit of a puzzle  

[Related: These newly discovered bioluminescent sea worms are named after Japanese folklore.]

“We wanted to figure out the timing of the origin of bioluminescence, and octocorals are one of the oldest groups of animals on the planet known to bioluminesce,” study co-author and  Smithsonian National Museum of Natural History postdoctoral scholar Danielle DeLeo said in a statement. “So, the question was when did they develop this ability?”

They turned to a detailed evolutionary tree of octocorals that was built in 2022. This map of evolutionary relationships–or phylogeny–used the genetic data from 185 different species of octocorals. The team then placed two octocoral fossils of known ages within the tree based on  their physical features. They were able to use the fossils’ ages and their respective positions in the evolutionary tree to determine roughly when octocoral lineages split apart to become two or more branches. The team ultimately mapped out the evolutionary relationships that featured all of the known bioluminescent species alive today.

With this evolutionary tree and branches that contained bioluminescent species labeled, the team used a statistical technique called ancestral state reconstruction to analyze the relationships between the species.

“If we know these species of octocorals living today are bioluminescent, we can use statistics to infer whether their ancestors were highly probable to be bioluminescent or not,” said Quattrini. “The more living species with the shared trait, the higher the probability that as you move back in time that those ancestors likely had that trait as well.”

Multiple different statistical methods all reached the same result. About 540 million years ago, the common ancestor of all octocorals was very likely bioluminescent. This is about 273 million years earlier than in the ostracod crustaceans that were previously considered the earliest evolutionary example of bioluminescence in animals.

According to the team, the octocorals’ thousands of living species and relatively high incidence of bioluminescence suggests that glowing played a role in the group’s evolutionary success. While this does not exactly answer what octocorals are using bioluminescence for, the fact that it has been retailed for so long shows how important this form of communication has become for their survival. 

Conservation implications

Now that the team knows that the common ancestor of all octocorals likely could already produce its own inner glow, they are interested in conducting a more thorough count of which of the group’s more than 3,000 known living species are still bioluminescent and which have lost the trait over time. This may have them pinpoint a set of ecological circumstances that correlate with bioluminesce and potentially shed some light on its function. 

The team is also working on creating a genetic test to determine if an octocoral species has functional copies of the genes for luciferase–an enzyme involved in bioluminescence. Future studies could even show that bioluminescence is even more ancient and embedded in coral’s evolutionary history. 

[Related: Surprise! These sea cucumbers glow.]

The study also points to evolutionary insight that could help monitor and manage octocorals in today’s oceans. They are currently threatened by mineral mining, fishing, oil and gas extraction and spills, and human-made climate change. 

The National Oceanic and Atmospheric Administration (NOAA) recently confirmed that the planet is currently experiencing the fourth global coral bleaching event on record and the second in the last 10 years due to heat stress from increasingly warming oceans. Octocorals can bleach the way that hard corals can under extreme temperatures. Understanding more about how they use bioluminescence could help scientists better identify their habitats and monitor their behaviors. Better knowledge of their genetics and what they need to survive can also inform better conservation policies for these marine organisms. 

The post Bioluminescence may have evolved 300 million years earlier than scientists previously thought appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Lampreys look like something out of a horror movie, with their sucky mouths chock full of teeth, eel-like bodies, and parasitic behaviors. These “water vampires” represent a bit of an evolutionary fork in the road between vertebrates and invertebrates, and the scientific debate about just how closely related we are to these carnivorous fish has taken yet another turn. 

Scientists found some evidence that lampreys have a rudimentary sympathetic nervous system–which is believed to control the fight-or-flight reaction in vertebrates. The findings are detailed in a study published April 17 in the journal Nature and could prompt a rethink of the origins of the sympathetic nervous system.

Lampreys are the closest living organisms scientists have to studying the fish ancestors that vertebrates evolved from some 550 million years ago. They belong to an ancient vertebrate lineage called Agnatha–or jawless fish. Some scientists believe that they represent the earliest group of vertebrates that is still living and can give us an evolutionary window into all vertebrate ancestors. Other scientists question the theories due to a lack of lamprey evidence in the fossil record. 

[Related: Giant prehistoric lamprey likely sucked blood—and ate flesh.]

Scientists previously believed that lampreys did not have sympathetic neurons. These neurons are part of the sympathetic nervous system, a system of nerves that target the internal organs throughout the body including the gut, pancreas, and heart. The system works together to respond to dangerous or stressful situations. It also helps an organism’s body maintain homeostasis, making sure that the heart keeps pumping, the digestive system keeps moving, and more. 

In this new study, a team used lampreys to look at how developmental changes may have promoted the evolution of vertebrate traits like fight-or-flight. They found evidence of the types of stem cells that eventually form sympathetic neurons. The presence of these cells in lampreys could revise the timeline of when the sympathetic nervous system began to evolve. 

“Over a hundred years of literature has suggested that lamprey lack a sympathetic nervous system,” study co-author and California Institute of Technology biologist Marianne Bronner said in a statement. “Surprisingly, we found that sympathetic neurons do, in fact, exist in lamprey but arise at a much later time in lamprey development than expected.”

Bronner and her team studied neural crest cells. These are a kind of stem cells that are specific to vertebrates and give rise to the multiple cell types found throughout the body. Scientists previously believed that lampreys lacked the neural crest-derived precursors, or progenitors, that ultimately build the sympathetic nervous system.

According to Bronner, researchers previously looked for evidence of a sympathetic nervous system too early in lamprey development compared to other animals. For example, the sympathetic nervous system forms in the first two to three days of development in birds. 

[Related: You might have more in common with the sea lamprey than you realize.]

Study co-author and Cal Tech evolutionary biologist Brittany Edens looked at the neural crest–derived progenitor cells in lampreys that ultimately give rise to sympathetic neurons. She found that in lampreys, the neural crest–derived progenitors appear much later than other animals. They can appear as long as one month after fertilization. The cells also do not fully mature into neurons until about four months of development, during the fish’s larval stage.

It is still not known whether the sympathetic nervous system of lampreys controls fight-or-flight-like behaviors similar to other vertebrates. According to the team, these findings suggest that the developmental program that controls the formation of sympathetic neurons remains across all vertebrates, from lamprey to mammals. 

The post Lampreys offer clues to the origin of our fight-or-flight instinct appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Evolution is quite a wondrous and lengthy process, with some random bursts of activity that are responsible for the diversity of life on our planet today. These can happen on large scales like with the evolution of more efficient limbs. They also occur at microscopic cellular level, such as when different parts of the cell were first formed. 

Now, a team of scientists have detected a sign of a major life event that has likely not occurred for at least one billion years. They’ve observed primary endosymbiosis–two lifeforms merging into one organism. This incredibly rare event occurred between a type of abundant marine algae and a bacterium was observed in a lab setting. For perspective, plants first began to dot our planet the last time this happened. The results are described in two papers recently published in the journals Cell and Science. 

Where the ‘powerhouse of the cell’ and chloroplasts come from

Primary endosymbiosis happens when one microbial organism engulfs another. It then begins to use the swallowed organisms as an internal organ. The host provides the organism–now called an endosymbiont–several benefits including nutrients, energy, and protection. When it can no longer survive on its own, the engulfed endosymbiont becomes an organ for the host called an organelle.

“It’s very rare that organelles arise from these types of things,” Tyler Coale, a co-author of the Cell study and a postdoctoral scholar at the University of California, Santa Cruz said in a statement. “The first time we think it happened, it gave rise to all complex life.”

Endosymbiosis where the host life form becomes fundamental to another organism’s function has only happened three known times. All of these instances were a major breakthroughs for evolution, since merging with their hosts became fundamental for the endosymbionts very existence.

The first event was roughly 2.2 billion years ago. This is when a single-celled organism called archaea swallowed up a bacterium that eventually became the mitochondria. This specialized organelle is what every biology student learns is the “powerhouse of the cell” and its formation allowed for complex organisms to evolve. 

“Everything more complicated than a bacterial cell owes its existence to that event,” said Coale. “A billion years ago or so, it happened again with the chloroplast, and that gave us plants,” Coale said.

This second event occurred when more advanced cells absorbed cyanobacteria. Cyanobacteria can harvest energy from sunlight and they eventually become organelles called chloroplasts that can harvest energy from sunlight. The chloroplasts gave us another core principle of biology–green plants that can make food from the sun. 

With this latest endosymbiosis event, it’s possible that the algae is converting nitrogen from the atmosphere into ammonia that it can use for other cellular processes. However, it needs the help of a bacterium.

A new organelle?

In the paper published in Cell, a team of scientists show that this process is occurring yet again. They looked at a species of algae called Braarudosphaera bigelowii. The algae engulfed a cyanobacterium gives it a bit of a plant superpower. It can “fix” nitrogen straight from the air and combine it with other elements to form more useful compounds. This is something that plants normally can’t do.  

Nitrogen is a very important nutrient for life to exist and plants normally get it through mutual relationships with the bacteria that remain separate from the plant or algae. The team first thought that the B. bigelowii algae had this kind of symbiotic relationship with a bacterium called UCYN-A. The relationship had actually gotten much more close and serious.  

[Related: You have no idea how much you need these bacteria.]

They found that the size ratio between the algae and UCYN-A bacterium remains similar across different species related to the B. bigelowii algae. The growth appears to be controlled by an exchange of key nutrients, linking up their metabolisms. This synchronization of growth rates led the researchers to call UCYN-A organelle-like.

“That’s exactly what happens with organelles,” study co-author and UC Santa Cruz microbial oceanographer Jonathan Zehr said in a statement. “If you look at the mitochondria and the chloroplast, it’s the same thing: they scale with the cell.”

Introducing the nitroplast

To look for more lines of evidence that this bactrium is an organelle, they needed to take a deeper look inside. The study published in the journal Science used advanced X-ray imaging to get a look at the interior of the living B. bigelowii algae cells. It revealed that the replication and cell division was synchronized between both the host algae and the UCYN-A bacterium. It provided even more evidence of this organism merging process of primary endosymbiosis at work.

“Until this paper, there was still a question of is this still an ‘endosymbiont’, or has it become a true organelle?” Carolyn Larabell, a study co-author and faculty scientist at Berkeley Lab’s Biosciences Area and Director of the National Center for X-Ray Tomography, said in a statement. “We showed with X-ray imaging that the process of replication and division of the algal host and endosymbiont is synchronized, which provided the first strong evidence.”

They also compared the proteins of isolated UCYN-A bacteria to the proteins inside of the algae  cells. The team found that the isolated bacterium can only make roughly half of the proteins it needs. It needs its algal host to provide it with the rest of the proteins necessary for living. 

“That’s one of the hallmarks of something moving from an endosymbiont to an organelle,” said Zehr. “They start throwing away pieces of DNA, and their genomes get smaller and smaller, and they start depending on the mother cell for those gene products–or the protein itself–to be transported into the cell.”

The team believes that this indicates that UCYN-A can be considered a full organelle. They gave it the name “nitroplast,” and it potentially began to evolve around 100 million years ago. While that sounds long to our human sense of time, it’s a mere millisecond in evolutionary time when compared with mitochondria and chloroplasts.

Plenty of other questions about UCYN-A and its algal host remain unanswered and the team also plans to figure out UCYN-A and the alga operate and study different strains. Further study of nitroplasts could also determine if they are present in other cells and what their benefits may be. For example, it could have wide applications in agriculture.

“This system is a new perspective on nitrogen fixation, and it might provide clues into how such an organelle could be engineered into crop plants,” said Coale.

According to Zehr, scientists will likely find other organisms that have similar evolutionary stories as UCYN-A, but this discovery is “one for the textbooks.”

The post For the first time in one billion years, two lifeforms truly merged into one organism appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Life may “find a way,” but how living things evolve is not a neat and orderly process. Instead of a tidy family tree with straight lines added for each new generation, the birth of a new species is much more tangled in reality. New research into one butterfly genus found in the Amazon shows just how entangled those evolutionary lines may be. Hybrids between some species can produce new butterfly species that are genetically distinct from both parent species and their earlier ancestors. The findings are described in a study published April 17 in the journal Nature. 

A third hybrid

In the study, the team focused on the brightly colored Heliconius genus of butterflies found in Central and South America. They are a common model for studying how butterfly wing patterns evolved due to the wide variety of wings within the group. In an 1861 letter to Charles Darwin, naturalist Henry Walter Bates referred to the Heliconius butterflies found in the Amazon as “a glimpse into the laboratory where Nature manufactures her new species.”

For a deeper look into Heliconius’ evolution, the team on this new study harnessed the power of whole-genome sequencing. All living organisms have DNA that is made of four nucleotide bases–adenine, thymine, cytosine, and guanine. If you know the sequence of bases, you can identify the organism’s unique DNA fingerprint called a pattern. Sequencing determines these patterns and whole genome sequencing in a lab can determine the orders of these bases in one process.  

[Related: You might have more in common with the sea lamprey than you realize.]

The whole-genome sequencing indicated that a hybridization event occurred about 180,000 years ago between Heliconius melpomene and the ancestor of today’s Heliconius pardalinus butterflies. This event produced a third hybrid species called Heliconius elevatus. While it is descended from hybrids, H. elevatus is also a distinct butterfly species and has its own individual traits. These include color pattern, wing shape, flight characteristics, how they choose mates, and more. All three of these distinct species now fly together across a wide area of Amazon and indicate more evidence that hybrids are not always sterile as sometimes previously thought. 

“Historically, hybridization was thought of as a bad thing that was not particularly important when it came to evolution,” study co-author and Harvard University biologist Neil Rosser said in a statement. “But what genomic data have shown is that, actually, hybridization among species is widespread. Over the last 10 or 15 years, there’s been a paradigm shift in terms of the importance of hybridization and evolution.”

An evolutionary surprise

According to the team, this may alter how we view species and speciation. Scientists had generally believed that hybridization inhibited the generation of new species. Hybrid organisms are often born unhealthy or sterile and can’t reproduce, particularly when they are born with two different sex chromosomes. Most species are not perfectly intact tight units, but instead exchange a lot of DNA and can be considered “quite leaky.” The species that are evolving are actually exchanging genes constantly and it can trigger the evolution of new lineages. 

“Normally, species are thought to be reproductively isolated. They can’t produce hybrids that are reproductively fertile,” study co-author and Harvard University biologist James Mallet said in a statement. 

This is a different case for Heliconius  butterflies. They show that hybridization is not only occurring, but has driven the evolution of a new species in itself. While there is now evidence of hybridization between species, confirming if hybridization is involved in speciation has been difficult. 

[Related: Butterflies can remember specific flower foraging routes.]

“The question is: How can you collapse two species together and get a third species out of that collapse?” said Mallet.

This new research provides scientists with a next step in understanding how hybridization and speciation work in evolution. It could also help play a role in the planet’s biodiversity crisis, since fully understanding the question of what we really mean by “species” on a genetic level is important for conservation. It may also help in understanding the carriers of certain diseases. Multiple species of mosquitoes carry malaria, and while they are closely related, we still do not know how they interact or create new hybrids the way Heliconius butterflies do. 

As with evolution itself, this area of study will only continue to untangle as biologists learn more about what really makes a species a species. 

The post This butterfly hybrid thrived against evolutionary odds appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Earth used to be absolutely crawling with more megafauna. The fossil record is full of enormous birds like New Zealand’s Heracles inexpectatus, giant lemurs from Madagascar, large marine reptiles that would put today’s sea snakes to shame. Paleontologists have now found evidence of three unusual new species of giant fossil kangaroo in present day Australia and New Guinea. The creatures are described in a study published April 14 in the journal Megataxa and indicate that these species were likely much more diverse in terms of shape, range of habitat, and hopping method. 

“Living kangaroos are already such remarkable animals, so it’s amazing to think what these peculiar giant kangaroos could have been getting up to,” study co-author and Flinders University PhD student Isaac Kerr said in a statement.

Meet the giant kangaroos

The three new species belong to an extinct genus of giant kangaroos called Protemnodon that lived from five million to about 40,000 years ago. They would have looked somewhat similar to modern gray kangaroos, but were generally more squat and muscular. Some species were roughly 110 pounds, but others were up to twice as large as today’s biggest living kangaroos.

Protemnodon fossils are fairly common across Australia, but they have historically been found as individual bones instead of in complete skeletons. This has made it difficult for scientists to determine just how many species there were and how they differed in geographic range, movement, and size. 

[Related: What prehistoric poop reveals about extinct giant animals.]

“The fossils of this genus are widespread and they’re found regularly, but more often than not you have no way of being certain which species you’re looking at,” study co-author and Flinders University paleontologist Gavin Prideaux said in a statement. 

For this study, the team was able to use multiple complete fossilized kangaroo skeletons from Lake Callabonna in South Australia, which may help give scientists a more clear picture of these giant kangaroos. Researchers also reviewed all known species of Protemnodon and found that they were all quite different from one another. The animals also adapted to live in different environments and even had different methods of hopping. 

One very heavy, wayfaring kangaroo

One of the new species is named Protemnodon viator. The word viator means ‘traveler’ or ‘wayfarer’ in Latin. This wandering marsupial was also much bigger than other known giant kangaroos at weighing up to 374 pounds. According to the team, this is roughly twice as much as the largest living male red kangaroos. 

Protemnodon viator was also likely well-adapted to its arid central Australian habitat. It lived in a smaller geographic area than the red kangaroos of today. It was also long-limbed and could hop quickly and efficiently. 

A ‘robust’ creature and a swamp wallaby-like kangaroo

Another of the new species is named Protemnodon mamkurra and it connects the paleontologists of today with a famous scientist of the past. British paleontologist and naturalist Sir Richard Owen famously coined the term ‘dinosaur’ in 1842, but also described the first species of Protemnodon in 1874.

When he first found these giant kangaroo fossils, he followed a common scientific approach at the time. He mainly focused on fossilized teeth, seeing slight differences between the teeth of his specimens. He ultimately described six species of Protemnodon and further study chipped away at some of Owen’s early descriptions. He also suggested that some or all Protemnodon have four legs, While not all of them do, this study agrees that one of his species–Protemnodon anak–likely did have four legs. 

[Related: Giant beasts once roamed Madagascar. What happened to them?]

“However, our study suggests that this is true of only three or four species of Protemnodon, which may have moved something like a quokka or potoroo–that is bounding on four legs at times, and hopping on two legs at others,” Kerr said. “The newly described Protemnodon mamkurra is likely one of these. A large but thick-boned and robust kangaroo, it was probably fairly slow-moving and inefficient. It may have hopped only rarely, perhaps just when startled.”

The best of these fossil species comes from the Green Waterhole Cave in southeastern Australia, on the land of the Boandik people. The species name mamkurra, means ‘great kangaroo’ and was chosen by Boandik elders and language experts in the Burrandies Corporation.

According to Kerr, it is unusual for a single genus of kangaroo to live in such varied environments. “For example, the different species of Protemnodon are now known to have inhabited a broad range of habitats, from arid central Australia into the high-rainfall, forested mountains of Tasmania and New Guinea.”

The third new species is named Protemnodon dawsonae. It is known from fewer fossils than the other two, so it is more of a mystery. The team believes it was likely a moderate speed hopper and potentially similar to the living swamp wallaby. It was named in honor of Australian paleontologist Lyndall Dawson.

While most species became extinct about 40,000 years ago on mainland Australia, they potentially lived longer in New Guinea and Tasmania. Future studies could shed more light on their extinction, as it is still an enduring paleontological mystery. 

The post Super-muscular 374-pound kangaroos once thumped around Australia and New Guinea appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

From a human perspective, chimpanzees and bonobos often represent two sides of our very nature. Chimpanzees are seen as more conflict ready. Bonobos are considered more peaceful, even demonstrating cooperation between groups. Some new research into both great ape species paints a more nuanced picture of both species and their behavior. Bonobos appear to be actually more aggressive than researchers previously thought within their own communities. The findings are described in a study published April 12 in the journal Current Biology.

“Chimpanzees and bonobos use aggression in different ways for specific reasons,” study co-author and Boston University anthropologist Maud Mouginot said in a statement. “The idea is not to invalidate the image of bonobos being peaceful—the idea is that there is a lot more complexity in both species.”

Pushing, biting, and chasing

In the study, the team focused in male aggression, which is often tied to reproduction. They analyzed three bonobo communities at the Kokolopori Bonobo Reserve in the Democratic Republic of Congo and two chimpanzee communities at Gombe National Park in Tanzania. Researchers observed the behavior of 12 bonobos and 14 chimpanzees with a method called focal follows. This involves tracking one individual animal’s behavior for an entire day and noting how often the animal engaged in aggressive interactions, who they acted aggressively with, and whether or not they were physical. In great apes, these physical engagements included pushing, biting, or chasing an adversary. 

[Related: Popular chimpanzees set hand-holding trends for the whole group.]

“You go to their nests and wait for them to wake up and then you just follow them the entire day—from the moment they wake up to the moment they go to sleep at night—and record everything they do,” said Mouginot.

They found that the male bonobos aggressive more frequently than chimpanzees. Overall, bonobos engaged in 2.8 times more aggressive interactions and three times as many physical aggressions than chimpanzees.

Bonobo males were also almost exclusively aggressive towards other males, while chimpanzees were more likely to be aggressive towards females. Chimpanzees were also more likely to use “coalitions” of males, with 13.2 percent of chimpanzee aggression and only one percent of bonobo aggressions featuring these groupings. 

The altercations involving groups of males can also cause more injuries and community infighting can potentially weaken the group’s ability to fight off different groups of chimpanzees. Bonobos do not appear to have this issue since most of their disputes are one on one. They have never been observed to kill one another and are not believed to be territorial, which leaves their communities more free to fight amongst themselves instead of outsiders. 

Male ‘coalitions’

The more aggressive males in both species also had greater mating success. The team was surprised to see this in bonobos because they have a co-dominant social dynamic where females often outrank males and can be more decisive with mates. Chimpanzees have male-dominated hierarchies, where these male coalitions coerce the females into mating.

“Male bonobos that are more aggressive obtain more copulations with females, which is something that we would not expect,” said Mouginot. “It means that females do not necessarily go for nicer males.”

The team notes that female bonobos and chimpanzees are not exactly passive, but that female aggression warrants its own future research.

The self-domestication hypothesis

These new findings of higher rates of male-male aggression in bonobos contradict a prevailing hypothesis in primate behavior called the self-domestication hypothesis. This idea that goes back as far as Charles Darwin posits that evolution has selected against aggression in bonobos and humans, but not chimpanzees. 

[Related: Primates have been teasing each other for 13 million years.]

Some of the findings do support some parts of the self-domestication hypothesis, specifically related to aggression towards females. Compared to chimpanzees, male bonobos direct less aggression towards females. According to the team, this aligns with earlier findings that male bonobos rarely use coercive mating strategies, even if they are physically larger.

The team could not assess the severity of aggressive interactions in terms of whether they caused wounds or injuries. They hope to collect this type of data in the future, along with comparing aggressive behavior that varies between communities and subspecies.

“I’d love to have the study complemented with comparable data from other field sites so we can get a broader understanding of variation within and between species,” said Mouginot.

The post ‘Peaceful’ bonobos bite and push each other, actually appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Dolphins and other toothed whales–or Odontocetes–use their heads to create sounds that help them communicate, navigate, and hunt in their murky marine world. These sometimes vocal-fry-like sounds reveal information about their murky marine world that is critical for survival. Some new genetic analysis suggests that the collections of fatty tissues that enable echolocation in toothed whales may have evolved from their skull muscles and bone marrow,changing how these animals eat and sense the world around them. The findings are described in a study published in the April 2024 issue of the journal Gene. 

Toothed whales include numerous dolphin species as well as orcas, sperm whales, belugas, and narwhals. Echolocation produced by a bulbous mass of fat tissue inside of their heads called the melon. 

Alongside of the jawbone of dolphins and toothed whales is a group of sound producing extramandibular fat bodies (EMFB). Another set of acoustic fat deposits called the intramandibular fat bodies (IMFB) are located inside the jawbone. The evolution of the melon, the extramandibular, and intramandibular fat bodies was critical for echolocation to develop in these marine mammals. However, little is known about how these fatty tissues themselves originated genetically. 

“Toothed whales have undergone significant degenerations and adaptations to their aquatic lifestyle,” Hayate Takeuchi, a study co-author and PhD student at Hokkaido University in Japan,  said in a statement. 

One of these adaptations was the partial loss of their sense of smell and taste, alongside the gain of echolocation. To look closer at this and other adaptations at a genetic level, the team from Hokkaido University studied DNA sequences of genes that are expressed in these acoustic fat bodies. They measured the gene expressions in harbor porpoises (Phocoena phocoena) and Pacific white-sided dolphins (Lagenorhynchus obliquidens). 

[Related: This dolphin ancestor looked like a cross between Flipper and Moby Dick.]

They found that the genes which are normally associated with muscle function and development were active in the melon and EMFB’s on the outside of the jawbone. There was also evidence of an evolutionary connection between this fat and a muscle called the masseter muscle. In humans, the masseter muscle connects the lower jawbone to the cheekbones and is one of the the key muscles used in chewing.

“This study has revealed that the evolutionary tradeoff of masticatory muscles for the EMFB—between auditory and feeding ecology—was crucial in the aquatic adaptation of toothed whales,” study co-author and genome scientist and evolutionary biologist Takashi Hayakawa said in a statement. “It was part of the evolutionary shift away from chewing to simply swallowing food, which meant the chewing muscles were no longer needed.”

[Related: We finally know how baleen whales make noise.]

When the team analyzed the gene expression in the intramandibular fat on the inside of the jawbone, they found active genes related to some elements of immune response and regulation of a group of white blood cells that fight infection called T cells. The team believes that this is due to its proximity to bone marrow–which helps produce T cells–and requires more study.

The team also credited the Stranding Network Hokkaido as another important aspect of the research, as the samples used in this study were collected by them. The organization has  collected specimens of stranded whales along the seashore and river mouth in Hokkaido. Performing necropsies on stranded marine mammals have been critical for sampling and research to learn more about the potential causes of strandings and death, but also anatomy, physiology, and evolution. 

The post Toothed whales traded chewing for echolocation to evolve appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Worm bodies might not seem all that interesting. However, a closer look can also reveal how some worms use extra appendages to move through the water like “magic carpets,” while others detach their butts to procreate. Scientists have now discovered that a type of bristle worm is equipped with a complex vision system dominated by two really big eyes.

The Vanadis bristle worm’s eyes can potentially use ultraviolet (UV) light to communicate and find mates and/or food, which has not been well documented or studied in nature. The worms could also be among the only known bioluminescent animals that use UV light to glow. The findings are described in a study published April 8 in the journal Current Biology. 

Meet Vanadis bristle worms

The Vanadis bristle worms in this study are found around the island of Ponza, in the Mediterranean Sea west of Naples, Italy. It is a member of a family of large-eyed bristle worms called polychaeta. They are about six inches long and primarily eat plankton, algae, and bits of organic matter from dead organisms. As a pair, the worm’s eyes weigh about 20 times as much as the rest of the worm’s head, and appear like two giant red orbs are strapped to its body. If human eyes are as proportionally large, we would need to carry around roughly 220 extra pounds.  Since the worms are nocturnal and disappear when the sun is out, scientists wondered what they do with their eyes after and what they are used for.

[Related: How do animals see the world?]

In the study, a team from the University of Copenhagen in Denmark, Lund University in Sweden, and Tuscia University in Italy examined three species of bristle worms that they collected by hand in shallow water. They brought them back to a lab, where they analyzed their eyes in close detail. The team found that Vanadis’ eyesight is better and more advanced than previously believed. Its eyes can see very small objects and track their movements, despite having a more simple nervous system.

A ‘secret language’–for mating

The team is still trying to figure out how they evolved such sharp eyesight. The worms’ bodies  are transparent, except for their eyes that need to register light to work properly. This means that they can’t be inherently transparent, so their eyes becoming visible must come with some evolutionary trade-offs. Some aspects about having a transparent body with visible eyes must have had evolutionary benefits that outweigh the consequences.

What the worms gain remains unclear partially because they do not come out during the day, when eyes typically work best. 

“No one has ever seen the worm during the day, so we don’t know where it hides. So, we cannot rule out that its eyes are used during the day as well,” University of Copenhagen marine and neurologist Anders Garm said in a statement. “What we do know is that its most important activities, like finding food and mating, occur at night. So, it is likely that this is when its eyes are important.”

[Related: Microscopic worms use electricity to ride bumblebees like EVs.]

The team believes that part of the explanation is that these worms can see different wavelengths of light than humans can. Like many birds, reindeer, and other more complex organisms, the worm’s vision can see UV light that is invisible to the human eye. This could indicate that the purpose of the eyes is to see bioluminescent signals in the pitch-black night time sea. Bioluminescence occurs when organisms can produce light on their own. Glow-worms are a famous example that use certain chemicals to produce light within their bodies. 

“We have a theory that the worms themselves are bioluminescent and communicate with each other via light. If you use normal blue or green light as bioluminescence, you also risk attracting predators,” said Garm. “But if instead, the worm uses UV light, it will remain invisible to animals other than those of its own species. Therefore, our hypothesis is that they’ve developed sharp UV vision so as to have a secret language related to mating.”

The worms also may need to be on the lookout for UV bioluminescent prey. Regardless of what it is used for, the Vanadis worm could become the first animal proven to naturally create UV bioluminescence to communicate, according to Garm.

Robotics research and evolutionary debates

The team has begun working with robotics researchers from the University of Southern Denmark to investigate how to better understand the mechanism behind these eyes well enough to translate it into technology.

“Together with the robotics researchers, we are working to understand how animals with brains as simple as these can process all of the information that such large eyes are likely able to collect,” said Garm. “This suggests that there are super smart ways to process information in their nervous system. And if we can detect these mechanisms mathematically, they could be integrated into computer chips and used to control robots.”

Beyond robotics, their eyes could also help settle a heavy debate around evolutionary theory. Did eyes only evolve once into every form we know today or have they arisen several times in evolutionary history?

Vanadis has eyes that are built relatively simply, but have very advanced functions. They have simultaneously evolved in only a few million years–a relatively short span of time in terms of evolution. These worm eyes likely developed independently of more complex eyes like humans, and could help prove that the development of vision is possible over a relatively short time.

The post Tiny worm with enormous eyes may have a ‘secret language’ appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Nature comes in wild colors, like the electric blue tarantulas and brightly spotted poison dart frogs. Named after bull fighters, matador bugs (Anisoscelis alipes) are known for vibrant flag-like red decorations on their hind legs. These insects are native to Colombia, Costa Rica, Ecuador, Panama, Venezuela, and Mexico, and scientists have been stumped as to what their signature red flags on their legs are used for. A study recently published in the journal Behaviors Ecology found that this fancy leg waving is actually part of the matador bug’s elaborate defense strategy.

In animals, some of the most obvious and showy traits are usually expressed by males, like an elk’s large antlers or a peacock’s loud plumage. A 2022 study suggested that matador bugs’ leg movements were not a sexual display. Both male and female matador bugs like to flaunt their removable hind legs and the waving behavior did not change if there were potential mates around or not. It led researchers to question if their leg waving warns predators about a potential chemical defense and bad flavor or divert attacks towards their removable hindlegs to increase their chances of getting out alive.

[Related: Cicadas pee in jet streams like bigger animals.]

To try to answer what is going on with their legs, the team on the new study worked in Gamboa, Panama, a small town near the Panama Canal. They attached red flags that mimicked the matador bug’s accessories to the legs of crickets, and observed how predatory birds called motmots responded to the red flags. Motmots are large birds with iridescent feathers, long tails, keen eyesight, and a strong taste for crickets. The team spent about a month just catching the birds for the experiment.

“We placed the nets in areas of the forest where we saw that the birds moved the most and, when an individual was captured, it was immediately taken to the cages and tested,” study co-author and a research associate at the Smithsonian Tropical Research Institute (STRI) Jorge Medina said in a statement. “When the birds were finished with the tests, we released them back in the same area where they were captured.”

They found that the strikes from the birds were not primarily aimed at the hind leg flags. This indicated that the flags were not used as a way to deflect predator attacks. However, it supported the idea that some sort of chemical defense was potentially being used by the bugs as self-defense. 

The regular crickets were always attacked, but the ones with flags got fewer hits. Matador bugs themselves were actively avoided by the bird, whether they had flags or not. According to the team, this indicates that the flags are just one component of their defense strategy.

[Related: Bug-munching plant turns insect nurseries into death traps.]

To further test the idea that the birds didn’t like the taste of matador bugs, they offered both crickets and matador bugs to baby birds that had never seen them before. With or without their flags, the matador bugs seemed to warn the predators to stay away. When the chicks attacked, they demonstrated that the bugs were distasteful by shaking their heads and often refusing to eat more matador bugs. However, the crickets were readily attacked and eaten. 

“I was fascinated to see that when we outfitted tasty crickets with the matador bug flags they immediately became less appealing to their bird predators,” study co-author and STRI post-doctoral fellow Juliette Rubin said in a statement. “It seems like this warning signal is enough to make the birds cautious, but bugs themselves are so well equipped with ‘don’t eat me!’ signals that even without the flags, experienced birds wouldn’t touch them.”

The team believes that the flags appear to signal to birds that matador bugs are not a tasty or safe choice of a snack. These flags also collaborate with other parts of the bug’s characteristics to emphasize that message. This indicates that they are part of a complex defense strategy that likely evolved to protect them from birds. 

The post These insects give off major red flags appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

The living mammal family tree is full of diverse species–big blue whales, great apes, bats, rodents, and humans, to name just a few. The early evolution of mammals is a little bit murky, with some placental mammals even likely living alongside dinosaurs and others arising much later. 

Now, some teeth and ear bones uncovered in present day Inner Mongolia are offering some fresh insight into early mammalian evolution. The findings are described in two studies published April 3 in Nature that feature the work of scientists from the United States, Inner Mongolia, China, and Australia.

Keeping up with the shuotheriids–and their teeth

In the first study, scientists focused on the shuotheriids. This family of mouse-sized mammals from the Jurassic period had molars that are different from those in any living mammal. Their molars had a pseudotalonid– or a basin-like structure in their lower molars more similar to reptiles. By comparison, living mammals have a tribosphenic pattern that interlocks with upper molars when chewing food.  

“This unique tooth pattern has hindered our comprehension of shuotheriid relationships and the first steps in the evolution of mammaliaform species,” study co-author and Monash University paleontologist Patricia Vickers-Rich said in a statement.

With these unique back teeth, where these animals fit in the timeline of mammal evolution has been puzzling. Shuotheriids have previously been linked to a group called australosphenidans. This group includes living mammals that lay eggs like the platypus called monotremes. However, this relationship has been a bit controversial among scientists and leaves more questions that aren’t explained by some features seen in later mammals like different molars.

The team analyzed two newly uncovered and well-preserved skeletal fossils of shuotheriids. They lived in the Middle Jurassic between 168–164 million years ago in what is now Inner Mongolia. The team found that the molars of these animals were more similar to another extinct mammal group called the docodontans and not the australosphenidans. The two specimens also belong to a new genus and species named Feredocodon chowi.

[Related: A boiling hot supercontinent could kill all mammals in 250 million years.]

“When you look at the fossil record, both for mammals and many other sorts of animals, teeth are the part of the body that you are most likely to recover,” study co-author and curator in the American Museum of Natural History’s Division of Paleontology Jin Meng said in a statement. “Yet since the 1980s, the perplexing tooth shape seen in shuotheriids has been a barrier to our efforts to understand early mammal evolution. These new specimens have allowed us to solve this longstanding problem.”

The team believes that some common mammal ancestor independently gave rise to major groups of mammaliaforms: Docodontiformes, Allotheria, and Holotheria.

Listen up!

The second study focuses on the fossilized skulls of Feredocodon chowi and second new species named Dianoconodon youngi. It lived in the Early Jurassic between 201–184 million years ago. It was similar to an extinct rat-like animal called Morganucodon that is widely regarded as one of the first mammals. 

The team looked at the structure of Dianoconodon youngi’s middle ear, which helps give modern mammals their sharp hearing. In the middle ear, the spot inside the eardrum that turns vibrations in the air into ripples in the inner ear’s fluids has three bones. These bones called auditory ossicles are a feature that is unique to mammals and birds and reptiles only have one middle ear bone. At some point during the early evolution of mammals, the bones that formed the joints of the jaw separated and became associated with hearing. 

[Related: A new evolutionary theory could explain the mystery of shrinking animals.]

Both Feredocodon chowi and Dianoconodon youngi specimens show some fossil evidence of this evolutionary transition in action, as mammals evolved from a group that includes lizards, crocodilians, and dinosaurs. The team believes that this transition began from an ancestral animal that had a double jaw joint. It likely had the joint of a mammal on the outside and a more reptilian joint on the inside.

Analyses on the older fossil (Dianoconodon youngi) show that one of its two joints, the reptilian one, was already beginning to lose its ability to handle the forces created by chewing. The younger fossil (Feredocodon chowi) had a more mammalian middle ear that was formed and adapted exclusively for hearing.

“Scientists have been trying to understand how the mammalian middle ear evolved since Darwin’s time,” said Meng. “While paleontological discoveries have helped reveal the process during the last a few decades, these new fossils bring to light a critical missing link and enrich our understanding of the gradual evolution of the mammalian middle ear.”

The post New fossils of tiny, toothy early mammals could be a major missing link appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

An enormous asteroid crashed into the Earth about 65 million years ago. While terrestrial dinosaurs like the famed Tyrannosaurus rex were wiped out, many avian animals really began to flourish. Considering that there are more than 10,000 species of birds on Earth, flourish may even be an understatement. Keeping birds organized in a neat family tree is a bit of a Herculean task, since there are so many species and their evolution has been a little unclear. However, some advances in genomic sequencing and analysis are beginning to create a more lucid picture of how the planet’s living dinosaurs evolved.

In two studies published April 1 in the journals Proceedings of the National Academy of Sciences (PNAS) and Nature, scientists reveal that a genetic event about 65 million years ago has misled them about the true history of avian evolution. A section of one chromosome hasn’t mixed together with nearby DNA as it should have. This section is only tiny fraction of the bird genome, but was enough to make it difficult for scientists to build a more detailed bird family tree.  

A sticky chunk of DNA

In 2014, advances in computer technology used to study genomes helped scientists piece together a family tree for the Neoaves. This group includes the majority of bird species. Using the genomes of 48 species, they split the Neoaves into two major categories. Doves and flamingos were in one group and all the other bird species belonged to the other group. 

When a similar genetic analysis was repeated using 363 bird species for this new study, the team saw a different family tree emerge. This one points to four main groups and reveals that flamingos and doves are more distantly related and it all came back to a specific spot in the chromosomes.

[Related: Birds are so specialized to their homes, it shows in their bones.]

Within these two family trees, the team looked for explanations that could tell them which one was correct. They found one spot on the genome, where the genes were not as mixed together as they should have been over millions of years of sexual reproduction. 

“When we looked at the individual genes and what tree they supported, all of a sudden it popped out that all the genes that support the older tree, they’re all in one spot,” a co-author of the study published in PNAS and University of Florida biologist Edward Braun said in a statement. “That’s what started the whole thing.”

Birds combine genes from a father and a mother into the next generation, but they first mix the genes they inherited from their parents when creating sperm and eggs. This process is called recombination and it is also something that occurs in humans. Recombination maximizes a species’ genetic diversity by ensuring that no two siblings are exactly the same.

One section of one chromosome did not mix with DNA nearby like it should have and has basically spent millions of years frozen in time. This chromosomal section makes up only two percent of the bird genome, but was enough to convince scientists that most birds could be grouped into two major categories–Passerera and Columbea. This new and more accurate family tree takes into account that  misleading section of the avian genome and identifies four main groups of birds.

The team also found evidence that this spot on the bird chromosome has suppressed the recombination process since around the time the dinosaurs disappeared. It is not clear if the Cretaceous-tertiary Extinction that wiped out the dinosaurs and these genomic anomalies are related.

The result of this genetic suppression is that the flamingos and doves looked similar to one another in this one sticky chunk of DNA, but two groups are actually more distantly related when looking at their entire genomes. Flamingos and doves can now be considered more distantly related genetically. According to the team, this kind of stuck genetic mystery could be lurking in the genomes of other organisms. 

Building a better bird family tree

The study published in Nature details an intricate chart detailing 93 million years of evolutionary relationships between 363 bird species, or about 92 percent of all bird families. This updated family tree revealed patterns in the evolutionary history of birds following the Cretaceous-tertiary Extinction.

[Related: Dinosaurs may have evolved into birds, but early flights didn’t go so well.]

The researchers noticed sharp increases in effective population size, substitution rates, and relative brain size in early birds. These evolutionary changes shed new light on the adaptive mechanisms that drove the diversification of bird species in the aftermath of this planet-altering extinction event. 

To do this, they harnessed the power of a suite of computer algorithms known as ASTRAL. This program helps infer evolutionary relationships quickly and accurately and enables the team to integrate the genomic data from more than 60,000 regions in bird genomes. They then examine the evolutionary history of individual segments across the genome and pieced together several gene trees to build out a larger species tree. 

“We found that our method of adding tens of thousands of genes to our analysis was actually necessary to resolve evolutionary relationships between bird species,” study co-author and University of California, San Diego computer engineer Siavash Mirarab said in a statement. “You really need all that genomic data to recover what happened in this certain period of time 65-67 million years ago with high confidence.”

These computational methods also helped the team shed light on that same particular section of one chromosome in the bird genome that has remained unchanged over millions of years and made it difficult for scientists to study these changes. 

“What’s surprising is that this period of suppressed recombination could mislead the analysis,” said Braun. “And because it could mislead the analysis, it was actually detectable more than 60 million years in the future. That’s the cool part.” 

In future studies, similar computer models could help reconstruct evolutionary trees for a variety of other animals. The team is hoping to continue their efforts to build a more complete picture of bird evolution. Biologists are also continuing to sequence the genomes of other bird species in an effort to expand their family tree even more. 

The work is part of the international Bird 10,000 Genomes (B10K) Project, a multi-institutional effort with the goal of generating draft genome sequences for about 10,500 living bird species.

The post We were very wrong about birds appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Keeping our teeth clean has been a pain for thousands of years, with some particularly painful methods historically used to take care of our chompers. Two 4,000-year-old human teeth unearthed in a limestone cave in Ireland were recently found to contain an “unprecedented quantity” of the bacteria that cause tooth decay and gum disease. The genetic analysis of these well-preserved microbiomes reveal how changes in diet shaped our oral health from the Bronze Age to today. The findings are described in a study published March 27 in the journal Molecular Biology and Evolution.

Fossilized dental plaques have been one of the best studied parts of the ancient human body. However, very few full genomes from oral bacteria in teeth prior to the medieval era have been uncovered. This means that scientists have limited data on how the human mouth’s microbiome was affected by changes in diet and from events like the spread of farming about 10,000 years ago.

Sugar-munching, acid producing bacteria

Both of the teeth belonged to the same male individual who lived in present day Ireland during the Bronze Age. The teeth contained the bacteria that cause gum diseases and the first 

high quality ancient genome from Streptococcus mutans (S. mutans). This oral bacterium is one of the major causes of tooth decay.

S. mutans is very common in modern human mouths, but is very rare in the ancient genomic record. One potential reason why it’s so sparse may be how the bacterium produces acid. The acid decays the tooth, but also destroys DNA and stops the dental plaque from fossilizing and hardening over time. Most ancient oral microbiomes are found inside these fossilized plaques, but this new study looked directly at the tooth. 

[Related: Vikings filed their teeth to cope with pain.]

Another reason why S. mutans may not have been present in ancient mouths may be due to a lack of sugary mouths for it to thrive in. S. mutans loves sugar and an increase of dental cavities can be seen in the archaeological record after humans began to grow and farm grains. However, the more dramatic increase occurred over the past few centuries when sugary foods became significantly more prevalent.  

The disappearing microbiota hypothesis

The sampled teeth were part of a larger skeleton found in Killuragh Cave, County Limerick, by the late Peter Woodman of University College Cork. Other teeth in the cave show advanced dental decay, but there wasn’t any evidence of any caries–or early cavities. A single tooth turned out to have a ton of mutans sequences. 

“We were very surprised to see such a large abundance of S. mutans in this 4,000 year old tooth,” study co-author and Trinity College Dublin geneticist Lara Cassidy said in a statement. “It is a remarkably rare find and suggests this man was at high risk of developing cavities right before his death.”

The cool, dry, and alkaline conditions of the cave may have contributed to the preservation of S. mutans DNA. While the S. mutans DNA was plentiful, other streptococcal species were mostly absent from the tooth sample. This indicates that the natural balance or the oral biofilm had been altered–mutans outcompeted the other bacteria species.

According to the team, the study adds more support behind the disappearing microbiota hypothesis. This idea proposes that our ancestors’ microbiomes were actually more diverse than our own today. More evidence that supports this hypothesis came from the two genomes for Tannerella forsythia (T. forsythia) that the team built from the tooth. T. forsythia still exists and causes gum disease. 

“The two sampled teeth contained quite divergent strains of T. forsythia,” study co-author and Trinity College Dublin PhD candidate Iseult Jackson said in a statement. “These strains from a single ancient mouth were more genetically different from one another than any pair of modern strains in our dataset, despite these modern samples deriving from Europe, Japan, and the USA. This is interesting because a loss of biodiversity can have negative impacts on the oral environment and human health.”

Shifting genes and mouths

Both reconstructed genomes revealed  dramatic changes in the oral microenvironment over the last 750 years. One lineage of T. forsythia has become dominant in global populations in recent years, which is a sign of an event geneticists call a selective episode. This is when one bacteria strain quickly rises in frequency due to a particular genetic advantage. The T. forsythia genomes that arose particularly after the Industrial Revolution acquired genes that helped it colonize the mouth and cause disease.

[Related: Bronze Age cauldrons show we’ve always loved meat, dairy, and fancy cookware.]

S. mutans also had evidence of recent lineage expansions and changes in gene content that both coincide with the popularization of sugar. However, modern S. mutans populations have remained even more diverse than T. forsythia, including some deep splits in the S. mutans evolutionary tree that pre-date the genomes uncovered in Ireland. The team believes that this is driven by differences in the evolutionary behind genome diversity in these bacteria species.

“S. mutans is very adept at swapping genetic material across strains,” said Cassidy “This allows an advantageous innovation to be spread across S. mutans lineages, rather than one lineage becoming dominant and replacing all others.”

Both of these disease-causing bacteria have essentially changed dramatically from the Bronze Age to today. However, it’s the very recent cultural transitions like more sugar consumption that appear to have had an outsized impact.

The post Rare traces of tooth decay and gum disease found in Bronze Age teeth appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Non-verbal gestures are an integral part of how humans and some other organisms communicate, as with various sign languages  and expressing emotions. A small-bird species called the Japanese tit (Parus minor) also may also use this more complex form of communication. In a study published March 25 Current Biology, a team from the University of Tokyo describes how this small bird appears to use this wing to say “after you” to indicate that the other bird.

According to the study, when a mating pair arrives at their nest box carrying food, the two will wait outside. One bird will then often flutter its wings towards the other, apparently indicating that the other bird can enter the home first. 

The team believes that this discovery challenges earlier beliefs that only a few species use gestures to communicate. Chimpanzees, bonobos, ravens, and some fish appear to use a form of communication called deictic gesturing. This is when simple gestures are deployed to point out objects or show something of interest. Symbolic gestures, such as how humans use an open hand to signal “after you,” requires more complex cognitive skills and have been difficult to observe.

CREDIT: Suzuki and Sugita, 2024/ Current Biology

“In our latest discovery, we revealed that the Japanese tit uses gestures to communicate with their mate,” study co-author and University of Tokyo animal linguist and biologist Toshitaka Suzuki said in a statement. “For over 17 years, I have been engaged in the study of these fascinating birds. They not only use specific calls to convey particular meanings, but also combine different calls into phrases using syntactic rules. These diverse vocalizations led me to initiate this research into their potential use of physical gestures.”

[Related: Why do humans talk? Tree-dwelling orangutans might hold the answer.]

During the spring, these birds form mating pairs and build their nests inside a tree cavity with a small entrance. In the study, Suzuki and his co-researcher Norimasa Sugita observed the behavior of 16 parent birds (eight pairs) breeding in nest boxes built in the wild. The birds enter one at a time when feeding their nestlings. The team noticed that when they’re carrying food back to the nest, the birds would often find a perch nearby first. Then, one would flutter its wings towards the other.

The team analyzed over 320 nest visitations in detail and observed that the wing-fluttering display promoted the mate who was being fluttered at the go into the nest box first. The other bird who fluttered entered second, seeming to mirror the “after you” gesture that humans sometimes use. 

“We were surprised to find that the results were much clearer than we had expected,” said Suzuki. “We observed that Japanese tits flutter their wings exclusively in the presence of their mate, and upon witnessing this behavior, the mate almost always entered the nest box first.”

Female birds performed the gesture more often than males and male birds usually entered the nest box first, regardless of which bird arrived first. Females usually entered the nest box first if she didn’t flutter her wings. 

[Related: Artificial intelligence is helping scientists decode animal languages.]

The team believes this behavior should be classified as a symbolic gesture. It only occurred in the presence of a mat, stopped after the mate entered the nest box, and encouraged the mate to enter without any physical contact. The wing-fluttering “after-you” gesture was also aimed at the mate and not the nest box, meaning that it wasn’t being used to point out where something of interest was located.

“There is a hypothesis that walking on two legs allowed humans to maintain an upright posture, freeing up their hands for greater mobility, which in turn contributed to the evolution of gestures,” said Suzuki. “Similarly, when birds perch on branches, their wings become free, which we think may facilitate the development of gestural communication.”

The team says that they will continue to look into what birds are talking about to learn more about animal languages and the evolution of human speech. 

The post These birds appear to be signaling ‘after you’ appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Not all dolphins live in the salty ocean. While rare, some river dolphins live and eat in freshwater and are best known for their candy colored hues. Now, paleontologists have uncovered a fossilized skull belonging to a 16-million-year-old extinct river dolphin species in Peru named Pebanista yacuruna. It could grow to about 10 to 11 feet long and is the largest known species of river dolphin known to science. Pebanista is described in a study published March 20 in the journal Science Advances. 

The name Pebanista yacuruna is inspired by the Yacuruna, a mythical aquatic people that legends say inhabit underwater cities in the Amazon basin and are similar to the god Neptune in Greek mythology. The fossilized skull was found in the Peruvian Amazon and belongs to the group Platanistoidea. This group was a common animal in the Earth’s ocean between 24 and 16 million years ago. The team believes that their primarily salt water dwelling ancestors invaded the prey-rich freshwater ecosystems of the early Amazon and learned to adapt to this new environment.

“Sixteen million years ago, the Peruvian Amazonia looked very different from what it is today,” Aldo Benites-Palomino, a study co-author and paleontologist at the University of Zurich in Switzerland, said in a statement. “Much of the Amazonian plain was covered by a large system of lakes and swamps called Pebas.” 

[Related: Eavesdropping on pink river dolphins could help save them.]

This landscape stretched across present day Colombia, Ecuador, Bolivia, Peru, and Brazil and included a variety of ecosystems in its lakes and swamps. About 10 million years ago, the Pebas system began to give way to the floodplain that Amazonia looks like today. Pebanista’s prey began to disappear as the landscape began to change, driving these giant dolphins to extinction. With Pebanista out of the picture, the relatives of today’s Amazon river dolphins called Inia had an opportunity to sneak in. 

While these pink dolphins may look similar to the extinct Pebanista, they are not directly related. Pebanista’s closest living relatives of this newly discovered species are actually found in South Asia.

“We discovered that its size is not the only remarkable aspect,” says Benites-Palomino. “With this fossil record unearthed in the Amazon, we expected to find close relatives of the living Amazon River dolphin–but instead the closest cousins of Pebanista are the South Asian river dolphins (genus Platanista).”

Both Pebanista and Platanista have highly developed facial crests that help them with echolocation. That is when they emit high-frequency sounds and listen to their echoes in order to “see” their prey through sounds. 

“For river dolphins, echolocation, or biosonar, is even more critical as the waters they inhabit are extremely muddy, which impedes their vision,” study co-author and University of Zurich paleontologist Gabriel Aguirre-Fernández said in a statement.

[Related: This dolphin ancestor looked like a cross between Flipper and Moby Dick.]

Pebanista’s elongated snout with many teeth suggests that it fed on fish the way other river dolphins do. Modern Amazon river dolphins called boto are considered critically endangered and their primary threats include habitat loss and degradation and getting entangled in fishing gear. 

The Amazon rainforest remains a very difficult place for paleontological fieldwork. Fossils like these are only accessible during the dry season, when water levels drop low enough to expose ancient layers of bedrock. If the fossils are not collected in time, they can be swept away during the rainy season. 

The specimen was found in 2018 in an expedition led by Peruvian paleontologist Rodolfo Salas-Gismondi, who completed his postdoctoral work at the University of Zurich. The team traveled more than 180 miles of the Napo River in northeastern Peru and collected dozens of other fossils. The dolphin skull is now housed at the Museo de Historia Natural in Lima.

The post Paleontologists uncover enormous fossilized river dolphin skull in Peru appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

It’s not easy being green, but a newly described amphibian ancestor is seeing limelight after decades safely tucked away in the Smithsonian’s National Fossil Collection in Washington DC. This new species is named Kermitops gratus, in honor of world-famous amphibian Kermit the Frog. It lived more than 270 million years ago and its discovery is altering the story of amphibian evolution. The findings are described in a study published March 21 in the Zoological Journal of the Linnean Society. 

A stout salamander-like creature 

Based on an inch-long skull fossil, scientists believed that Kermitops likely would have resembled a stout salamander. The fossil has large, oval-shaped eye sockets, much like the distinct eyes on the Muppet it is named after. Kermitops was likely a temnospondyl–a member of a diverse group of early amphibian relatives that lived for more than 200 million years from the Carboniferous Period up to to the Triassic. 

“It probably was a little more terrestrial than some other frogs and salamanders,” study co-author and Smithsonian vertebrate paleontologist Arjan Mann tells PopSci. “The ecosystems that would have inhabited probably marginal pond environments, similar areas to where you find amphibians living today. 

At times, Kermitops’ environment was potentially similar to the swamp where viewers first meet Kermit singing and strumming the banjo in 1979’s The Muppet Movie. This prehistoric ecosystem also saw large shifts in seasonal rainfall and dry spells, similar to the monsoons seen today in the Southwestern United States and Southeast Asia.

[Related: These pleasantly plump salamanders dominated the Cretaceous period.]

“That rainfall would really feed this ecosystem in pulses,” study co-author and George Washington University evolutionary biologist and PhD student Calvin So tells PopSci. “That’s what sustained animals like Kermitops and modern amphibians have some of the same or similar constraints.”

Paleontological patience

The fossil was originally found by the late Smithsonian paleontologist Nicholas Hotton III. Hotton made several research trips to dig for fossils from a group of rock outcrops in north central Texas called the Red Beds. These rust-colored rocks date back to more than 270 million years ago to the Permian Period and are full of the fossilized remains of ancient reptiles, amphibians, and even some precursors to modern mammals called sail-backed synapsids.

Hotton’s team collected so many fossils that they couldn’t study them all in close detail. This included a small proto-amphibian skull that they found in a rock layer called Clear Fork Formation in 1984–the same year The Muppets Take Manhattan was released. The skull was labeled as an early amphibian and spent decades before researchers could take a closer look. It caught Mann’s eye in 2021 when he was a postdoctoral paleontologist at the Smithsonian. 

“It was easily identifiable as a taxa that that’s something new and different from anything we knew,” Mann tells PopSci. 

A head that snaps

Mann and So worked together to determine what kind of prehistoric creature the fossil belonged to. It has a mix of traits that appeared different from the skulls of older tetrapods–the ancient ancestors of amphibians and living four-legged vertebrates. The region of the skull behind the animal’s eyes was also much shorter than its longer and curved snout. These skull proportions likely helped it quickly grab food like a modern day snapping turtle.

“It may have been predisposed for these quick snapping motions,” says So. “Because of its small size, it was probably feeding on things smaller than itself, like insects, worms and vertebrates, but also potentially smaller amphibians.”

Since the skull had such unique features, the team concluded that it belonged to an entirely new genus they named Kermitops. It is a play on the amphibian’s wide-eyed face and is a mix of the words “Kermit” and the Greek suffix “-ops,” for face. The word Gratus represents the team’s gratitude to Hotton and the rest of the team that originally unearthed the fossil so many years ago. 

The team also hopes that naming it after the beloved frog who was created by puppeteer Jim Henson in 1955, can help get more people excited about the discoveries that scientists make using museum collections.

[Related: These legless, egg-laying amphibians secrete ‘milk’ from their butts.]

“There’s so many implications for reaching a broader audience,” says So. “We don’t only want to inspire future generations of paleontologists, but we hope to broaden what science is, from this very dedicated field to something that may potentially integrate with more creative and artistic things. “

In a statement sent to PopSci, Kermit the Frog wrote: “When the Smithsonian team approached me asking to name a newly-discovered amphibian species after me, I was truly honored… and a little puzzled. I don’t quite see the resemblance, but Miss Piggy and the other Muppets assured me it’s uncanny! Wait ‘til I tell my family in the swamp about our new great-great-great-great-great aunt or uncle–although we never got any gifts from them, so maybe they’re not that great.”

[Related: These spiky frog skulls look more like dinosaur fossils.]

Small fossil, big deal

Despite being such a tiny specimen, Kermitops is filling in some large evolutionary gaps for amphibians. The early fossil record of amphibians and their ancestors is very fragmented, which makes it difficult for scientists to put together how frogs, salamanders, axolotls, and their kin evolved. Finding more early forms of amphibious life is essential for building out the early branches of the amphibian family tree.

“Amphibian evolution was believed to be sort of a linear pattern before, but fossils like Kermitops, kind of put a wrench in that by showing maybe this wasn’t as simple as we thought,” says Mann. “It might have been a process that occurred over many lineages at the same time. Paleontology is always more than just dinosaurs, and there are lots of cool evolutionary stories and mysteries still waiting to be answered.”

The post New proto-amphibian species named after Kermit the Frog appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Despite their reputation for being easy for aspiring plant parents to destroy, orchids can be found all over the planet. There are more than 25,000 known species of these plants, with more discovered every year. An international team of scientists have now found a new species of orchid in Madagascar with an impressive nectar spur and has a tie to Charles Darwin. Solenangis impraedicta is described in a study published March 11 in the journal Current Biology. 

[Related: This new species of pink orchid looks like delicate glasswork.]

Madagascar is known for flowers with long floral tubes that are pollinated by long-tongued hawkmoths. The most famous orchid species on the island is Angraecum sesquipedale, which is also called Darwin’s orchid. The famed naturalist and orchid enthusiast had a theory that the flower was pollinated by a moth that was unknown at time. About 41 years after this prediction, scientists officially described the large hawkmoth proving Darwin correct. 

The newly discovered species is appropriately named Solenangis impraedicta. In Latin, impraedicta translates to “unpredicted” and is a nod to Darwin’s eventually correct prediction that a specific moth is the orchid’s primary pollinator. The newly discovered orchid has a nectar spur that is almost 13 inches long, despite having petals that are less than one inch. These tube-like projections from a plant’s petals produce and retain nectar for pollinators like bees, butterflies, and moths. Solenangis impraedicta has the third longest spur scientists have ever recorded. 

“The contrast between the little 2 centimeter (0.7 inches) flowers and the hyper-long nectar tube is mind-blowing,” study co-author and Coimbra University Botanic Garden botanist João Farminhão said in a statement. 

The species with dainty white petals and a yellow-ish stem was first collected by Missouri Botanical Garden field botanist Patrice Antilahimena, during a baseline environmental impact study of a mine site in central eastern Madagascar. A new location of these orchids was discovered about 10 years later by Brigitte Ramandimbisoa and a Ph.D. student at the New York Botanical Garden Simon Verlynde. 

It belongs to the angraecoid orchids group also called “Darwin’s pollination guild.” It is currently threatened by mining activities and possibly by poaching for the orchid trade. The authors hope that the discovery will boost conservation efforts.

“Discovering a new orchid species is always an exciting event, but finding such amazing and charismatic species happens only once in a scientist’s career,” study co-author and Missouri Botanical Garden botanist Tariq Stévart said in a statement. “I really hope that this highly threatened species draws attention to the urgent crisis that is affecting Madagascar’s biodiversity and helps support [Missouri Botanical] Garden’s program there.”

[Related: This incredibly rare orchid survives by making male beetles horny.]

The between Solenangis impraedicta’s discovery and its formal scientific description allowed the team to bank some of its seeds and grow them in undisclosed locations to help conserve the plants.

“A precautionary approach is required when publishing such a spectacular new species,” said Stévart. “Wild populations must be protected and monitored and detailed information on their precise coordinates must be kept out of the public domain. So, don’t ask us to reveal where we found it, somewhere in Madagascar.”

The post ‘Spectacular’ new orchid species is pollinated by moths appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

The idea that most biologically male members of a species are physically larger than the females goes back to Charles Darwin’s 1871 book The Descent of Man. While this is typically true for some species including gorillas, buffalo, and elephants, it is not necessarily a one size fits all fact. 

A study published March 12 in the journal Nature Communications found that the males in most mammalian species are not bigger than the females. Monomorphism–or both sexes being roughly the same size–is very common and females can be larger in some cases. The authors suggest that biases in scientific literature from over more than a century and a focus on more charismatic species like primates and carnivores has likely led to this misconception.

A persistent narrative

For some mammals, physical differences in size do vary depending on competition for mates and the differences in how mothers and fathers invest time and energy in their offspring. Male lions and baboons typically engage in physical competition for mates and the males are larger than the females. It has been assumed that sexual dimorphism–where the sexes differ in size–is most common in animals. Additionally, the idea that males of a species are always larger, which is the case in lions, applies to most species has also stuck around for decades.

“That’s how Darwin laid out the scene,” study co-author and evolutionary biologist Kaia Tomback tells PopSci. “And it’s very Victorian Era thinking about gender roles.”

[Related: A new evolutionary theory could explain the mystery of shrinking animals.]

During the 1970’s, a mammalogist and conservation biologist named Katherine Ralls was among the first to take a real scientific look at this narrative and push back against this idea that most male mammals are larger. Ralls found evidence that most mammals do not have an extreme dimorphism. More typically, the female members of the species are the same size as the males. Larger females are surprisingly common in nature. According to Tombak, Ralls has also been commonly misquoted as supporting the larger male narrative.

“Science is always changing, so it’s possible that the story will change,” says Tombak, who is currently a postdoctoral researcher at Purdue University. “But [the idea] has been a misconception in the sense that it’s this scientific narrative with very weak evidence.”

From bats to lemurs to elephant seals

In this new study, Tombak and her colleagues went through available scientific literature and compared the male and female body masses of 429 animal species in the wild. In the majority of cases, they found that the males are not larger than the females. In many species, including lemurs, golden moles, horses, zebra, and tenrec, both sexes are the same size.

A male and female plains zebra interacting in Kenya. Males and females are the same size in this species. CREDIT: Severine B.S.W. Hex

Some species did show significantly larger males, including the northern elephant seal. This is what Tombak calls a “famously dimorphic” species, with male northern elephant seals weighing in at about three times larger than females.

On the other end of the spectrum is the peninsular tube-nosed bat. Females are about 40 percent larger than the males. 

“If you want to talk about most mammals, most mammals are rodents and bats, by far,” says Tombak. “Just almost half of bats have larger females. Some hypotheses suggest that for female [bats], it’s better to be bigger so that they can fly carrying fetuses and offspring more easily. Others have said that for males competing for mates, maybe agility matters more in fighting than size.”

A more complicated reproductive story

While the study did not sample all mammalian species, the team did identify trends that made sense given when a lot of these earlier studies were conducted. They believe that the reason for this persistent larger male narrative is related to more studies focusing on charismatic keystone species like primates and seals who have larger bodied males that compete with each other for mates. 

[Related: These female hummingbirds don flashy male feathers to avoid unwanted harassment.]

“As we read through the literature, there was just so much cool biology that we got into,” says Tombak. “I think what the study brings about is that there’s probably way more to reproductive strategies. A diversity of strategies is probably more common than just the males fighting physically for females.”

One example includes the topi, a type of antelope where females have been documented fighting each other for access to mates. Challenging this belief has met resistance and has been understudied, as it goes against the ideas of a seminal figure like Darwin.

“The story is really one of like the other side of the story of having been ignored for a long time,” says Tombak. “In terms of the science, I think it’s important because there’s just so much focus on the male perspective, male mating competition, and sexual selection theory.”

Tombak and her co-authors recommend more research on female biology across species to create a more realistic view of animal size and sex selection and are working on follow-up papers. The authors also caution that findings in this study could change, as more robust data on mammal body sizes is gathered in the future.

The post Sorry, Darwin: Most male mammals aren’t bigger than females appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

It was a mosquito full of dinosaur blood and encased in amber that helped bring the fictional Jurassic Park to life. While real world bugs stuck in sticky substances don’t lead to dangerous dinosaur parks (yet), they do offer scientists a peek into their past shapes and behaviors. A pair of 38 million year-old termites trapped in tree resin in the middle of a mating behavior are helping scientists understand the mating behaviors of extinct insects. The finding is detailed in a study published March 5 in the Proceedings of the National Academy of Sciences (PNAS).

The two termites are an extinct species called Electrotermes affinis (E. affinis) and the discovery of this fossil was a bit lucky. Study co-author and entomologist from the Czech Academy of Sciences Aleš Buček saw the piece of amber in an online shop for fossil collectors.

“Termite fossils are very common, but this piece was unique because it contains a pair,” Buček said in a statement. “I have seen hundreds of fossils with termites enclosed, but never a pair,” 

[Related: A 50-million-year-old insect testicle is one lucky find.]

Buček purchased the fossil and a team from the Okinawa Institute of Science and Technology’s (OIST) Evolutionary Genomics Unit in Japan used an X-ray micro-CT to take a closer look at the bugs. 

“Identifying the species was actually not easy, because there were bubbles in front of important parts of the termite’s bodies,” study co-author and OIST postdoctoral researcher Simon Hellemans, said in a statement. 

The scan revealed what species they belonged to and also that the trapped termites were a female and male laying side by side. The female’s mouthparts were touching the tip of the male’s abdomen. This positioning was familiar to the researchers, as present day termites engage in a mating behavior called tandem running. The insects display coordinated movements to keep themselves together while exploring a new nest site. 

However, the fossilized pair’s irregular side-by-side positioning in the amber also stood out. A pair typically  would have been observed lying behind each other. The team believed that since the preservation in the amber is not an instantaneous process, the termite’s normal mating behaviors gets interrupted. Their positions then shift while they are being encased in the super sticky tree resin. To test out this hypothesis, they simulated the process in the lab. 

“Our approach focused on how fossils are created and how behavior changes during the insect’s death,” study co-author and Auburn University entomologist Nobuaki Mizumoto said in a statement. 

[Related: When insects got wings, evolution really took off.]

They looked at mating termite pairs and found that even if the leading individual got trapped on a sticky surface, the follower did not escape or abandon their partner. Instead, they walked around them and also got stuck in a position like the termites stuck in amber. 

“If a pair encounters a predator, they usually escape but I think on a sticky surface they do not realize the danger and get trapped,” said Mizumoto.  

According to the team, this new way of recreating the process of getting stuck in tree resin allowed them to analyze the behaviors of an extinct species with a new amount of precision.“For some things, fossils are simply the best evidence, a direct window to the past,” said Buček and Mizumoto.

The post These extinct termites have been stuck in a mating position for 38 million years appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

If dissecting a frog in biology class had you begging to be sent home, new 3D scans of thousands of vertebrate species are here to help by letting you peek at animal insides without the mess. The newly completed openVertebrate (oVert) project took five years and brought together 18 natural history institutions to create the free online museum, showing the anatomy and physiology of over 13,000 specimens. A summary of the work was published March 6 in the journal BioScience. 

From 2017 to 2023, oVert project members took detailed CT scans of more than half the genera of all amphibians, reptiles, fishes, and mammals. The scanners used high-energy X-rays to look past the organism’s scales, fur, or skin to view the dense bone structure beneath. Scientists stained some of the specimens with a temporary contrast-enhancing solution that allows the team to visualize their soft tissues, including muscle, skin, and other organs. 

“Museums are constantly engaged in a balancing act,” David Blackburn, principal investigator of the oVert project and curator of herpetology at the Florida Museum, said in a statement. “You want to protect specimens, but you also want to have people use them. oVert is a way of reducing the wear and tear on samples while also increasing access, and it’s the next logical step in the mission of museum collections.”

Take a look at some of the incredible scans below. It will be like stepping back into high school biology, without the scalpel, Bunsen burners, or safety glasses.  

Check out more of the scans here.

The post Take a look inside 13,000 animals–no scalpel required appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

If you take a look at a horseshoe crab, you are essentially peering back in time millions of years. Animals like horseshoe crabs, coelacanths, and the duck-billed platypus are what Charles Darwin called “living fossils” since alive specimens show very few physical differences from their ancestors in the fossil record dating back millions of years.

[Related: A new evolutionary theory could explain the mystery of shrinking animals.]

Now, an ancient group of ray-finned fishes called gars may be the ultimate living fossils, evolving slower than any other of these vertebrates. A study published March 4 in the journal Evolution found that they have the slowest rate of molecular evolution among all jawed vertebrates and its genome changes much more slowly than other animals.

What are gar?

There are seven known species of gar. They are found in North America and can live in fresh, brackish, and salt water and commonly live in slow-moving bodies of water like estuaries. They have bodies shaped like darts and a long beak that acts like a pair of forceps. They also lay green colored eggs that are highly toxic to any predators who want to eat them.

All seven living species of gar species are nearly identical to the earliest known fossil gars. These specimens date back about 150 million years ago to the Jurassic period. As early as 100 million years ago (Mid-Cretaceous period) one of the two living major lineages of gars began to appear in the fossil record. 

Looking at hybridization

In this new study, the team analyzed a dataset containing 1,105 exons–DNA’s coding region–from a sample of 471 jawed vertebrate species. They found that the gars’ DNA consistently evolves up to three times more slowly than any other major group of vertebrates. Sturgeon and paddlefish also showed slow rates of change, but their rate of changes was not as relaxed as gar. 

Researchers then looked at a process called hybridization, where two different species produce viable offspring that have the ability to reproduce when they reach maturity. For example, a horse and a donkey are two different species, but they can mate and produce mules. However, mules are usually born sterile and can’t reproduce. Some gar species can mate and their offspring will remain fertile when they reach sexual maturity. 

The team looked at the alligator gar and longnose gar, two different gar species found in the Brazos and Trinity River systems in Texas. Both species last shared a common ancestor at least 100 million years ago, yet are still producing viable and fertile babies, but not new species. This successful reproduction by two different species of gar is likely linked to how slowly their DNA changes  and keeping their numbers of species at only seven.  

“The slower a species’ genome is mutating, the more likely it is that it will be able to interbreed with a separate species that it’s been genetically isolated from over a long stretch of time,” study co-author and Yale University PhD student Chase D. Brownstein said in a statement. 

According to the study, gars have the oldest identified parental split among all animals, plants, and fungi that can produce offspring that can survive and reproduce. The previous record holders were two fern species and the gar’s common ancestor is about 60 million years older than the shared ancestor of both ferns.

Not an evolutionary accident

The team believes that gars have an unusually strong DNA repair apparatus. This allows the fish to correct somatic and germline mutations. These mutations are changes to the DNA that occur both before and after conception. Gars may be able to alter these mutations more efficiently than many other vertebrates and understanding that process could have future implications for human health.

[Related: We probably have big brains because we got lucky.]

“Most cancers are somatic mutations that represent failures of an individual’s DNA repair mechanisms,” study co-author and Yale University evolutionary biologist Thomas J. Near said in a statement. “If further study proves that gar DNA repair mechanisms are extremely efficient, and discovers what makes them so, we could start thinking about potential applications to human health.”

According to the team, the study indicates that Earth’s living fossils are not just freak evolutionary accidents.They are living, breathing depictions of how evolution works in nature.

“It shows that analyzing patterns in living fossils’ evolutionary history might have implications for our own story,” said Brownstein. “It not only helps us better understand the planet’s biodiversity, but potentially could one day be applied to medical research and improve human health.”

The post Meet the new king of the ‘living fossils’ appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

It has been an enduring evolutionary mystery since the days of Charles Darwin: When did humans lose their tails? Apes–including humans and chimpanzees–are all primates who do not have long tails like lemurs and our other monkey relatives. Thanks to some advances in gene-editing technology, a new clue to ape tail loss has been uncovered. A genetic diversion in our ancient ancestors about 25 million years ago, according to a study published February 28 in the journal Nature.

[Related: Our tree-climbing ancestors evolved our abilities to throw far and reach high.]

Apes vs. monkeys

Tail loss in apes began as the group evolved away from Old World monkeys between 20 and 25 million years ago. After this evolutionary split, apes evolved the formation of fewer tail vertebrae. This formed our coccyx–or tailbone. 

While the reason why apes lost their tails in the first place is uncertain, some scientists not having a tail may have been better suited for vertical bodies living on the ground. Tailed primates generally use these appendages to help them swing from tree branches and walk on along them horizontally. Gibbons and orangutans are tailless apes that still live in trees, but they move differently than monkeys who have tails and hang below branches. 

Previous studies have linked over 100 genes to the development of tails in vertebrates, so the general belief has been that tail loss occurred through changes in DNA’s code–or mutations–on more than one gene. 

Jumping genes

In the new study, a team of researchers compared the DNA of six species of apes–including humans–and 15 species of monkeys. They found an insertion of DNA that is shared by apes and humans, but is not present in monkeys. It is located on a gene called TBXT, which is known to affect animal tail length. 

Once they pinpointed this mutation, they used CRISPR to edit the same spot on the gene of mouse embryos in a lab. The mice with the altered TBXT genes were born with a variety of tail effects, including some that were born without tails at all. 

Interestingly, the differences in tail outcomes didn’t just result from the mutations to TBXT genes. DNA is in a twisted-ladder or double-helix of bundles of different genes with various functions. DNA allows animals to evolve with changes to genes, but some of the changes only occur on a single rung of DNA’s twisted ladder. Other changes are more complicated and happen on multiple rungs. These Alu elements are repetitive DNA sequences that can create bits of RNA that can then change back to DNA. Once they’ve switched back to DNA, they randomly insert themselves into the genome. These types of “jumping genes” can then disrupt or enhance a gene’s function when it is inserted. 

[Related: A scientific exploration of big juicy butts.]

The team found two Alu elements in the TBXT gene that are present in great apes, but not in monkeys. These jumping genes exist only in primates and have been behind this genetic diversion for millions of years.  

Genetic trade-off?

According to the team, any advantage of tail loss must have been very powerful. Genes can often influence more than one bodily function, changes that bring an advantage in one area may prove detrimental somewhere else. The team did find a small increase in neural tube defects in the mice they had inserted with the TBXT gene.  

Future studies could test the theory that an ancient evolutionary genetic trade-off of losing a tail contributed to neural tube birth defects. These defects include spina bifida, which is seen in roughly one in 1,000 human babies. 

The post Why we don’t have tails appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

In a square-rectangle sort of way, snakes are technically lizards, but for semantics’ sake and because snakes are so distinctive, biologists separate snakes and lizards into different categories. Despite being nested within the same branch of the tree of life, legless, lengthy, and slithering snakes–capable of unhinging their jaws and delivering a venomous bite–stand out from their reptilian clade-mates. New research sheds light on just how unique snakes are, and underscores an enduring mystery. 

The singularity of snakes

There are about 4,000 known, living species of snakes that make up one-eighth of all terrestrial vertebrate diversity. Snakes thrive in an amazing array of different habitats and under wildly varying conditions, as tree-climbers, burrowers, swimmers, and even gliders. No single trait can explain the origins of all that diversity, according to a study published February 22 in Science.

Instead, it all comes down to what the researchers call a “singularity of snakes.” In broad terms, a singularity is when small and unpredictable changes add up to big, unexpected outcomes. In physics, a singularity is a point in reality where the rules break down, and rapid expansion of the fabric of space-time can occur. The big bang theory posits that our entire universe emerged from such a singularity. In biology, a singularity might happen when an explosion of species stems from a series of changes clustered so tightly together as to appear instantaneous and inseparable on the order of evolutionary time.

All the many species of snakes are the result of a biological singularity event, according to the new research. 

Thinking of evolution in terms of singularities is a perspective shift for a field where processes are generally understood to unfold incrementally and slowly. The emergence of new species is usually explained as happening on islands through geographic separation, or as the result of drawn out predator-prey interactions, or emerging from disease pressure over time. All of these things still happen and are important for understanding evolution, but snakes (and similarly diverse animal groups like rodents and passerine birds) suggest that maybe big, sudden jumps are part of how the tree of life has grown too. Sometimes, life moves quickly.

Snake explosion

The new research shows that snakes are “fundamentally evolving at a very fast rate,” says Daniel Rabosky, senior study author and a ecology and evolutionary biology professor at the University of Michigan. “Lizards are kind of on the evolutionary moped or go-kart in terms of how fast they are changing. But snakes are on the bullet train,” he explains. Through this speed, “snakes have been able to diversify into lots of different ecological ways of life, more so than many other groups of animals,” Rabosky adds. Though what, exactly, has enabled snakes to evolutionarily outpace other reptiles remains unresolved. The proliferation of snakes was likely spurred by many lucky changes occurring in rapid succession. And because the snake singularity only happened once, it’s nearly impossible to parse out the relative effects of one trait from the other and unknowns remain, Rabosky says. Nonetheless, the study offers some interesting insights. 

Using new genetic sequences from more than 1,000 species and additional existing data from nearly 7,000 reptile species, the researchers constructed one of the most detailed ever evolutionary trees of lizards and snakes, which together are known as squamates. Their phylogenetic map confirmed that snakes are evolving into new ecological niches and physical forms about three times faster than other squamates, and that most of that evolution has occurred over the past 70 to 100 million years or so. 

And this multiplication of snakes is still ongoing, says Rabosky. There’s no sign that things are slowing down anytime soon, he emphasizes, and there’s likely lots out there left to discover. Indeed, scientists are finding new species of snakes all the time. In one example from earlier this month, biologists uncovered that the largest known species of snake, the green anaconda, is actually two genetically distinct species.

Separating the snakes from lizards

Many groups of non-snake lizards have independently evolved some snake-like traits. There are legless lizards, elongated lizards, venomous lizards, lizards with specialized skulls and highly flexible jaws, and lizards that can smell similarly to snakes. Yet despite this, the researchers found that none of these other lizard groups have diversified or evolved at anywhere near the rate that snakes have. “There are lots of notable features in snakes, but they’re not necessarily unique to snakes,” says Pascal Title, lead study author and an assistant professor of evolutionary biology and ecology at Stony Brook University. And at the same time, “we don’t see a consistent cause and effect of any one trait appearing and then leading to lots of reptile species.” 

Based on nearly 70,000 observations of individual animals’ stomach contents, the researchers analyzed the difference between snake and lizard diets. They did find that snakes feed much more heavily on vertebrates, where lizards tend to eat insects and other invertebrates. Additionally, snakes specialize on food sources, while lizards are more likely to be generalists, according to the study. Still though, the dietary differences alone aren’t sufficient to explain what makes snakes so evolutionary adept.

“Snakes are special and weird,” says Nick Longrich, an evolutionary biologist and paleontologist at the University of Bath in the UK who has previously researched snakes’ diversification but was uninvolved in the new study. “I think that, here, they’ve successfully quantified it”.  

Sara Ruane, a herpetologist and assistant curator at the Field Museum in Chicago, agrees that the new study breaks ground. “The amount of natural history information collated and sheer number of species [referenced here] is remarkable,” she says. It’s “an exciting way to better understand [snakes’] success on a global scale.” Plus, Ruane adds that many future studies of snakes and lizards are likely to come out of the impressive dataset. 

Enduring unknowns 

Yet despite their strides, the study authors are caught up on all the things we still don’t understand. Ten years of research and tens of thousands of samples has proven to Rabosky “how little we know about the basic biology of enormous fractions of life on Earth.”  Even with all the work, digging back through museum collections and compiling genetic data, he says there are “entire chunks of the world” where we don’t know what species are present, in what numbers, and how they interact with each other, especially in the tropics. Title agrees. “There’s still a lot of species we just don’t have information for,” he says. 

That deficit, Rabosky notes, means “we’re flying in the dark” when it comes to conservation, understanding the intricacies of ecosystems, and assessing human impacts on the world. To do better, he says “we need to massively upscale our efforts to collect basic information about what animals do in nature.” Snakes may be quick to evolve into new forms, but people could be haphazardly pruning those buds and branches off the tree of life before they’ve even been spotted. 

The post Why are there so many snakes? appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

As the adage goes, you can pick your friends, but you can’t pick your relatives. This even applies to your distant evolutionary cousins. In terms of a very specific genetic function, humans are a little bit more closely related to the sea lamprey than scientists once believed. According to a study published February 20 in the journal Nature Communications, we share similar hindbrains as these 500-million-year-old animals with suction-cup mouths and sharp teeth.

[Related: Giant prehistoric lamprey likely sucked blood—and ate flesh.]

What is the hindbrain?

There are three basic units of an vertebrate brain–the midbrain, forebrain, and the hindbrain. According to the National Institutes of Health, the hindbrain includes the upper part of the spinal cord, the brain stem, and the cerebellum. It controls some of the vital functions that are necessary to our survival, including blood pressure, heart rate, respiratory rhythm, motor activity, sleep, and wakefulness.

The hindbrain is an older region that has been evolutionarily conserved, or virtually unchanged throughout the process of evolution. Studying it can help evolutionary biologists peer back into the past and put together timelines for brain development and other physical features.

Sea lampreys are fish native to the Atlantic Ocean and Great Lakes. They spend about 12 to 18 months in a parasitic stage where they suck on other fish to live, before they detach. They have remained unchanged for the last 340 million years, but have a backbone and skeleton like other vertebrates. However, they are missing a jaw on their heads. Since most vertebrates have jaws, this difference in sea lampreys makes them crucial for understanding vertebrate evolution. 

“There was a split at the origin of vertebrates between jawless and jawed around 500 million years ago,” study co-author and Stowers Institute for Medical Research geneticist Alice Bedois said in a statement. “We wanted to understand how the vertebrate brain evolved and if there was something unique to jawed vertebrates that was lacking in their jawless relatives.”  

The role of Vitamin A

The team built on previous work that found that the genes that build and subdivide the sea lamprey hindbrain are identical to those genes in jawed vertebrates. However, these genes are part of an interconnected network–or circuit–that has to be initiated and guided on how to correctly build a hindbrain.

In the new study, the team pinpointed a common molecular cue that is part of the gene circuitry that guides the hindbrain development in sea lampreys. The cue comes from something that is probably in your daily multivitamin–retinoic acid, or vitamin A. The team already knew that retinoic acid can cue the gene circuitry to construct the hindbrain in complex species. However, it was not believed to be involved in the hindbrains for more primitive species including sea lampreys.

To their surprise, the team found that the sea lamprey core hindbrain circuit is also initiated by retinoic acid. This provides some evidence that these sucky-mouthed sea monsters and humans are much more closely related than the team anticipated.  

“We found that not only are the same genes but also the same cue is involved in sea lamprey hindbrain development, suggesting this process is ancestral to all vertebrates,” said Bedois.    

Common ancestry sea lampreys and humans

According to the team, understanding how the cues retinoic acid provides are used to form normal head and facial structures in vertebrates is crucial for understanding how this process can misfire. Since retinoic acid is a major player that cues vital steps in development of the brain stem, better understanding the process could help in cases where the brain stem does not develop properly in humans and other animals. 

[Related: Our four-legged ancestors evolved from sea to land astonishingly quickly.]

“People thought that because sea lampreys lack a jaw, their hindbrain was not formed like other vertebrates,” study co-author and Stowers Institute for Medical Research developmental biologist Robb Krumlauf said in a statement. “We have shown that this basic part of the brain is built in exactly the same way as mice and even humans.”  

If hindbrain formation is also a shared and passed on feature for all back-boned animals, other mechanisms must also be responsible to explain their incredible diversity.  

“We all derived from a common ancestor,” said Bedois. “Sea lampreys have provided an additional clue. Now we need to look even further back in evolutionary time to discover when the gene circuitry governing hindbrain formation first evolved.”  
Research from 2021 threw some cold water on the idea that humans and lampreys are more closely related, based on fossils of Paleozoic lamprey larvae. Either way, the enduring mystery of how closely humans and sea lamprey fit on the vertebrate family tree will continue.

The post You might have more in common with the sea lamprey than you realize appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Baleen whales, including today’s blue, humpback, and fin whales rely on sounds to live in their watery world. Their songs must be able travel far in the murky, dark ocean so that they can find their kin and migrate hundreds of thousands of miles. In the more than 50 years that scientists have been studying whale song, it’s remained unclear what physical structures baleen whales use to make noise until now. A  study published February 21 in the journal Nature finds that baleen whales evolved unique parts in their larynx that create their complex vocalizations.

[Related: The planet’s first filter feeder could be this extinct marine reptile.]

“Whales are absolutely amazing creatures, they are the biggest animals to have ever lived. They’re way bigger than the largest dinosaurs, they can dive deep, and are very social,” Coen Elemans, study co-author and a voice scientist at the University of Southern Denmark, tells PopSci. “Because it is so difficult to find another animal in a huge ocean, many of these behaviors are guided by sound. Thus understanding how they make sound is crucial to understand the biology of whales in general.”

Toothed whales vs. baleen whales

Whales fall into two main groups–toothed whales (Odontocetes) and baleen whales (Mysticetes). Toothed whales include, orcas, sperm whales, dolphins, and porpoises. Many of these species have visible teeth that they use to crush their prey.

Baleen–or whalebone–is a hard substance made up of keratin. It grows from the whale’s upper jaw in plates with bristle-like fringes. It works like a sieve to filter out the small fish or zooplankton that it eats. 

“Baleen whales make sound with their larynx and toothed whales in their nose,” explains Elemans. “Both use the same mechanism of vibrating tissues just like human vocal folds, but with completely new structures.”

Evolving new vocal structures

In the study, the team examined three stranded whales. Each specimen was from different baleen species–sei, common minke, and humpback whale. Whales that strand themselves on  the beach can provide researchers with an opportunity to study their anatomy closer. After the larynx of each whale species was extracted, the team built a computational model of the entire whale larynx in the lab. The model included accurate 3D shapes of the muscles surrounding the larynx, which made it possible to simulate how the sound frequency is controlled by muscle movement.

They found that baleen whales evolved to produce sound with the  vibrations of specific internal structures in the larynx, that toothed whales do not have. These specialized structures in baleen whales allow for sound to be produced and air recycled, while preventing the whales from inhaling water. 

While both types of whales can still produce sound with their larynx, baleen whales have novel structures that do this. They use cartilages called the arytenoids that are also found in the human larynx. The arytenoids change the position of human vocal folds. In baleen whales, they appear as  large, long cylinders at the base of a U-shaped rigid structure that covers the full length of the larynx, instead of small cartilage. This helps keep their airway open when moving large amounts of air through their massive bodies and not choke. 

“The toothed and baleen whales evolved from land mammals that had a larynx serving two functions: protecting the airways and sound production,” Tecumseh Fitch, a study co-author and  biologist at the University of Vienna in Austria, said in a statement. “However, their transition to aquatic life placed new and strict demands on the larynx to prevent choking underwater.”

Turn it down

While the study showed how baleen whales produce low frequency vocalizations for the first time, thesound production that they have honed over millions of years of evolution is becoming threatened in an increasingly noisy ocean. 

“They can’t make sound very deep and most species can’t make high frequencies,” says Elemans. “This limits the range of their communication. On top of that, these depths and frequencies overlap with human made noise in the oceans, such as boat traffic, and thus the whales cannot escape this noise by singing for example higher.”

[Related: Is it loud in the ocean?]

The authors cite the flurry of conservation and political activity in the wake of the first acoustic recordings of humpback whale song in 1970. Roger and Katy Payne’s album Songs of the Humpback Whale was considered so important that selections from it were included on a record aboard the Voyager 1 spacecraft, to give any extraterrestrials who may find the spacecraft an idea of what life on Earth is like. The oceans have only gotten noisier since the 1970s, and similar conservation efforts are needed to reduce noise. 

“We need strict regulations for such noise, because these whales are dependent on sound for communication,” Elemans said in a statement. “Now we show that despite their amazing physiology they literally cannot escape the noise humans make in the oceans.”

The post We finally know how baleen whales make noise appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

The reproduction of giant sea spiders in Antarctica has been a puzzle for over a century. Studying their habits requires deep dives under thick Antarctic ice in frigid ocean temperatures. Now, a group of scientists may have finally solved the 140-year-old mystery of why the giant sea spiders lay their eggs on the bottom of the seafloor, unlike other sea spider species who carry them around. The findings are described in a study published February 11 in the journal Ecology.

[Related: Sea spiders use their guts to pump oxygen through their freaky little bodies.]

Polar giants

Sea spiders belong to a group of invertebrates found in marine habitats around the world. These marine arthropods are in the order Pantopoda. They are related to, but not the same as land spiders who are in the order Arachnida. 

While most sea spider species are smaller than a human fingernail, Antarctica’s giant sea spiders (Colossendeis megalonyx) have a leg span that is more than one foot apart. They can grow up to 20 inches wide, or the size of a dinner plate. C. megalonyx is a famous example of polar gigantism–where certain organisms in the Arctic and Antarctic grow larger than their relatives in warmer regions. Living on a diet of sea anemones, jellyfish, and other invertebrates.

C. megalonyx’ above average size and a unique parenting style sets them apart from other animals, not just those that live at the poles. Many sea spider species carry their eggs around until they hatch, in a behavior biologists call brooding.

“In most sea spiders, the male parent takes care of the babies by carrying them around while they develop,” study co-author and University of Hawaiʻi at Mānoa marine invertebrate ecologist Amy Moran said in a statement. “What’s weird is that despite descriptions and research going back over 140 years, no one had ever seen the giant Antarctic sea spiders brooding their young or knew anything about their development.”

Collecting mating spiders

In October 2021, Moran and PhD students Aaron Toh and Graham Lobert dove under thin ice during a field expedition in the Antarctic. They hand-collected groups of giant sea spiders that appeared to be mating and took them back to tanks for observation. 

“We were so lucky to be able to see this,” Toh said in a statement. “The opportunity to work directly with these amazing animals in Antarctica meant we could learn things no one had ever even guessed.”

The two different mating groups produced thousands of eggs in a gelatinous cloud. One parent–likely the father–spent two days attaching the eggs to the rocky bottom of the tank. There, the eggs developed for several months before hatching as tiny larvae. 

After a few weeks, the eggs became overgrown with microscopic algae. This created the perfect camouflage to keep them hidden from predators including sea stars, rays, and crabs. The protective camouflage explains why the eggs can be left on the floor and why it has been harder for researchers to spot them.

[Related: What an ancient jawbone reveals about polar bear evolution.]

“We could hardly see the eggs even when we knew they were there, which is probably why researchers had never seen this before,” Lobert said in a statement.

Taking care of embryos this way may represent a middle-ground breeding strategy. It could be a step between free spawning–where larvae are shot out into the water like in corals–and the brooding that sea spiders and octopuses perform. This first glimpse of their reproductive strategy is important for learning more about the biology and natural history of these and other animals living in polar regions. 

The post Giant Antarctic sea spiders’ reproductive mystery solved after 140 years of confusion appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Earth is home to some pretty gnarly carnivorous plants that will use sticky digestive juices to eat bugs and other plants that will even trick flies into mating with them. New research into the plant genus Arisaema points to an unusual evolutionary process within the plant kingdom. The relationship between a species of the carnivorous Arisaema plant genus may have a more nuanced relationship with its insect prey. The gnats that end up escaping from Arisaema’s waxy flowers may help by eating some of its decaying flowers. The findings are described in a study published February 19 in the journal Plants People Planet.

[Related: Two newly discovered Andes Mountain plant species have an appetite for insects.]

Luring pollinators to their deaths

Many plants rely on animals like bees, butterflies, and moths for pollination. Most also offer some kind of reward like nectar for their reproductive services. However, some plants like species in the genus Arisaema deceive their pollinators.

“It is famous as the only plant that achieves pollination at the expense of the pollinator’s life,” Kenji Suetsugu, a study co-author and biologist at Kobe University in Japan, said in a statement.

These plants use a musky odor to lure the fungus gnats that typically feed and lay their eggs on mushrooms into their cup-shaped flowers. The fungus gnats can escape from male Arisaema flowers, but only after being covered in the plant’s pollen. Females provide no means of escape. Once the insects are in a female Arisaema flower, the gnats will struggle to find an exit since they can’t get a hold of the wavy interior. This kills the gnats and ensures that the flower will be pollinated. 

Looking beyond an ‘antagonistic’ relationship

Suetsugu’s team sought to challenge traditional views in pollination biology and designed experiments to look for more nuanced interactions between Arisaema plants and their prey. In the study, they collected male and female flowers of the species Arisaema thunbergii. They looked closer at what species of insects got trapped and what happens to the flowers after pollination.  

They found the main pollinator was a fungus gnat named Leia ishitanii. The insect lays its eggs into the flowers and its larvae actually feed on the decaying flowers. The developing fungus gnats then emerge after a few weeks in this plant nursery. The younger insects sometimes come away from the flowers without any adult corpses from fellow members of its species. According to the team, this suggests that at least some of the fungus gnats can escape the flower’s trap. 

This interaction between insect and plant appears to be a new example of mutualism. This is where two different species form a bond for mutual benefits, like when oxpecker birds feed on the insects that live in large mammals’ fur. The larvae eating the decaying flowers could be beneficial to the A. thunbergii in a similar way, but more study is needed to confirm this. 

[Related: Carnivorous pitcher plants may use tempting aromas to lure prey to their death.]

“The interaction between the plant and the insect probably still differs from other typical examples of nursery mutualism,” said Suetsugu.

The fungus gnats do not depend on A. thunbergii as its only source of a nursery and the bugs that are permanently trapped in the flower are deprived of further egg-laying opportunities elsewhere. Interacting with these carnivorous flowers does appear to be costly to the insects. 

Full of surprises

A. thunbergii may be an example of an unusual evolutionary process that moves from deception solely for food towards a more mutualistic relationship where the gnats get a nursery and the plants have their decaying leaves taken care of. The team speculates that taking a closer look at other members of the Arisaema genus may yield similar kinds of interactions.

“This finding adds a new dimension to our knowledge of plant-insect interactions, but the most exciting aspect is that even in well-studied fields, there is still much to learn,” said Suetsugu. “Nature is full of surprises!”

The post Bug-munching plant turns insect nurseries into death traps appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

This article was originally featured on High Country News.

Increasing frequent and intense fires are shaping how species change, according to a paper published last year in the journal Trends in Ecology & Evolution. While previous research tended to focus on a blaze’s immediate impacts—Did population numbers go up or down?—scientists are starting to consider a longer timeline, said study co-author Gavin Jones, a Forest Service research ecologist at the Rocky Mountain Research Station.

Fire kills some animals but helps others survive, thereby determining which animal’s genes are passed on to future generations. The process of some individuals surviving better than others is natural selection, the driver of evolution. Sometimes, the survivors have traits that allow them to not only live through a fire but actually thrive in the burned ecosystem and later reproduce successfully.

Fire can also act as a connector, creating habitat that encourages members of a species to mingle over a larger range. Conversely, it can sometimes split populations into smaller, more isolated groups. That may result in inbreeding and eventual extinction—or the need for human intervention to keep an isolated population alive. 

Can wildlife adapt to a fiery future quickly enough to thrive? Species with large populations and short generations, like insects, tend to evolve faster than those with longer generations, which might have a harder time. “A lot of species are not going to be able to adapt,” Jones said, and will likely go extinct. “But we’re not at a total loss. Some species will be able to adapt.”

Animals with fire-adapted traits have already been identified throughout the West. Here are five examples of what Jones calls “evolution in action.”   

Black fire beetle

Black fire beetles love fire. In fact, they chase it—seeking out newly burned stumps to lay their eggs. Fires also drive off predators that might eat the beetles’ eggs before they hatch. So the bugs have developed sensory pit organs on their sides, tucked behind their legs, that can sense heat, letting them know where active blazes or smoldering, charred areas are, even from dozens of miles away. Highly sensitive infrared receptors within these organs contain small pockets of water that expand when they detect heat, which triggers the beetle to follow the heat to its source.

Black-backed woodpecker

Black-backed woodpeckers nest in charred snags and standing dead trees, where their plumage blends in with their sooty surroundings. But research on juveniles’ survival rates found that the closer nests are to unburned forest—where there’s more protective tree cover—the more likely they will survive to adulthood and pass on their genes. Offspring hatched in the middle of severely burned forests likely won’t survive, which selects for the genes of birds who nest closer to undisturbed forest. Additional research found that the woodpeckers flock to burned areas three to five years post-fire looking for beetles, which allows different populations to mix and share genes if they mate.

Western fence lizards

If an animal’s skin, scales or feathers match the surface it’s on, it’s camouflaged from potential predators and therefore more likely to survive and procreate. Mismatches can be deadly. Western fence lizards, common reptiles that live throughout the West, have sky-blue bellies and backs that range from black to gray to brown. In Southern California, they perch on the blackened stalks of burned shrubs for several years after fires and avoid white surfaces that don’t match their scales. Over time, this behavior can boost the number of darker-colored lizards.

Spotted owl 

Spotted owls need lush old-growth forests to survive. But even after a big fire, not all the birds will die or relocate. GPS tracking found that spotted owls actually like to hunt in severely burned patches of forest—particularly patches that are relatively small, between about 2.5 and 25 acres, and still surrounded by intact green trees for nesting. The ideal size of a burned area corresponds with the patches created by historically high-severity fires in the Sierra Nevada, suggesting that, over centuries, spotted owls have adapted their behavior to their habitat’s wildfire patterns.

Boisduval’s blue butterfly

Lupine wildflowers, a popular food choice for the larvae of butterflies and other pollinators, flourish after wildfires. In California’s Yosemite National Park, wildfires have encouraged isolated populations of Boisduval’s blue butterflies to interact, boosting their genetic diversity and the species’ overall health and resiliency. The butterfly, a silvery blue-winged species with 25 recognized subspecies (including one listed as federally endangered and another as federally threatened), isn’t the only animal that benefits from the vegetative bursts that often occur post-fire: Many invertebrates rely on the new growth that emerges after a blaze. Prescribed burns can stimulate the same effect.

The post Fire is driving animals’ evolution appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Even before most human babies can say “mama,” they can tease. This behavior is important, because playful teasing is a critical part of human interaction and development. A baby must have enough social intelligence and be able to recognize and appreciate that their actions can mess with another person’s expectation of what’s coming next. 

[Related: The best science jokes to make you laugh, groan, and Google.]

Teasing can start when human babies are as young as eight months-old, but we are not the only primates who can do it. This silly behavior has now been documented in four different species of great ape. These basic forms of humor likely evolved in the human lineage at least 13 million years ago. The findings are described in a study published February 13 in the journal Proceedings of the Royal Society B Biological Sciences.

“Great apes are excellent candidates for playful teasing, as they are closely related to us, engage in social play, show laughter and display relatively sophisticated understandings of others’ expectations,” Isabelle Laumer, a study co-author and primatologist and cognitive biologist affiliated with the University of California, Los Angeles (UCLA) and the Max Planck Institute of Animal Behavior, said in a statement. 

Play and provocative non-compliance

Early teasing generally involves an infant pulling off some kind of surprise. Babies can playfully offer a toy and then take it back. Psychologists call this behavior provocative non-compliance. Developmentally, it shows that a baby is beginning to understand that there are social rules or expectations that can be violated.

In the study, a team of scientists from institutions in Germany and the United States observed captive orangutans, chimpanzees, bonobos, and gorillas. They analyzed spontaneous social interactions that appeared to be playful, mildly harassing, or provocative. The team watched and noted the teaser’s actions, bodily movements, facial expressions, and how long the target of the teasing responded. They also assessed what the teaser’s intention could have been by searching for evidence that the behavior was directed towards a specific target, that the behavior continued or intensified, and that teasers waited for a response from their target.

All four species showed intentionally provocative behavior and these actions were frequently accompanied by characteristics of play. The team identified 18 distinct teasing behaviors, including tickling, poking, hair pulling, and hiding under an object. Many of these behaviors appeared to be used to get response from the target or at least get their attention. 

“It was common for teasers to repeatedly wave or swing a body part or object in the middle of the target’s field of vision, hit or poke them, stare closely at their face, disrupt their movements, pull on their hair or perform other behaviors that were extremely difficult for the target to ignore,” study co-author and UCLA and Indiana University anthropologist and linguist Erica Cartmill said in a statement.

Primate ‘playface’

While the playful teasing took many forms, it differed from general play in several ways. According to the authors, great apes playfully tease in a more one sided way, where it is often coming from the teaser and is rarely reciprocated.

[Related: Adolescent chimpanzees might be less impulsive than human teens.]

“The animals also rarely use play signals like the primate ‘playface,’ which is similar to what we would call a smile, or ‘hold’ gestures that signal their intent to play,” said Cartmill.

The apes’ playful teasing primarily happened when they were relaxed. It also typically involved a one-sided provocation, where the teaser looked right at their target’s face to wait for a reaction. The authors note that primatologist Jane Goodall and others in the field mentioned similar behaviors in chimpanzees several years ago, but this study is the first known to systematically study playful teasing. 

“From an evolutionary perspective, the presence of playful teasing in all four great apes and its similarities to playful teasing and joking in human infants suggests that playful teasing and its cognitive prerequisites may have been present in our last common ancestor, at least 13 million years ago,” said Laumer. 

The post Primates have been teasing each other for 13 million years appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Plenty of robots are inspired by existing animals, but not as many take their cue from extinct creatures. To design their own new machine, Carnegie Mellon University researchers looked over 500-million years back in time for guidance. Their result, presented during the 68th Biophysical Society Annual Meeting, is an underwater soft robot modeled after one of the sea urchin’s oldest ancestors.

[Related: Watch robot dogs train on obstacle courses to avoid tripping.]

Pleurocystitids swam the oceans around half a billion years ago—about the same time experts now believe jellyfish first appeared. While an ancient precursor to invertebrates such as sea stars, pleurocystitids featured a muscular, tail-like structure that likely allowed them to better maneuver underwater. After studying CT scans of the animal’s fossilized remains, researchers fed the data into a computer program to analyze and offer mobility simulations.

While no one knows for sure exactly how pleurocystitids moseyed around, the team determined the most logical possibility likely involved side-to-side sweeping tail motions that allowed it to propel across the ocean floor. This theory is also reinforced by fossil records, which indicate the animal’s tail lengthened over time to make them faster without the need for much more energy expenditure. From there, engineers built their own tail-touting, soft robot pleurocystitid.

To the casual viewer, footage of the mechanical monster clumsily inching across the ground may seem to hint at why the pleurocystitid is long gone. But according to Richard Desatnick, a Carnegie Mellon PhD student under the direction of mechanical engineering faculty Phil LeDuc and Carmel Majidi, the ancient animal likely deserves more credit.

“There are animals that were very successful for millions of years and the reason they died out wasn’t from a lack of success from their biology—there may have been a massive environmental change or extinction event,” Desatnick said in a recent profile.

Geologic records certainly reinforce such an argument. What’s more, given that today’s animal world barely accounts for one percent of all creatures to ever roam, swim, or soar above the planet, there is a wealth of potential biomechanical inspirations left to explore. Desatnick and his colleagues hope that their proof-of-concept pleurocystitid will help inspire new entries into a field they call paleobionics—the study of Earth’s animal past to guide some of tomorrow’s robotic creations.

The Carnegie Mellon team believes future iterations of their soft robot could offer a variety of uses—including surveying dangerous geological locations, and helping out with underwater machine repairs. More agile robo-pleurocystitids may one day glide through the waters. Even if nearby sea stars and urchins don’t recognize it, neither would exist without their shared source of inspiration.

The post A sea creature extinct for half a billion years inspired a new soft robot appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Paleontologists in Kentucky and Alabama discovered fossils belonging to three new ancient shark species. These long-dead predatory fish lived during a time when the region was covered by a shallow sub-tropical sea and a waterways that connected ancient land masses older than Pangea.

[Related: Prehistoric shark called Kentucky home 337 million years ago.]

An accidental dental discovery 

One of the new sharks is the species Palaeohypotodus bizzocoi and it is described in a study published February 7 in the open-access journal Fossil Record. Palaeohypotodus translates to “ancient small-eared tooth,” and it had small needle-like fangs on the sides of the teeth. Finding its fanged teeth allegedly happened by accident.

“A few years ago, I was looking through the historical fossil collections at the Geological Survey in Alabama and came across a small box of shark teeth that were collected over 100 years ago in Wilcox County,” Jun Ebersole, study co-author and Director of Collections at the McWane Science Center, said in a statement. “Having documented hundreds of fossil fish species over the last decade, I found it puzzling that these teeth were from a shark that I didn’t recognize.” 

Upon investigating the teeth, Ebersole found that it likely belonged to a new species. It lived roughly 65 million years ago, during the Paleocene Epoch. This is just after the dinosaurs began to die out and more than 75 percent of life on Earth went extinct. The team believes that P. bizzocoi was a leading predator at a time that ocean life was beginning to recover. 

“This time period is understudied, which makes the discovery of this new shark species that much more significant,” Lynn Harrell, Jr, a study co-author fossil collections curator at the Geological Survey of Alabama, said in a statement. “Shark discoveries like this one give us tremendous insights into how ocean life recovers after major extinction events and also allows us to potentially forecast how global events, like climate change, affect marine life today.”

325 million-year-old seaway sharks

On February 1, paleontologists from Mammoth Cave National Park announced the discovery of two new species of ancient shark. According to the National Park Service, Troglocladodus trimblei and Glikmanius careforum, were identified by fossils collected in deposits from Mammoth Cave in Kentucky and northern Alabama. Both of these shark species lived about 325 million years ago and are ctenacanths. These ancient cousins of modern sharks all had barbs on their spines used for defense. 

Scientists found juvenile teeth that belonged to Troglocladodus trimblei. It was likely about 10 to 12 feet long, roughly the same size of a modern oceanic white tip shark. The name Troglocladodus means “cave branching tooth,” in reference to its “forky-looking” chompers.

Glikmanius careforum pushes the origins of this Glikmanius genus of ctenacanth back over 50 million years earlier than expected. It was identified from teeth and a partial set of jaws and gills that belonged to a young Glikmanius. Scientists estimate that it also reached lengths of 10 to 12 feet. By the shape of its jaw, it likely would have had a powerful bite that it used for hunting bony fish, squid-like orthocones, and smaller sharks. 

[Related: The ‘meg’ may have been longer and less chonky than previously thought.]

Both species would have hunted the ancient near-shore habitats. The region was once an ancient seaway that connected present day eastern North America, Europe, and northern Africa. The waterway later disappeared as the supercontinent Pangea formed. 

Over 400 unique species of sharks and bony fishes have already been uncovered in Alabama alone, making it a very diverse fish fossil deposit. Ongoing research like the Paleontological Resources Inventory at Mammoth Cave National Park could continue to uncover even more new fossil sharks. 

The post Three new ancient shark species discovered in Alabama and Kentucky appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Paleontologists in the United Kingdom have discovered a new species of pterosaur on Scotand’s Isle of Skye. This reptile lived roughly 168 to 166 million years ago during the Middle Jurassic Era, when scientists previously thought that pterosaurs were only in present-day China. So the remains of a flying reptile showing up even in dinosaur-rich Scotland was quite a surprise. The new pterosaur is described in a study published February 5 in the Journal of Vertebrate Paleontology.

[Related: Dinosaur Cove reveals a petite pterosaur species.]

Meet Ceoptera

The new species is named Ceoptera evansae. It comes from the Scottish Gaelic word for mist or “cheò” and references the Gaelic name for the island “Eilean a’ Cheò,” or Isle of Mist. Evansae honors scientist Susan E. Evans, for her years of paleontological and morphological research, particularly on the Isle of Skye.

Scientists at the University of Bristol in England made digital models of the fossils using a CT scanner and believe that it likely had a wingspan of about three to five feet. It was likely a pterosaur species between the primitive and advanced stages of evolution. Pterosaurs in the Middle Jurassic were going through some major anatomical changes. Early smaller pterosaurs like the raven-sized Dimorphodon were giving way to later pterosaurs like Pteranodon, with the wingspans of small airplanes.

Ceoptera is likely part of the Darwinoptera clade of pterosaurs. Its discovery reveals that this clade–or a group of organisms that evolved from a common ancestor–is significantly more diverse than previously believed. The clade may have lasted more than 25 million years and species within the clade spread all over the world.  

“Ceoptera helps to narrow down the timing of several major events in the evolution of flying reptiles. Its appearance in the Middle Jurassic of the UK was a complete surprise, as most of its close relatives are from China,” study co-author and Natural History Museum vertebrate paleontologist Paul Barrett said in a statement. “It shows that the advanced group of flying reptiles to which it belongs appeared earlier than we thought and quickly gained an almost worldwide distribution.”

A new 15-year-old discovery

The team used specimens from the reptile’s wings, backbone, shoulders, and legs that were first uncovered embedded in a rock on a beach in 2006. It took Natural History Museum fossil technicians Lu Allington-Jones close to two years to prepare the fossils for study because the rocks on the island are very hard and the fossil bones are delicate. According to the authors, the specimen is of the most complete pterosaur fossils found in the UK since paleontologist Mary Anning found the first one in 1828. 

Pterosaur fossils are often found crushed, distorted, or incomplete. Like birds, they had hollow bones that were easily crushed and distorted over millions of years. The pterosaur record from both the Jurassic and the later Cretaceous Period (about 145-66 million years ago) in the UK has been sparse. Ceoptera helps fill in some of those evolutionary gaps.

“The time period that Ceoptera is from is one of the most important periods of pterosaur evolution, and is also one in which we have some of the fewest specimens, indicating its significance,” study co-author and University of Bristol paleobiologist Liz Martin-Silverstone said in a statement. “To find that there were more bones embedded within the rock, some of which were integral in identifying what kind of pterosaur Ceoptera is, made this an even better find than initially thought. It brings us one step closer to understanding where and when the more advanced pterosaurs evolved.”

[Related: This flightless pterosaur ancestor had enviable claws and a raptor-like beak.]

When pterosaurs dominated the sky

While insects were the first animals to take to the skies, pterosaurs were the first vertebrates to fly. Pterosaurs are technically not dinosaurs, but their evolutionary cousins. The biggest pterosaur scientists know of is Quetzalcoatlus northropi, which was found in Texas. Since everything is bigger in Texas, this pterosaur had a wingspan of about 32 to 36 feet. Australia’s largest pterosaur, Thapunngaka shawi, boasts a wingspan of roughly 22 feet.

Paleontologist and evolutionary biologist Steve Brusatte from the University of Edinburgh told the BBC that this Ceoptera was likely unique to Scotland. 

“This is the time before birds, so pterosaurs ruled the sky,” said Brusette, who was not involved in the study. “This research shows that pterosaurs were common animals in Scotland, soaring over the heads of dinosaurs.”

The post New pterosaur species discovered in Scotland appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

About a decade ago, the theory that Neanderthals had bred with Homo sapiens outside of Africa rocked the anthropological, archeological, and genetics worlds. Some scientists looked down on these now extinct human cousins, but quickly learned that they themselves could share as much as four percent of their DNA with Neanderthals. The question of how long ago and where this interbreeding occurred is still being debated. Now, some new analysis is further filling in the timeline of Neanderthal and modern human interactions and the two may have intermingled for quite some time.  

[Related: Neanderthals were likely creating art 57,000 years ago.]

A new genetic analysis of bone fragments from an archaeological site in central Germany shows that modern humans had reached northern Europe 45,000 years ago. This means that their arrival overlapped with the Neanderthals who had been living there for several thousand years before going extinct. The evidence also adds to the suspicion that the movement of modern humans into Europe and Asia about 50,000 years ago helped drive Neanderthals into extinction. The findings are described in three new papers published January 31 in journals Nature and Nature Ecology and Evolution.

Evidence from Stone Age tools

Neanderthals were living in northern Europe for more than 500,000 years by the time that modern humans began to arrive. A multidisciplinary team of researchers studied bone fragments and stone tool blades from a site near Ranis, Germany. It was first explored in the 1930s, but a team from institutions in Austria, China, Denmark, France, Germany, Italy, Spain, Sweden, Switzerland, the United Kingdom, and the United States re-excavated the area from 2016 to 2022.

This site is best known for some finely flaked, leaf-shaped stone tool blades called leaf points. The leaf points found there were dated to the final years of the Middle Paleolithic period— between 300,000 and 30,000 years ago—or the beginning of the Upper Paleolithic, which starts around 50,000 years ago. The tools are among the oldest confirmed sites of modern human Stone Age culture in north central and northwestern Europe.

The leaf points are similar to stone tools that have been uncovered at several sites in the United Kingdom, Poland, Moravia, and elsewhere in Germany. Archaeologists believe that they were all produced by the same culture known as the Lincombian–Ranisian–Jerzmanowician (LRJ) culture.

Previous dating of the Ranis site estimated that it was 40,000 years old or older. However, without recognizable bones to indicate who crafted the tools found there, it was not clear if Neanderthals or Homo sapiens made them. In order to know if a Neanderthal or Homo sapien crafted the tools, it would take some DNA.

The DNA evidence

During the re-excavation, the team was able to get to some rocks that 20th Century scientists couldn’t get to, to look for LRJ culture bones or more tools. 

“After removing that rock by hand, we finally uncovered the LRJ layers and even found human fossils. This came as a huge surprise, as no human fossils were known from the LRJ before, and was a reward for the hard work at the site,” Marcel Weiss, a study co-author neurophysicist at Friedrich-Alexander-Universität Erlangen-Nürnberg and the Max Planck Institute for Evolutionary Anthropology in Germany, said in a statement.

[Related: Neanderthals may have been early risers.]

These human remains meant that they could perform genetic analysis to see who could have made the stone tools. The extracted DNA in the ancient bones was highly fragmented. Study co-author and University of California, Berkeley research fellow Elena Zavala isolated and sequenced the basic DNA and all of the mitochondrial DNA that was inherited from the mother.  

“We confirmed that the skeletal fragments belonged to Homo sapiens. Interestingly, several fragments shared the same mitochondrial DNA sequences—even fragments from different excavations,” Zavala said in a statement. “This indicates that the fragments belonged to the same individual or their maternal relatives, linking these new finds with the ones from decades ago.”

These bone fragments were initially identified as human through analysis of bone proteins by study co-author Dorothea Mylopotamitaki, a doctoral student at the Collège de France. The team compared the Ranis mitochondrial DNA sequences with other mitochondrial DNA sequences from human remains at other paleolithic sites in Europe. 

They used this data to construct a family tree of early Homo sapiens across Europe. They found that all but 13 fragments from the Ranis cave were similar to one another. They also resembled mitochondrial DNA from a 43,000-year-old skull of a woman found in a cave in the Czech Republic. The only standout in the sample was an individual from Italy.

“That raises some questions: Was this a single population? What could be the relationship here?” Zavala said. “But with mitochondrial DNA, that’s only one side of the history. It’s only the maternal side. We would need to have nuclear DNA to be able to start looking into this.”

The DNA revealed that Homo sapiens were present at least in this part of Germany, not just Neanderthals.

Insights into human diet

The cave excavation also found traces of DNA from multiple mammals. There were traces of horses, cave bears, woolly rhinoceroses, and reindeer, which indicates that the area had a colder climate similar to the tundra of Siberia and northern Scandinavia today. 

It also indicates that the human diet at the time was based on these large land animals. 

[Related: Neanderthals caught and cooked crabs 90,000 years ago.]

“Zooarchaeological analysis shows that the Ranis cave was used intermittently by denning hyaenas, hibernating cave bears, and small groups of humans,” Geoff Smith, a study co-author and zooarchaeologist from the University of Kent and the Max Planck Institute for Evolutionary Anthropology, said in a statement.  “While these humans only used the cave for short periods of time, they consumed meat from a range of animals. Although the bones were broken into smaller pieces, they were exceptionally well preserved and allowed us to apply the latest cutting-edge methods from archaeological science, proteomics and genetics.”

It also indicates that earlier groups of Homo sapiens dispersing across Eurasia could adapt to harsh changes in climate conditions. 

“Until recently, it was thought that resilience to cold-climate conditions did not appear until several thousand years later, so this is a fascinating and surprising result,” study co-author and University of La Laguna in Spain paleoclimatologist Sarah Pederzani said in a statement. 

Revising the timeline

Radiocarbon dating of human and animal bones from different layers of the site was used to build a timeline of the cave. Many of the bones had traces of human modifications on their surfaces, which links their dates to the presence of humans from the LRJ culture in the area.

“We found very good agreement between the radiocarbon dates from the Homo sapiens bones from both excavation collections and with modified animal bones from the LRJ layers of the new excavation, making a very strong link between the human remains and LRJ,” study co-author and Postdoctoral Fellow at the Francis Crick Institute Helen Fewlass said in a statement. “The evidence suggests that Homo sapiens were sporadically occupying the site from as early as 47,500 years ago.”

The post Neanderthals and modern humans intermingled in Europe 45,000 years ago appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

An international team of scientists believe they have finally found the elusive answer to the question of why moths are drawn to light. The artificial light appears to trap moths and other flying insects in a wonky flight pattern. The light makes them lose their sense of up and down, since they are used to following light in the night sky instead of on the ground. The moths aren’t necessarily attracted to the light, but are more likely trapped in its glow. The findings are described in a study published January 30 in the journal Nature Connections.

[Related: Light pollution is messing with coral reproduction.]

Millions of years of evolution

Moths and butterflies have called Earth home for at least 200 million years. Through that time, 

moths and other insects that fly at night may have evolved to tilt their heads back towards whatever direction is brightest. This light source was originally the stars and moonlight in the sky and not on the ground. This ensured that the bugs knew which way was up and kept them flying level. 

When artificial light sources began to fill up the Earth, the moths found themselves tilting their backs at lamps in the street or fires. This caused them to fly in endless loops around the streetlamp, as they were trapped by instincts learned through millions of years of evolution.  

“This has been a prehistorical question. In the earliest writings, people were noticing this around fire,” study co-author and Florida International University biologist Jamie Theobald said in a statement. “It turns out all our speculations about why it happens have been wrong, so this is definitely the coolest project I’ve been part of.”

Monitoring flight paths

In the study, a team of international researchers in the Costa Rican cloud forest used high resolution and high-speed infrared video recordings to capture insect flight paths around artificial lights. They collected over 477 videos spanning more than 11 insect orders. This technology was able to capture the insects’ fast and frenzied orbits by the lights and was used to reconstruct points of their flight paths in three dimensions. The team noticed that moths and dragonflies turned their backs to artificial lights, which appeared to drastically change their flight paths. The insects may have thought that the lights were a source of light in the sky and not on the ground.

“If the light’s above them, they might start orbiting it, but if it’s behind them, they start tilting backwards and that can cause them to climb up and up until they stall,” study co-author and Imperial College London entomologist Sam Fabian told The Guardian. “More dramatic is when they fly directly over a light. They flip themselves upside down and that can lead to crashes. It really suggests that the moth is confused as to which way is up.”

The research has some entomologists buzzing, since it provides a potential answer to a phenomenon in nature that is millions of years old.

Conservation concerns

This study is the first known documentation of this behavior in nocturnal insects and provides a new possible explanation of why lights seem to attract moths. While it appears to confirm that light is disruptive, it also gives new insights into a conservation concern. Light pollution is a major reason behind recent declines in insect populations. Moths and other insects can become trapped in the lights and become easy prey for bats. The fake light can also make moths believe that it is daytime and signal that it is time to sleep and not eat.

[Related: City lights could trigger a baby boom for some moths and butterflies.]

The study also suggests light direction matters when designing and installing exterior lights. According to the team, the worst direction is an upward facing or bare bulb. Shrouding or shielding a lightbulb could help offset the negative impacts.

Scientists are also beginning to think about how light color impacts flying nocturnal insects. The unexplained mystery of how these insects are initially attracted to light over great distances also still remains. 

“I’d been told before you can’t ask why questions like this one, that there was no point,” Yash Sondhi, a postdoctoral researcher at the Florida Museum of Natural History and study co-author, said in a statement. “But in being persistent and finding the right people, we came up with an answer none of us really thought of, but that’s so important to increasing awareness about how light impacts insect populations and informing changes that can help them out.”

The post Why artificial light—and evolution—trap moths appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Tracing how some primates went from getting around on all fours to walking around on two legs  has been difficult. The fossil record hasn’t always presented a clear evolutionary history of bipedalism. These days, our species primarily walks upright on two legs, but primates can also climb up trees using arms and legs to propel the body. Some primates like great apes typically walk using all four limbs and smaller monkeys gracefully swing among tree branches. Scientists are now beginning to see more clearly how humans developed our bipedal walking ability, by studying the inner ears of the extinct primate Lufengpithecus—likely, an evolutionary stepping stone.

[Related: Our tree-climbing ancestors evolved our abilities to throw far and reach high.]

A team of scientists used three-dimensional CT-scans of a 6-million-year-old fossilized Lufengpithecus skull’s bony inner ear and found a structure that looks similar to some of today’s bipedal mammals. This inner ear area likely played a role in bipedal evolution. The findings are described in a study published January 29 in the journal The Innovation.

Meet Lufengpithecus

Lufengpithecus lived in East Asia during the Miocene Era, about 23 million to five million years ago. The land-dwelling animals at this time were starting to look more like the animals we see today, but some of their earlier and intermediate forms like Lufengpithecus were still living. 

“It would have been about the size of a chimpanzee. We don’t have too many clues to this, but we can be pretty sure it was primarily specializing in fruit,” study co-author and New York University biological anthropologist Terry Harrision tells PopSci. “It did seem to have relatively long arms and it would have been quite fragile moving around the trees. Most of its time would have been spent in the trees.”

The team examined skulls that were first discovered in China’s Yunnan Province in the early 1980s. Unfortunately, the skulls have become damaged over time and previous work on them revealed that the crucial and delicate semicircular canals in the inner ear were not well preserved.

“The semicircular canals, located in the skull between our brains and the external ear, are critical to providing our sense of balance and position when we move, and they provide a fundamental component of our locomotion that most people are probably unaware of,” Yinan Zhang, a study co-author and Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences (IVPP) PhD student, said in a statement. “The size and shape of the semicircular canals correlate with how mammals, including apes and humans, move around their environment. Using modern imaging technologies, we were able to visualize the internal structure of fossil skulls and study the anatomical details of the semicircular canals to reveal how extinct mammals moved.”

Recreating a six-million-year old inner ear

To get a more accurate look inside Lufengpithecus’ inner ears, the team needed to recreate the damaged semicircular canals using data from the fossil record. The team used three-dimensional scans to virtually recreate the inner ear’s bony canals. They then compared the scans to living and fossil apes and humans from Africa, Europe, and Asia. 

[Related: Foraging in trees might have pushed human ancestors to walk on two feet.]

“Our analyses show that early apes shared a locomotor repertoire that was ancestral to human bipedalism,” study co-author and IVPP paleoanthropologist Xijun Ni, said in a statement. “It appears that the inner ear provides a unique record of the evolutionary history of ape locomotion that offers an invaluable alternative to the study of the postcranial skeleton.”

From this comparison, the team believes that three steps led to the evolution of human bipedalism. Apes first moved in the trees in a style that is similar to how today’s gibbons swing through trees. The last common ancestor of both apes and humans used a combination of climbing, clambering, walking on four limbs while on the ground, and using only two limbs in trees to get around. It was from this mix of motion that bipedalism eventually became dominant in humans. It’s possible that once our species got a solid grasp of walking on two legs, more fine motor skills that are related to the inner ear like balance could be refined over time. 

“Even though humans generated bipedalism during their evolutionary history, we did come from a group of very unusual primates that developed unique ways of moving around their environment,” says Harrison. “So we are an oddity.”

Incredible ape diversity

As a species that is in the middle of an evolutionary tree, Lufengpithecus gives scientists a window into understanding how ape diversity originated over 20 million years ago. The team also believes that climate changes may have been an important environmental catalyst of how apes and their ways of movement evolved. Ice sheets began to form in the Northern Hemisphere and temperatures began to cool about 3.2 million years ago. These environmental changes corresponds to an uptick of changes in the bony labyrinth of the inner ear. 

Future research is needed to determine exactly why evolving this way of walking around was particularly helpful as the ice sheets in the Northern Hemisphere were growing and why ape diversity began to decrease worldwide. 

“The modern [living] apes are just a small sampling of the incredible diversity that we’ve had in the past. We wouldn’t have known about this incredible diversity haven’t had if it hadn’t been for the fossil record,” says Harrison. “It’s confusing, and it won’t be figured out in my lifetime, but the fact is, we’re getting a lot closer to really beginning to understand it.”

The post Extinct ape’s inner ear holds clues to how humans learned to walk upright appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Marsupials are anything but a boring group of mammals. Kangaroos have some of the most powerful kicks in the animal kingdom, wombats are known for their poop cubes, koalas have a toxic diet, and the mouse-sized antechinus has its busy sex life. These small Australian marsupials will sacrifice multiple hours of sleep every night during their fast and furious mating season to make more time for reproduction. These new findings are described in a study published January 25 in the journal Current Biology and shows the first known direct evidence of this kind of sleep deprivation in a land-dwelling mammal.

[Related: These animals spend their whole lives waiting to have sex, and then they die.]

Strange breeding system for a mammal

Antechinuses are small carnivorous marsupials that live in wooded areas of northern and eastern Australia. There are currently 15 recognized species of antechinus, including the brown antechinus, swamp antechinus, and fawn antechinus. They are primarily nocturnal and eat insects, spiders, and even some small reptiles and frogs. 

Their unique breeding system is more reminiscent of the short-lived bugs that they feast on than other mammals. While females can live for two years, male antechinuses only live for a year. They can only reproduce once in that short lifetime and the males will typically all die at about the same time following their short and intense mating season. 

“The males have one shot at fathering offspring during a single three-week mating period,” study co-author John Lesku, a zoologist who specializes in sleep at La Trobe University in Melbourne, Australia, said in a statement. “We found that male, but not female, dusky antechinuses, become restless during their only breeding season.”

The sleep vs. sex trade-off

Males will trade off between sleep and reproduction that is likely driven by strong sexual selection. For animals–including humans–not catching enough Z’s can typically lead to numerous issues including irritability, lack of concentration, and increase the risk of high-blood pressure, and heart disease. During mating season, antechinuses lose sleep at a rate that would make an average human act as though they were intoxicated, according to the study’s authors.

“Using a combination of techniques, we showed that males lose sleep during the breeding season, with one male halving his sleep during this mating period,” study co-author and La Trobe University PhD student Erika Zaid said in a statement. “In humans and other animals, restricting the normal amount of sleep leads to worse performance while awake, an effect that compounds night after night. And yet, the antechinus did just that: they slept three hours less per night, every night, for three weeks.”

[Related: Why do people need to sleep?]

The team used accelerometers to track the patterns of movement of 15 dusky antechinus (10 males) from captive and wild settings, both before and during mating season. They took blood samples to measure hormonal changes and electrophysiological recordings from four of the males to determine how much they were sleeping. Additional blood samples were taken from 38 wild agile antechinus (20 males) to check if a biomarker for sleep loss called oxalic acid similarly decreased in mating season. 

Females lose sleep too

The results showed that the males were sleeping three hours less every night for weeks. The antechinus may have some unknown way to thrive with less sleep during their mating season. They also may simply accept the physical downsides of sleep deprivation in order to improve their chances of producing offspring. 

The decrease in oxalic acid suggests that the agile antechinus were sleep deprived during mating season, but there was no significant difference between the males and females. This could suggest that the females are also sleep deprived because of male harassment during mating season. 

Biologists are still not certain what causes the males to die after breeding season, but do not suspect that sleep loss alone is the culprit. The males that the team observed sleeping were not the ones in the worst condition. The team wants to learn more about how these marsupials handle their sleep loss. In part that’s because the males they saw sleeping the least were not the ones in the worst condition.

“Are antechinus equally compromised, but just get on with it?” they ask. “Or are they resilient to the negative effects of sleep restriction?” 

The post Sex is more important than sleep for these marsupials appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

In animal evolution, a classical yet controversial idea posits that bigger is better. Bigger animals can reign supreme as hunters, fighters, and mates by simply out-bulking the competition. Living large enables easier survival, so the long-held theory goes. Called “Cope’s Rule,” after paleontologist Edward Drinker Cope, the concept first emerged among paleobiologists in the 19th century. Initially, Cope’s Rule seemed like a good explanation for the mega mammals like wooly mammoths and saber tooth tigers that once roamed North America. For dinosaurs, too, Cope’s Rule appears to fit. But exceptions to the trend soon became apparent. 

Over millennia, some animal species and populations have grown smaller, not larger, according to the fossil record. Ice Age horses that occupied Alaska in the distant past, some anole lizards living on Caribbean islands, many types of turtles, and even dragonflies all shrunk through time, research suggests. These observations run counter to prevailing expectations of animal size, and have gone largely unexplained for decades. A newly proposed evolutionary hypothesis, tested via computer modeling, could help solve the mystery. 

Intense levels of competition between species and a high risk of extinction leads animals to trend smaller, according to the theory outlined in a study published January 18 in the journal Communications Biology. The researchers built a complex computer model of community evolution with 20 different mathematical parameters including things like predation rate and baseline mortality. They tracked a modeled group of interacting organisms through a time progression across multiple scenarios and explored how body size, species abundance, and ecological niche shifted under different circumstances.  Through their model, they explored various resource and risk dynamics and found size outcomes changed depending on the scenario. 

In some set-ups, Cope’s Rule does indeed appear to hold true. When resource competition between species is low and the overall risk of extinction is minimal, the model suggests that animals do trend larger. Similarly, when top predators go extinct, animals lower down on the ecological ladder may evolve larger to take advantage of the open niche. Yet in more cutthroat scenarios–where competition for prey, habitat, or other basic needs is extreme across the web of life–animal populations may maintain their size or even shrink, says lead study author Shovonlal Roy, a professor and ecological modeler at the University of Reading in the United Kingdom. 

“We really didn’t expect that,” Roy says. He and his colleagues did not set out to disprove Cope’s Rule, but to see if it would hold up to modeling. The more-than-a-century-old theory has been debated for decades. Some evolutionary biologists and paleontologists have dismissed it as an artifact of selection bias for big animals, while others have remained loyal to the theory, which seems to hold for so many species. 

The study results suggest that reality is more complicated than a single notion of body size. Moreover, the model findings offer an evolutionary explanation for exceptions to the rule, says Roy: these are not accidents or aberrations, but outcomes resulting from clear, mathematically interpretable pressures. 

For scenarios in which species shrink over time, the researchers propose a “recurrent inverser Cope’s rule.” By the guidance of this new theory, high competition forces animals to diversify their ecological niches, seeking out new foods or habitats. Yet, Roy explains, there will always be pressure to return to the original resource, for which an animal was initially well-suited. Accessing that sought-after resource is easier the smaller you are. Smaller animals take up less space and require less energy. Sure, there are advantages to being big, but sometimes small is superior. 

Previously, science offered exceptions to the rule with no overarching explanation. Now, there’s a proposed “common framework” which biologists and others can work off of, says Roy. This complementary evolutionary theory could shed light on certain trends, even currently unresolved mysteries like the world’s shrinking bird problem. Birds in many habitats worldwide seem to be getting smaller, and the change correlates with rising temperatures. But physics doesn’t appear to explain the whole story. The recurrent inverse Cope’s Rule might offer insight. 

[ Related: These extinct, nearly 10-foot-tall apes could not adapt to shifting seasons ]

In all of the models the researchers ran, animals that rapidly grew larger or shrunk were headed towards extinction. But that’s the way of the world, says Roy. For most species, especially at the extreme ends of the size spectrum, extinction is inevitable over the long arc of evolutionary time because extremes are vulnerable to change. A recent study suggests that the largest primate to ever live, an ape clocking in at almost 10 feet tall and weighing more than 550 pounds, likely went extinct because its massiveness made adapting to climate shifts more difficult. Again, Roy says this extinction aligns with their model. 

Yet all of this is still theoretical. Though the researchers’ computer model is intricate and took years to fine tune, real-world tests and data are needed to back up the idea. Roy says he hopes to see future research take on the recurrent inverse Cope’s Rule and assess its validity in the fossil record. He’d also like to use paleontological data to build better and more comprehensive versions of the model that account for variables like temperature and habitat loss. For now, what’s proven is that animals aren’t the only things that evolve: our understanding of the world can too.

The post A new evolutionary theory could explain the mystery of shrinking animals appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Unlike some pretty metal plants that thrive in the darkness, yeast generally doesn’t function well in the light. This fungi turns carbohydrates into ingredients for beer or bread when left to ferment in the dark. It must be stored in dark dry places, as exposure to light can keep fermentation from happening all together. However, a group of scientists have engineered a strain of yeast that may actually work better with light that could give these fungi an evolutionary boost in a simple way. The findings are described in a study published January 12 in the journal Current Biology.

[Related: The key to tastier beer might be mutant yeast—with notes of banana.]

“We were frankly shocked by how simple it was to turn the yeast into phototrophs (organisms that can harness and use energy from light),” study co-author and Georgia Institute of Technology cellular biologist Anthony Burnetti said in a statement. “All we needed to do was move a single gene, and they grew 2 percent faster in the light than in the dark. Without any fine-tuning or careful coaxing, it just worked.”

Giving yeast such an evolutionarily important trait may help us understand how phototropism originated and how it can be used to study evolution and biofuel production, as well as how cells age. 

Give it some energy

Previous work on the evolution of multicellular life by this research group inspired the new study. In 2023, the group uncovered how a single-celled model organism called snowflake yeast could evolve multicellularity over 3,000 generations. However, one of the major limitations to their evolution experiments was a lack of energy.

“Oxygen has a hard time diffusing deep into tissues, and you get tissues without the ability to get energy as a result,” said Burnetti. “I was looking for ways to get around this oxygen-based energy limitation.”

Light is one of the ways organisms can get an energy boost without oxygen. However, from an evolutionary standpoint, an organism’s ability to turn light into usable energy can be complicated. The molecular machinery that allows plants to use light for energy requires numerous proteins and genes that are difficult to synthesize and transfer into other organisms. This is difficult in the lab and through natural processes like evolution. 

A simple rhodopsin

Plants are not the only organisms that can convert light into energy. Some on-plant organisms can also use this light with the help of rhodopsins. These proteins can convert light into energy without any extra cellular machinery.

“Rhodopsins are found all over the tree of life and apparently are acquired by organisms obtaining genes from each other over evolutionary time,” study co-author and Georgia Tech Ph.D. student Autumn Peterson said in a statement. 

[Related: Scientists create a small, allegedly delicious piece of yeast-free pizza dough.]

A genetic exchange like this is called a horizontal gene transfer, where genetic information is shared between organisms that are not closely related. A horizontal gene transfer can cause large evolutionary leaps in a short period of time. One example of this is how bacteria can quickly develop resistance to certain antibiotics. This can happen with all kinds of genetic information and is particularly common with rhodopsin proteins.

“In the process of figuring out a way to get rhodopsins into multi-celled yeast,” said Burnetti, “we found we could learn about horizontal transfer of rhodopsins that has occurred across evolution in the past by transferring it into regular, single-celled yeast where it has never been before.”

Under the spotlight

To see if they could give a single-celled organism a solar-powered rhodopsin, the team added a rhodopsin gene synthesized from a parasitic fungus to common baker’s yeast. This individual gene is coded for a form of rhodopsin that would be inserted into the cell’s vacuole. This is a part of the cell that can turn chemical gradients made by proteins like rhodopsin into needed energy. 

With this vacuolar rhodopsin, the yeast grew roughly 2 percent faster when it was exposed to light. According to the team, this is a major evolutionary benefit and the ease that the rhodopsins can spread across multiple lineages might be key. 

“Here we have a single gene, and we’re just yanking it across contexts into a lineage that’s never been a phototroph before, and it just works,” said Burnetti. “This says that it really is that easy for this kind of a system, at least sometimes, to do its job in a new organism.”

Yeasts that function better in the light could also increase its shelf life. Vacuolar function may also contribute to cellular aging, so this group has started collaborating with other teams to study how rhodopsins may reduce aging effects in the yeast. Similar solar-powered yeast is also being studied to advance biofuels. The team also hopes to study how phototrophy changes yeast’s evolutionary journey to a multicellular organism. 

The post This yeast loves light appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Beginning about 2.6 million years ago, giant primates almost 10 feet tall weighing 551 pounds roamed the plains of southern China. Gigantopithecus blacki (G. blacki) towered over today’s largest monkeys by about five feet and is believed to be the largest primate to ever roam the Earth. However, it went extinct just as other primates–like orangutans–were thriving. 

[Related: These primate ancestors were totally chill with a colder climate.]

Now, a team of scientists from China, Australia, and the United States believe that this giant ape went extinct between 295,000 and 215,000 years ago because it could not adapt its food preferences and behaviors and was vulnerable to extreme changes in the planet’s climate. The findings are detailed in a study published January 10 in the journal Nature. 

“The story of G. blacki is an enigma in paleontology–how could such a mighty creature go extinct at a time when other primates were adapting and surviving? The unresolved cause of its disappearance has become the Holy Grail in this discipline,” Yingqi Zhang, study co-author and Institute of Vertebrate Palaeontology and Palaeoanthropology at the Chinese Academy of Sciences (IVPP) paleontologist, said in a statement. 

Seasonal shifts 

Roughly 700,000 to 600,000 years ago, the rich forest environment that G. blacki lived in began to change. The new study proposes that as Earth’s four seasons began to strengthen and G. blacki’s habitat saw more variability in temperature and precipitation, the structure of these forest communities began to change. 

In response, G. blacki’s close relatives the orangutans adapted their habitat preferences, behavior, and size over time. However, G. blacki was not quite as nimble. Based on its dental anatomy, these giant apes were herbivores that had adapted to eat fibrous foods like fruits. However, when its favorite food sources were not available, the team believes that G. blacki relied on a less nutritious backup source of sustenance, decreasing the diversity of its food. They likely suffered from a reduced geographic range for foraging, became less mobile, and saw chronic stress and dwindling numbers. 

“G. blacki was the ultimate specialist, compared to the more agile adapters like orangutans,  and this ultimately led to its demise,” said Zhang. 

Honing in on a date

G. blacki left behind roughly 2,000 fossilized teeth and four jawbones that helped paleontologists put together the story of G. blacki’s time on Earth, but more precise dating of these remains was needed to determine its extinction story. To find definitive evidence of their extinction, the team took on a large-scale project that explored 22 cave sites in a wide region of Guangxi Province in southern China. 

[Related: Nice chimps finish last—so why aren’t all of them mean?]

Determining the exact time when a species disappears from the fossil record helps paleontologists determine a timeframe that they can work to rebuild from other evidence. 

“Without robust dating, you are simply looking for clues in the wrong places,” Kira Westaway, a study co-author and geochronologist at Macquarie University in Australia, said in a statement

In the study, the team used six dating techniques the samples of cave sediments and teeth fossils. The techniques produced 157 radiometric ages that were combined with eight sources of environmental and behavioral evidence. They took this combined figure and applied it to 11 caves that had evidence of G blacki in them and 11 caves of a similar age range that did not have any remains of G. blacki.

The primary technique that helped the team hone in on a date range was luminescence dating. It measures a light-sensitive signal that is found in the burial sediments that encased the G. blacki fossils. Uranium series and electron-spin resonance were also critical in dating the G. blacki teeth themselves. 

“By direct-dating the fossil remains, we confirmed their age aligns with the luminescence sequence in the sediments where they were found, giving us a comprehensive and reliable chronology for the extinction of G. blacki,” Renaud Joannes-Boyau, a study co-author and geochronologist at Southern Cross University  in Australia, said in a statement. 

Building a world from teeth and pollen 

Researchers also used a detailed pollen analysis to reconstruct what the plant life looked like hundreds of thousands of years ago, a stable isotope analysis of the teeth, and a detailed analysis of the cave sediments to re-create the environmental conditions leading up to the time G blacki went extinct. Trace element and dental microwear textural analysis of the apes’ teeth enabled the team to model what G. blacki’s behavior likely looked like when they were flourishing, compared to their demise. 

[Related: An ‘ancestral bottleneck’ took out nearly 99 percent of the human population 800,000 years ago.]

“Teeth provide a staggering insight into the behavior of the species indicating stress, diversity of food sources, and repeated behaviors,” said Joannes-Boyau.

The dates of the fossils combined with the pollen and teeth analysis revealed that G.blacki went extinct between 295,000 and 215,000 years ago, earlier than scientists previously assumed. The team believes that studying their lack of adaptation has implications for today’s changing climate and the need for adaptation. 

“With the threat of a sixth mass extinction event looming over us, there is an urgent need to understand why species go extinct,” said Westaway. “Exploring the reasons for past unresolved extinctions gives us a good starting point to understand primate resilience and the fate of other large animals, in the past and future.”

The post These extinct, nearly 10-foot-tall apes could not adapt to shifting seasons appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Some fruit bats eat up to twice their body weight in sugary mangoes, bananas, or figs every day to not only survive, but thrive. Unlike humans, these flying mammals can have an essentially permanent sweet tooth and do not develop some of the negative health consequences such as diabetes. A study published January 9 in the journal Nature Communications found that genetic adaptations have helped keep their sugary diets from becoming harmful. 

[Related: How do bats stay cancer-free? The answer could be lifesaving for humans.]

The study could have future implications for treating diabetes, which affects an estimated 38 million Americans, according to the Centers for Disease Control and Prevention (CDC). It is the eighth leading cause of death in the United States and the leading cause of kidney failure, lower-limb amputations, and adult blindness.

“With diabetes, the human body can’t produce or detect insulin, leading to problems controlling blood sugar,” study co-author and University of California, San Francisco geneticist Nadav Ahituv said in a statement. “But fruit bats have a genetic system that controls blood sugar without fail. We’d like to learn from that system to make better insulin-or sugar-sensing therapies for people.”  

Fruit bats vs. insect bats

Every day, fruit bats wake up after about 20 hours of sleep and feast on fruit before returning back to their caves, trees, or human-built structures to roost. To figure out how they can eat so much sugar and thrive, the team in this study focused on how the bat pancreas and kidneys evolved. The pancreas is an abdominal organ that controls blood sugar. 

Researchers compared the Jamaican fruit bat with an insect-eating bat called the big brown bat. They analyzed the gene expression–which genes were switched on or off–and regulatory DNA that controls gene expression. To do this, the team measured both the gene expression and regulatory DNA present in individual cells. These measurements show which types of cells primarily make up the bat’s organs and also how these cells regulate the gene expression that manages their diet. 

They found that the compositions of the pancreas and kidneys in fruit bats evolved to accommodate their sugary diet. The pancreas had more cells to produce insulin, an essential hormone that tells the body to lower blood sugar. It also had more cells that produce another sugar-regulating hormone called glucagon. The fruit bat kidneys had more cells to trap scarce salts and electrolytes as they filter blood.  

Changes in DNA

Taking a closer look at the genetics behind this, the team saw that the regulatory DNA in those cells had evolved to switch the appropriate genes for fruit metabolism on or off. The insect-eating big brown bats had more cells that break down protein and conserve water and the gene expression in these cells was calibrated to handle a diet of bugs. 

[Related: Vampire bats socially distance when they feel sick.]

“The organization of the DNA around the insulin and glucagon genes was very clearly different between the two bat species,” study co-author and Menlo College biologist Wei Gordon said in a statement. “The DNA around genes used to be considered ‘junk,’ but our data shows that this regulatory DNA likely helps fruit bats react to sudden increases or decreases in blood sugar.” 

While some of the fruit bat’s biology resembled what is found in humans with diabetes, the bats are not known to have the same health effects.

“Even small changes, to single letters of DNA, make this diet viable for fruit bats,” said Gordon. “We need to understand high-sugar metabolism like this to make progress helping the one in three Americans who are prediabetic.” 

Studying bats for human health

Bats are one of the most diverse families of mammals and everything from their immune systems to very particular diets are considered by some scientists to be examples of evolutionary triumph. This study is one of recent examples of how studying bats could have implications for human health, including in cancer research and virus prevention. 

For this study, Gordon and Ahituv traveled to Belize to participate in an annual Bat-a-Thon, where they took census of wild bats and field samples. One of the Jamaican fruit bats that they captured at the Bat-a-Thon was used to study sugar metabolism.  

“For me, bats are like superheroes, each one with an amazing super power, whether it is echolocation, flying, blood sucking without coagulation, or eating fruit and not getting diabetes,” Ahituv said. “This kind of work is just the beginning.” 

The post Why fruit bats can eat tons of sugar without getting diabetes appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

The nearly half a billion year old remains of some enormous and extinct carnivorous worms have been discovered near the top of the world by an international team of researchers. The ancient creature named Timorebestia, or ‘terror beasts’ in Latin, lived in the water column of North Greenland over 518 million years ago. The new fossils indicate that the worms had fins on the sides of their bodies, a head with a long antenna, and enormous jaw structures on the insides of their mouth. They could grow to almost 12 inches long. These were some of the largest swimming animals of the Early Cambrian period and are described in a study published January 3 in the journal Science Advances.

[Related: A three-eyed organism roamed the seas half a billion years ago.]

An ‘explosion’ of life

When these terror beasts were alive over 500 million years ago, the Earth was undergoing a major expansion of life called the Cambrian Explosion. This is when most major groups of animals first appear in the fossil record, partially due to cooler temperatures and tectonic changes. All of this biological diversification also occurred in a relatively short period of time–in about 30 million years. 

The Timorebestia fossils were found during a 2017 expedition to the Early Cambrian Sirius Passet fossil locality in a very remote section of North Greenland. Timorebestia may be some of the earliest carnivorous animals to have colonized the water column here and reveal a past potential dynasty of predators that were previously unknown to scientists. Early arthropods were known to be the dominant predators during the Cambrian period, including some “weird shrimp from Canada” called anomalocaridids.

“Our research shows that these ancient ocean ecosystems were fairly complex with a food chain that allowed for several tiers of predators,” study co-author and University of Bristol paleontologist Jakob Vinther said in a statement. “Timorebestia were giants of their day and would have been close to the top of the food chain. That makes it equivalent in importance to some of the top carnivores in modern oceans, such as sharks and seals back in the Cambrian period.”

Timorebestia is also a distant but close relative of living arrow worms called chaetognaths. These worms are much smaller than today’s enormous ocean predators and only eat zooplankton, a far cry from their apex predator days of the past.

Opening a 518 million-year old digestive system 

The fossils from the Sirius Passet were exceptionally well preserved so the team was able to study the remains of their muscle anatomy, nervous systems, and digestive systems very closely. When they looked inside Timorebestia’s fossilized digestive system, they found the remains of a common, swimming arthropod called Isoxys. 

“We can see these arthropods was a food source [for] many other animals,” study co-author and University of Bristol paleontologist Morten Lunde Nielsen said in a statement. “They are very common at Sirius Passet and had long protective spines, pointing both forwards and backwards. However, they clearly didn’t completely succeed in avoiding that fate, because Timorebestia munched on them in great quantities.”

While arthropods like Isoxys appear in the fossil record about 521 to 529 million years ago, modern living arrow worms can be traced back at least 538 million years. Since arrow worms and these more early Timorebestia were swimming predators, the team believes that they dominated the oceans before arthropods took off. Their dynasty may have lasted about 10 to 15 million years before they were superseded by other groups of marine predators. 

Jaw predator evolution

The discovery of Timorebestia is also helping paleontologists understand where jawed predators came from. The arrow worms living today have bristles on their heads for catching prey, instead of having jaws inside of its head like Timorebestia. By comparison, today’s microscopic jaw worms have an oral setup that is more similar to Timorebestia, so arrow worms and jaw worms likely shared an ancestor over half a billion years ago.Timorebestia and some of the other specimens that the team found on this expedition are revealing the evolutionary links between organisms that may look different, but are closely related. It is also helping paint a better picture of how arrow worms evolved over hundreds of millions of years. 

[Related: A 500-million-year-old sea squirt is the evolutionary clue we need to understand our humble beginnings.]

“Living arrow worms have a distinct nervous center on their belly, called a ventral ganglion. It is entirely unique to these animals,” study co-author and Korean Polar Research Institute paleontologist Tae Yoon Park said in a statement. “We have found this preserved in Timorebestia and another fossil called Amiskwia. People have debated whether or not Amiskwia was closely related to arrow worms, as part of their evolutionary stem lineage. The preservation of these unique ventral ganglia gives us a great deal more confidence in this hypothesis.”

The team collected a wide variety of organisms during the expedition and plan to continue to study these specimens to learn more about how the planet’s earliest animal ecosystems evolved. 

The post Extinct ‘terror beasts’ were some pretty formidable worms appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Frogs are well known for their sticky, whip-like tongues, lumpy warts, and the colorful, poisonous skin covering some species. One group of frogs in Southeast Asia has another distinguishing feature–fangs. Scientists recently discovered a new species of fanged frog that uses these bony jaws jutting out of their lower jawbone to fight with other frogs and hunt shelled prey like giant centipedes and crabs. Limnonectes phyllofolia is also the smallest known species of fanged frog and is described in a study published December 20 in the journal PLOS ONE.

[Related: Female frogs appear to play dead to avoid mating.]

“This new species is tiny compared to other fanged frogs on the island where it was found, about the size of a quarter,” study co-author and biologist Jeff Frederick said in a statement. “Many frogs in this genus are giant, weighing up to two pounds. At the large end, this new species weighs about the same as a dime.” Frederick is a postdoctoral researcher at the Field Museum in Chicago and conducted this research as a doctoral candidate at the University of California, Berkeley.

The frogs were found on the mountainous island of Sulawesi in Indonesia. It’s a large 71,898 square mile-long island with a large network of volcanoes, mountains, lowland rainforest, and cloud forests in the mountains.

“The presence of all these different habitats mean that the magnitude of biodiversity across many plants and animals we find there is unreal—rivaling places like the Amazon,” said Frederick.

Members of a joint United States-Indonesia amphibian and reptile research team noticed something surprising on the leaves of tree saplings and moss-covered boulders in the jungle–frog eggs.

Frogs lay eggs covered by a jelly-like substance instead of a hard and protective shell like a bird. To keep them from drying out, most amphibians will lay their eggs in water. Instead, these frogs left their egg masses on leaves and mossy boulders above the ground. After finding these nests, the team began to see the small, brown frogs. 

“Normally when we’re looking for frogs, we’re scanning the margins of stream banks or wading through streams to spot them directly in the water,” Frederick says. “After repeatedly monitoring the nests though, the team started to find attending frogs sitting on leaves hugging their little nests.” 

The close contact with the eggs allows the adults to coat them with the right compounds to keep them moist and safe from bacterial and fungal contamination. They were named Limnonectes phyllofolia, which translates to “leaf-nester.”

[Related: Go (virtually) adopt an axolotl, the ‘Peter Pan’ of amphibians.]

The frogs who laid these eggs on leaves and boulders were tiny members of the fanged frog family. The caretakers of the nests were all males. According to Frederick, egg-guarding behavior from male frogs is uncommon, but not unheard of. The team theorizes that the frogs’ unusual reproductive behaviors may also relate back to their smaller fangs. While some of their relatives have larger fangs that help them ward off competition, these frogs likely evolved a way to lay their eggs away from the water and lost the need for such big fangs. 

“It’s fascinating that on every subsequent expedition to Sulawesi, we’re still discovering new and diverse reproductive modes,” says Frederick. “Our findings also underscore the importance of conserving these very special tropical habitats. Most of the animals that live in places like Sulawesi are quite unique, and habitat destruction is an ever-looming conservation issue for preserving the hyper-diversity of species we find there. Learning about animals like these frogs that are found nowhere else on Earth helps make the case for protecting these valuable ecosystems.”

The post This tiny ‘leaf-nester’ is the smallest known fanged frog appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

To survive the dark and snowy Arctic winters, reindeer have evolved unique visual systems. Their eyes change color to adjust to the huge swings in sunlight between Arctic summer and winter, but may do even more to help them forage. A study published December 15 in the journal i-Perception found that their eyes may have evolved to see light in the ultraviolet spectrum to help them find their favorite food in their desolate  home.

[Related: Jackrabbit’s color-changing fur may prepare them for climate change.]

Reindeer primarily eat Cladonia rangiferina (C. rangiferina), which is appropriately nicknamed reindeer moss. This plant is not a moss, but a species of algae-fungus called lichen. It forms a thick and crunchy blanket on the ground across the Earth’s northern latitudes and helps play an important role in the ecosystem as a food source. 

In the study, the team worked in the Cairngorms mountains in the Scottish Highlands, home to Britain’s only reindeer herd. Reindeer were locally hunted to extinction, but began to be reintroduced from Scandinavia in 1952. The Cairngorms are home to more than 1,500 species of lichen, but the reindeer here only rely on C. rangiferina during the winter months

“A peculiar trait of reindeer is their reliance on this one type of lichen,”  study co-author and Dartmouth College anthropologist and evolutionary biologist Nathaniel Dominy said in a statement. “It’s unusual for any animal to subsist so heavily on lichens, let alone such a large mammal.”

When up against snow, the white lichen is invisible to the human eye.. However, co-authors Catherine Hobaiter and Julie Harris from the University of St. Andrews found that C. rangiferina and some other lichen species that supplement the reindeer diet absorb ultraviolet (UV) light. The team used spectral data from the lichen and light filters that were made to mimic reindeer vision and found that the plants may look like dark patches against a bright landscape to the reindeer. They stand out like Dalmatian spots and are easier for the reindeer to locate.

According to Dominy, this is one of the first studies to use a visual approximation of how these mammals may see their world. 

“If you can put yourself in their hooves looking at this white landscape, you would want a direct route to your food,” Dominy said. “Reindeer don’t want to waste energy wandering around searching for food in a cold, barren environment. If they can see lichens from a distance, that gives them a big advantage, letting them conserve precious calories at a time when food is scarce.”

Some animals that can see on the UV spectrum include dogs, cats, pigs, and even ferrets. They generally do this with the short blue photoreceptors called cones present in their eyes. 

Earlier studies have shown that reindeer eyes change from golden in the summer and a vivid blue in the winter. The light-enhancing membrane that gives many animals a shiny eye called the tapetum transitions every season. The blue hue of their eyes is believed to amplify the low levels of sunlight present during polar winters. 

[Related: How do animals see the world?]

“If the color of the light in the environment is primarily blue, then it makes sense for the eye to enhance the color blue to make sure a reindeer’s photoreceptors are maximizing those wavelengths,” Dominy says.

However, the blue tapetum also lets up to 60 percent of UV light pass through to the eye’s color sensors. The reindeer likely see the winter world as a shade of purple the way a human may see a room with a black light. Snow and other UV-reflecting surfaces then shine brightly while surfaces that absorb UV light are dark.

Scientists have investigated why an Arctic animal that is active during the day would have eyes that are so receptive to UV light that reflects off of the snow. This study suggests that the answer to this question is tied to C. rangiferina and other lichens, since UV light doesn’t reflect from those organisms. The team believes that it is possible that reindeer eyes are optimized to single out lichens during the times of year where it is most difficult to find since it is a food staple. 

The post Reindeer can see UV light—and we may know why appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Adjusting to life in cold air temperatures has been key to survival for the Arctic’s seals. Those adaptations go beyond thick layers of blubber for insulation and up into the pinniped’s nose. A study published December 14 in the Biophysical Journal found that Arctic seals have more convoluted nasal passages than seals that live in more mild places. 

[Related: Hungry seals may have begun following their whiskers 23 million years ago.]

Warming the air

In cold and dry places, animals lose moisture and heat when they breathe. Warmer and wet air is important for lung function, so breathing in cold air can put the lungs in danger and may make humans more susceptible to respiratory viruses. To help minimize the risk, most birds and mammal species have complex bones called maxilloturbinates inside their nasal cavities. These porous, bony shelves are covered with mucus and tissues that warm and humidify inhaled air. Maxilloturbinates also reduce the amount of heat and moisture that is lost when an organism breathes out.

Researchers believe that the nose structure helps Arctic seals efficiently retain moisture and heat as they inhale and exhale. 

“Thanks to this elaborate structure in their nasal cavities, Arctic seals lose less heat through nasal heat exchange than subtropical seals when both are exposed to the same conditions,” Signe Kjelstrup, a study co-author and physical chemist at the Norwegian University of Science and Technology, said in a statement. “This provides an evolutionary advantage, especially in the Arctic where heat loss is energy dissipation, which must be replenished by food.”

According to Kjelstrup, Arctic seals retain 94 percent of the moisture in the air when they breathe in and out. Most of the water added to the air when they inhale is then recovered when they exhale.  

‘You can’t find reindeer in the middle of the Mediterranean’

The structure of maxilloturbinates varies between species. Reindeer noses also enable efficient heat exchange, but since they are only found in colder climates, Kjelstrup’s team turned to seals.

“You can’t find reindeer in the middle of the Mediterranean, but seals live in many different environments, so they allowed us to test this question,” said Kjelstrup. “And we knew from a previous study that Arctic seal noses are sponge-like and very dense, whereas the Mediterranean seal nose has a more open structure.”

In the study, the team used computer tomography to create 3D models of the nasal cavities of two seal species–the Arctic bearded seal (Erignathus barbatus) and the Mediterranean monk seal (Monachus monachus). Next, they used energy dissipation models to compare how well each species warmed and moistened air when they inhaled and reduced the amount of heat and moisture lost when they exhaled.

[Related: Baby seals sing bass notes when they want attention.]

They tested the models of both species’ noses under Arctic conditions of -22°F and at about 50°F, or a cold day for a Mediterranean monk seal. They also adjusted different parameters within the model to highlight the crucial geometrical features of the nasal cavity.

According to the model, Arctic bearded seals are more efficient at retaining heat and water exchange in both Arctic and subtropical temperatures. At -22°F, the Mediterranean monk seals lost 1.45 times as much heat and 3.5 times as much water per breath cycle than the bearded seals lost. At 50°F, the Mediterranean monk seals lost 1.5 times as much heat and 1.7 times as much water.

It appears that the Arctic seal’s more complex and dense nasal cavity provided this advantage. Specifically, the team found that the increased perimeter of the Arctic seal’s maxilloturbinates is the key to limiting energy dissipation at lower ambient temperatures. 

While the study looked at the amount of heat loss for one inhalation and exhalation, the role breathing rate plays remains unclear. These breathing cycles are particularly complicated for seals, who will pause their breathing for several minutes at a time when they dive under water and ice.

Energy efficient pinnipeds

The team hopes to look deeper into the nasal structures of other species to see if different parts provide evolutionary advantages in other climates. 

“The camel, for instance, doesn’t need to save much on heat, but it does need to save on water, so one may speculate that it could tell us something about relative importance of the two,” said Kjelstrup.

They also plan to look to animals for cues on how to build more efficient heat exchange and ventilation systems. 

“If nature manages to create such great heat exchangers, I think we should copy that in engineering to create more efficient processes, for instance, in air conditioners,” said Kjelstrup.  

The post Arctic seals have special noses appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

If you naturally wake up earlier in the morning, some very old genetic variants may be behind your sleep patterns. Humans’ internal circadian clocks might be partially influenced by genetic material left behind by extinct Neanderthals. The findings are described in a study published December 14 in Genome Biology and Evolution and provides a window into how the sleep cycles of Neanderthals differed from our earliest ancestors. Studies like this one could be a step towards a better understanding of how genetic material from extinct hominins affects modern humans.   

Our bodies respond to the environment

Modern Homo sapiens trace their origins back 300,000 years. Biological features in these early humans were shaped by environmental factors like sunlight or altitude. Roughly 70,000 years ago, the ancestors of modern Eurasian humans began to migrate out of Africa north towards Europe and Asia. Here, they experienced new environments and more seasonal variation in both temperatures and daylight. 

[Related: Night owls can become early birds. Here’s how.]

“We also know from other species that live across broad ranges of latitude that their circadian clocks often adapt to the differences in light/dark cycles,” study co-author and University of California, San Francisco computational biologist Tony (John) Capra tells PopSci. “In particular, in higher latitudes there is more seasonal variation in light/dark cycles over the course of the year than in more equatorial latitudes.”

They also encountered different types of early hominins as they left Africa, including Denisovans and Neanderthals. The different environmental conditions on these northern continents meant that Neanderthals and Denisovans had different genetic variations from those coming out of Africa. When they began to interbreed with Neanderthals about 50,000 years ago, it created the potential for humans to get some of the genetic variants that were already adapted to this environment.

Which genes stay and which genes go

Roughly two percent of the present-day Eurasian genome is derived from Neanderthal genetic variants, but which two percent varies. Neanderthal genes have been shown to influence nose shape and even pain sensitivity. Natural selection can remove this older genetic ancestry that is not deemed beneficial to humans as we evolve. However, some of the older hominin genetic variants that remain in today’s human genome have evidence of adaptation. For example, Tibetans living at higher altitudes have variants associated with immune resistance to new pathogens, levels of skin pigmentation, fat composition, and differences in hemoglobin levels.

In the new study, Capra and co-authors were curious if the Neanderthals who lived at higher latitudes may have genetic variants that adapted to changes in environment over hundreds of thousands of years. They also wondered if the interbreeding influenced variation in the circadian rhythm that can make someone an early riser. 

[Related: Sex, not violence, could’ve sealed the fate of the Neanderthals.]

The researchers identified about 200 genes that are related to how light and temperature affects our circadian clock and about 20 that are crucial to our internal clocks themselves. “It turns out that the genes themselves are very similar, but what really matters is how much and when they are made,” says Capra. 

After pinpointing these genes, the team explored if the variants that moved from Neanderthals into modern humans have any associations with the body’s preferences for wakefulness and sleep. They looked at genetic data from the UK Biobank and found that many of the Neanderthal variants in modern humans affect sleep preference. In particular, the tendency to wake up early–or morningness–stuck out. Increased morningness is associated with a shortened circadian clock that is likely beneficial for those living at higher latitudes. Morningness has been shown to enable a faster alignment of the external cues that it’s time to fall asleep or wake up, like changes in sunlight. 

“We used machine learning methods to predict from Neanderthal DNA sequences how the ways that they turned the circadian genes on and off differed from in modern humans,” says Capra. “In general, it seems that having a faster running clock leads people (and other organisms) to be earlier risers and have an easier time adapting to seasonal variation.”

This increased morningness may have been evolutionarily beneficial for our ancestors living in higher latitudes, so the genetic variants associated with it would have been worth keeping. 

Sentinel hypothesis

Exploring the genetics behind what makes some of us early birds and others night owls is part of an emerging–yet difficult to prove–evolutionary theory called sentinel hypothesis. There could be an evolutionary benefit to having a mixture of sleep and wake patterns and in a given human population. To increase chances of survival, animals living in groups should trade off keeping watch, with some sleeping while others are awake. Study co-author and Vanderbilt University computational biologist Keila S. Velazquez-Arcelay identified a few genetic variants that could provide evidence for this.

“Keila discovered a few genetic variants that are associated with chronotype that have evidence of long-term ‘balancing’ selection. In other words, evolution appears to have preferred to maintain variation at these sites,” says Capra. 

In future work, the team from this study is interested in testing the effects of these Neanderthal genetic variants on circadian clocks in cells. According to Capra, using cells allows them to quickly introduce the Neanderthal variants and evaluate their effects. They are also curious to find patterns across different populations and see if this analysis technique can be applied to genes involved in immune system function, thermoregulation, and metabolism.

The post Neanderthals may have been early risers appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

When bioluminescent ostracods or ‘sea fireflies’ mate, they perform a courtship dance complete with glowing blue mucus. The males sway together in sync while basking in the light of the shiny slime. This mating ritual is detailed for the first time in a study published November 29 in the journal Proceedings of the Royal Society B.

[Related: Surprise! These sea cucumbers glow.]

Ostracods are tiny crustaceans that are about the size of a sesame seed. They are found in a variety of fresh and saltwater environments, from deep ocean depths to shallow seas to rivers, lakes, and estuaries. The dancing, shrimplike species in the study is called the entraining grassbed downer and was observed in the Caribbean Sea near Panama. 

During this dance routine, male EGDs create their distinct patterns of bioluminescence to attract females. They secrete packets of protein from a specialized gland. The females respond by angling themselves to these bright blue luminous displays and swimming towards the males. According to study co-author Nicholai Hensley, a Cornell University evolutionary biologist who specializes in animal behavior, the other males will then join in a synchronous light display and repeat the same pattern in the water during each dance.

The study found that this very coordinated swim also doesn’t happen randomly. The mating dance sequence only occurs after sunset at nautical twilight, when the moon isn’t bright in the night sky. The team found their level of precision and coordination very surprising. 

“This precise timing leads to the unexpected phenomena of huge waves of light that cascade across the grass bed, with hundreds of males displaying at the same time,” Hensley tells PopSci. “Amazingly, this is very similar in appearance to the fireflies most people are familiar with, where some species are also synchronized. But ostracods and fireflies last shared a common ancestor 500 million years ago, when most animal life was evolving beyond looking slightly more than worm-like.”

Ostracods are special because they evolved their bioluminescence and bioluminescent behaviors completely independently from other animals that act like them. “They are also spectacular little animals, whose whole world escapes notice by 98 percent of people unless you know where to look,” says Hensley.

Luckily, some of Hensley’s collaborators knew where to look and had some luck on their side. In 2017, James Morin, a professor emeritus of ecology and evolutionary biology at Cornell and Todd Oakley, a professor at the University of California, Santa Barbara were diving near the Smithsonian Tropical Research Institute’s Bocas del Toro island research station in Panama. When Morin turned on his dive light to test it out, hundreds of ostracods responded with their own light. According to Morin, there are more than 100 species of signaling ostracods in the Caribbean alone.

[Related: These newly discovered bioluminescent sea worms are named after Japanese folklore.]

“What’s really remarkable about EGD is the duration, the brightness and the density,” Morin said in a statement. “It was a remarkable experience. They really jump out at you. I’ve worked with ostracods for years and this species is spectacular.”

With this discovery, Hensley and study-co-author Trevor Rivers from the University of Kansas set up some preliminary experiments to determine just what the animals were responding to when a light flashed on them. They found that the EDGs are very sensitive to both the time and intensity of a light. 

“It’s how they coordinate their own signals with one another,” says Hensley.

The courtship ritual with snotty light likely evolved about 20 million years ago. However, why the males perform these gyrations is still a mystery. The team only knows that these displays are for attraction purposes, and are still figuring out the other functions. It’s possible that the males are competing with one another for attention, which leads to what Hensley calls a “giant free-for-all.” They also may be cooperating to make a brighter display that could attract more females. The team plans on testing how these displays look to females and measuring their behaviors to better understand this mating dance.

“There’s a whole world filled with new questions and unexplored ideas out there if you pay attention to the little details around you,” says Hensley. “Get out there, pay attention, and take chances, make sure to seize the moments of the rare opportunities that come your way. You can’t predict where it will lead, but you can be sure you learn something along the way.”

The post Watch the mucus-filled, synchronized mating dance of bioluminescent ‘sea fireflies’ appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Crocodiles are some of the most fierce ambush-predators in the world. There are only 24 crocodilian species around the world and seven are considered Critically Endangered by the international Union for Conservation of Nature and Natural Resources. Now, a team of scientists have mapped the crocodile family tree, including their extinct relatives called Pseudosuchia. The family tree is detailed in a study published December 4 in the journal Nature Ecology & Evolution and offers insight into the role that the environment has historically played on crocodile evolution. 

[Related: Why scientists gave vaccines to farmed crocodiles.]

Ruling reptiles

Crocodiles and birds share an evolutionary heritage with dinosaurs and pterosaurs, despite there being 11,000 living bird species compared to only 24 crocodile species. Crocodiles are the only living members of a mostly extinct clade called archosaurs or “ruling reptiles.” Archosaurs date back to the Early Triassic, about 251 million to 200 million years ago. 

Archosaurs belong to a group called Pseudosuchia, which includes multiple species that are more closely related to crocodiles than they are to birds. Pseudosuchias went extinct at or before the Triassic–Jurassic extinction event about 201.4 million years ago. However, one group called the crocodylomorphs, survived the major extinction and gave rise to the crocodiles. 

“The fossil record is a rich source of valuable information allowing us to look back through time at how and why species originate, and crucially, what drives their extinction,” study co-author and University of York biologist Katie Davis said in a statement. 

In the study, a team of researchers used the fossil record to build a large phylogeny, or evolutionary family tree of a species or group. The phylogeny included crocodiles and their extinct relatives, so the team could map out how many new species were being formed and how many species were going extinct over time. They then combined this family tree with data on past changes in climate. They were particularly interested in changes to temperature and sea levels to see if the emergence and extinction of species could be linked to climate change. 

Climate change and competition

They found that climate change and competition with other species have shaped the diversity of modern-day crocodiles and their extinct relatives. Surprisingly, the phylogeny also revealed that whether species lives in freshwater, in the sea, or on land plays a key role in its survival. 

When global temperatures increased, the number of species of the modern crocodile’s sea-dwelling and land-based relatives also went up. 

[Related: Crocodiles’ ancient ancestors may have walked on two legs.]

The crocodile’s freshwater relatives were not affected by changes in temperatures. Rising sea levels proved to be their greatest risk for extinction. According to the team, these results provide important insights for conservation efforts of crocodiles and other species in the face of human-made climate change. 

“With a million plant and animal species perilously close to extinction, understanding the key factors behind why species disappear has never been more important,” said Davis. “In the case of crocodiles, many species reside in low-lying areas, meaning that rising sea levels associated with global warming may irreversibly alter the habitats on which they depend.”

To look at how competition might have played a role, the team used the Information Theory. They calculated estimates of numbers of species present at any point in time and compared that number against new species and extinctions. These calculations allowed the team to estimate where climate change or species interactions like competition had a direct impact on whether new species were emerging or going extinct. Unsurprisingly, an increase in competition for resources, possibly from sharks, marine reptiles, or dinosaurs, likely caused the extinction of some species. 

“Crocodiles and their extinct relatives offer unique insights into climate change and its impact on biodiversity in the past, present and future,” said Davis. “Our findings advance our understanding of what factors have shaped, and continue to shape, life on Earth.”

The post Tracing the crocodiles’ curious evolutionary family tree appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

If you’ve ever been bitten by a mosquito, it was a female insect that chomped on your skin. Female mosquitoes are hematophagous, which means that they feast on animal blood. They then use the blood to produce their eggs. Male mosquitoes living today are not hematophagous. Instead, they survive on plant nectar because their piercing mouthparts–the proboscis–aren’t strong enough to pierce skin.

[Related: When insects got wings, evolution really took off.]

However, male mosquitoes may have been blood suckers hundreds of millions of years ago. A team of paleontologists found two male mosquito fossils from the Lower Cretaceous period with intact piercing proboscis and sharp mandibles needed to suck blood. The specimens are described in a study published December 4 in the journal Current Biology and help to narrow a “ghost-lineage gap” for mosquitoes.

Hematophagy is the ability for insects to suck on the blood of other animals. It’s believed to have evolved from a shift to using piercing-sucking mouthparts to extract fluids from plants instead of animals. Fleas that currently suck animal blood possibly arose from earlier species of the insects that primarily fed on plant nectar. The evolution of hematophagy has been more difficult to trace, partially due to gaps in the insect fossil record.

The fossils examined for this study were found preserved in amber in Lebanon and date back about 130 to 125 million years. Amber is a fossilized tree resin and deposits in Lebanon are some of the oldest known amber samples that contain traces of living things including insects. Studying this material can close “ghost-lineage gaps,” or a chain of ancestors that does not usually appear in the fossil record. Coelacanths are a famous example of a ghost-lineage gap. These lobe-finned have a long fossil record from the Devonian to the Cretaceous–or a period of about 300 million years. However, they were not found in sediments younger than the Cretaceous, so scientists assumed that they had been extinct 80 million years. A living coelacanth was caught off the coast of South Africa in 1938 and another population lives in Indonesia. Coelacanths have just not left any fossils over the past 80 million years. 

Amber deposits can also offer scientists clues into how pollinating bugs and flowering plants co-evolved over time. The pollinators include some members of the Culicidae family of arthropods which has over 3,000 species of mosquitoes. 

“Molecular dating suggested that the family Culicidae arose during the Jurassic, but previously the oldest record was mid-Cretaceous,” study co-author and entomologist at the National Museum of Natural History of Paris André Nel said in a statement. “Here we have one from the early Cretaceous, about 30 million years before.”

[Related: How can we control mosquitos? Deactivate their sperm.]

In the new study, the team describes the fossils of two male mosquitoes from the Cretaceous period that have piercing mouthparts. The parts include a very sharp triangular mandible and elongated structure with small, tooth-like denticles. The presence of these parts suggest that male mosquitoes living during the Late Cretaceous could have been strong enough to pierce the skin and feed on animal blood like their modern female descendents. 

The team also reports that the mosquitoes’ preservation in amber stretches the family tree of insects further back into the Cretaceous period. The fossils also suggest that the evolution of blood-sucking behavior was more complicated than they had previously suspected. According to Nel, the team hopes to investigate why being hematophagous was advantageous to Cretaceous male mosquitoes and why it no longer exists in future studies. 

The post Millions of years ago, male mosquitoes may have been blood suckers too appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Cooperation between different groups of humans lies at the root of our social norms, traditions, and culture. Groups of a great ape species called bonobos may also work collaboratively with other cliques, according to a study published November 16 in the journal Science.

[Related: Bonobo ladies get to choose their mates and boy oh boy are they picky.]

Along with chimpanzees, bonobos are some of our closest living relatives. Studying their relationships can help scientists reconstruct what human traits appear to be more innate and how they evolve. However, both species of primate exhibit different levels of cooperation despite living in similar social groups that have multiple adult members of both sexes. 

Chimpanzees appear to have more hostile relationships between different groups. Even lethal aggression is not uncommon. This hostility has led researchers to assume that group conflict is an innate part of human nature. 

Bonobos might be telling a different story about how social structures and communities have evolved over time. 

“The ability to study how cooperation emerges in a species so closely related to humans challenges existing theory, or at least provides insights into the conditions that promote between-group cooperation over conflict,’ study co-author and German Primate Center evolutionary biologist Liran Samuni said in a statement.

The study looked at two groups of 31 wild adult bonobos in the Kokolopori Bonobo Reserve in the Democratic Republic of Congo over a period of two years. When the different groups of bonobos met up, they often fed, rested, and traveled together. 

“Tracking and observing multiple groups of bonobos in Kokolopori, we’re struck by the remarkable levels of tolerance between members of different groups,” Samuni said. “This tolerance paves the way for pro-social cooperative behaviors such as forming alliances and sharing food across groups, a stark contrast to what we see in chimpanzees.” 

The authors also did not observe disputes that led to the lethal aggression that has been observed in chimpanzees. The bonobos did not not interact randomly between groups. Cooperation only happened among a select few group members. 

“They preferentially interact with specific members of other groups who are more likely to return the favor, resulting in strong ties between pro-social individuals,” study co-author and Harvard University evolutionary biologist Martin Surbeck said in a statement. “Such connections are also key aspects of the cooperation seen in human societies. Bonobos show us that the ability to maintain peaceful between-group relationships while extending acts of pro-sociality and cooperation to out-group members is not uniquely human.”

[Related: Humans owe our evolutionary success to friendship.]

Cooperation between human groups leads to exchanges of ideas, knowledge, innovation, and resources. The Bonobos in the study also shared food resources across groups without any strong cultural influence. The authors believe that this challenges another existing idea that a shared culture and traits are necessary components for groups to cooperate with one another. 

The study also highlights the importance of collaboration when studying bonobos that live in remote and largely inaccessible parts of the preserve. 

“It is through strong collaborations with and the support of the local Mongandu population in Kokolopori, in whose ancestral forest the bonobos roam, that studies of this fascinating species become possible,” said Subeck, who directs research in the Kokolopori Bonobo Reserve. “Research sites like Kokolopori substantially contribute not only to our understanding of the species’ biology and our evolutionary history, but also play a vital role in the conservation of this endangered species.”

The post Wild bonobos show surprising signs of cooperation between groups appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Dinosaur Mysteries digs into the secretive side of the “terrible lizards” and all the questions that keep paleontologists up at night.

YOU NEVER KNOW how small you are until you’re next to a big ol’ dinosaur. Find the right lighting in the museum hall and you can literally stand in the shadow of the skeletons of Apatosaurus, Patagotitan, Brachiosaurus, and other reptiles that grew far larger than any other terrestrial creature in the past 66 million years. But even after nearly two centuries of research, we have only the haziest notions of why some dinosaurs were larger than any terrestrial mammal to date.

While a number of dinosaurs fell in the supersized category—Tyrannosaurus rex weighed more than a mature male African elephant—the sauropods were the all-time titleholders. They had small heads with simple teeth, impressively long necks, hefty bodies, and tapering tails. So many sauropod species reached more than 100 feet in length, paleontologists still aren’t sure which one stretched the farthest. While the largest land mammals, like the hornless rhino Paraceratherium and the biggest fossil elephants, got to be about 18 tons, sauropods evolved to have more mass at least 36 times during their evolutionary history—an ongoing reprisal of gargantuan herbivores through the Jurassic and Cretaceous.

The stunning heft of these creatures has often led us to wonder why they got to be so much bigger than any terrestrial creature before or since. But in the realm of paleontology, “why” questions are extremely difficult to answer. Queries starting with “why” are matters of history, and in this case, the history plays out dozens of times on multiple continents over the course of more than 130 million years. Though we see the end effect, we can’t quite make out the causes.

Dinosaurs have a habit of digging their claws into our imaginations, however, so researchers have kept on, turning up a few clues in the past two decades about the surfeit of superlative sauropods. While higher oxygen levels have been linked to bigger body sizes in a few ancient insects, the atmosphere in the heyday of the dinosaurs was about the same as today’s. What’s more, the Earth’s gravitational force was just as strong in the Mesozoic era as in the modern era. So we know that the impressive size of Argentinosaurus and other top sauropods was not a matter of an abiotic factor like increased oxygen in the atmosphere or lower gravity. Our explanation lies elsewhere.

Paleontologists are getting closer to the truth by looking at the dinosaurs themselves. For example, experts have identified a suite of characteristics that set sauropods apart from the mastodons and giant rhinos of the Cenozoic. Eggs have a great deal to do with it.

The largest mammals of all time were placentals, gestating their offspring on the inside so they could come out more developed. This reproductive strategy comes with some constraints. To reach even larger adult sizes, females of each species would need to carry their babies in the womb for longer. African elephants, for example, already gestate for about two years—during which much can go wrong. But sauropods, like all nonavian dinosaurs, laid multiple eggs at a time, bypassing the reproductive constraints of live birth and flooding their ecosystems with tons of babies that had the potential to grow huge (even if most ended up as snacks for the carnivores of the time). The different reproductive strategies gave dinosaurs some advantages over mammals.

Camarasaurus and other sauropods also got some assistance from their anatomical peculiarities. Sauropods had complex air-sac systems in their respiratory tracts that created air pockets within and around their bones. These nifty features kept their skeletons light without sacrificing strength, and also made extracting oxygen from the air and shedding excess body heat more efficient. The distinctive dinosaurs could grow long necks too, because they didn’t have heavy heads full of massive, grinding teeth like large herbivorous mammals over the past 66 million years. Instead, sauropods had small, light noggins full of spoon- or pencil-shaped teeth that were mostly just capable of cropping vegetation to be broken down and fermented through their gastrointestinal tracts. In other words, their guts did the work, not their teeth. Studies of ginkgoes, horsetails, and other common Mesozoic plants indicate that the ancient vegetation was more calorie-rich than previously supposed, so the abundance of green food likely fueled the reptilian giants’ unprecedented growth.

But these facts only show us what allowed sauropods to become big. The dinosaurs didn’t have to drift in that direction. In fact, some were relatively small: The island-dwelling species Magyarosaurus was about the size of a large cow. Sauropods could have thrived at smaller sizes, but they instead kept spinning off lineages of giants. We know something about what made living large possible, but what we still don’t know is what evolutionary pressures drove sauropods to evolve enormous bodies.

Predators certainly played their part. All sauropods were born small—even the largest species hatched from eggs about the size of a soccer ball. They were vulnerable to various Jurassic and Cretaceous carnivores, but growing up quickly was one way to stave off those hungry jaws. Hunting megafauna can be dangerous and even deadly, as we see with lions, wolves, and even humans today, and so sauropods may have plumped up to be less appealing to the likes of Allosaurus and T. rex.

But if carnivorous appetites were the main driver of sauropod size, we’d see a more uniform and extended “arms race” between the dinosaurs over time, resulting in gradually larger predators and prey. The fossil record instead shows that sauropods scaled up in different times and places, likely for an array of reasons ranging from local grub to what mating sauropods found sexy in each other. The repeated evolution of gigantic dinosaurs hints that there were many pathways to the sauropods’ impressive stature, not just one. Biology was as complicated back then as it is now, and we’ll never get the full story without experiencing 100-foot-long reptiles ourselves.

Read more PopSci+ stories.

The post The mystery of why some dinosaurs got so enormous appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

While the majority of fish are cold-blooded and rely on the temperature outside of their bodies to regulate their internal temperatures, less than one percent of sharks are actually warm-blooded. The extinct but mighty megalodon and the living great white shark generate heat with their muscles the way many mammals do. However, they are not the only sharks with this warm quirk. A study published November 7 in the journal Biology Letters found that there are more warm blooded sharks than scientists initially believed. 

[Related: Megalodons were likely warm-blooded, despite being stone-cold killers.]

Warmer muscles might help these giant carnivores be more powerful and athletic, by using that heat to generate more energy. Regional endothermy in fish has been seen in apex predators like the great white or giant tuna, but there has been debate on when this warm bloodedness evolved in sharks and if the megalodon was warm blooded. A previous study from June 2023 found that the megalodon was warm blooded and that the amount of energy it used to stay warm may have contributed to its extinction about 3.6 million years ago.

The new study looked at the results of autopsies from some unexpected shark strandings in Ireland and southern England earlier in 2023. The sharks belonged to a rarely seen species called the smalltooth sand tiger shark. These sharks are found around the world in temperate and tropical seas and in deep waters (32 to 1,700 feet deep). They have a short and pointed snout, small eyes, protruding teeth, and small dorsal and anal fins and can reach about 15 feet long. Smalltooth sand tiger sharks are considered a “vulnerable” species by the International Union for the Conservation of Nature. While they are not targeted by commercial fisheries, the sharks may be mistakenly caught in nets and may face threats from pollution. 

Smalltooth sand tiger sharks are believed to have diverged from the megalodon at least 20 million years ago. The autopsies from this year’s stranded sharks unexpectedly served as a timeline that took marine biologists from institutions in Ireland, South Africa, and the United States back millions of years. 

The team found that these rare sharks have physical features that suggest they also have regional endothermy like the megalodon, great white, and some filter-feeding basking sharks. This new addition means that there are likely more warm-blooded sharks than scientists thought and that warm bloodedness evolved quite a long time ago.

“We think this is an important finding, because if sand tiger sharks have regional endothermy then it’s likely there are several other sharks out there that are also warm-bodied,” study co-author and marine biologist Nicholas Payne said in a statement. “We used to think regional endothermy was confined to apex predators like the great white and extinct megalodon, but now we have evidence that deep water ‘bottom dwelling’ sand tigers, and plankton-eating basking sharks also are warm bodied. This raises plenty of new questions as to why regional endothermy evolved, but it might also have important conservation implications.” Payne is affiliated with Trinity College in Dublin, Ireland. 

[Related: Were dinosaurs warm-blooded or cold-blooded? Maybe both.]

Scientists believe that the megalodon’s warmer body allowed it to move faster, tolerate colder water, and spread all over the world’ oceans. However, this evolutionary advantage could have contributed to its downfall. The megalodon lived during the Pliocene Epoch (5.33 million years to 2.58 million years ago) when the world cooled and sea levels changed. These ecosystem changes and competition with newcomers in the marine environment like great whites may have led to its extinction. 

Understanding how extinct sharks met their end could help scientists gauge how today’s warm-blooded sharks could fare due to warmer ocean temperatures from human-caused climate change. It has potential conservation implications and could explain some shifting patterns of where sharks are foraging. 

“We believe changing environments in the deep past was a major contributor to the megalodon’s extinction, as we think it could no longer meet the energetic demands of being a large regional endotherm,” study co-author and Trinity College marine biologist Haley Dolton said in a statement. “We know the seas are warming at alarming rates again now and the smalltooth tiger that washed up in Ireland was the first one seen in these waters. That implies its range has shifted, potentially due to warming waters, so a few alarm bells are ringing.”   

The post Megalodon’s warm-blooded relatives are still circling the oceans today appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Humans are the only primates currently living in the wild in North America, but that was not always the case. The continent was once home to non-human primates, including big-eyed tarsier-like animals called omomyiforms and long-tailed critters called adapiforms. About 30 million years ago, a lemur-like creature named Ekgmowechashala was the last primate to inhabit the continent before Homo sapiens arrived. In a study published November 6 in the Journal of Human Evolution, fossil teeth and jaws shed some new light on this mysterious creature. 

[Related: 12-million-year-old ape skull bares its fangs in virtual reconstruction.]

From China to Nebraska

Understanding the origins of North America’s primates has been a paleontological puzzle. It’s been unclear whether they evolved on the continent or arrived from somewhere else via land bridges. The first first primates in North America date back about 56 million years at the beginning of the Eocene Epoch. Scientists believe that the primates like Ekgmowechashala generally flourished on the continent for over 20 million years. 

Ekgmowechashala was about five pounds and only one foot tall. They lived in what is now the American Plains just after the Eocene-Oligocene transition. At this time, a huge cooling and dying event made the continent much less hospitable for primates. Ekgmowechashala went extinct about 34 million years ago. 

For the study, paleontologists first had to reconstruct Ekgmowechashala’s family tree with the help of  an older “sister taxon,” or a closely related group of animals. Both groups generally share a branch on their family trees, but diverged at some point and have different lineages. This sister animal originates in and the team named it Palaeohodites, which means “ancient wanderer.” The fossils were collected by paleontologists from the United States in the 1990s from the Nadu Formation in Guangxi, an autonomous region in China. The fossils closely resembled the Ekgmowechashala material that had been found in North America in the 1960s, when the primate was still quite mysterious to North American paleontologists.

The Palaeohodites fossil potentially helps resolve the mystery of Ekgmowechashala’s strange presence in North America. It was likely a migrant to the continent instead of being the product of local evolution.

“Due to its unique morphology and its representation only by dental remains, its place on the mammalian evolutionary tree has been a subject of contention and debate. There’s been a prevailing consensus leaning towards its classification as a primate,” study co-author and University of Kansas PhD candidate Kathleen Rust said in a statement. “But the timing and appearance of this primate in the North American fossil record are quite unusual. It appears suddenly in the fossil record of the Great Plains more than 4 million years after the extinction of all other North American primates, which occurred around 34 million years ago.”

[Related: These primate ancestors were totally chill with a colder climate.]

The Ekgmowechashala fossils found in the US during the 1960s include an upper molar that looks very similar to the Palaeohodites molars found in China, according to study co-author and University of Kansas paleontologist Chris Beard. The team from Kansas closely analyzed the fossils to establish evolutionary relationships between the American Ekgmowechashala and its cousin Palaeohodites. 

The paleontologists believe that Ekgmowechashala did not descend from an older North American primate that survived the climate shift roughly 33 million years ago that caused other North American primates to go extinct. Instead, Ekgmowechashala’s ancestors likely crossed over the icy Beringian region that once connected Asia and North America millions of years later.

Rising from the dead

Ekgmowechashala is an example of the “Lazarus effect” in paleontology. This is where a species suddenly appears in the fossil record long after their relatives have died off. It is a reference to Lazarus who, according to New Testament mythology, was raised from the dead. It is also a pattern of evolution seen in the fossil record of North American primates, who went extinct about 34 million years ago. 

“Several million years later Ekgmowechashala shows up like a drifting gunslinger in a Western movie, only to be a flash in the pan as far as the long trajectory of evolution is concerned,” Beard said in a statement. “After Ekgmowechashala is gone for more than 25 million years, Clovis people come to North America, marking the third chapter of primates on this continent. Like Ekgmowechashala, humans in North America are a prime example of the Lazarus effect.”

The past is prologue?

Studying the way primates were affected by previous changes in climate can provide important insight to today’s human-driven climate change. Organisms generally retreat to more hospitable regions with the available resources or end up going extinct. 

“Around 34 million years ago, all of the primates in North America couldn’t adapt and survive. North America lacked the necessary conditions for survival,” said Rust. “This underscores the significance of accessible resources for our non-human primate relatives during times of drastic climatic change.

The post North America was once home to some unusual wild monkeys appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Scavenging has been maligned as a food gathering strategy and is generally associated with animals like vultures and hyenas. Millions of years ago, carnivorous dinosaurs may have evolved this technique of taking meat from dead carcasses too. The findings are described in a study published November 1 in the open-access journal PLOS ONE.

[Related: Dinosaur cannibalism was real, and Colorado paleontologists have the bones to prove it.]

Carnivorous dinosaurs like the cannibalistic Allosaurus were surrounded by both living and dead prey. The bodies of large sauropod dinosaurs, some of whom could weigh more than 500,000 pounds, could have provided an important food source for carnivores.

In this study, a team of researchers from Portland State University created a simplified computer simulation of a dinosaur ecosystem from the Jurassic age. They used the animals that have been found in the 163.5 to 145 million year-old Morrison Formation in the western United States as the basis. This enormous fossil formation was once home to a wide variety of plants and dinosaurs.

The model included large carnivores common to the area like Allosaurus, large sauropods and their carcasses, and a large group of living and huntable Stegosaurus’. The carnivores were assigned traits that would improve their hunting abilities with the energy from living meat sources or their scavenging abilities with the sustenance from the carcasses. The model then measured the evolutionary fitness of the simulated predators. 

The model found that when there were a large amount of sauropod carcasses around, scavenging was more profitable than hunting for the Allosaurus. Meat eaters in these kinds of ecosystems may have evolved specialized traits to help them detect and exploit these large carcasses.

“Our evolutionary model demonstrates that large theropods such as Allosaurus could have evolved to subsist on sauropod carrion as their primary resource,” the authors wrote in a statement. “Even when huntable prey was available to them, selection pressure favored the scavengers, while the predators suffered from lower fitness.”

[Related: This 30-pound eagle would take down 400-pound prey and dig through their organs.]

This model represents only a simplified depiction of a complex ecosystem, so more variables like additional dinosaur species may alter the results. While theoretical, using models like this one can help scientists better understand how the availability of meat from carcasses can influence how predators evolve. A September 2023 modeling study found that even early humans living in southern Europe roughly 1.2 to 0.8 million years ago were scavengers. They may have competed in groups of five or more to fight off extinct giant hyenas for the carcasses of animals that had been abandoned by larger predators like saber-toothed cats.

“We think allosaurs probably waited until a bunch of sauropods died in the dry season, feasted on their carcasses, stored the fat in their tails, then waited until the next season to repeat the process,” the authors wrote. “This makes sense logically too, because a single sauropod carcass had enough calories to sustain 25 or so allosaurs for weeks or even months, and sauropods were often the most abundant dinosaurs in the environment.”

The post When a Jurassic giant died, predatory dinos probably feasted on the carcass appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

When looking at a sea star–or starfish–it’s not really clear which part of its identical five pointed body is considered its head. This question has puzzled biologists for decades, but some new research says that a starfish’s whole body could function like a head. The findings are described in a study published November 1 in the journal Nature and might have solved the mystery of how sea stars and other echinoderms evolved their distinctively shaped bodies.

[Related: This strange 500-million-year-old sea urchin relative lost its skeleton.]

Searching for heads and trunks 

Sea stars are invertebrates that belong to a group of animals called echinoderms.This group also includes sea urchins and sand dollars and they all have bodies that are arranged in five equal and symmetric sections. Early in their evolution, echinoderms had a bilaterally designed ancestor with two mirrored sides more like a human’s. 

“How the different body parts of the echinoderms relate to those we see in other animal groups has been a mystery to scientists for as long as we’ve been studying them,” Jeff Thompson, a co-author of the study and evolutionary biologist at the University of Southampton in the United Kingdom, said in a statement. “In their bilateral relatives, the body is divided into a head, trunk, and tail. But just looking at a starfish, it’s impossible to see how these sections relate to the bodies of bilateral animals.”

In the new study, an international team of scientists compared the molecular markers in sea stars with a wider group of animals called deuterostomes. This group includes echinoderms like sea star and bilateral animals including vertebrates. Deuterostomes all share a common ancestor, so comparing their development can offer clues into how echinoderms evolved their more unique five-pointed body plan.

They used multiple high-tech molecular and genomic techniques to see where different genes were expressed during a sea star’s development and growth. Micro-CT scanning also allowed the team to understand the shape and structure of the animals in closer detail.

Sea star mapping

Team members from Stanford University, the University of California, Berkeley, and Pacific BioSciences, used techniques called RNA tomography and in situ hybridization to build a three-dimensional map of a sea star’s gene expression to see where specific genes are being expressed during development. They specifically mapped the expression of the genes that control the growth of a sea star’s ectoderm, which includes its nervous system and skin. 

They found gene signatures associated with head development almost everywhere in juvenile sea stars. The expression of genes that code for an animal’s torso and tail sections were also largely missing.

[Related: What’s killing sea stars?]

“When we compared the expression of genes in a starfish to other groups of animals, like vertebrates, it appeared that a crucial part of the body plan was missing,” said Thompson. “The genes that are typically involved in the patterning of the trunk of the animal weren’t expressed in the ectoderm. It seems the whole echinoderm body plan is roughly equivalent to the head in other groups of animals.”

The molecular signatures that are typically associated with the front-most portion of an animal’s head were also localized towards the middle of each of the sea star’s five arms. 

“It’s as if the sea star is completely missing a trunk, and is best described as just a head crawling along the seafloor,” study co-author and Stanford University evolutionary biologist Laurent Formery said in a statement. “It’s not at all what scientists have assumed about these animals.” 

Sea stars and other echinoderms may have evolved their five-section body plan by losing the trunk region that their bilateral ancestors once had. This chance would have allowed them to move around and feed differently than animals with two symmetrical arms.

“Our research tells us the echinoderm body plan evolved in a more complex way than previously thought and there is still much to learn about these intriguing creatures,” said Thompson. “As someone who has studied them for the last ten years, these findings have radically changed how I think about this group of animals.”

This research was supported by the Leverhulme Trust, NASA, the NSF, and the Chan Zuckerberg BioHub.

The post The sea star’s whole body is a head appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Lampreys are the vampires of the ocean and the lakes they can invade. While these eel-like parasitic vertebrates don’t use two sharp fangs to suck blood, lampreys have a toothed oral sucker that latches onto their prey and feasts on their host’s blood. Modern day lampreys are found in temperate zones of most of the world’s oceans except in Africa. However, specimens of their extinct ancient ancestors are fairly rare in the fossil record, despite dating back roughly 360 million years. Now, paleontologists in northern China have found two unusually large fossilized lamprey species that fill a large evolutionary gap. The specimens are described in a study published October 31 in the journal Nature Communications.

[Related: Why sea lampreys are going to be a bigger problem for the Great Lakes.]

“We found the largest fossil lampreys ever found in the world,” study co-author and Chinese Academy of Sciences paleontologist Feixiang Wu tells PopSci. “Based on these fossils, our study assumed that the most recent common ancestor of modern lampreys was likely eating flesh rather than sucking blood as conventionally believed.”

The earliest known lampreys date back about 360 million years ago during the Paleozoic Era. These early species are believed to have been only a few inches long and had weak feeding structures. The 160 million-year-old fossils in this new study were discovered in the Lagerstätte Yanliao Biota in northeastern China and date back to the Jurassic. The longer of the two specimens is named Yanliaomyzon occisor. It is more than 23 inches long and is estimated to have had 16 teeth. The shorter 11 inch-long species is named Yanliaomyzon ingensdentes and had about 23 teeth. By comparison, modern lampreys range from six to 40 inches long.

Their well-preserved oral discs and “biting” structures indicate that these lamprey species had already evolved enhanced feeding structures, bigger body size, and were predators by the Jurassic period. It also appears that they had already evolved a three-phased life cycle by this point

Lampreys begin their lives as burrowing freshwater larvae called ammocetes. During this stage, they have rudimentary eyes and feed on microorganisms with their toothless mouths. They spend several years in this stage, before transforming into adults. Some move into saltwater, while others will remain in freshwater. As adults, they become parasites that attach to a fish with their mouths and feed on their blood and tissue. Lampreys eventually return to freshwater to reproduce, where they build a nest, then spawn, and then die.

It is still unclear when lampreys evolved this lifecycle and their more complex teeth for feeding. These new well-preserved fossils fill an important gap in the fossil record and give some insights into how its lifecycle and feeding originated. 

[Related: Evolution made mosquitos into stealthy, sensitive vampires.]

The study also pinpoints where and when today’s lamprey’s first appeared. “We put modern lampreys’ origin in the Southern Hemisphere of the Late Cretaceous,” says Wu. 

The Late Cretacous lasted from 100.5 million years ago to 66 million years ago and ended with the mass extinction event that wiped out the dinosaurs. In future research, the team would like to search for specimens from the Cretaceous. According to Wu, this time period could be very important to their evolutionary history.

More fossilized specimens could also provide more accurate ideas of what kinds of flesh ancient lampreys feasted on with all those teeth and how that has evolved over time. 

“Living lampreys are always hailed as ‘water vampires,’ but their ancestor might be a flesh eater, their teeth tell,” says Wu. 

The post Giant prehistoric lamprey likely sucked blood—and ate flesh appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Paleontologists in North Dakota have discovered new species of mosasaur. These giant meat-eating aquatic lizards swam the Earth’s seas about 80 million years ago during the late Cretaceous period. This new species is named Jormungandr walhallaensis after a sea serpent in Norse mythology named Jörmungandr and Walhalla, North Dakota where its fossils were found. The findings are described in a study published October 30 in the Bulletin of the American Museum of Natural History.  

[Related: Dinosaurs who stuck together, survived together.]

“If you put flippers on a Komodo dragon and made it really big, that’s what it would have looked like,” study co-author and Richard Gilder Graduate School PhD student Amelia Zietlow, said in a statement.

The first mosasaur specimens were discovered over 200 years ago and the word “mosasaur” even predates the word “dinosaur” by roughly 20 years. There are still several unanswered questions about these ancient sea lizards, including how many times they evolved to have flippers and when they became fully aquatic. Scientists believe that they evolved to have their signature flippers at least three times and possibly four or more. It is also still a mystery if mosasaurs are more closely related to present day monitor lizards or snakes or another living creature entirely. This new specimen fills in some knowledge gaps of how the different groups of mosasaurs are related to each other.

“As these animals evolved into these giant sea monsters, they were constantly making changes,” Zietlow said. “This work gets us one step closer to understanding how all these different forms are related to one another.”

Researchers in northeastern North Dakota first discovered the Jormungandr fossil in 2015. It included a nearly complete skull, jaws, and cervical spine, and a number of vertebrae. An extensive analysis revealed that the fossil is of a new species that has multiple features that are also seen in two other mosasaurs: Clidastes and Mosasaurus. Clidastes is a smaller animal of about six to 13 feet long that lived roughly 145 million years ago. Mosasaurus was much larger at almost 50 feet long and lived about 99.6 to 66 million years ago alongside the Tyrannosaurus rex. 

[Related: This four-legged snake fossil was probably a skinny lizard.]

The new specimen is about 24 feet long and has flippers. It also has a shark-like tail similar to other early mosasaur species. It also likely would have had “angry eyebrows,” caused by a bony ridge on its skull. Its slightly stumpy tail would have also been shorter than the rest of its body.

Jormungandr was likely a precursor to the bigger Mosasaurus. 

“This fossil is coming from a geologic time in the United States that we don’t really understand,” study co-author and paleontologist from the North Dakota Geological Survey Clint Boyd said in a statement. “The more we can fill in the geographic and temporal timeline, the better we can understand these creatures.”

In Norse mythology, Jörmungandr is an enormous sea serpent or worm who encircles the Earth. Jörmungandr is believed to be the middle child of the trickster god Loki and the giantess Angrboða. Thor the god of thunder also has an ongoing battle with Jörmungandr and it is believed that the two will fight to the death during Ragnarok, or the end of the world. 

The post Newfound mosasaur was like a giant Komodo dragon with flippers appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Living long lives past reproductive age is a real rarity for female members of the animal kingdom. Humans and some species of toothed whales are the only known animals to go through menopause and the reasons behind it are an evolutionary puzzle. A team of primatologists recently found that a group of wild chimpanzees in Uganda also show signs of menopause. The findings are described in a study published October 26 in the journal Science and could provide more insight into this rare biological phenomenon.

[Related: Adolescent chimpanzees might be less impulsive than human teens.]

In humans, menopause typically occurs between the ages of 45 and 55 and is characterized by a natural decline in reproductive hormones and the end of ovarian functions. Some symptoms in humans include chills, hot flashes, weight gain, and thinning hair. The evolutionary benefits of this process are still a mystery for biologists. It is also still unclear why menopause evolved in humans but not in other known long-lived primates. 

“During our ongoing twenty five year study of chimpanzees at Ngogo in Kibale National Park, Uganda, we noticed that many old females did not reproduce for decades,” study co-author and Arizona State University primatologist Kevin Langergraber tells PopSci. “It’s a surprising trait from the perspective of evolution: how and why can natural selection favor the extension of lifespan past the point at which individuals can no longer reproduce? We need to know in what species it occurs and which it doesn’t as a first step [to that question].”

To look closer, the authors calculated a metric called the post-reproductive representation (PrR). This measurement is the average proportion of adult lifespan that an animal spends in its post-reproductive state. Most mammals have a PrR close to zero, but the team found that Ngogo chimpanzees have a PrR of 0.2. This means that the female chimpanzees in this group live 20 percent of their adult years in a post-reproductive state. 

Urine samples from 66 female chimpanzees from different stages in their reproductive lives also showed that the transition to this post-reproductive state was marked by changes in hormones like gonadotropins, estrogens, and progestins. 

While similar hormonal variations are also a way to tell that this transition is happening in humans, the post-reproductive chimpanzees were not involved in raising their offspring’s children. In these chimpanzees, the common grandmother hypothesis, where females live longer after menopause to help take care of future generations, does not appear to apply. This contrasts with some populations of orca whales, where grandmothers are a critical part of raising their offspring’s young to ensure their survival. 

[Related: Nice chimps finish last—so why aren’t all of them mean?]

According to the team, there are two possible explanations for these longer post-reproductive lifespans. Chimpanzees and other mammals in captivity can have artificially long post-reproductive lifespans because they are protected from natural predators and some pathogens. Even though they’re a wild population, the Ngogo chimpanzees could also be similarly protected and live artificially long lives. They live in a relatively remote area that is undisturbed by logging and hunting by humans and are exposed to fewer human pathogens. Their current habitat could also be closer to what existed in their evolutionary past compared with other populations of primates that are more affected by humans.

“The study both illuminates and raises questions about the evolution of menopause,” University of Exeter evolutionary biologist Michael Cant wrote in a related review on the study. “It also highlights the power of difficult long-term field studies–often run on small budgets and at constant risk of closure–to transform fundamental understanding of human biology and behavior.” Cant is not an author of the study.

Langergraber says future studies like this one could answer the question of how common substantial post-reproductive lifespans have been throughout chimpanzee evolutionary history and if impacts from humans have kept their survivorship rates artificially low.

The post Wild chimpanzees show signs of potential menopause—a rarity in the animal kingdom appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

With its 19 feet-long torpedo-shaped body and long teeth the newly-described Lorrainosaurus was a fearsome mega predator. The fossilized remains of a 170-million-year-old marine reptile is the oldest-known pliosaur and dates back to the Jurassic era. The discovery is described in a study published October 16 in the journal Scientific Reports.

[Related: Millions of years ago, marine reptiles may have used Nevada as a birthing ground.]

Pliosaurs were members of a group of ocean-dwelling reptiles that are closely related to the more famous long-necked plesiosaurs. Unlike their cousins, these pliosaurs had short necks and massive skulls. From snout to tail, it was likely about 19 feet long and very little is known about the plesiosaurs from this time.

“Famous examples, such as Pliosaurus and Kronosaurus–some of the world’s largest pliosaurs–were absolutely enormous with body-lengths exceeding 10m [32 feet]. They were ecological equivalents of today’s killer whales and would have eaten a range of prey including squid-like cephalopods, large fish and other marine reptiles. These have all been found as preserved gut contents,” study co-author and Uppsala University paleontologist Benjamin Kear said in a statement.

Pliosaurs first emerged over 200 million years ago and remained relatively small players in marine ecosystems. Following a landmark restructuring of the marine predator ecosystem in the early to middle Jurassic era (about 175 to 171 million years ago) they reached apex predator status.

“This event profoundly affected many marine reptile groups and brought mega predatory pliosaurids to dominance over ‘fish-like’ ichthyosaurs, ancient marine crocodile relatives, and other large-bodied predatory plesiosaurs,” study co-author and paleobiologist at the Institute of Paleobiology of the Polish Academy of Sciences Daniel Madzia said in a statement.

The fossils in this study were originally found in 1983 in northeastern France, but were recently analyzed by an international team of paleontologists who identified this new pliosaur genus called Lorrainosaurus. The teeth and bones represent what was once a complete skeleton that decomposed and was spread along the ancient seafloor by scavengers and ocean currents. 

[Related: The planet’s first filter feeder could be this extinct marine reptile.]

“Lorrainosaurus was one of the first truly huge pliosaurs. It gave rise to a dynasty of marine reptile mega-predators that ruled the oceans for around 80 million years,” Sven Sachs, a study co-author and paleontologist from the Naturkunde-Museum Bielefeld in Germany, said in a statement.

Other than a short report published in 1994, these fossils remained obscure until the team reevaluated the specimens. Finding Lorrainosaurus’ remains indicates that the reign of gigantic mega-predatory pliosaurs likely began earlier than paleontologists previously thought. These giants were also locally responsive to the major ecological changes in the marine environments that covered present day Europe during the early Middle Jurassic.

“Lorrainosaurus is thus a critical addition to our knowledge of ancient marine reptiles from a time in the Age of Dinosaurs that has as yet been incompletely understood,” said Kear.

The post This Jurassic-era ‘sea murderer’ was among the first of its kind appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Honeybees are a model of teamwork in nature, with their complex society and hives that generate enough energy to create an electrical charge. They also appear to be some of the rare animals that display a unique trait of altruism, which is genetically inherited. The findings were described in a study published September 25 in the journal Molecular Ecology.

[Related: Bee brains could teach robots to make split-second decisions.]

Giving it all for the queen bee

According to the American Psychological Association, humans display altruism through behaviors that benefit another individual at a cost to oneself. Some psychologists consider it a uniquely human trait and studying it in animals requires a different framework for understanding. Animals experience a different level of cognition, so what drives humans to be altruistic might be different than what influences animals like honeybees to act in ways that appear to be altruistic.

In this new study, the researchers first looked at the genetics behind retinue behavior in worker honeybees. Retinue behavior is the actions of worker bees taking care of the queen, like feeding or grooming her. It’s believed to be triggered by specific pheromones and worker bees are always female. 

After the worker bees are exposed to the queen’s mandibular pheromone (QMP), they deactivate their own ovaries. They then help spread the QMP around to the other worker bees and they only take care of the eggs that the queen bee produces. Entomologists consider this behavior ‘altruistic’ because it benefits the queen’s ability to produce offspring, while the worker bees remain sterile. 

The queen is also typically the mother of all or mostly all of the honeybees in the hive. The genes that make worker bees more receptive to the queen’s pheromone and retinue behavior can be passed down from either female or male parent. However, the genes only result in altruistic behavior when they are passed down from the female bee parent.

“People often think about different phenotypes being the result of differences in gene sequences or the environment. But what this study shows is it’s not just differences in the gene itself—it’s which parent the gene is inherited from,” study co-author and Penn State University doctoral candidate Sean Bresnahan said in a statement. “By the very nature of the insect getting the gene from its mom, regardless of what the gene sequence is, it’s possibly going to behave differently than the copy of the gene from the dad.”

A battle of genetics 

The study supports a theory called the Kinship Theory of Intragenomic Conflict. It suggests that a mothers’ and fathers’ genes are in a conflict over what behaviors to support and not support. Previous studies have shown that genes from males can support selfish behavior in mammals, plants, and honeybees. This new study is the first known research that shows females can pass altruistic behavior onto their offspring in their genes. 

[Really: What busy bees’ brains can teach us about human evolution.]

Worker bees generally have the same mother but different fathers, since the queen mates with multiple male bees. This means that the worker bees share more of their mother’s genes with each other. 

“This is why the Kinship Theory of Intragenomic Conflict predicts that genes inherited from the mother will support altruistic behavior in honeybees,” Breshnahan said. “A worker bee benefits more from helping, rather than competing with, her mother and sisters—who carry more copies of the worker’s genes than she could ever reproduce on her own. In contrast, in species where the female mates only once, it is instead the father’s genes that are predicted to support altruistic behavior.”

Pinpointing conflict networks

To look closer, the team crossbred six different lineages of honeybees. Bresnahan says that this is relatively easy to do in mammals or plants, but more difficult in insects. They used honeybee breeding expertise from co-author Juliana Rangel from Texas A&M University and Robyn Underwood at Penn State Extension to create these populations.

Once the bee populations were successfully crossed and the offspring were old enough, the team assessed the worker bees’ responsiveness to the pheromone that triggers the retinue behavior. 

“So, we could develop personalized genomes for the parents, and then map back the workers’ gene expression to each parent and find out which parent’s copy of that gene is being expressed,” Bresnahan said.

The team identified the gene regulatory networks that have this intragenomic conflict, finding that more genes that have a parental bias were expressed. These networks consisted of genes that previous research showed were related to the retinue behavior.

“Observing intragenomic conflict is very difficult, and so there are very few studies examining the role it plays in creating variation in behavior and other traits,” study co-author and Penn State entomologist Christina Grozinger said in a statement. “The fact that this is the third behavior where we have found evidence that intragenomic conflict contributes to variation in honeybees suggests that intragenomic conflict might shape many types of traits in bees and other species.”

The team hopes that this research will help provide a blueprint for more studies into intragenomic conflict in other animals and plants.

The post Female honeybees may pass down ‘altruistic’ genes appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

A team of scientists from Spain and the United States reconstructed the skull of an extinct great ape species from a set of well-preserved, but damaged skeletal remains. The bones belonged to Pierolapithecus catalaunicus who lived roughly 12 million years ago. Studying its facial features could help us better understand human and ape evolution and the findings are described in a study published October 16 in the journal Proceedings of the National Academy of Sciences (PNAS).

[Related: This 7th-century teen was buried with serious bling—and we now know what she may have looked like.]

First described in 2004, Pierolapithecus was a member of a diverse group of extinct ape species that lived during the Miocene Epoch (about 15 to 7 million years ago) in Europe. During this time, horses were beginning to evolve in North America and the first dogs and bears also began to appear. The Miocene was also a critical time period for primate evolution.

In the study, the team used CT scans to virtually reconstruct Pierolapithecus’ cranium. They then used a process called principal components analysis and compared their digital reconstruction of the face with other primate species. They then modeled the changes occurring to some key features of ape facial structure. They found that Pierolapithecus shares similarities in its overall face shape and size with fossilized and living great apes. 

However, it also has distinct facial features that have not been found in other apes from the Middle Miocene. According to the authors, these results are consistent with the idea that Pierolapithecus represents one of the earliest members of the great ape and human family. 

“An interesting output of the evolutionary modeling in the study is that the cranium of Pierolapithecus is closer in shape and size to the ancestor from which living great apes and humans evolved,” study co-author and AMNH paleoanthropologist Sergio Almécija said in a statement. “On the other hand, gibbons and siamangs (the ‘lesser apes’) seem to be secondarily derived in relation to size reduction.”

Studying the physiology of extinct animals like Pierolapithecus can help us understand how other species evolved. This particular primate species is important because the team used a cranium and partial skeleton that belonged to the same individual ape, which is a rarity in the fossil record. 

[Related: Our tree-climbing ancestors evolved our abilities to throw far and reach high.]

“Features of the skull and teeth are extremely important in resolving the evolutionary relationships of fossil species, and when we find this material in association with bones of the rest of the skeleton, it gives us the opportunity to not only accurately place the species on the hominid family tree, but also to learn more about the biology of the animal in terms of, for example, how it was moving around its environment,” study co-author Kelsey Pugh said in a statement. Pugh is a primate palaeontologist with the American Museum of Natural History (AMNH) in New York and Brooklyn College.

Earlier studies on Pierolapithecus suggest that it could have stood upright and had multiple adaptations that allowed these hominids to hang from tree branches and move throughout them. However, Pierolapithecus’ evolutionary position is still debated, partially due to the damage to the specimen’s cranium.  

“One of the persistent issues in studies of ape and human evolution is that the fossil record is fragmentary, and many specimens are incompletely preserved and distorted,” study-coauthor and AMNH biological anthropologist Ashley Hammond said in a statement. “This makes it difficult to reach a consensus on the evolutionary relationships of key fossil apes that are essential to understanding ape and human evolution.”

The post 12-million-year-old ape skull bares its fangs in virtual reconstruction appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Sam Kreigman and his colleagues made headlines a few years back with their “xenobots”— synthetic robots designed by AI and built from biological tissue samples. While experts continue to debate how to best classify such a creation, Kriegman’s team at Northwestern University has been hard at work on a similarly mind-bending project meshing artificial intelligence, evolutionary design, and robotics.

[Related: Meet xenobots, tiny machines made out of living parts.]

As detailed in a new paper published earlier this month in the Proceedings of the National Journal of Science, researchers recently tasked an AI model with a seemingly straightforward prompt: Design a robot capable of walking across a flat surface. Although the program delivered original, working examples within literal seconds, the new robots “[look] nothing like any animal that has ever walked the earth,” Kriegman said in Northwestern’s October 3 writeup.

And judging from video footage of the purple multi-“legged” blob-bots, it’s hard to disagree:

After offering their prompt to the AI program, the researchers simply watched it analyze and iterate upon a total of nine designs. Within just 26 seconds, the artificial intelligence managed to fast forward past billions of years of natural evolutionary biology to determine legged movement as the most effective method of mobility. From there, Kriegman’s team imported the final schematics into a 3D printer, which then molded a jiggly, soap bar-sized block of silicon imbued with pneumatically actuated musculature and three “legs.” Repeatedly pumping air in and out of the musculature caused the robots’ limbs to expand and contract, causing movement. During testing, the robot could walk half its body length per second—roughly half as fast as the average human stride.

“It’s interesting because we didn’t tell the AI that a robot should have legs,” Kriegman said. “It rediscovered that legs are a good way to move around on land. Legged locomotion is, in fact, the most efficient form of terrestrial movement.”

[Related: Disney’s new bipedal robot could have waddled out of a cartoon.]

If all this weren’t impressive enough, the process—dubbed “instant evolution” by Kriegman and colleagues—all took place on a “lightweight personal computer,” not a massive, energy-intensive supercomputer requiring huge datasets. According to Kreigman, previous AI-generated evolutionary bot designs could take weeks of trial and error using high-powered computing systems. 

“If combined with automated fabrication and scaled up to more challenging tasks, this advance promises near-instantaneous design, manufacture, and deployment of unique and useful machines for medical, environmental, vehicular, and space-based tasks,” Kriegman and co-authors wrote in their abstract.

“When people look at this robot, they might see a useless gadget,” Kriegman said. “I see the birth of a brand-new organism.”

The post AI design for a ‘walking’ robot is a squishy purple glob appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Neanderthals cooked crab and created art, but they also could have haunted cave lions and used their skins. Some 48,000 year-old puncture wounds on a cave lion’s ribcage suggest that the big cat was killed by a Neanderthal’s wooden spear. The findings are described in a study published October 12 in the journal Scientific Reports and may be the earliest known example of lion hunting and butchering by these extinct humans.

[Related: Sensitive to pain? It could be your Neanderthal gene variants.]

For about 20,000 years, cave lions were the most dangerous animals in Eurasia, with a shoulder height of about 4.2 feet high. They lived in multiple environments and hunted large herbivores including mammoth, bison, hose, and cave bear. They get the name cave lions due to the fact that most of their bones have been found in Ice Age caves. The fearsome creatures went extinct at the end of the last Ice Age, but live on through their bones and the 34,000 rock art panels at Grotte Chauvet in France. 

In 1985, an almost complete cave lion skeleton was uncovered in Siegsdorf, Germany. The bones are believed to be from an old, medium-sized cave lion. There are cut marks across bones including two ribs, some vertebrae, and the left femur, which lead scientists to believe that ancient humans butchered the big cat after it died.  

However, the authors in this new study took another look at the remains. They describe a partial puncture wound located on the inside of the lion’s third rib. The wound appears to match the impact mark left by a wooden-tipped spear. The puncture is angled, which suggests that the spear entered the left of the lion’s abdomen and penetrated its vital organs before impacting the third rib on its right side. 

“The rib lesion clearly differs from bite marks of carnivores and shows the typical breakage pattern of a lesion caused by a hunting weapon,” Gabriele Russo, a study co-author and zooarchaeology PhD student at Universität Tübingen in Germany, said in a statement. 

The characteristics of the puncture wound also resemble the wounds found on deer vertebrae which are known to have been made by Neanderthal spears. The new findings could represent the earliest evidence of Neanderthals purposely hunting cave lions.

“The lion was probably killed by a spear that was thrust into the lion’s abdomen when it was already lying on the ground.” study co-author and University of Reading paleolithic archaeologist Annemieke Milks said in a statement. 

[Related: How many ancient humans does it take to fight off a giant hyena?]

The team also analyzed the findings from a 2019 excavation at the Unicorn Cave–or Einhornhöhle–in the Harz Mountains in Germany. The remains of several animals dating back to the last Ice Age or about 55,000 to 45,000 years ago were found, including some cave lion bones. They looked at bones from the toes and lower limbs of three cave lion specimens. These bones also had cut marks that are consistent with the markings generated when an animal is skinned.

The cut marks suggest that great care was taken while skinning the lion to ensure that the claws remained preserved within the fur. This finding could be the earliest evidence of Neanderthals using a lion pelt, potentially for cultural purposes.

“The interest of humans to gain respect and power from a lion trophy is rooted in Neanderthal behavior and until modern times the lion is a powerful symbol of rulers!” Thomas Terberger, a study co-author and archaeologist at the Universität Göttingen in Germany said in a statement. 

Future studies of cave lion bones could reveal more details of more complex Neanderthal behaviors and how the animal may have laid the basis for cultural development by our own species—Homo sapiens. 

The post Neanderthals may have hunted mighty cave lions appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

In the years since the Neanderthal genome was first sequenced, geneticists have been peering into the past to look for traces of this extinct group of humans within our genes. The presence of these ancient genes could make carriers more at risk for severe COVID-19, influence nose shape, and even make some people more sensitive to pain. 

[Related: Neanderthal genomes reveal family bonds from 54,000 years ago.]

A new study published October 10 in the journal Communications Biology found that those carrying three Neanderthal gene variants are actually more sensitive to pain from skin pricking after prior exposure to mustard oil. In this case, mustard oil acts as an agonist, or a substance that initiates a physiological response. Adding it to the skin causes a quick response by neurons called nociceptors that create a sense of pain. 

SCN9A is a key gene in the perception of pain that is located on chromosome 2. It is highly expressed nociceptors that are activated when a sharp point or something hot is applied to the body. The neurons encode proteins within the body’s sodium channel and alert the brain which leads to the perception of pain. Earlier research found three variations in the SCN9A gene–M932L, V991L, and D1908G–in sequenced Neanderthal genomes and reports of greater sensitivity to pain among the living humans who have all three of these variants. 

“It has been shown in previous studies that some rare mutations in this gene that stop the channel from working can cause insensitivity to pain,” study co-author and University of Oxford neuroscientist David Bennett tells PopSci. “We were, however, interested in these other mutations, which were shown to have an opposite effect of enhancing the activity of this channel, thus leading their carriers to be somewhat more sensitive than non-carriers.”

According to Andrés Ruiz-Linares, study co-author and University College London human geneticist, earlier studies show that the mutations are quite rare in the British populations, but they are very frequent in Latin American populations. 

“We thus realized that we had, in our hands, the perfect dataset to not only replicate their study but also go further and identify the pain modality that was at work here,” Ruiz-Linares tells PopSci. 

In the study, the team measured the pain thresholds of 1,963 individuals from Colombia in response to a range of stimuli. The D1908G variant was present in roughly 20 percent of chromosomes within this population. About 30 percent of chromosomes carrying this variant also carried the M932L and V991L variants. All three variants were associated with a lower pain threshold in response to skin pricking after the skin was exposed to mustard oil, but not in response to pressure or heat. Additionally, carrying all three of these variants was associated with greater pain sensitivity than carrying only one of them. 

[Related: Neanderthals were likely creating art 57,000 years ago.]

The team then analyzed the genomic region that houses SCN9A using genetic data from 5,971 individuals from Peru, Chile, Brazil, Colombia, and Mexico. They found that the three Neanderthal variants were more common in regions where the population had a higher proportion of Native American ancestry, such as the Peruvian population.

“They [the mutations] have a rather wide range in these countries, from 2 to 42 percent,” study co-author and University College London statistical geneticist Kaustubh Adhikari tells PopSci. “Up to 18 percent of their populations could carry two copies of the mutation. These are, however, gross estimations. We also know, from the previous study, that these mutations are pretty rare in European populations.”

The team believes that the Neanderthal variants may sensitize the sensory neurons by changing the threshold at which a nerve impulse is generated. The variants could also be more common in populations with higher proportions of Native American ancestry due to random chance as well as population bottlenecks that occurred during when the Americas were first colonized by Europeans. 

“Although Neanderthal intermixing with Europeans is now well-known in popular culture, their genetic contribution to other human groups, such as Native Americans in this case, is less talked about,” study co-author and population geneticist at the National Research Institute for Agriculture, Food and the Environment in France Pierre Faux tells PopSci. “In this study, we saw how important and relevant it is to study genetic backgrounds that are under-represented in medical cohorts.”

Since acute pain can play a role in moderating behavior and preventing further injury, the team is planning additional research to determine if carrying these variants and having greater sensitivity to pain was advantageous during human evolution. Understanding how these variants work could also help physicians understand and treat chronic pain.

“Genes are just one of many factors, including environment, past experience, and psychological factors, which influence pain,” says Bennet. 

The post Sensitive to pain? It could be your Neanderthal gene variants. appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Meet Garumbatitan morellensis, a new species of large sauropod dinosaur. The Giganotosaurus relative called the present-day Iberian Peninsula home about 122 million years ago. The remains of this titan were discovered in Morella, Spain, and this discovery could help fill in some major evolutionary gaps. The findings were described in a study published September 28 in the journal Zoological Journal of the Linnean Society.

[Related: Cushy feet supported sauropods’ gigantic bodies.]

G. morellensis belongs to the sauropod group of dinosaurs, which includes some well-known favorites like Diplodocus and Brachiosaurus. Sauropods were four-legged Early Jurassic and Cretaceous Era dinos known for their long necks that could reach up to 49 feet long in some species and lengthy tails. G. morellensis is also a member of a subgroup of sauropods known as titanosaurs. These giants were the largest of an already big group and titanosaurs survived right up until the asteroid that wiped out the dinosaurs struck about 66 million years ago.

This new dinosaur’s remains were found and excavated in the Sant Antoni de la Vespa fossil-site in 2005 and 2008. This fossil deposit is home to one of the largest concentrations of sauropod dinosaur remains that date back to the Lower Cretaceous period in Europe (about 145 million to 66 million years ago). Scientists found the remains of a giant unidentified sauropod in Portugal in 2022 that could be Europe’s oldest known dinosaur fossil at 150 million-years-old. 

The team of paleontologists from Portugal and Spain found the remains of three G. morellensis individuals and one other sauropod. Their lucky find included a rare set of footprints. They also uncovered giant vertebrae, leg bones, and two near-complete sets of foot bones. 

“One of the individuals we found stands out for its large size, with vertebrae more than one meter wide [3.2 feet], and a femur that could reach two meters [6.5 feet] in length. We found two almost complete and articulated feet in this deposit, which is particularly rare in the geological record,” study co-author and University of Lisbon paleontologist Pedro Mocho said in a statement. 

G. morellensis was probably close to an average-size titanosaur and could have been near 94 feet long. Its leg shape and foot bones suggest that it was one of the more primitive sauropods from a subgroup called Somphospondyli, according to the authors. Somphospondylan fossils have been found on every present-day continent, but paleontologists are not sure where they originated. This discovery of such an early specimen in Spain points to Europe as a possible origin point for this subgroup, but more evidence is needed.  

[Related: Europe’s largest dinosaur skeleton may have been hiding in a Portuguese backyard.]

This discovery also highlights how complex the evolutionary history of sauropods in the Iberian Peninsula and the rest of Europe is. Species related to these lineages have been found in Asia, North America, and possibly Africa. This points to a potentially long period of dinosaur dispersal within continents and this fossil deposit might fill in some major gaps of evolutionary history. 

“The future restoration of all fossil materials found in this deposit will add important information to understand the initial evolution of this group of sauropods that dominated dinosaur faunas during the last million years of the Mesozoic era,” study co-author and Universidad Nacional de Educación a Distancia in Madrid paleontologist Francisco Ortega said in a statement.

The post A newly discovered sauropod dinosaur left behind some epic footprints appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

In 2006, a cluster of mysterious dark spots on a lakebed of White Sands National Park in New Mexico caught the attention of archaeologists. The shapes stroked their curiosity until they eventually excavated the site three years later. Waiting for them was one of the rarest and soon-to-be controversial discoveries in history—a set of fossilized human footprints. 

The preserved markings were found on the shore of a lake that existed during the most recent ice age, and could be one of the earliest signs of biped migration to North America. Some experts claim they are the steps of the Clovis people, the continent’s first human inhabitants and the ancestors for most Native Americans. The Clovis are thought to have made the journey to North America 13,000 to 13,500 years ago using a land bridge that connected Asia to Alaska. From there, they continued to move as far down south as Central and South America. 

“This was groundbreaking to the archaeologic community, and it was also a tough pill to swallow,” says Kathleen Springer, a research geologist for the United States Geological Survey (USGS) who helped analyze the fossilized steps. “Having 23- to 21,000-year-old footprints is much earlier than the prevailing paradigm of Clovis or pre-Clovis that are known in this part of North America.”

The finding initially received some pushback. When the results were first revealed in 2021, concerned archaeologists wrote comments and papers challenging the results, citing the need for better evidence. More specifically, they criticized the study method and the decision to use radiocarbon dating on the seeds of an aquatic plant that was excavated from the same site. 

Part of the debate came down to an isotope that’s often used in archaeological work. Carbon-14 forms in the air and is introduced to photosynthetic plants and the animals that eat them. When flora and fauna are alive, they have the same amount of carbon-14 as the Earth’s atmosphere; when they die, it decays in their remains. Scientists can then measure how much of the isotope is left and use that metric to calculate an organism’s approximate age. But as some experts have pointed out, aquatic plants like the ones sampled at White Sands can get carbon from the water they live in, which can skew the measurements and make a specimen seem older than it really is.

“It’s called the hard water effect, and it’s a really well-known problem with radiocarbon dating,” explains Jeffrey Pigati, a USGS research geologist who co-authored both studies with Springer. He says the general argument with the first paper is that there were large hard-water effects that made them overestimate the age of the footsteps when they should have been around 15,000 or 17,000 years old.

The COVID pandemic delayed many of the follow-up experiments Pigati and Springer wanted to complete when investigating the site in 2020. Three years later, they finally did with two new methods that corroborate their original estimate of the footprints’ age: radiocarbon dating of pollen and luminescence dating.

To avoid heavy-water effects, the team extracted pollen grains from the same sediment as the White Sands footprints. According to Pigati, this is a time-consuming and laborious process because it involves breaking down rock into one cubic centimeter of material and separating pollen from other organic material before measuring carbon-14 levels. Additionally, pollen is extremely light—experts need to sample thousands of grains to meet the minimum mass requirement for a single radiocarbon measurement. In total, they successfully isolated 75,000 pollen grains. When the they compared the measurements to ones from the seeds of the aquatic plant, the ages matched.

The second technique was optically stimulated luminescence (OSL) dating. Unlike radiocarbon dating, OSL dating is based on the buildup of luminescence properties in quartz crystals over time; in some rare cases, it can date sediments as far back as 400,000 years ago. The USGS team dated three different mineral samples from the same area where the footprint was discovered and calculated ages that were similar to the ones measured in the seeds.

Still, this does not mean we have a complete picture of our species’ migration to North America. Paulette Steeves, an archaeologist and author of The Indigenous Paleolithic of the Western Hemisphere, who was not involved in the White Sands research, says there are archaeological sites in both North and South America that date to as early as 11,000 to 200,000 years ago. While she argues it’s not the oldest sign of human habitation in the Americas and may not be proof of the first Indigenous group, “the White Sands footprints site is a great addition to the record of early people in the Western Hemisphere.”

The footprints are just one piece of the puzzle. Archaeologists still don’t know exactly how people lived in the middle of an ice age and weathered harsh climate. Future projects at White Sands could include tracking the footprints to a campsite or further scouring the area for stone tools that could give some insight into their survival. “Every day we’re working out there is amazing because you never know what is going to be discovered,” Pigati says. “This is all a part of science in action.”

The post Do the ancient human footprints at White Sands date back to the last ice age? appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Over 1,500 animal species, from bonobos to sea urchins to penguins are known to engage same-sex sexual behavior. Still, scientists don’t understand exactly how it came to be or why it happens. While some say the behavior might have existed since the animal kingdom first arose more than half a billion years ago, it may have actually evolved repeatedly in mammals. A study published October 3 in the journal Nature Communications suggests that the behavior possibly plays an adaptive role in social bonding and reducing conflict, and evolved multiple times.

[Related: A massive study confirms no one ‘gay gene’ controls sexual preference.]

The behavior is particularly prevalent in nonhuman primates. It has been observed in at least 51 species from small lemurs up to bigger apes. For one population of male macaques, same-sex sexual behavior may even be a common feature of reproduction and is related to establishing dominance within groups, handling a shortage of different-sex partners, or even reducing tension following aggressive behavior. 

In this new study, the team from institutions in Spain surveyed the available scientific literature to create a database of records of same-sex sexual behavior in mammals. They traced the behavior’s evolution across mammals and tested for any evolutionary relationships with other behaviors. 

The team found that same-sex sexual behavior is widespread across mammal species, occurs in similar frequency in both males and females, and likely has multiple independent origin points. This analysis found that the behavior helps establish and maintain positive social relationships in animals including chimpanzees, bighorn sheep, lions, and wolves.

“It may contribute to establishing and maintaining positive social relationships,” study co-author José Gómez told The New York Times. “With the current data available, it seems that it has evolved multiple times.” Gómez is an evolutionary biologist at the Experimental Station of Arid Zones in Almería, Spain. 

Importantly, they caution that the study should not be used to explain the evolution of sexual orientation in humans. This research focused on same-sex sexual behavior defined as short-term courtship or mating interactions, instead of a more permanent sexual preference. 

Additionally, male same-sex sexual behavior was likely evolved in species with high rates of male adulticide–-when adult animals kill other adults. The team believes that this suggests the behavior may be an adaptation meant to mitigate the risks of violent conflict between males.

Harvard University primatologist Christine Webb, who did not participate in the study, told The Washington Post that the findings add to other research and widen the scope of what it means for a behavior to be considered adaptive.

[Related: Same-sex mounting in male macaques can help them reproduce more successfully.]

“This general question of evolutionary function—that behavior must aid in survival and reproduction—what this paper is arguing is that reaffirming social bonds, resolving conflicts, managing social tensions, to the extent that same-sex sexual behavior preserves those functions—it’s also adaptive,” Webb said. 

Webb also added that it makes sense that other animals would have sex for a variety of reasons the way that humans do.

The authors caution that these associations could also be driven by other evolutionary factors. Same-sex sexual behavior has also only been carefully studied in a minority of mammal species, so our understanding of the evolution of same-sex sexual behavior may continue to change as more mammalian species are studied.

The post Mammals may use same-sex sexual behavior for conflict resolution, bonding, and more appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Parrots are the chatterboxes of the animal kingdom. These famously social birds can learn new sounds throughout their lives and even produce calls that can be individually recognized by other members of their flock. A new study of monk parakeets found that individual birds have a unique tone of voice similar to humans called a “voice print.” The findings are described in a study published October 3 in the journal Royal Society Open Science.

[Related: The next frontier in saving the world’s heaviest parrots: genome sequencing.]

“It makes sense for monk parakeets to have an underlying voice print,” Simeon Smeele, a co-author of the study and biologist studying parrot social and vocal complexity at the Max Planck Institute of Animal Behavior, said in a statement. “It’s an elegant solution for a bird that dynamically changes its calls but still needs to be known in a very noisy flock.”

In humans, our voice print leaves a unique signature in the tone of our voice across every word we say. These voice prints remain even though humans have a very complex and flexible vocal repertoire. Other social animals also use similar cues to recognize one another. Individual dolphins, bats, and birds have a “signature call” that makes them identifiable to other members of their groups. However, signature calls encode identity in only one call type, and there hasn’t been much evidence that suggests animals have unique signatures that last throughout their entire repertoire of calls. 

Parrots use their tongue and mouth to modulate calls similar to the way humans speak. According to Smeele, “their grunts and shrieks sound much more human than a songbird’s clean whistle.” 

Parrots also live in large groups with fluid membership where multiple birds vocalize at the same time. Members need a way to keep track of which individual is making what sound. The question became if the right physical anatomy coupled with the need to navigate complex social lives, helped parrots evolve a voice print. 

In the study, Smeele and his team traveled to Barcelona, Spain—home to the largest population of individually marked parrots in the wild. The parakeets are considered an invasive species and they swarm Barcelona’s parks in flocks with hundreds of members. The Museu de Ciències Naturals de Barcelona has been marking the parakeets for 20 years and have individually identified 3,000 birds.

The team used microphones to record the calls of hundreds of individuals and collected over 5,000 vocalizations in total. They also re-recorded the same individuals over a period of two years, which revealed the stability of the calls over time.

Using a set of computer models, they detected how recognizable individual birds were within each of the five main call types given by this species (contact, tja, trrup, alarm, and growl). They found high variability in the “contact call” that birds use to broadcast their identity. According to the team, this overturned a long-held assumption that contact calls contain a stable individual signal. The new findings suggested that the parakeets are actually using something else for individual recognition.

[Related: These clever cockatoos carry around toolkits to get to food faster.]

To investigate if voice prints were at play, the team used a machine learning model widely used in human voice recognition. The model detects the identity of the speaker using the quality, or timbre, of their voice. The team trained the model to recognize calls of individual birds that were categorized as “tonal” in sound. They then tested to see if the model could detect the same individual from a separate set of calls that were classified as “growling” in sound. The model was able to identify the individual parrots three times better than expected, providing evidence that monk parakeets do actually have a recognizable, individual voice print. 

While exciting, the authors caution that this evidence is still preliminary. Future experiments and analyses could use the parrot tagging work from the team in Barcelona. The GPS devices could help determine how much individuals overlap in their roaming areas.

“This can provide insight into the species’ remarkable ability to discriminate between calls from different individuals,” study co-author and ecologist from Museu de Ciències Naturals de Barcelona Juan Carlos Senar said in a statement.

The post No two parakeets sound exactly the same appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

We all know the line: For more than 150 million years, dinosaurs ruled the Earth. We imagine bloodthirsty tyrannosaurs ripping into screaming duckbills, gigantic sauropods shaking the ground with their thunderous footfalls, and spiky stegosaurs swinging their tails in a reign of reptiles so magnificent, it took the unexpected strike of a six-mile-wide asteroid to end it. The ensuing catastrophe handed the world to the mammals, our ancestors and relatives, so that 66 million years later we can claim to have taken over what the terrible lizards left behind. It’s a dramatic retelling of history that is fundamentally wrong on several counts. Let’s talk about some of the worst rumors and what really happened in the so-called “Age of Dinosaurs.”

Myth: Dinosaurs dominated the planet from their origin.

Fact: Dinosaurs started as cute pipsqueaks.

The oldest dinosaurs we know about are around 235 million years old, from the middle part of the Triassic Period. Those reptiles didn’t rule anything. From recent finds in Africa, South America, and Europe, we know that they were no bigger than a medium-sized dog and were lanky, omnivorous creatures that munched on leaves and beetles. Ancient relatives of crocodiles, by contrast, were much more abundant and diverse. Among the Triassic crocodile cousins were sharp-toothed carnivores that chased after large prey on two legs, “armadillodiles” covered in bony scutes and spikes, and beaked, almost ostrich-like creatures that gobbled up ferns.

Even as early dinosaurs began to evolve into the main lineages that would thrive during the rest of the Mesozoic, most were small and rare compared to the crocodile cousins. The first big herbivorous dinosaurs, which reached about 27 feet in length, didn’t evolve until near the end of the Triassic, around 214 million years ago. But everything changed at the end of the Triassic. Intense volcanic eruptions in the middle of Pangaea altered the global climate; the gases released into the air caused the world to swing between hot and cold phases. By then, dinosaurs had evolved warm-blooded metabolisms and insulating coats of feathers, leaving them relatively unfazed through the crisis, while many other forms of reptiles perished. Had this mass extinction not transpired, we might have had more of an “Age of Crocodiles”—or at least a very different history with a much broader cast of reptilian characters. The only reason the so-called Age of Dinosaurs came to be is because they got lucky in the face of global extinction.

Myth: Dinosaurs spanned the entire planet.

Fact: Dinosaurs never evolved to live at sea.

Of course, these ecosystems were built on a foundation of plankton. Without disc-shaped algae called coccoliths, the rest of the charismatic swimmers of the Triassic, Jurassic, and Cretaceous wouldn’t have thrived. It’s the abundant, small forms of life that let charismatic creatures like marine reptiles prosper—a further reminder that the animals that impress us on land or sea wouldn’t exist without various tiny organisms that set the foundations of food webs. What we might see as dominance, in any ecosystem, is really a consequence of many relationships and interactions that often go unnoticed.

Myth: Dinosaurs suppressed the evolution of mammals.

Fact: Mammals thrived throughout the Age of Dinosaurs.

The classic example of dinosaur dominance is a twitchy little mammal chasing an insect through the Cretaceous night. Dinosaurs would gobble up any beast that got too big or was foolish enough to wander out in the daylight, the argument went, so mammals evolved to be small and nocturnal until the asteroid allowed our ancestors and relatives to emerge from the shadows. The small size and insect-hunting adaptations of some Mesozoic mammals were taken as indicators that mammals were constrained by the success of the dinosaurs, preventing them from becoming larger or opening new niches.

In the past 20 years, however, paleontologists have rewritten the classic story to show that mammals and their relatives thrived alongside the dinosaurs. Throughout the Mesozoic there were furry beasts that swam, dug, glided between the trees, and even ate little dinosaurs. Ancient equivalents of squirrels, raccoons, otters, beavers, sugar gliders, aardvarks, and more evolved through the Jurassic and Cretaceous, including early primates that scampered through the trees over the heads of T. rexes. While it’s true that all the Mesozoic mammals we presently know of were small—the largest was about the size of an American badger— researchers have realized that the way our ancient ancestors interacted with each other was much more important to shaping their evolution than the dinosaurs were. In fact, even with the dinosaurs gone, most new mammal species stuck to being small. We get so hung up on size that we’ve missed the real story, closer to the ground.

Myth: Dinosaurs dominated the planet for millions of years.

Fact: No single species can dominate a planet.

The post 4 reasons dinosaurs never really ruled the Earth appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Sea turtles have been around for at least 110 million years, yet relatively little is known about their evolution. Two of the most common sea turtles on Earth are olive ridley and Kemp’s ridley turtles that belong to a genus called Lepidochelys that could help fill in some of the gaps of sea turtle biology and evolution. A team of paleontologists not only discovered the oldest known fossil of turtle from the Lepidochelys genus, but also found some traces of ancient turtle DNA. The findings are detailed in a study published September 28 in the Journal of Vertebrate Paleontology.

[Related: 150 million-year-old turtle ‘pancake’ found in Germany.]

The DNA comes from the remains of a turtle shell first uncovered in 2015 in the Chagres Formation on Panama’s Caribbean coast. It represents the oldest known fossil evidence of Lepidochelys turtles. The turtle lived approximately 6 million years ago, curing the upper Miocene Epoch. At this time, present day Panama’s climate was getting cooler and drier, sea ice was accumulating at Earth’s poles, rainfall was decreasing, sea levels were falling.

“The fossil was not complete, but it had enough features to identify it as a member of the Lepidochelys genus,” study co-author and Universidad del Rosario in Bogotá, Colombia paleontologist Edwin Cadena tells PopSci. Cadena is also a research associate at the Smithsonian Tropical Research Institute in Panama.

The team detected preserved bone cells called osteocytes. These bone cells are the most abundant cells in vertebrates and they have nucleus-like structures. The team used a solution called DAPI to test the osteocytes for genetic material.

“In some of them [the osteocytes], the nuclei were preserved and reacted to DAPI, a solution that allowed us to recognize remains of DNA. This is the first time we have documented DNA remains in a fossilized turtle millions of years old,” says Cadena.

According to the study, fossils like this one from vertebrates preserved in this part of Panama are important for our understanding of the biodiversity that was present when the Isthmus of Panama first emerged roughly 3 million years ago. This narrow strip of land divided the Caribbean Sea and the Pacific Ocean and joined North and South America. It created a land bridge that made it easier for some animals and plants to migrate between the two continents.

[Related: Hungry green sea turtles have eaten in the same seagrass meadows for about 3,000 years.]

This specimen could also have important implications for the emerging field of molecular paleontology. Scientists in this field study ancient and prehistoric biomatter including proteins, carbohydrates, lipids, and DNA that can sometimes be extracted from fossils. 

Molecular paleontology aims to determine if scientists can use this type of evidence to determine more about the organisms than their physical shape, which is typically what is preserved in most fossils. Extracting this tiny material from bones was critical in sequencing the Neanderthal genome, which earned Swedish scientist Svante Pääbo the 2022 Nobel prize in physiology or medicine.

“Many generations have grown up with the idea of extracting and bringing back to life extinct organisms,” says Cadena. “However, that is not the real purpose of molecular paleontology. Instead, its goal is to trace, document, and understand how complex biomolecules such as DNA and proteins can be preserved in fossils.”

This new turtle specimen could help other molecular paleontologists better understand how soft tissues can be preserved over time. It could also shift the idea that original biomolecules like proteins or DNA have a specific timeline for preservation in fossils and encourage re-examining older specimens for traces of biomolecules. 

The post This 6-million-year-old turtle shell still has some DNA appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

One of the most enduring mysteries about our earliest ancestors and extinct human relatives is how they ate and procured enough food to sustain themselves millions of years ago. We believe that archery first arrived in Europe about 54,000 years ago and Neanderthals were cooking and eating crab about 90,000 years ago, but scavenging was likely necessary to get a truly hearty meal. A modeling study published September 28 in the journal Scientific Reports found that groups of hominins roughly 1.2 to 0.8 million years ago in southern Europe may have been able to compete with giant hyenas for carcasses of animals abandoned by larger predators like saber-toothed cats.

[Related: An ‘ancestral bottleneck’ took out nearly 99 percent of the human population 800,000 years ago.]

Earlier research has theorized that the number of carcasses abandoned by saber-toothed cats may have been enough to sustain some of southern Europe’s early hominin populations. However, it’s been unclear if competition from giant hyenas (Pachycrocuta brevirostris) would have limited hominin access to this food source. These extinct mongoose relatives were about 240 pounds–roughly the size of a lioness–and went extinct about 500,000 years ago. 

“There is a hot scientific debate about the role of scavenging as a relevant food procurement strategy for early humans,” paleontologist and study co-author Jesús Rodríguez from the National Research Center On Human Evolution (CENIEH) in Burgos, Spain tells PopSci. “Most of the debate is based on the interpretation of the scarce and fragmentary evidence provided by the archaeological record. Without denying that the archaeological evidence should be considered the strongest argument to solve the question, our intention was to provide elements to the debate from a different perspective.”

For this study, Rodríguez and co-author Ana Mateos looked at the Iberian Peninsula in the late-early Pleistocene era. They ran computer simulations to model competition for carrion–the flesh of dead animals–between hominins and giant hyenas in what is now Spain and Portugal. They simulated whether saber-toothed cats and the European jaguar could have left enough carrion behind to support both hyena and hominin populations—and how this may have been affected by the size of scavenging groups of hominins. 

They found that when hominins scavenged in groups of five or more, these groups could have been large enough to chase away giant hyenas. The hominin populations also exceeded giant hyena populations by the end of these simulations. However, when the hominins scavenged in very small groups, they could only survive to the end of the simulation when the predator density was high, which resulted in more carcasses to scavenge.  

[Related: Mysterious skull points to a possible new branch on human family tree.]

According to their simulations, the potential optimum group size for scavenging hominins was just over 10 individuals. This size was large enough to chase away saber-toothed cats and jaguars. However, groups of more than 13 individuals would have likely required more carcasses to sustain their energy expenditure. The authors caution that their simulations couldn’t specify this exact “just right” group size, since the numbers of hominins needed to chase away hyenas, saber-toothed cats, and jaguars were pre-determined and arbitrarily assigned.

“The simulations may not determine the exact value of the optimum, but show that it exists and depends on the number of hominins necessary to chase away the hyenas and of the size of the carcasses,” says Rodríguez.

Scavenged remains may have been an important source of meat and fat for hominins, especially in winter when plant resources were scarce. This team is working on simulating the opportunities hominins had for scavenging in different ecological scenarios in an effort to change a view that scavenging is marginal and that hunting is a more “advanced” and more “human” behavior than scavenging. 

“The word for scavenger in Spanish is ‘carroñero.’ It has a negative connotation, and is frequently used as an insult. We do not share that view,” says Rodríguez. “Scavengers play a very important role in ecosystems, as evidenced by the ecological literature in the last decades. We view scavenging as a product of the behavioral flexibility and cooperative abilities of the early hominins.”

The post How many ancient humans does it take to fight off a giant hyena? appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Scientists in Thailand have discovered a new species of tarantula with a very unique blue hue. The tarantula is named Chilobrachys natanicharum and is also called the electric blue tarantula. The findings were described in a study published September 18 in the journal ZooKeys 

[Related: Before spider mites mate, one of them gets their skin removed.]

The new colorful arachnid was discovered in southern Thailand’s Phang-Nga province. It follows the identification of another new species of tarantula called Taksinus bambus, or the bamboo culm tarantula.

“In 2022, the bamboo culm tarantula was discovered, marking the first known instance of a tarantula species living inside bamboo stalks,” study co-author and Khon Kaen University entomologist Narin Chomphuphuang said in a statement. “Thanks to this discovery, we were inspired to rejoin the team for a fantastic expedition, during which we encountered a captivating new species of electric blue tarantula.”

The team that found the first not-so-blue bamboo culm tarantula included a local wildlife YouTuber named JoCho Sippawat. This year, Chomphuphuang joined up with Sippawat for a surveying expedition in the province to learn more about tarantula diversity and distribution. They identified this new species by this very distinctive coloration during the expedition.

“The first specimen we found was on a tree in the mangrove forest. These tarantulas inhabit hollow trees, and the difficulty of catching an electric-blue tarantula lies in the need to climb a tree and lure it out of a complex of hollows amid humid and slippery conditions,” Narin said. “During our expedition, we walked in the evening and at night during low tide, managing to collect only two of them.”

The color blue is very rare in nature. It can even exist in other animals that aren’t usually this color, including the blue lobsters that have recently been found in Massachusetts and France. Some animals also evolved wild colors including blues, yellows, and reds to appear poisonous to try and keep other animals from eating them.  

In order for an organism to appear blue, it must absorb very small amounts of energy while reflecting high-energy blue light. Since penetrating molecules that are capable of absorbing this energy is a complex process, the color blue is less common than other colors in the natural world. 

According to the study, the secret behind the electric blue tarantula’s wild color comes from the unique structure of their hair and not from a presence of blue pigment. Their hair incorporates nanostructures that manipulate the light shining on it to create the blue appearance. Their hair can also display a more violet hue depending on the light, which creates an iridescent effect. 

[Related: Blue-throated macaws are making a slow, but hopeful, comeback.]

This species was previously found on the commercial tarantula market, but there hadn’t been any documentation describing its natural habitat or unique features. 

“The electric blue tarantula demonstrates remarkable adaptability. These tarantulas can thrive in arboreal as well as terrestrial burrows in evergreen forests,” Narin said. “However, when it comes to mangrove forests, their habitat is restricted to residing inside tree hollows due to the influence of tides.”

To name the new species, the authors conducted an auction campaign and the scientific name of Chilobrachys natanicharum was selected. It is named after executives Natakorn and Nichada Changrew of Nichada Properties Co., Ltd., Thailand and the proceeds of the auction were donated to support the education of Indigenous Lahu children in Thailand and for cancer patients in need of money for treatment.

The authors say that this discovery points to the continued importance of taxonomy as a basic aspect of research and conservation. It also highlights the need to protect mangrove forests from continued deforestation, as the electric blue tarantula is also one of the world’s rarest tarantulas. 

“This raises a critical question: Are we unintentionally contributing to the destruction of their natural habitats, pushing these unique creatures out of their homes?” the researchers ask in their conclusion.

The post Meet the first electric blue tarantula known to science appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Parasitic plants make up about 1 percent of flowering species within the plant kingdom and their quirks and tricks continue to come with surprises. Some parasitic plants are now potentially evolving to be so dependent on their host plants, that they are losing sizable amounts of genomes related to basic biological processes like photosynthesis. The findings are described in a study published September 21 in the journal Nature Plants.

[Related: How a peculiar parasitic plant relies on a rare Japanese rabbit.]

Plants in the Balanophoraceae family that are found in tropical and temperate regions in Asia and tropical Africa generally resemble fungi growing around the roots of trees in the forest, but there is a lot more than meets the eye. The structures that look like mushrooms are instead inflorescences, or a cluster of flowers intricately arranged on a stem.  

However, unlike other parasitic plants that extend a skinny projection called a haustorium into a host’s tissue to steal its nutrients, plants in the Balanophora genus actually induce their host plant’s vascular system to grow into a tuber to store nutrients. This forms a unique underground organ made from tissue of both the host plant that Balanophora then uses to eat..

To learn more about how these subtropical extreme parasitic plants evolved into this unique form, a team from the Beijing Genomics Institute (BGI) and the University of British Columbia compared Balanophora’s genomes with another parasitic plant genus called Sapria that has a very different vegetative body. Sapria are members of the family Rafflesiaceae, including some very smelly corpse flowers, and can generally be found in tropical forests of Asia.

The study found that Sapria has lost 38 percent of its genomes and Balanophora has lost 28 percent of their genomes over time, while evolving their parasitic behaviors, which the authors say is a record genetic shrinking for flowering plants.

“The extent of similar, but independent gene losses observed in Balanophora and Sapria is striking,” study co-author and BGI Research plant geneticist Xiaoli Chen said in a statement. “It points to a very strong convergence in the genetic evolution of holoparasitic lineages, despite their outwardly distinct life histories and appearances, and despite their having evolved from different groups of photosynthetic plants.”

They found that both Balanophora and Sapria have even lost almost all of the genes associated with photosynthesis and other key biological processes, including nitrogen absorption, root development, and the regulation of flower development. 

“The majority of the lost genes in Balanophora are probably related to functions essential in green plants, which have become functionally unnecessary in the parasites,” study co-author and University of British Columbia botanist Sean Graham said in a statement.

[Related: We’re finally figuring out how plants pass on genetic memories.]

Since these parasitic plants don’t necessarily need to rely on sunlight and water to make food through photosynthesis and instead use the resources of their host plants, they appear to be losing those genes. 

Notably, the genes related to the synthesis of a major hormone responsible for plant stress responses and signaling called abscisic acid (ABA) have also been lost in Balanophora and Sapria. Even with the loss, the team still recorded a build up of the ABA hormone in Balanophora’s flowering stems and saw that genes involved in the response to ABA signaling are still retained in the parasites. According to the team, this gene loss could be beneficial to the plant. 

“The loss of their entire ABA biosynthesis pathway may be a good example. It may help them to maintain physiological synchronization with the host plants,” said Graham. “This needs to be tested in the future.”

The team says that this study deepens the major genomic alterations occurring within parasitic plants and is important in the context of a project working to sequence the genomes of 10,000 plant species called 10KP.

The post These parasitic plants force their victims to make them dinner appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Just in time for spooky season, scientists have learned more about how a tiny parasitic flatworm called the lancet liver fluke infects and controls the brains of ants. With their complex four-step cycle, the flukes could be cunningly adjusting to daily changes in air temperatures to infect more hosts. The findings were recently published in the journal Behavioral Ecology.

[Related: Mind-controlling ‘zombie’ parasites are real.]

Step 1: The Zombie Ant

The parasite hijacks an ant’s brain after an ant eats a ball of snail mucus infested with fluke larvae. The larvae then mature inside the brain, where the parasite can make the ant climb up a blade of grass and clamp down on the blade. This strategic height makes it easier for the parasite’s next potential host—a cow, sheep, deer, or other grazer—to eat the flukes and offer it another place to live and breed. This new study found that the liver fluke can even get the ant to crawl back down the blade of grass when it gets too hot.

“Getting the ants high up in the grass for when cattle or deer graze during the cool morning and evening hours, and then down again to avoid the sun’s deadly rays, is quite smart. Our discovery reveals a parasite that is more sophisticated than we originally believed it to be,” University of Copenhagen biologist and study co-author Brian Lund Fredensborg said in a statement. Fredensborg conducted the research with his former graduate student Simone Nordstrand Gasque, now a PhD student at Wageningen University in the Netherlands.

In their study, the team tagged several hundred infected ants in the Bidstrup Forests near Roskilde, Denmark. “It took some dexterity to glue colors and numbers onto the rear segments of the ants, but it allowed us to keep track of them for longer periods of time,” said Fredensborg.

The team observed how the infected ants behaved to humidity, light, time of day, and temperature and it was clear that temperature has an effect on their behavior. During cooler temperatures, the ants were more likely to be attached to the top of a blade of grass. When the temperature rose, the ants let go of the grass and crawled back down. 

“We found a clear correlation between temperature and ant behavior,” said Fredensborg. “We joked about having found the ants’ zombie switch,’”

Step 2: The Grazer

Once the liver fluke infects the ant, several hundred parasites invade the insect’s body. Only one of these parasites will make it to the brain where it then influences the ant’s behavior. The remaining liver flukes conceal themselves in the ant’s abdomen inside of its intestine. There, the liver flukes find their way through the bile ducts and into the liver, where they suck blood and develop into adult flukes that begin to lay eggs. 

[Related: ‘Brainwashing’ parasites inherit a strange genetic gap.]

“Here, there can be hundreds of liver flukes waiting for the ant to get them into their next host. They are wrapped in a capsule which protects them from the consequent host’s stomach acid, while the liver fluke that took control of the ant, dies. You could say that it sacrifices itself for the others,” said Fredensborg. 

The eggs are then excreted in the host animal’s feces.

Step 3: The Snail

Once the fluke eggs have been excreted, they remain on the ground waiting for a snail to crawl by and eat the feces. When the eggs are inside the snail, the eggs develop into larval flukes that reproduce asexually and can multiply into several thousand. 

“Historically, parasites have never really been focused on that much, despite there being scientific sources which say that parasitism is the most widespread life form,” said Fredensborg. “This is in part due to the fact that parasites are quite difficult to study.”

Step 4: The Slime Ball

To exit the snail and move on to their next host, the larval flukes make the snail cough. The flukes are then expelled from the snail in a lump of mucus. The ants are attracted to this moist ball, eat it, and unwittingly ingest more fluke larvae and the cycle begins all over again.

The tiny liver fluke is widespread in Denmark and other temperate regions around the world and researchers are still trying to understand more of the mechanisms behind how they take over a host’s brain. 

“We now know that temperature determines when the parasite will take over an ant’s brain. But we still need to figure out which cocktail of chemical substances the parasite uses to turn ants into zombies,” Fredensborg said. “Nevertheless, the hidden world of parasites forms a significant part of biodiversity, and by changing the host’s behavior, they can help determine who eats what in nature. That’s why they’re important for us to understand.”

The post This parasite deploys mucus slime balls to make ‘zombie ants’ appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Dinosaur Mysteries digs into the secretive side of the “terrible lizards” and all the questions that keep paleontologists up at night.

WE STILL LIVE in an age of dinosaurs. Pigeons, penguins, and partridges are all members of the only lineage to survive the asteroid-driven disaster of 66 million years ago. The realization that at least some dinosaurs still flock among us has given a greater depth to paleontology than the field’s founders could have imagined. What we learn about living dinosaurs can help us better understand the species we can touch only as fossils. But even though we can trace the origins of birds from their Velociraptor-like ancestors, there’s one critical part of the story that we don’t fully understand. How on earth did dinosaurs such as Microraptor evolve the ability to fly?

The definition of flight can be a little tricky—it’s not simply about moving through the air. After all, there are marsupials, frogs, snakes, and other animals capable of gliding for impressive distances. Flight is something more specific, requiring the evolution of not only wings but a wing stroke. Watch a raven flap by and you’re watching a dinosaur demonstrate the exact mechanics of keeping itself aloft with one wingbeat after another. The question paleontologists face is how dinosaurs went from terrestrial reptiles scurrying over the ground to feathery, fluttering wonders.

Archaeopteryx lithographica, the earliest recognized bird at about 150 million years old, is of limited help. When the fossil was uncovered in the late 19^th century, the splash of feathers found around the Jurassic dinosaur’s bones were quickly taken as an indication that its kind soared over the forests of prehistoric Bavaria. Over time, however, the genus Archaeopteryx started to look more awkward than aerodynamic. The avian ancestor had asymmetrical flight feathers with a shallow leading edge, a critical adaptation for powered flight—but its skeletal anatomy didn’t look capable of flight the way we see it in living birds. The contradiction led to a longstanding debate over whether Archaeopteryx actively flapped into the air, primarily glided, or perhaps even used a different flight stroke from its modern relatives. Whatever the answer, the solution to the mystery can’t be found in its bones alone. And as further feathery dinosaur species have been uncovered, the caper has only grown more complex.

Since the mid-1990s, paleontologists have uncovered dozens of feathery dinosaurs. Many of them are close relatives of Mesozoic birds or otherwise have adaptations related to flight, including the genus Microraptor, which had long feathers on its legs as well as its long arms. In fact, paleontologists think powered flight evolved at least three times among dinosaurs: once among birds and twice among their close dinosaur relatives such as Rahonavis ostromi. That’s not counting the number of feathery species whose anatomy made them more aerodynamically adept than others, but that still weren’t quite capable of keeping themselves aloft by flapping. Instead of a neat, orderly pattern of flight-related traits among birds and their ancestors, the emerging picture shows a tangled mess.

That changes the entire backstory of flying beasts. Up until recently, feathery dinosaurs were cast as representatives of stages in the evolution of flight. Now paleontologists have to figure out how they evolved flight independently multiple times among both birds and feathery nonavian dinosaurs. The path the ancestors of Archaeopteryx took might not be the same as the path taken by predecessors of Microraptor or Rahonavis.

Experts have tossed plenty of ideas about the origins of flight against the proverbial wall. These are broadly divided into “ground-up” and “trees-down” hypotheses, with most paleontologists favoring explanations that focus on how a ground-dwelling, Velociraptor-esque avian ancestor could evolve the ability to fly. Maybe feathery bird ancestors chased insects, leaping after them and trying to trap them with their arm feathers, which would favor dinosaurs able to stay in the air longer. Or maybe flight started with gliding and dinosaurs climbing trees to swoop through the forest, which would give an advantage to those that could flap their arms to soar just a little farther. The behavior of modern birds has provided some clues too, like the way chukar partridges flap their wings to better stabilize themselves while running up inclines.

Every hypothesis about how airborne dinosaurs evolved focuses on the behavior of animals we can’t observe in life. Experts have to draw out what clues they can from feathers, bones, the universal mechanics of flight, and how birds today manage to get into the air and stay there. While it’s possible to conduct wind-tunnel experiments based on skeletal mechanics and other inferred details to calculate how an Archaeopteryx would have fared while flying, there will always be a difference between what a prehistoric species could have done and how it actually behaved back in the Mesozoic. Evolution is not a tidy progression towards a particular outcome, but a story of constant change full of repeats, dead ends, and diversity.

There can’t be a single solution to the puzzle of how dinosaurs evolved to fly because scientists have more than one case to consider. Whether it consists of birds or nonavian dinosaurs, the history of each lineage has to be studied on its own terms. More than that, what seemed like a basic question about the first flying dinosaurs only creates more questions about what led different dinosaurs in different places and times, many miles and millions of years apart, to evolve similar abilities. Pterosaurs—fuzzy, flying reptiles that were related to dinosaurs—reigned over the skies more than 50 million years before Archaeopteryx, so it’s not as if Earth weren’t already full of fliers before dinosaurs caught on. The stories we now deduce of how flying dinosaurs gained their astonishing ability are far more complex than the ones we had even 20 years ago. When you see a house finch alight on a feeder or a turkey vulture slowly turn over a thermal, you’re catching a glimpse of one of the greatest secrets still cached in the fossil record.

Read more PopSci+ stories.

The post We still don’t know how animals evolved to fly appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Space tourism is already becoming so commonplace that Virgin Galactic’s second private astronaut flight on September 8 went off without much fanfare. And although a brief press announcement only announced the names of its three-man passenger list after the trip, the recap didn’t mention Galactic 03’s historic “first” cargo—fossilized bones from two of humanity’s closest ancestors.

According to Tim Nash’s Virgin Galactic biography, the “entrepreneur, adventurer, conservationist and member of the Hubbard Council of The National Geographic Society,” carried with him the clavicle of a nearly 2-million-year-old Australopithecus sediba, as well as a roughly 250,000-year-old thumb bone from Homo naledi. Both hominid remains were previously discovered within the Cradle of Humankind UNESCO World Heritage Site outside Johannesburg, South Africa—sebedi is considered one of the potential candidates that presaged humanity’s Homo genus.

The initiative’s organizers, including researchers at the University of Witwatersrand, Johnnesburg, intended the gesture to represent “humankind’s appreciation of the contribution of all of humanity’s ancestors and our ancient relatives,” said Lee Berger, a National Geographic Explorer in Residence, Carnegie Fellow and Director of the Centre for the Exploration of the Deep Human Journey. “Without their invention of technologies such as fire and tools, and their contribution to the evolution of the contemporary human mind, such extraordinary endeavors as spaceflight would not have happened.”

[Related: Virgin Galactic’s second commercial flight sent three tourists to space’s edge.]

Berger’s son, Matthew, discovered the sebida clavicle in 2008 when he was 9 years old during an expedition alongside his father within the Cradle of Humankind heritage site. Matthew Berger traveled last week to Virgin Galactic’s Spaceport America in New Mexico to hand deliver the bones to Nash, a conservationist involved with human origins research. Caretakers stored both bone fragments within a carbon fiber container prior to their suborbital excursion.

“These fossils represent individuals who lived and died hundreds of thousands of years ago, yet were individuals who likely gazed up at the stars in wonder, much as we do,” Berger said in a September 8 statement via the University of Witwatersrand.

“The magnitude of being among the first civilians going into space, and carrying these precious fossils, has taken a while to sink in, during all of the preparations for the flight,” Nash said via the University of Witwatersrand statement, “But I am humbled and honored to represent South Africa and all of humankind, as I carry these precious representations of our collective ancestors, on this first journey of our ancient relatives into space.”

Nash, alongside Las Vegas real estate entrepreneur Ken Baxter and British engineer and racecar company founder Adrian Reynald, purchased their Virgin Galactic seats as far back as 2004 from company founder and multibillionaire Richard Branson. Tickets for the few minutes’ worth of suborbital weightlessness alongside views of the Earth’s curvature reportedly cost between $250,000 and $450,000.

“We sincerely hope it brings further awareness of the importance of our country and the African continent to understanding the journey of humankind that has led to this historic moment where commercial spaceflight is possible,” says Cradle of Humankind World Heritage Site CEO Matthew Sathekge said via University of Witwatersrand’s announcement.

The post Virgin Galactic’s latest cargo? Ancient human bones appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

The lives of corvid, or the family of birds that include crows, are shockingly complex. They hold ‘monogamish’ relationships, build tools, hold funerals, solve puzzles, and may even have their own form of democracy. Now, researchers have provided the latest peek into corvid life that adds a new element to their intricate and complicated lives—social climbing. Yes, even birds will ditch their old friends if something better comes along, according to a new study published September 11 in Nature.

For their recent experiment, scientists at universities of Exeter and Bristol utilized the Cornish Jackdaw Project to split a group of jackdaws, members of the crow family found in Europe, western Asia and North Africa, into two randomly sorted groups—A and B. They then tagged the birds with transponder chips, worn like little anklets, to tell who was who. 

[Related: Crows and ravens flexed smarts and strength for world dominance.]

As many animal studies go, there’s got to be some kind of snack involved. This time, the scientists set up a feeding source with two locked doors—one filled with grain, a merely okay morsel for a hungry crow, and the other with a much yummier rendition of some grain and some dried mealworms. If a bird visited alone, only the low-quality snack door opened. With a buddy from the same-tagged group, say two As or two Bs, either both doors unlocked or just the high-quality snack door. But when a jackdaw visited the snack dispenser with a member of the opposite-tagged clique, there were no goodies for anybody.

The choice for the birds then was either loyalty or tasty treats. 

“The jackdaws turned out to be very strategic, quickly learning to hang out with members of their own group and ditching old ‘friends’ from the other group so they could get the best rewards,” author Alex Thornton, a professor of cognitive evolution at Exeter, said in a release.

The same couldn’t always be said for familial relationships. Despite the potentially disappointing outcome, jackdaws would still stick with their offspring, siblings, or mating partners. Some long-term relationships, it turns out, were more important to the feathery creatures than a chance at a delicious morsel. 

“The fundamental idea is that if you need to keep track of interactions you have had with other individuals, remember the outcomes of those interactions and use those to adjust your [behavior],” Thornton told the Guardian. “What we were able to do here was test the idea: can individuals keep track of the outcomes of past interactions and update their relationships. It turns out they can.”

For the authors, these results can give us clues to the evolution of intelligence, memory, and social status in the animal kingdom—and even in the human world. 

“Our findings also help us to understand how societies emerge from individual decisions,” author and Exeter PhD student Josh Arbon said in a release. “The balance between strategically playing the field for short-term benefits and investing in valuable long-term partners ultimately shapes the structure of animal societies, including our own.”

The post These crow relatives put food over friendship appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Australia is currently home to the only living species of their endangered and iconic koalas, but there once were multiple species spread across the continent. Now, the discovery of another marsupial ancient relative is helping scientists fill in a 30 million year evolutionary gap. The findings are detailed in a study published September 4 in the journal Scientific Reports.

[Related: With bulging eyes and a killer smile, this sabertooth was an absolute nightmare.]

In 2014 and 2020, study co-author Arthur Crichton, a PhD student at Flinders University in Adelaide, Australia, found fossil teeth of the new species, named Lumakoala blackae, at the Pwerte Marnte Marnte fossil site in central Australia. The teeth are believed to be roughly 25 million years old. 

“Our computer analysis of its evolutionary relationships indicates that Lumakoala is a member of the koala family (Phascolarctidae) or a close relative, but it also resembles several much older fossil marsupials called Thylacotinga and Chulpasia from the 55 million-year-old Tingamarra site in northeastern Australia,” Crichton said in a statement. 

According to Chrichton, it was previously suggested that the enigmatic Thylacotinga and Chulpasia may have been more closely related to marsupials from South America.  This new discovery of Lumakoala suggests that they could actually be early relatives of herbivorous Australian marsupials including possums, kangaroos, koalas, and wombats.

“This group (Diprotodontia) is extremely diverse today, but nothing is known about the first half of their evolution due to a long gap in the fossil record,” said Crichton. 

If the study’s hypothesis is correct, the diprotodontian fossil record would be aged back by another 30 million years. Additionally, wombats, kangaroos, koalas and possums split off from other marsupials between roughly 65 million and 50 million years ago.

“These Tingamarran marsupials are less mysterious than we thought, and now appear to be ancient relatives of younger, more familiar groups like koalas,” Robin Beck, study co-author and evolutionary biologist at the University of Salford in England, said in a statement. “It shows how finding new fossils like Lumakoala, even if only a few teeth, can revolutionize our understanding of the history of life on Earth.” 

The study also raises some new questions, including whether these relatives of herbivorous marsupials in Australia once lived in Antarctica and South America. According to Beck, some South American fossils look very similar to the marsupials found at the Tingamarra site. 

[Related: This 500-pound Australian marsupial had feet made for walkin.’]

It also reports that two other types of koala called Madakoala and Nimiokoala lived alongside Lumakoala and filled in different ecological niches in the forests that flourished in central Australia about 25 million years ago. The late Oligocene (about 23–25 million years ago) was  “kind of the koala heyday,” according to the Flinders University paleontologist and study co-author Gavin Prideaux.

“Until now, there’s been no record of koalas ever being in the Northern Territory; now there are three different species from a single fossil site,” Prideaux said in a statement. “While we have only one koala species today, we now know there were at least seven from the late Oligocene – along with giant koala-like marsupials called ilariids.”  

At this time, iliariids were the largest marsupials living in Australia, weighing in at up to 440 pounds. Iliariids lived alongside a strong-toothed wombat relative named Mukupirna fortidentata and a strange possum named Chunia pledgei.

The post Scientists discover a cat-sized ancient koala in Australia appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

A newly discovered early bird-like dinosaur species is filling in some of the holes in the dinosaur-to-bird evolutionary story. The new species, named Fujianvenator prodigiosus, has a strange mixture of physical features shared with other extinct prehistoric animals from therapod dinosaurs to birdlike troodontids. This unique beast was described in a study published September 6 in the journal Nature. 

[Related: Birds are dinosaurs, and this fossil detective has rooms full of bones to prove it.]

Birds diverged from theropod dinosaurs by the Late Jurassic (about 161 million to 146 million years ago), but the general understanding of the earliest evolution of the clade comprising most modern birds, known as Avialae, has been slowed due to a limited diversity of fossils from the Jurassic. No known avialans have been reported from the Yanliao Biota paleontological site in northeast China, which dates back to the Middle–Late Jurassic about 166–159 million years ago or in the the slightly younger German Solnhofen Limestones, which preserves an early genus of avian dinosaurs called Archaeopteryx. This leaves a gap of about 30 million years before the oldest known record of Cretaceous birds. 

Jurassic era avialans are a critical key to deciphering the evolutionary origin of the avialan body,  and this elusive group is key to piecing together the origin of birds. That’s where the fossilized remains of the 148 to 150-million-year-old avialan theropod Fujianvenator prodigiosus comes in. It has some physical traits shared with extinct avialans, the small and bird-like troodontids that lived during the Cretaceous Period, and theropod dinosaurs called dromaeosaurids that were similar to raptors and also lived during the Cretaceous. According to the team on this study, this mixture shows the impact of evolutionary mosaicism–different rates of evolutionary change in body structures and function– in early bird evolution.

A joint research team from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences in Beijing and the Fujian Institute of Geological Survey (FIGS) described and the avialan theropod that was found in Zhenghe County, Fujian Province in southeastern China.

“Our comparative analyses show that marked changes in body plan occurred along the early avialan line, which is largely driven by the forelimb, eventually giving rise to the typical bird limb proportion,” study co-author and paleontologist Min Wang from IVPP said in a statement. “However, Fujianvenator is an odd species that diverged from this main trajectory and evolved bizarre hindlimb architecture.”

[Related: Birds are so specialized to their homes, it shows in their bones.]

During the Late Jurassic-Early Cretaceious, southeastern China saw some intense tectonic activities that resulted in a lot of movement of magma below the Earth’s surface. This created some deep basins with the Earth including where Fujianvenator was found.

Fujianvenator prodigiosus was likely about the size of a present day pheasant and had a tibia (lower leg) that is twice as long as its femur (thigh), which is a previously unknown condition for non-avian dinosaurs. This suggests that the bird was either a high-speed runner or a long-legged wader and it likely lived in swamps. This new finding contrasts with other early avialans, which are believed to have been more tree and sky-dwelling.  

Fujianvenator’s remains were found among a diverse collection of vertebrate fossils dominated by aquatic and semiaquatic species, including turtles and ray-finned fish. The authors named this fossil collection the Zhenghe Fauna. This diverse array of inhabitants and environment suggests that it was the site of emerging Jurassic vertebrate fauna around the time when Fujianvenator was there. This find and timing fills in an important gap in our understanding of ecosystems in Late Jurassic Northeast Asia and the team plans to continue to explore Zhenghe and other nearby areas.

The post Leggy dinosaur species could be the latest feathery clue to bird evolution appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

The mechanics of how athletes like New York Giants quarterback Daniel Jones’ are able to throw a perfect spiral or how wide receiver Darius Slayton may extend his elbow to reach for the catch may have ancient roots. These skills may have first evolved as a natural braking system for our primate ancestors who simply needed a safe way to get out of trees. 

[Related: Chilly climates may have forged stronger social bonds in some primates.]

In a study published September 6 in the journal Royal Society Open Science, a team from Dartmouth found that apes and early human ancestors likely evolved free-moving shoulders and flexible elbows as a way to slow their descent from trees while gravity pulled down on their bodies. Versatile appendages that could throw spears for hunting and defense, climb trees, and gather food were essential for survival—especially as early humans left forests for grassy savannas.

“There’s a lot we still don’t understand about the origin of apes,” study co-author and Dartmouth University paleoanthropologist Jeremy DeSilva tells PopSci. “There was a common ancestor to monkeys and apes that lived about 25 to 30 million years ago and then there was a divergence and now we have these two different kinds of primates. But why the convergence?”

One of the possibilities is different ecological, physical, and behavioral niches related to primate size. The first apes evolved about 20 million years ago and are bigger than other early primates. Getting out of a tree presented a new set of challenges for these bigger primates, since typically the bigger the animal, the greater the risk of injury from a fall. Natural selection would have eventually favored anatomies that allowed early apes to safely descend from the trees. 

In the study, the team used sports-analysis and statistical software to compare videos and still-frames of chimpanzees and small monkeys called mangabeys climbing in the wild. They saw that mangabeys and chimps climbed up the trees similarly, with their shoulders and elbows mostly bent close to the body. 

However, when it was time to climb down, chimpanzees extended their arms above their heads to hold onto branches, similar to how a person going down a ladder, as their weight pulls them down. This process called “downcliming” appears to be significant in the evolution of apes and early humans.

“Our study broaches the idea of downclimbing as an undervalued, yet incredibly important factor in the diverging anatomical differences between monkeys and apes that would eventually manifest in humans,” study co-author and Dartmouth graduate student Luke Fannin said in a statement. 

[Related: How to hike downhill safely and comfortably.]

These flexible shoulders and elbows passed on from ancestral apes would have allowed early humans such as Australopithecus to climb into trees at night for safety and then come down in the daylight unscathed. Once Homo erectus could use fire to protect itself at night, the human form took on the broader shoulders capable of a 90-degree twist that worked with free moving shoulders and elbows to make human ancestors excellent shots with a spear for hunting.

“The idea that downclimbing could be such a strong evolutionary force as to change the nature of how our bones and range of motion evolved was very fascinating,” study co-author Mary Joy tells PopSci. “Not a lot of the field really thinks about downclimbing as its own motion with implications on natural selection.” Joy brought her experience as a trail runner and athlete to the study to bring in a different perspective to looking at biological sciences and evolution. 

The team also used skeletal collections from Harvard University to study the anatomical structure of chimpanzee arm alongside remains in The Ohio State University’s collections to study  mangabey arms. Chimpanzees are more like humans than mangabeys and have a shallow ball-and-socket shoulder that allows for a greater range of movement. Chimps can also fully extend their arms due to a reduced length of bone located just behind the elbow called the olecranon process.

Mangabeys and other monkeys are built more like four-legged animals like cats and dogs, with deep pear-shaped shoulder sockets and elbows that have a protruding olecranon process, which makes the joint look like the letter L. These joints are more stable, but they have a more limited range of movement and flexibility.

The analysis showed that the angle of a chimp’s shoulders was 14 degrees greater during their descent than when scaling a tree. The arm also extended outward at the elbow 34 degrees more when climbing down a tree than climbing up. The angles at which the mangabeys positioned their shoulders and elbows were only about four degrees or less when ascending a tree versus downclimbing.

“If cats could talk, they would tell you that climbing down is trickier than climbing up and many human rock climbers would agree. But the question is why is it so hard,” study co-author and 

anthropologist and evolutionary biologist Nathaniel Dominy said in a statement. “The reason is that you’re not only resisting the pull of gravity, but you also have to decelerate. 

[Related: Lucy, our ancient human ancestor, was super buff.]

According to DeSilva, the question of “how did we not see this before” in regards to downclimbing was one of the most surprising parts of the study. The fresh eyes of both Joy and graduate student Fannin were crucial in uncovering one of evolution’s hidden wonders. 

“Our evolutionary ancestry is this wonderful example of how evolution just sort of tinkers and tweaks pre-existing forms,” says DeSilva. “Our bodies are bodies that have been just tweaked and modified through natural selection over millions of years, to give us the bodies we have now, but there are all these wonderful echoes of our ancestry in our bodies today.”

The post Our tree-climbing ancestors evolved our abilities to throw far and reach high appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Finding lasting love can be really difficult. We’ve all heard the annoying adages like “there’s plenty of fish in the sea,” not to mention the old “opposites attract” chestnut. However, many people tend to end up being quite similar to their partners, according to the results of a study published August 31 in the journal Nature Human Behaviour.

[Related: Social relationships are important to the health of aging adults.]

The new research included numerous studies dating back more than a century. The team examined 130 traits from millions of couples, ranging from political leanings to age of first sexual intercourse to substance use habits. For between 82 and 89 percent of traits analyzed, partners were more likely than not to be similar. In only one part of the analysis, and for only three percent of studied traits, did individuals tend to be coupled with someone who is demonstrates an opposing trait.

In addition to shedding light on some of those unseen forces that may shape human relationships, this research could have some important implications for the field of genetic research.

“A lot of models in genetics assume that human mating is random. This study shows this assumption is probably wrong,” study co-author and University of Colorado at Boulder psychologist and neuroscientists Matt Keller, said in a statement. Keller noted that a tendency called assortative mating—when individuals with similar traits couple up—can actually skew findings of genetic studies.

To find their results, the team conducted both a meta-analysis of previous research and their own original data analysis. In the meta-analysis, they examined 22 traits across 199 studies of millions of male-female co-parents, engaged pairs, married pairs, or cohabitating pairs. The oldest study in this analysis was conducted back in 1903. They also used a dataset called the UK Biobank to analyze 133 traits across almost 80,000 opposite-sex pairs in the United Kingdom.

Same sex couples were not included in the research because the patterns in these types of partnerships may differ significantly. The authors are now pursuing those relationships in a separate study.

[Related: These fuzzy burrowers don’t need oxytocin to fall in love.]

Traits such as political and religious attitudes, level of education, and certain measures of IQ showed particularly high correlations. For example, on a scale of 0 meaning no correlation and 1 meaning couples always share a trait, the correlation for political values was .58. Traits surrounding substance use also showed high correlations, with heavy drinkers, smokers, and teetotalers tending to strongly pair with those who share similar traits. Traits like height and weight, medical conditions, and personality showed much lower but still positive correlations. For example, the correlation for neuroticism was .11.

Interestingly, some traits, such as extroversion, did not have much of a correlation.

“People have all these theories that extroverts like introverts or extroverts like other extroverts, but the fact of the matter is that it’s about like flipping a coin: Extroverts are similarly likely to end up with extroverts as with introverts,” study co-author and University of Colorado at Boulder PhD student Tanya Horwitz said in a statement. 

The meta-analysis found “no compelling evidence” that on any trait that opposites attract. However, in the sample from the UK Biobank, the team did find a handful of traits in which there seemed to be a small negative correlation, including hearing difficulty, tendency to worry, and whether someone is more of a morning person or night person (called chronotype). Additional studies will be needed to understand those findings, according to the team. 

Some of the less-frequently studied traits including number of sexual partners and whether an individual had been breastfed as a child also showed some correlation.

“These findings suggest that even in situations where we feel like we have a choice about our relationships, there may be mechanisms happening behind the scenes of which we aren’t fully aware,” said Horwitz.

According to the authors, couples could share traits for a variety of reasons, including growing up in a similar area. Some people are simply attracted to those who are similar based on the traits studied, and some couples grow more similar the longer they stay in the relationship. 

These pairings could lead to some downstream genetic consequences. For example, if short people are more likely to produce offspring with a similar height and vice versa, there could be more people at the height extremes in the next generation. This same thing apply for medical, psychiatric, and other traits according to Horowitz. 

Some of the social implications include those with similar educational backgrounds continuing to pair up, which could widen socioeconomic divides.

The team cautions that the correlations found were fairly modest and should not be overstated or misused to promote an agenda. Assortative mating has historically been dangerously co-opted by the eugenics movement, which gained traction during the early 20th century.

The post Couples often share more common traits than we might think appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

A newly discovered three-eyed relative is disappointingly unrelated to the eerie three-eyed ravens of Game of Thrones. But this Cambrian-era beast is a relative of today’s insects and boasts some fearsome limbs. The unique fossilized animal was described in a study published August 28 in the journal Current Biology. 

[Related: This ancient ‘mothership’ used probing ‘fingers’ to scrape the ocean floor for prey.]

The animal, scientific name Kylinxia, was found in 520 million year old rocks in a fossil deposit called the Cambrian Chengjiang biota near the town of Chengjiang in southern China. More than 250 species of exceptionally well-preserved fossil organisms have already been described from this location, which gives scientists a glimpse of what was going on in the world’s oceans as they developed. 

Importantly, Kylinxia is filling in some evolutionary gaps in our understanding of the evolution of animals known as arthropods. This phylum of animals includes insects, crabs, shrimp, scorpions, spiders, and centipedes among others. Arthropods have an exoskeleton made of a tough material called chitin that is mineralized with calcium carbonate, as well as a body divided into segments and paired jointed appendages. They are considered some of Earth’s most successful species and over 85 percent of all known animal species are classified as arthropods.

Kylinxia was about the size of a large shrimp, had a pair of limbs that it likely used to catch prey, and a signature trio of eyes on its head. 

“Most of our theories on how the head of arthropods evolved were based on these early-branching species having fewer segments than living species,” Greg Edgecombe, a co-author of the study and arthropod evolution expert at London’s Natural History Museum, said in a statement. “Discovering two previously undetected pairs of legs in Kylinxia suggests that living arthropods inherited a six-segmented head from an ancestor at least 518 million years ago.”

After its initial discovery, Kylinxia was imaged using a CT scanner. The scan revealed that more soft parts of the animals’ anatomy were also buried in the rock. While there are plenty of species of arthropods preserved in the fossil record, most fossils only preserve the hard skeletons. 

[Related: Newly discovered fossils give a whole new meaning to jumbo shrimp.]

“The preservation of the fossil animal is amazing,” study co-author and University of Leicester PhD student Robert O’Flynn said in a statement. “After CT-scanning we can digitally turn it around and literally stare into the face of something that was alive over 500 million years ago. As we spun the animal around, we could see that its head possesses six segments, just as in many living arthropods.”

This new specimen was nearly complete, which enabled the team to identify the six segments that made up its body: the head, a second segment with its grasping limbs, and the other four segments which have a pair of jointed limbs.

“Robert and I were examining the micro-CT data as part of his doctoral thesis in the hope of refining and correcting previous interpretation of head structures in this genus, Kylinxia,” study co-author and Yunnan Key Laboratory for Palaeobiology paleobiologist Yu Liu said in a statement. “Amazingly, we found that its head is composed of six segments, as in, e.g., insects.”

The post A three-eyed organism roamed the seas half a billion years ago appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

If the mighty Ice Age sabertooth tiger called out in a forest, and no one was around to hear it, did it even make a sound? A team of researchers from North Carolina State University set out to answer that philosophical question by investigating if sabertooth cats had a throaty purr or a mighty roar. They found that tiny bones in the tiger’s throat might present a more  nuanced answer. Their findings were published August 21 in the Journal of Morphology. 

[Related: Life in Los Angeles was brutal for saber-toothed cats.]

Present-day cats belong to two subfamilies who make different vocalizations. The pantherine or “big cats” include lions, jaguars, and tigers who typically roar. Felinae or “little cats” includes domestic cats, ocelots, lynxes, and cougars who purr. For cats that roar, the structures that surround their larynx (or voice box) generally aren’t stiff enough to make the purring sound.

“Evolutionarily speaking, sabertooths split off the cat family tree before these other modern groups did,” study co-author and NC state biologist Adam Hartstone-Rose said in a statement. “This means that lions are more closely related to housecats than either are to sabertooths.

Vocalization is driven by the larynx and soft tissue in the throat, not bones. However anatomists noticed that the bones responsible for anchoring those tissues in place called the hyoid bones differed in both number and size between purring and roaring cats. 

“While humans have only one hyoid bone, purring cats have nine bones linked together in a chain and roaring cats have seven,” co-author and NC State Ph.D. student Ashley Deutsch said in a statement. “The missing bones are located toward the top of the hyoid structure near where it connects to the skull.”

According to the team, sabertooth tigers only have seven bones in their hyoid structure, but the shape and size look eerily similar to some purring cats’ bones. If vocalization is related to the number of bones in the hyoid structure, then the sabertooths roared. However, if it is about shape, they may have purred. 

“You can argue that since the sabertooths only have seven bones they roared, but that’s not the whole story,” said Hartstone-Rose. “The anatomy is weird. They’re missing extra bones that purring cats have, but the shape and size of the hyoid bones are distinct. Some of them are shaped more like those of purring cats, but much bigger. 

[Related: Orangutans can make two sounds at the same time.]

According to the team, if the missing bones (the epihyoid bones) were the key to different vocalizations, then the bones that are most closely connected to them should appear different between purrers and roarers. Those bones actually looked very similar in shape in the purring variety of cats.

The team saw more shape variation in the bones that are closer to the vocal apparatus, like the the thyrohyoid and basihyoid bones. Having these key hyoid bones shaped like those belonging to purring cats may indicate that they purred like a kitten instead of roaring like a lion, but it is still a bit of a prehistoric mystery. 

“It is perhaps most likely that the size of the hyoids plays a role in the pitch of vocalization,” said Deutsch. “Although Smilodon wasn’t quite as big as the largest modern cats, its hyoid bones are substantially larger than those of any of their living relatives, so potentially they had even deeper vocalizations than the largest tigers and lions.”

The post Mighty sabertooth tigers may have purred like kittens appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Ocean temperatures are surging worldwide largely due to human-made climate change and natural El Niño driven patterns. The rise is wreaking havoc on the planet’s coral reefs, however a study published August 22 in the journal Nature Communications found that the coral reefs in one part of the Pacific Ocean can likely adjust to some rises in temperature. This adaptation has the potential to reduce future coral bleaching as the climate continues to change. 

[Related: The heroic effort to save Florida’s coral reef from a historic heatwave.]

“We know that coral reefs can increase their overall thermal tolerance over time by acclimatization, genetic adaptation or shifts in community structure, however we know very little about the rates at which this is occurring,” study co-author and Newcastle University coral reef ecologist James Guest said in a statement. 

The rate at which coral reefs can naturally increase thermal tolerance, and if it can match pace with warming, is largely unknown. So the team started their work by investigating historic mass bleaching events that have occurred since the late 1980s in a remote Pacific coral reef system. 

They focused on a reef system Palau, an island country in the western Pacific Ocean, and found that increases in the heat tolerance of reefs is possible. Reefs here are known as a bevy of biodiversity and provide a barrier from storms. The team used decades of data to create models of multiple future coral bleaching trajectories for Palauan reefs. Each model had a different simulated rate of thermal tolerance enhancement. The team found that if coral heat tolerance continues to rise throughout this century at the most-likely high rate, significant reductions in bleaching impacts are actually possible.

The results affirm the general scientific consensus that the severity of future coral bleaching will depend on reducing carbon emissions. For example, if the commitments of the 2015 Paris Agreement to limit future warming to 2.7 degrees Fahrenheit, high-frequency bleaching can be fully mitigated at some reefs under low-to-middle emissions scenarios. These bleaching impacts are unavoidable under high emissions scenarios where society continues to rely on fossil fuels.  

Coral communities will need to persist under constant climate change and will likely need to endure progressively more intense and frequent marine heatwaves. The team believes that the observed increase in tolerance suggests that some natural mechanisms, such as genetic adaptation or acclimatization of corals or their symbiotic microalgae, may contribute to the increased heat tolerance. 

[Related: To save coral reefs, color the larvae.]

While this is some positive news for Pacific coral, the resilience comes at a high cost. Adaptations like these can reduce reef diversity and growth, and without cutting future greenhouse gas, the Pacific’s reefs won’t be able to provide the habitat resources and protection from waves that residents depend on.

“Our study indicates the presence of an ecological resilience to climate change, yet also highlights the need to fulfill Paris Agreement commitments to effectively preserve coral reefs,” study co-author and Newcastle University coral reef ecologist Liam Lachs said in a statement. “We quantified a natural increase in coral thermal tolerance over decadal time scales which can be directly compared to the rate of ocean warming. While our work offers a glimmer of hope, it also emphasizes the need for continued action on reducing carbon emissions to mitigate climate change and secure a future for these vital ecosystems.”

The post Some Pacific coral reefs can keep pace with a warming ocean appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

As if the thought of a flying pterosaur with a 6.5 foot wingspan dominating Earth’s skies wasn’t terrifying enough, paleontologists have now found an even older pterosaur ancestor with some prominent claws. The latest find might not have its signature wings just yet, but boasts a beak and sharp claws. The roughly 230-million-year-old lagerpetid unearthed in Brazil is described in a study published on August 16 in the journal Nature. 

[Related: This pterosaur ancestor was a tiny, flightless dog-like dinosaur.]

Pterosaurs and dinosaurs both evolved about 235 million years ago in the Middle to early Late Triassic (about 235 million years ago). Dinosaurs went on to dominate the land during the Jurassic Period (201.3 to 145 million years ago) and the winged pterosaurs took over the skies during the Cretaceous Period (145.5 to 66 million years ago). 

While some new discoveries including finding Scleromochlus taylori in 2022 have filled in evolutionary gaps and helped paleontologists learn more about these winged critters, the fossil record from this time still remains relatively scarce. Lagerpetids like this newly discovered clawed specimen are the closest known non-flying group to pterosaurs.

In this new study, a team describes the well-preserved partial skeleton of a lagerpetid that they named Venetoraptor gassenae. The team estimates that V. gassenae would have been about 27.5 inches tall and about 39 inches long. The bone features indicate that this particular animal was an adult when it died. It also had feather-like fur on its body and a long tail.

“Because cranial remains are so scarce for lagerpetids, this is the first reliable look into the face of these enigmatic reptiles,” study co-author and paleontologist Brazil’s Universidade Federal de Santa Maria Rodrigo Müller told Gizmodo. “The unusual skeleton of Venetoraptor gassenae reveals a completely new morphotype of pterosaur precursors.”

V. gassenae’s more notable features include a raptorial-like beak and large hands with claws that resemble a curved sword. The team believes that the Veneraprot was highly specialized to its ecological niche. Its claws may have helped it climb or handle its prey, and V. gassenae also has an elongated fourth digit on its fossilized right hand. According to Müller, this has not been seen in other lagerpetids, which hints that V. gassenae is especially closely related to pterosaurs.

[Related: Dinosaur Cove reveals a petite pterosaur species.]

“This elongated fourth digit supports the wings in pterosaurs, so V. gassenae may represent the transition of lagerpetids towards pterosaurs,” Müller told LiveScience.

It’s unclear what role that its long beak played. Beaks obviously can help animals eat, but they can also have many functions beyond feeding, including sexual displays, vocalization, and regulating body temperature. 

By studying this fossil alongside the remains from 18 dinosaur and 10 pterosaur species from this time period, the team believes that lagerpetids were as morphologically diverse as Triassic pterosaurs and even more morphologically diverse than Triassic dinosaurs. It shows that this level of biodiversity was already starting to flourish in the precursors of both dinosaurs and pterosaurs and was not something that only emerged after both groups originated. 

The post This flightless pterosaur ancestor had enviable claws and a raptor-like beak appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

On August 15, a schooner set sail from Plymouth on the southern coast of England to recreate the South America-bound voyage taken by biologist Charles Darwin almost 200 years ago. The Dutch tall ship Oosterschelde began its two year mission as a floating laboratory, where about 200 conservationists and naturalists will gather along the way to take part in a project called Darwin200.

[Related: Let’s talk about Charles Darwin’s sexy theory of selection.]

In 1831, the HMS Beagle set sail from Plymouth with a then 22-year-old Charles Darwin aboard. The five-year journey was primarily intended to explore the coastline of South America and chart its harbors, with Darwin tasked to make scientific observations. He explored Brazil, Argentina, Chile, and the remote areas of the Galápagos Islands. Over the course of the journey that Darwin said was “by far the most important event in my life,” he brought back specimens of more than 1,500 different species and this work influenced his book On the Origin of Species and the theory of evolution.

The Oosterschelde is expected to make the 40,000 nautical mile expedition and hopes to anchor in 32 ports, including all the major ports visited by the Beagle. It expected to make its first landing in the Canary Islands and then cross the Atlantic Ocean to Brazil. It will then follow along South America’s eastern coast, up the west coast, and out to the Galápagos. It will then sail to Australia and New Zealand, before stopping in South Africa, and returning to England.

“I always think it is very much worth reminding ourselves on a daily basis that humans and the rest of the living world share a common origin,” Sarah Darwin, a botanist and the great-great-granddaughter of Charles Darwin told the Associated Press. “Darwin was saying that 160 years ago, that we were related with all other nature. We’re not above it, we are part of nature.” 

The Darwin200 project has been in the works for at least a decade and aims to empower a new generation of exceptional environmental leaders through training some of the world’s top young conservationists ranging from 18 to 25 years-old. 200 young people were selected based on their accomplishments aimed at making the world a better place and will join the voyage at different stages. 

“This is about hope, it’s about [the] future and it’s about changing the world,” leader Stewart McPherson told the AP. 

[Related: Letters From Charles Darwin.]

Today’s naturalists are studying a world a bit different than Darwin. The planet’s birds, reptiles, mammals, fish, and amphibians have already shown population declines of around 68 percent since the 1970s and 10 percent of terrestrial biodiversity is set to decrease by 2050 if new policies are not immediately put in place. In December 2022, 200 countries’ delegates  at the United Nations Biodiversity Conference (COP 15) reached the 30 by 30 deal, vowing to protect 30 percent of the Earth’s wild land and oceans by 2030, thus representing the most significant effort ever to protect the world’s dwindling biodiversity. The deal also provides funding in an effort to save and preserve biodiversity in lower-income countries. Currently, only 17 percent of terrestrial and 10 percent of marine areas are protected through legislation.

Still, more work is needed as some scientists believe current estimates of biodiversity loss are even higher than scientists first expected. One of the goals of Darwin200 is to develop projects to save the species it is studying along the way before it’s too late.

“We all know we’re in the midst of the sixth great extinction with a lot of doom and gloom about the problems facing the environment, climate change and loss of biodiversity,” Famed primatologist and Darwin200 supporter Jane Goodall told Reuters. “This voyage will give many people an opportunity to see there is still time to make change.”

The post Mission to recreate Darwin’s scientific Beagle voyage sets sail appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Over 23 million years ago, an ancient relative of modern seals called Potamotherium valletoni was possibly one of the first pinnipeds to use their whiskers to forage for food and explore their watery world. The findings were published August 17 in the journal Communications Biology and provide more insight into how ancient seals transition from a life lived on land into one mostly underwater. 

[Related: Baby seals are born with a great sense of rhythm.]

The relatives of present day pinnipeds primarily lived on land and in freshwater environments, unlike our recognizable harbor seals which spend most of their time under the waves in saltwater. These early seals had legs for walking instead of flippers, a long tail, and were much longer, and looked a bit like present-day otters. 

“Pinnipeds (seals, sea lions and walruses) diversified tremendously since their ancestors entered the seas,” study co-author Alexandra van der Geer, a vertebrate paleontologist at the Naturalis Biodiversity Center in the Netherlands tells PopSci. “All living pinnipeds are very distantly related to Potamotherium, so one could say that in a way all living pinnipeds are equally closely related to Potamotherium. That is why Potamotherium is called a stem (or basal) pinniped.”

Some early species used their forelimbs to explore their surroundings, and prior to this study, scientists were unsure when seals and their relatives began using their whiskers to forage. Whiskers are thick wiry hairs with tons of nerve endings at their base and they’re very sensitive to movement. They can be used to help detect vibrations in the water, making it easier to find fish. 

Van der Geer and colleagues from institutions in Italy, Greece, and Sweden were inspired to look into this area of neurobiology by a visit to Chicago’s Field Museum. There, they studied the museum’s collection of special skull models called endocasts.  “An endocast is the infilling of the inside of the skull, so it fills up the space of the (former) brain. The brain is soft tissue and does not fossilize, but decomposes and disappears after death,” explains van der Geer.

In the study, they used these endocasts to investigate the evolution of whisker-foraging behaviors. They compared the brain structures of Potamotherium with six extinct and 31 living carnivorous mammals, including bears, mustelids, and seal relatives. The team compared the size and structure of a brain region called the coronal gyrus. Some earlier studies suggest that this region is involved in processing signals from seal whiskers. 

[Related: Seals snooze during 20-minute ‘sleeping dives’ to avoid predators.]

They found that Potamotherium had a larger coronal gyrus than both ancient and living land-based mammals that use their forelimbs to forage, such as the Asian small-clawed otter. However, it had a similar sized coronal gyrus to other ancient seal relatives and semiaquatic mammals that use whiskers to explore, including the Eurasian otter. This shows that Potamotherium may have used a combination of forelimbs and whiskers to forage.  

The team was surprised by the convergent evolution they saw in their study. “Not just seals but also some otters, civets and other carnivore mammals that are unrelated to seals, yet use their whiskers for foraging their prey underwater in the same way as seals, developed the same part of the brain,” van der Geer says. 

Additionally, they were surprised to see that coronal gyrus looks the same species with the same behavior, independent of their family ties. The team believes that whisker-based foraging may have already been present in seal relatives before they transitioned to their fully aquatic lifestyles of today. Using whiskers may have helped the Miocene-era creatures adapt to finding food underwater.

The study also shows the value of studying brain endocasts to look into the past. “By looking at the details of the brain endocast one can infer behavior and function in fossil species,” says van der Geer.

The post Hungry seals may have begun following their whiskers 23 million years ago appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

This article is excerpted from Roberto Battiston’s book “First Dawn: From the Big Bang to Our Future in Space.” This article originally published on MIT Press Reader.

By the time we realized that there was an extrasolar intruder, ‘Oumuamua, named after the Hawaiian word for “scout,” had already passed its closest point to the Sun and was leaving, as fast and stealthily as it had arrived. We are talking about the first sighting, in 2017, of an asteroid from another area of the galaxy, a messenger from distant worlds. What do we know about this dark, probably cigar-shaped shard, which visited our solar system with a trajectory and velocity that allowed it to leave so quickly?

Very little. We know that it was not made of ice, so it must be of the rocky type. It did not ignite like a comet as it approached the Sun. We know that it does not emit electromagnetic radiation. The most powerful radio telescopes have found no trace of it. Its orbit is gravitational, determined by the attraction of the Sun; a small, non-inertial component can be explained by the effect of the pressure of the radiation in our star’s vicinity. We know that its speed, before entering the solar system, was compatible with the characteristic speeds of celestial bodies in the region of the Milky Way, of which our solar system is part. This allows us to exclude the idea that it comes from one of the dozen stars closest to us, as its velocity would have been too high. However, we have identified four more distant stars near which it could have passed in the last million years, with a velocity low enough that it could have originated in one of these star systems.

So, we don’t know exactly where it comes from, if it has already been in our solar system, how many other systems it has visited, or its composition. According to one hypothesis, it could be a fragment of an exoplanet destroyed by tidal effects. In this case it would be an object much rarer than main belt asteroids or objects from the Oort cloud, which formed directly from the original nebula. What is certain is that, on timescales of the order of millions or tens of millions of years, fragments like ‘Oumuamua can bring different star systems into contact. One estimate even predicts that 10,000 extrasolar asteroids cross Neptune’s orbit on a daily basis.

On timescales of the order of millions or tens of millions of years, fragments like ‘Oumuamua can bring different star systems into contact.

It would be interesting to be able to explore one to see what it was made of. This type of asteroid would seem to be the kind of vector suitable for transporting life, in hibernating form, from one part of the galaxy to another. While a space mission of this kind would be difficult because of the speed at which these fragments are moving, it wouldn’t be impossible, considering that in the future our observational capacity will improve considerably, allowing us to identify these bodies sooner than we were able to identify ‘Oumuamua. Another idea has to do with the possibility that some of these extrasolar objects have become trapped in our solar system after having lost some of their energy in a close encounter with Jupiter; a few candidates have already been identified. This approach would make an exploratory mission much easier to accomplish.

However, even the planets in our own solar system are in communication and exchanging material at a fairly high rate. Not everyone knows that we have about 10 rock samples from Mars here on Earth, even though there has not yet been a mission that brought back material from that planet. The meteorite bombardment on Mars results in fragments that, given its thin atmosphere, can be projected into space. Some of them can reach the Earth, penetrate our atmosphere, and fall like normal meteorites. By comparing the isotopic composition of various meteorites with those measured on Mars during NASA’s robotic missions to the planet, we are able to identify and distinguish Martian meteorites from all the others.

Finally, we should remember that it takes the solar system about 220 million years to revolve around the center of the galaxy. Since it formed 4.5 billion years ago, it has made the full circuit about 20 times. This means that, in the timescale in which life emerged on Earth, the newborn solar system made at least three complete circuits, coming into contact with fragments from distant star systems.

In 2019 I participated in a Breakthrough Discuss conference in Berkeley on “Migration of Life in the Universe.” I was puzzled by the conference theme: We know almost nothing about life in the universe, I thought, so how we could talk about migration of life? But recalling the observation of ‘Oumuamua, I did participate and I am glad I did. I was surprised by the scientific quality of the talks and by the extreme fascination of the topic. Life probably doesn’t need massive, rocky starships to move from one planetary system to another. Considering the minuscule size of bacteria, the smallest living organisms we know, or even viruses, which can live and reproduce inside bacteria, we can also imagine other mechanisms suitable for this kind of transport.

Microscopic ice crystals and dust, for example, containing bacteria and spores capable of withstanding the conditions in space, can spread into space from areas of a planet’s upper atmosphere. When the dimensions become microscopic, the relationship between gravitational force, which is dependent on mass, and the thrust due to stellar radiation, which is dependent on surface area, tips the balance in favor of the latter. It is as if a planet were leaving a trail of perfume behind it. Planetary dust containing hibernating life can be pushed by radiation until it reaches high velocities and moves beyond a given star system, spreading to other systems or nebulae, where it can find suitable conditions to reproduce and evolve. We are used to thinking of space as vast and mostly empty, completely unsuitable for life. Perhaps we should change our minds. Space is less empty than we might think. In reality, the different parts of the galaxy communicate by exchanging material on timescales comparable to those of the appearance of life on our planet.

We know of various living species that can endure extremely hostile conditions such as those in space: a nearly perfect vacuum, extreme temperatures, and ionizing radiation.

But how possible is it for life to survive in space? Well, even here, nature surprises us. In fact, we know of various living species that can endure extremely hostile conditions such as those in space: a nearly perfect vacuum, extreme temperatures, and ionizing radiation. Different kinds of lichens, bacteria, and spores are able to survive, losing all of their water and entering into a condition of total inactivity — which can last for extremely long periods — from which they can emerge, once they find themselves in a humid atmosphere again. Tests of this kind have been done on the International Space Station and in various laboratories. Even plankton, made of more complex organisms, shows a capacity to resist these prohibitive conditions.

A truly extraordinary case is that of the tardigrades. These very common micro-animals are about a half a millimeter long and live in water. They have eight legs, a mouth and a digestive system, as well as a simple nerve and brain structure. They are also able to sexually reproduce. They exist in nature in thousands of different versions and have a metabolism with unique characteristics. In order to withstand prolonged drought conditions, their bodies can achieve complete dehydration, losing around 90 percent of their water and curling up into a tiny, barrel-shaped structure. In other words, it’s as if they freeze-dry themselves. Once this process is complete, their metabolism becomes 10,000 times slower. The most amazing thing is that they can stay in this state for decades, only to wake up again within 20 or 30 minutes once exposed to moisture. But there’s more. When in a dehydrated state, they can withstand the vacuum of space as well as pressures higher than normal atmospheric pressures, temperatures near absolute zero or temperatures up to 150°C. Their radiation tolerance threshold is hundreds of times higher than what would be deadly for humans. The secret of their ability to harden is due to a sugar, trehalose, which is also widely used in the food industry. When dried, this sugar replaces the water molecules in the cells, leaving the animal in a kind of vitrified state.

In addition, the tardigrade’s DNA is protected by a protein that reduces radiation damage. Is this information enough to make us assume that these micro-animals come from space? I would say no. Their unusual metabolism is more likely the result of evolutionary adaptation that happened on our planet. In fact, tardigrades are among the very few living beings that have emerged unscathed from all five extinction events that have occurred on Earth. That is why they are the best candidates for a long journey into space aboard a meteorite or a comet. Recently, tardigrades have achieved a bit of media notoriety resulting from the Beresheet mission, a private probe launched by Israel, that crashed on the Moon in early April of 2019. The probe was carrying a colony of these micro-animals, in their dehydrated state. Given their microscopic size, it is likely that they survived the crash and will remain inactive for a long time to come, ready to be reawakened from their hibernation. By replacing the Israeli probe with an asteroid, we have a textbook example of how life might have arrived on Earth.

Or how life could have migrated from Earth to other planets in our galaxy.

By replacing the Israeli probe with an asteroid, we have a textbook example of how life might have arrived on Earth.

So, the problem of the origin of life remains open, even if, step by step, we are making progress toward a solution. In the last decade, increasingly powerful calculation instruments have allowed us to reproduce, starting from the first principles of quantum mechanics, the formation of increasingly large and complex molecular systems, now made up of thousands of atoms. The field of computational biology is growing at a formidable rate; it is now only a matter of computing power.

At the same time we have dramatically developed our ability to decode and manipulate DNA, up to the creation of the first simplified genomic structures, derived from living organisms and able to reproduce. We are now talking about synthetic life, built around human-designed DNA, a field with huge development prospects.

Therefore, it is likely that the creation of the complex molecular structures needed for life or the confirmation of the existence of islands of genomic stability in the evolution of viral and bacterial species are objectives that, in future, will be within our reach. At that point, we will have another tool for understanding how life on Earth developed. Who knows? Perhaps we will discover that aliens are particular biological life forms that have lived with us since the beginning of time; and we were looking for them on Mars or below the icy surface of Jupiter and Saturn’s moons!

Roberto Battiston is a physicist who specializes in the field of experimental fundamental and elementary particle physics, both with particle accelerators and in space. He is the author of several books, including “First Dawn,” from which this article is excerpted.

The post How might life migrate through the universe? appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

A 300,000 year-old fossilized skull discovered in China is proving to be an evolutionary puzzle. The specimen dating back to the late middle Pleistocene doesn’t look like other skulls that have been found from this time period, and could possibly point to a previously unknown human species. The findings were published late last month in the Journal of Human Evolution.

[Related: Leftovers of a 2,000-year-old curry discovered on stone cooking tools.]

A team of scientists from institutions in Spain, the United Kingdom, and China found the lower jaw–or mandible–and 15 other separate specimens in eastern China’s Hualongdong region in 2015. The mandible in question is named HLD 6 and dates back to an important period in hominin evolution, just before some of the traits that are still seen in modern humans began to evolve in East Asia. 

The study noted that HLD 6 was “unexpected” since it doesn’t currently fit into any known taxonomic groups. The skull has similar facial features to those of early modern humans. The skull could potentially belong to a direct human ancestor called Homo erectus sometime between 550,000 and 750,000 years ago. 

However, it also shares some of the characteristics of the Denisovans, who belong on a different branch on the human family tree than Homo Erectus. HLD 6 does not appear to have a chin, just like previously discovered Denisovan specimens. Denisovans are now extinct and split from Neanderthals about 400,000 years ago.

Given that the specimen has a mixture of Homo erectus and Denisovan characteristics, they believe this was potentially a hybrid of modern human and ancient hominid. The team notes that this combination of facial features hasn’t been observed in East Asia hominids, which suggests that some of the traits found in modern humans began to appear as far back as 300,000 years ago.

[Related: A javelin-like stick shows early humans may have been keen woodworkers.]

They believe that the fossils belonged to a 12- to 13-year-old child. The team did not have an adult skull belonging to this same species to compare it with, but they used Middle and Late Pleistocene hominin skulls of similar and adult age. They noticed that the shape patterns remained the same regardless of age, which they say supports the theory that this could be a different human species. 

The history of the human family tree is constantly changing, as scientists develop better techniques for finding and analyzing specimens. A study published in June proposed that humans entered the forests of Asia about 400,000 years earlier than they previously believed. Humans and Neanderthals also could have been interbreeding earlier and in three separate waves that eventually led to the extinction of Neanderthals. 
If this new theory proves to be correct, a new “pre-sapiens specimen” branch could be added to this complex family tree and bring more insight into human evolution.

The post Mysterious skull points to a possible new branch on human family tree appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

What goes into the body, must ultimately come out.  The same goes for the parasites living within a host. The parasite-host relationship is also pretty old, and some newly found fossilized feces show the ancient parasites infected an aquatic predator more than 200 million years ago. The findings are published August 9 in the open-access journal PLOS ONE.

[Related: ‘Brainwashing’ parasites inherit a strange genetic gap.]

Despite being a common and important player in the food web due to their role in regulating overpopulation within the ecosystem, ancient parasites are difficult to study in the fossil record. They typically inhabit their host’s soft tissues, which are not usually preserved in fossils like tougher parts like bones. However, traces of parasites can sometimes be identified in fossilized feces which are called coprolites. 

“Coprolite is a significant paleontological treasure trove, containing several undiscovered fossils and expanding our understanding of ancient ecosystems and food chains,” the authors wrote in a statement.

In this study, the team describes evidence found in coprolite dating back to the Late Triassic from Thailand’s Huai Hin Lat Formation, which is over 200 million years old. The coprolite is shaped like a cylinder and more than 2.7 inches long. The team believes that it was likely produced by some species of a crocodile-like predator called a phytosaur based on the shape of the fossilized poop and the remains of phytosaurs have been found in the area for decades. 

Within the thin sections of coprolite, the team found six small, round, organic structures roughly between only 50 to 150 micrometers long. One of these microscopic beauties is an oval-shaped structure with a thick shell which the team identified as the egg of a parasitic nematode worm called Ascaridida. The other five structures possibly represent additional worm eggs or protozoan cysts. 

“The discovery of at least six parasites with at least five different morphotypes in a single coprolite suggests that multi-parasite infection was common had already diversified by the late

Triassic,” the authors wrote in the study. 

It is believed to be the first record of parasites in a terrestrial vertebrate host in Asia from the Late Triassic period, when the Earth was warmer and more humid than it is today. It also offers a glimpse into an ancient animal who was infected by multiple species of parasite as it went about its life. 

[Related: What prehistoric poop reveals about extinct giant animals.]

“The presence of the Ascaridida eggs and the evidence for multi-infection found in the coprolite can presumably be explained by the predatory habits of the host, which would have been parasitized by feeding on parasitized fishes, amphibians, or other reptiles,” they wrote.

This finding also adds to the few known examples of nematode eggs preserved within the fossilized poop in prehistoric animals and will add more understanding to how parasites were distributed on Earth millions of years ago.

The post Rare parasites found in 200 million-year-old reptile poop appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

WHEN YOU LIVE in a big city, sometimes nature comes at you secondhand—a photo from the apple farm upstate, eggs in the grocery store. But for Miami-born and Brooklyn-based Divya Anantharaman, the founder of Gotham Taxidermy, nature is hardly that binary. “Nature is the pigeon that’s on the sidewalk under the Gowanus Bridge,” they say. “It’s the squirrels you see at the park. It doesn’t exist in this pristine box separate from humanity.”

In their work, nothing is quite binary. In Anantharaman’s fantastical, ethereal creations, the beauty of life is captured after death. In many of the pieces, what you see isn’t strictly textbook science or purely creative. For a two-headed goat kid, the chances of surviving more than a week are one in 3 million according to the World Oddities Expo, which now owns this piece. But in Anantharaman’s work, the joy of being young and alive is frozen in time through anatomical specificity and an artful eye. 

↑ Nobody looks their best after death—including adorable little birds. Here, before skinning it, Anantharaman uses a syringe filled with water and a mild soap to inject a little life into the bird’s eyes and body. 

↑ In all of Anantharaman’s work there is a strong sense of kindness, something that isn’t always seen in the world of taxidermied creatures. Taxidermied bats, for example, are popular trinkets with a questionable ethical background. These lifelike Victorian bats are replicas—the gothic aesthetic with no loss of life. 

↑ The predator-prey dynamic is more than a lion stalking a gazelle on Animal Planet. Small, unassuming creatures must also compete to survive in the life-giving, complex ritual. In a transfixed stare-down between a black-throated magpie and its potential rodent dinner, Anantharaman displays the hunter and the hunted with a sense of tenderness. 

↑ One of the biggest misconceptions about taxidermy, Anantharaman says, is that it’s just embalming. Taxidermy literally means “to move the skin,” they add. This process requires care and delicacy in removing the slightest bones and breakable skull so they can be re-created to reflect a living creature’s symmetry and movement.

↑ Rarities draw us in—a lost antique, a precious gem. For some, that always-out-of-reach prize is a rare or endangered animal. But Anantharaman can still build the unattainable, such as by creating a snowy owl replica using the feathers of chickens and turkeys. With its menacing glower, you’d never know this Arctic predator is a fake.  

↑ Like something out of a fairy tale, a curious fawn steps out into a soft field filled with fruits and flowers. But there is a darker secret to this project—the laminated butterfly wings that gently cover the young deer’s petite frame mirror the real-life attraction of the insects to dead bodies. 

↑ This glowing Chilean flamingo is a work in progress, even if its dignified face would tell you otherwise. The tiny pins along its graceful neck are holding the skin and feathers of its deceased form in place as Anantharaman adds the finishing touches to its wacky, but realistic, final pose. 

↑ Many of the creatures in Anantharaman’s menagerie belonged to no one but themselves, but this cat skull is different. It was once part of an adored pet, whose owner requested this gorgeous, but often taboo, celebration of life. “With pets, you’re not just working on someone’s memories of their animal,” they say. “You’re working on the relationship they had to that animal.” 

↑ In the process between death and rebirth, bits and pieces of an animal can shrink or change. In making a creature as dynamic after death as it was in life, even the finest taxidermists need a little help in the form of a head or leg when the real thing doesn’t do its subject justice. 

↑ The history of taxidermy can be painful, presenting often literal representations of brutality. But for those given the remains of a rare creature, honoring its memory for as long as possible can mean revitalizing what is left of the magnificent beast.

↑ This budgie parakeet, another cherished pet, rests in peaceful slumber just as it did during its life—a bit fluffed out, with a sleepy head tucked under its wing. The beloved bird’s owner was fond of drawing the sweet creature in mystical settings, which Anantharaman re-created with a smattering of soft moss and dainty crystal raindrops. 

↑ Some taxidermy jobs start in the garbage, like this spectacular cassowary. When this mishap was found in a waste facility, not much could be salvaged. But with patience and a hand-sculpted, wrinkle-filled “dinosaur head,” Anantharaman was able to go beyond just restoring its former glory while preserving its traditional essence. 

↑ Owls have what’s called a facial disc, a cupped arrangement of feathers surrounding the eyes. In life, this unique feature helps owls collect sound waves, and the bird can adjust its shape to focus on prey shuffling under snow cover or hiding in plants. Placing the feathers requires patience, impeccable grooming, and a sense of humor. “It’s really funny to see it in this halfway state,” Anantharaman says. “It’s just a little owl in progress.”

↑ In museums and scientific displays, the taxidermied creatures might look far different from the ones we encounter in our day-to-day lives. This project, which Anantharaman is building for a high school, features deceased local birds collected by an enthusiastic (and permitted, of course) teacher who hopes to bring an ecological diorama to the classroom. 

↑ Anantharaman’s workshop is no morgue, but it still requires saws, respirators, and other devices for the rough-and-tumble aspects of taxidermy. Keeping an impeccably organized wall of tools is also emotional for the artist—a celebration of the space they use to create their multidimensional work. 

↑ When you think of an artist’s model, your brain may go to a scantily clad human muse. This starling is certainly nude, but it’s also an expert poser that Anantharaman can move however they like. Once this specimen is out of the freezer, Anantharaman has around 20 minutes to turn it into a dynamic fighter or a stately presence. 

Read more PopSci+ stories.

The post Life after death never looked so beautiful appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Baleen whales like humpbacks, northern and southern rights, and minkes are some of nature’s best known filter feeders. These mammals use the tough keratin baleen plates in their mouths to literally take in huge amounts of water and extract the small organisms like krill or plankton to snack on. However, an ancient reptile may have been the first animal to eat this way. 

[Related: This dolphin ancestor looked like a cross between Flipper and Moby Dick.]

A team of scientists from the United Kingdom and China found some remarkable new fossils that belong to a group of reptiles that were already using filter feeding about 250 million years ago. The findings are described in a study published August 7 in the journal BMC Ecology and Evolution.

Whales are not the only modern day animals to use filter feeding. Fish like basking sharks use their gills to take in food from water. Until now, there has been very little evidence from the fossil record that suggests ancient marine reptiles from the Mesozoic Era (about 252 to 66 million years ago) were filter feeders. 

In this study, the team found two new fossilized skulls that belong to an early marine reptile called Hupehsuchus nanchangensis. The roughly three foot long creature lived in China about 248 million years ago in the Early Triassic period. The high competition for food at this time may have caused H. nanchangensis to develop a specialized feeding system.

“This was a time of turmoil, only three million years after the huge end-Permian mass extinction which had wiped out most of life. It’s been amazing to discover how fast these large marine reptiles came on the scene and entirely changed marine ecosystems of the time,” study co-author and University of Bristol vertebrate paleontologist Michael Benton said in a statement. 

One of the specimens is well-preserved from head to clavicle (collarbone), and the other is a nearly complete skeleton. The team compared the shape and dimensions of the latter skull to 130 skulls from different aquatic animals, including 15 species of baleen whale, 52 species of toothed whale, 23 seal species, 14 crocodilians, 25 bird species, and the platypus. 

They found that Hupehsuchus skulls had soft structures such as an expanding throat region, which likely allowed the reptiles to take in huge amounts of water that had tiny shrimp-like prey, and baleen whale-like structures that filtered the food as it swam forward.  

[Related: Biologists vastly underestimated how much whales eat and poop.]

The Hupehsuchus skulls also have some grooves and notches located along the edge of its jaws that are similar to baleen whales. These present day mammals have keratin strips in their mouths instead of teeth like Odontoceti or toothed whales. 

The mostly complete fossilized skulls also had a long snout composed of unfused and straplike bones, as well as a long space between them and the length of the animal’s snout. This skull shape is only seen in baleen whales and is what allows them to eat krill. 

“We were amazed to discover these adaptations in such an early marine reptile,” study co-author and Wuhan Center of China Geological Survey paleontologist Zichen Fang said in a statement. “The hupehsuchians were a unique group in China, close relatives of the ichthyosaurs, and known for 50 years, but their mode of life was not fully understood.” 

Due to its rigid body, H. nanchangensis was likely a slow swimmer, and this lack of speed suggests that it may have filter fed similarly to today’s bowhead or right whales. These whales swim with their mouths wide open near the surface of the ocean to strain the food from the water. 

These new findings are an example of convergent evolution, a process where similar features evolved independently in different species.

The post The planet’s first filter feeder could be this extinct marine reptile appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Spatial learning is an important and complex skill in the animal kingdom, as it helps animals find a meal when food sources are scarce. Insects such as bees and ants that are social and live in communal nests are known to do this, and now we know some butterflies can as well.  A study published August 7 in the journal Current Biology found that the Heliconius butterfly genus is capable of spatial learning. 

[Related: A ‘butterfly tree of life’ reveals the origins of these beautiful insects.]

According to the authors, the results provide the first known experimental evidence of long-range spatial learning for traplining in any butterfly or moth species. Heliconius or “passion vine” butterflies are tropical butterflies from South and Central America known for a variety of wing patterns. The beautiful creatures have evolved a novel foraging behavior amongst butterflies which includes feeding on pollen that utilizes large scale spatial information, according to the team. 

“Wild Heliconius appear to learn the location of reliable pollen sources and establish long-term traplines,” study co-author and University of Bristol evolutionary neurobiologist Stephen Montgomery said in a statement. “Traplines are learnt foraging routes along which food sources are repeatedly returned to over consecutive days, an efficient foraging strategy similar to the behavior of some orchid bees and bumblebees. However, the spatial learning abilities of Heliconius, or indeed any butterfly, had not yet been experimentally tested.”

In the study, the team conducted spatial learning experiments in Heliconius butterflies over three spatial scales that each represented ecologically-relevant behaviors.  

First, they tested the insect’s ability to learn the location of a food reward in a grid made up of 16 fake flowers. This test represented foraging within a single resource patch.  

Next, the team increased the spatial scale and tested if Heliconius could learn to associate food with either the left or right side of a two-armed maze, to represent multiple plants at a single place.  

Finally, they increased the distances and used a facility of outdoor cages called the Metatron in southern France to test if Heliconius can learn the location of good in a 196 foot wide maze shaped like the letter T. This set up represents foraging between places and is closer to the range Heliconius forages in in the wild. 

[Related: What busy bees’ brains can teach us about human evolution.]

The experiments that the Heliconius does show signs of spatial learning and can memorize the spatial location of their food sources. In future studies, the team plans to test if Heliconius are more proficient spatial learners than closely related species that don’t eat pollen. Understanding this would help reveal how enhanced cognitive abilities can be shaped by an animal’s ecology. 

The team also plans to uncover the unknown mechanisms by which Heliconius navigates. Panoramic views and other visual cues are believed to be important for these butterflies, but the insects may rely on other cues such as a sun or geomagnetic compass in addition to what they can see.  

 “It’s been almost a century since the publication of the first anecdotal story on the spatial capabilities of these butterflies,” study co-author and Universidade Federal do Rio Grande do Norte biologist Priscila Moura said in a statement. “Now we are able to provide actual evidence on their fascinating spatial learning. And this is just the beginning.”

The post Butterflies can remember specific flower foraging routes appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

It’s hard to deny that whales are some of the most charismatic megafauna on our planet. The blue whale, specifically, with its massive size, friendly demeanor, and devastating backstory is one that has captured imaginations for decades. But there may be a new contender for the largest animal to live on earth—or at least there was one around 40 million years ago.

An international team of scientists recently uncovered some giant bones in a fossil-filled coastal desert Peru, namely 13 vertebrae, four ribs and a hip bone. These fossils lead them to a discovery of a sea-dwelling mammal that would’ve weighed up to 340 metric tons. Blue whales have gotten to around 190 metric tons at their heaviest, and the most massive dinosaur, the supersized sauropod Argentinosaurus, was estimated to weigh around 76 tons. 

[Related: Millions of years ago, marine reptiles may have used Nevada as a birthing ground.]

Despite their incredible size, the newly-named Perucetus colossus was likely not a fighter, similar to some of the world’s other favorite sea mammals. 

“Because of its heavy skeleton and, most likely, its very voluminous body, this animal was certainly a slow swimmer. This appears to me, at this stage of our knowledge, as a kind of peaceful giant, a bit like a super-sized manatee. It must have been a very impressive animal, but maybe not so scary,” paleontologist Olivier Lambert of the Royal Belgian Institute of Natural Sciences in Brussels told Reuters. Lambert and his colleagues published their findings August 2 in Nature. 

The chilled-out attitude of the Perucetus was likely not the only thing they had in common with today’s manatees. Its dense, vast skeleton was even estimated to be twice as heavy as a blue whale’s at 5 to 8 tons, even though length-wise, the blue whale still had them beat. 

“It took several men to shift them [the fossils] into the middle of the floor in the museum for me to do some 3D scanning,” author Rebecca Bennion from the Royal Belgian Institute of Natural Sciences in Brussels told the BBC. “The team that drilled into the center of some of these vertebrae to work out the bone density—the bone was so dense, it broke the drill on the first attempt.”

This characteristic doesn’t exist in today’s cetaceans (the family including whales, dolphins and porpoises), but it does appear in sirenians. One author especially noted the Steller’s sea cow, which was discovered in the 1700s only to go extinct within three decades of its discovery due to overhunting. 

[Related: These now-extinct whales were kind of like manatees.]

Like manatees, the Perucetus also appears to have had front limbs. Strangely enough, the animal also possessed vestigial back limbs, a possible evolutionary hangover from when whales evolved from land-based, dog-sized mammals 50 million years ago. 

One looming question about the Perucetus is how it ate—the researchers unfortunately didn’t find it’s skull, so the authors have multiple hypotheses: it may have scavenged, ate sea grass, or even scooped up shellfish and worms from the mud floor like today’s gray whales. 

Nevertheless, just finding a creature that could’ve been this size opens a whole new can of worms for paleontologists to uncover. 

“The extreme skeletal mass of Perucetus suggests that evolution can generate organisms with characteristics that go beyond our imagination,” study author and Italian paleontologist Giovanni Bianucci told CNN. And that is a massive deal. 

The post This giant sea cow-like whale may have been the heaviest creature to ever live on Earth appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Despite lacking blood, a heart, or a brain, slimy jellyfish are one of Earth’s most ubiquitous sea creatures and various species live in all of the planet’s oceans. They are some of the Earth’s oldest animals, having been around for roughly more than 500 million years (that’s 250 million years older than the earliest dinosaurs). Now, scientists with Toronto’s Royal Ontario Museum have found the oldest swimming jellyfish in the fossil record. The discovery of the newly named Burgessomedusa phasmiformis is described in a study published August 1 in the journal Proceedings of the Royal Society B.

[Related: These jellyfish seem to cheat death. What’s their secret?]

Jellyfish belong to a clade of animals called medusozoans, which includes the box jellies, hydroids, stalked jellyfish, and true jellyfish that swim in the oceans today. Medusozoans are part of the group Cnidaria, which also includes sea anemones and corals. The discovery of Burgessomedusa shows that large, swimming jellyfish that are bell or saucer-shaped had already evolved over 500 million years ago.  

Jellyfish are made of roughly 95 percent water, making them tricky to capture in the fossil record. However, the Burgessomedusa fossils are exceptionally well preserved in the Burgess Shale in the Canadian Rockies.  The Royal Ontario Museum now holds close to 200 specimens that were used to learn more about the internal anatomy and tentacles of ancient jellyfish, with some specimens measuring more than seven inches long. Like some modern jellyfish, Burgessomedusa would also have been capable of free-swimming. Their tentacles would have helped it catch pretty big prey.

“Although jellyfish and their relatives are thought to be one of the earliest animal groups to have evolved, they have been remarkably hard to pin down in the Cambrian fossil record. This discovery leaves no doubt they were swimming about at that time,” study co-author and University of Toronto PhD candidate Joe Moysiuk said in a statement. 

This study uses fossil specimens that were discovered at the Burgess Shale during the late 1980s and 1990s. The fossils demonstrate that the Cambrian food chain was much more complex than paleontologists previously believed, and the large swimming arthropods of the time like Anomalocaris were not the only predators. 

[Related: Italian chefs are cooking up a solution to booming jellyfish populations.]

One of the more gnarly parts of the complex life cycle of Cnidarians is that they can have more than one body form. A vase-shaped and non-free swimming body is called a polyp, while medusozoans have a bell or saucer-shaped body–called a medusa or jellyfish–that can be free-swimming or not. Fossilized polyps have been found in about 560-million-year old rocks, but the origin of the more free-swimming medusa or jellyfish is not well understood. Their evolutionary history is primarily based on microscopic fossilized larval stages and molecular studies performed on living species. 

“Finding such incredibly delicate animals preserved in rock layers on top of these mountains is such a wondrous discovery. Burgessomedusa adds to the complexity of Cambrian foodwebs, and like Anomalocaris which lived in the same environment, these jellyfish were efficient swimming predators,” study co-author and Royal Ontario Museum’s invertebrate paleontology curator Jean-Bernard Caron said in a statement. “This adds yet another remarkable lineage of animals that the Burgess Shale has preserved chronicling the evolution of life on Earth.”

The post Jellyfish may have been roaming the seas for at least 500 million years appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Some of our planet’s power pollinators may have originated tens of millions of years earlier than scientists once believed. In a study published July 27 in the journal Current Biology, a team of researchers traced bee genealogy back over 120 million years to the ancient supercontinent Gondwana. This former continent includes parts of present day Africa, Madagascar, South America, Australia, Antarctica, India, and Arabia, and it began to break apart during the early Jurassic period about 180 million years ago. 

[Related: Bee brains could teach robots to make split-second decisions.]

While looking deeper into bee history, the team found evidence that bees originated earlier, diversified faster, and spread wider than previously suspected, putting together pieces of a puzzle on the spatial origin of these pollinators. They likely originated in parts of present day Africa and South America before Gondwana broke apart.

In the study, an international team of scientists sequenced and compared genes from over 200 bee species. They then compared these bees with the traits from 185 different bee fossils and extinct fossils to develop an evolutionary history and genealogical model for how bees have historically been spread around the world. The team was able to analyze hundreds of thousands of genes at a time to make sure that the relationships they inferred were correct.  

“This is the first time we have broad genome-scale data for all seven bee families,” study co-author and Washington State University entomologist Elizabeth Murray said in a statement. 

Earlier studies established that the first bees potentially evolved from wasps, transitioning from predators up to collectors of pollen and nectar. According to this study, bees arose in the arid regions of western Gondwana during the early Cretaceous period, between 145 million years ago to 100.5 million years ago.

“There’s been a longstanding puzzle about the spatial origin of bees,” study co-author and Washington State University entomologist Silas Bossert said in a statement. “For the first time, we have statistical evidence that bees originated on Gondwana. We now know that bees are originally southern hemisphere insects.”

The team found evidence that as new continents formed, the bees moved northward. They continued to diversify and spread in parallel partnership with flowering plants called angiosperms. The bees later moved into India and Australia and all major bee families appear to have split off from one another before the beginning of the Tertiary period (65 million years ago). 

[Related: Like the first flying humans, honeybees use linear landmarks to navigate.]

The team believes that the exceptionally rich flora in the Western Hemisphere’s tropical regions may be due to their longtime association with bees. About 25 percent of all flowering plants belong to the large and diverse rose family of plants, and these beautiful flowers make up a large share of the tropical and temperate hosts for bees. 

The team plans to continue sequencing and studying the history and genetic profiles of more species of bees. Understanding how flowering plants and bees evolved together can help inform conservation efforts for pollinators and how to keep their populations healthy.

“People are paying more attention to the conservation of bees and are trying to keep these species alive where they are,” said Murray. “This work opens the way for more studies on the historical and ecological stage.”

The post The world’s earliest bees may have called Gondwana home appeared first on Popular Science.

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.