TIME animals

Scientists Trace Back the First Sexual Act Ever, to Weird Ancient Fish

Ancient fish were the first to copulate. And according to a world renowned paleontologist, it looked a lot like square dancing

Scientists have discovered the origins of sex, and like anyone’s first time it sounds pretty awkward.

Now light some candles and let’s set the scene: The first act of copulation occurred in the nippy Scottish sea some 385 million years ago. The fornicators in question were a set of primitive jawed, bony fish aptly called Microbrachius dicki. The dirty details? Well, according to Australian paleontologist John Long, “With their arms interlocked, these fish looked more like they are square dancing the do-se-do rather than mating.”

Not only had scientists previously thought that the first sex act occurred on land at a later date, but Long says, “We didn’t expect these little suckers to have reproductive organs.”

But the M. Dicki were endowed, as is explained by Long and his colleagues in a paper that was published in Nature Monday. Although their genitalia are not described in romantic terms.

Long, a professor at Flinders University, explained to the BBC that the fish’s arms linked them together, “so the male can get this large L-shaped sexual organ into position to dock with the female’s genital plates, which are very rough like cheese graters. They act like Velcro, locking the male organ into position to transfer sperm.”

This is also the first species that displayed a different appearance between the male and female.

TIME animals

Study: Chimps Learn How to Use New Tools From Other Chimps

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A chimpanzee holds a lettuce at the zoo in Abidjan on June 12, 2014. Sia Kambou—AFP/Getty Images

This means chimps have a prerequisite for human culture

A new study from PLOS Biology found that chimpanzees can learn group-specific behavioral traits from each other, widely considered a prerequisite for human-style culture. The results suggest the foundations of human culture can be traced back to our common ancestry with apes.

Researchers in Uganda noticed that a few chimps in a group started using new kinds of sponges to drink water. Usually, chimps use clumps of leaves to extract the water, but the team observed one chimp using moss instead. Once the other chimps saw him using moss, seven other chimps made and used moss sponges over a six-day period. There was also another variation on the leaf-sponge (re-using an old leaf sponge) that also spread through the group.

“Basically, if you saw it done, you learned how to do it, and if you didn’t you didn’t,” lead researcher Dr. Catherine Hobaiter told the BBC. “It was just this wonderfully clear example of social learning that no one had [witnessed] in the wild before.”

TIME Evolution

The Remarkable, Movable Whale Penis: It’s Just Science, People

No snickering please: A humpback whale on the prowl
No snickering please: A humpback whale on the prowl Gerard Soury; Getty Images

A new study of cetacean pelvic bones reveals how pleasing the ladies gave some male ocean mammals a reproductive edge

It’s hard to imagine what a dolphin or a whale needs a pelvic bone for. Sure, the structure was important 40 million years ago, when the ancestors of these seagoing mammals were walking around on land and had actual legs attached to actual hips. But for a legless swimmer, there doesn’t seem to be any point. No wonder evolutionary biologists have long considered these small, apparently useless bones purely vestigial, destined eventually to vanish.

“Apparently” is the key word here, however. A team of biologists has figured out what the pelvic bones of dolphins and whales are good for—and it’s a lot more fun than walking. The bones anchor muscles that control the animals’ penises, and far from fading away, they appear to be evolving to give the animal even more, well, finesse.

“We’ll never be able to ask a female whale, ‘was it good for you?'” says Jim Dines of the Natural History Museum of Los Angeles County, co-author of a new study in the journal Evolution. “But it’s plausible that if you can maneuver the penis in a slightly different way, there could be an evolutionary advantage.”

The advantage, in case it’s not obvious, is that keeping a female cetacean happy (“cetacean” being the umbrella term that covers both whales and dolphins) would give a particularly expert lover a better chance of getting his sperm to its destination. That in turn would give him more descendants with the ideal, pelvis-anchored musculature to keep their partners happy, producing even more descendants, and so on. The triumph of the agile penis.

That’s the theory, anyway, and while it’s not quite a slam-dunk, there’s plenty of circumstantial evidence to support it. To start with, Dines and his co-authors examined the pelvic bones of 130 whales and dolphins from 29 different species—not just superficially, but using a laser scanner that made exquisitely detailed 3-D models of the bones that could be digitally compared for similarities and differences.

It turned out that the animals with the largest pelvic bones in relation to overall body size also had larger testicles than the other species. That’s important, says co-author Matthew Dean, of the University of Southern California: “Species that are the most promiscuous tend to have the largest testes.” The reason: the animals’ strategy for providing their sperm to as many receptive females as possible is to make a whole lot of it. For example, he says, “chimpanzees have gigantic testes—they’re almost as big as their brains.” Now that this image is forever lodged in your head, the more important point is that there’s a direct line from larger, more evolved pelvic bones to larger testicles to more sperm to more babies—which is the entire point.

When it comes to whales and dolphins particularly, things are more complex still. Consider that cetacean penises are, for want of a better word, prehensile. “The penis of a whale or a dolphin is very dextrous,” says Dean. “It has a mind of its own.” Specifically, it’s controlled by two strong muscles that pull with differing tension to let the organ change shape. “I think of it like a trick kite, controlled by two strings and capable of complex motion. That’s a whale’s penis to me.” And now, surely, to all of us.

To make sure the authors weren’t kidding themselves, they also looked at the ribs of big-testicled cetaceans to rule out the possibility that the relationship between large gonads and large pelvic bones was a coincidence—that all of the bones in the skeletons of these species were oversized and the pelvis bones were just going along for the ride. But nope, a bigger pelvic bone didn’t correspond with bigger rib bones. Improved sexual performance remained the leading theory.

The pelvic structures that make certain cetacean species such sexual virtuosos probably evolved very rapidly. “Male genitalia evolve much faster than other parts of the body,” says Dean, because even the slightest mating advantage can give an individual more offspring. Still, in the case of the cetaceans’ maneuverable penises, Dean concedes, “It’s a speculation. We don’t know for sure.”

Here’s hoping they prove it soon; it’s too good a story not to be true.

TIME Research

Humans and Neanderthals Were Actually Neighbors

Paleontologists know plenty about our nearest human cousins, the Neanderthals. They know that this highly successful species walked the Earth for some 300,000 years (we’ve been around for less than 200,000). They know the Neanderthals kept their caves surprisingly tidy; that they ate things other than raw meat; that they practiced recycling, wore jewelry and were generally much more sophisticated than their popular reputation would suggest.

Yet it didn’t take long after our own species invaded their last known outpost in Europe that the Neanderthals went utterly extinct. Now a new paper in Nature suggests it happened over a period of between 2,600 and 5,400 years or so—which is twice as fast as anyone had thought. The two groups did, evidently, coexist: “They lived in Europe at the same time,” says lead author Tom Higham, of Oxford, “although they were spatially separated. It was like a mosaic.” Agrees William Davies, of the University of Southampton, who wrote a commentary on the new research, also in Nature, “It’s not a neat story. It’s quite complex.”

The key to the new analysis was an unusually large sample of human and Neanderthal remains from 40 different sites across Europe, along with improved methods for filtering out contaminants from the samples before attempting to date them. In many cases, the remains weren’t bones but rather stone tools thought to characteristic of one species or the other—so-called Mousterian and Châtelperronian tools for the Neanderthals and Uluzzian tools for our own ancestors.

That raises, if not a red flag, then at least a sort of pinkish one, according to Davies. “In the old days, we had very few assemblages of tools, so it was quite easy to say that Mousterian tools represented Neanderthals, while tools with longer blades reflect anatomically modern humans.” But with more and more tools in their collections, paleontologists have become less sure. “The whole thing has become more blurred and less certain.”

The new analysis doesn’t depend entirely on who made what tools, however, and, says Davies, “the areas they’ve chosen to analyze are places where we can be more confident than most.” What makes the work so potentially important, he says, is that it gives a much finer-grained picture than ever before of where Neanderthals and modern humans lived and when, and how those patterns changed as Neanderthal numbers dwindled, then vanished.

That in turn will help anthropologists figure out how the Neanderthals vanished—what force or forces drove them extinct by about 40,000 years ago. “We think the Neanderthals had very low population numbers when modern humans arrived,” says Higham, perhaps in part because Europe was in the throes of an Ice Age at the time, so they were struggling against harsh conditions that couldn’t support large numbers of individuals. Modern humans, Higham observes, had been living in Africa, which was much more benign. “Modern humans also seemed to have more modern technology,” he says, “which wouldn’t have been a huge advantage, but over the long duration might have given them an edge.”

Scientists also know that Neanderthals and modern humans interbred at some level, which is why about 2% of our genes, on average, are Neanderthal in origin. The details of those interactions are still completely unknown—for now, anyway. “For me,” says Davies, “the big achievement here is that we now have a way of getting much more information out of both skeletal and archaeological remains. We can look at the molecular level on genetic inheritance, movement patterns, even what they were eating.”

The mystery of when and where the Neanderthals made their last stand may be just about wrapped up. And the answer to why they disappeared might not be a mystery for much longer.

 

TIME Culture

Study: Society Flourished When Humans Got Less Manly

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A model of Peking man (Homo erectus pekinensis), who lived 1-2 million years ago Getty Images

Does lower T lead to higher tech? Research links decrease in manly traits to an increase in sophisticated toolmaking in early humans

Some anthropologists now believe that advanced human behaviors like toolmaking only developed when early humans evolved to have lower levels of testosterone than their ancestors, according to a new study published in Current Anthropology.

“All of a sudden, in the archeological record, culture and advanced technology suddenly becomes more widespread. And at that time we also see a decrease in testosterone,” said the study’s lead author Bob Cieri, a graduate student at the University of Utah. “Before 50,00 years ago, there were brief flashes of advanced behavior and artifacts, but they’re not persistent and widespread.”

Cieri measured the browridge of different human skulls, which indicates the level of testosterone in the skeleton. Heavier brows and longer faces indicate more testosterone, and more rounded heads indicate less testosterone, according to Stephen Churchill, the Duke professor who supervised Cieri’s work. Cieri measured 13 human skulls that were more than 80,000 years old; 41 skulls between 10,000 and 38,000 years old; and over 1,200 20th-century skulls from different ethnic populations. He found that the modern skulls had substantially more rounded features and less heavy brows than the early skulls, indicating a drop in testosterone between our early ancestors and modern humans.

Cieri says the decrease in testosterone levels could be attributed to the rise in the Homo sapiens population, which meant that people had to be nicer to each other because they were living in closer quarters. “If population density starts increasing, not only are there more people in your immediate environment that you have to get along with, but all land would be occupied with human groups,” he explains. “You wouldn’t just go across to the other side of the valley to hunt bison by yourself, you’d go to the other side of the valley and maybe make a treaty with the other people who live there.”

It’s important to note that these early humans didn’t yet have “culture” as we know it — they were still hunter-gatherers, Cieri says, but they were much less aggressive about it. But he thinks this lowering of testosterone led to more cooperation between people, which laid crucial groundwork for cultural advances thousands of years later.

So if you’re still worried about low T after reading TIME’s recent cover story, “Manopause?!,” consider that a little less T isn’t always a bad thing.

TIME Paleontology

Want to See a Live Dinosaur? Set Up a Bird Feeder

An exciting new study lays out in detail how our fine feathered friends evolved from the same ancestors as the T. Rex and velociraptors over the course of millions of years, and how they managed to avoid the same doomed fate as their dinosaur cousins

When the theory first arose that birds evolved directly from dinosaurs, it was enormously controversial. It was even more contentious when some paleontologists argued that birds are dinosaurs—the only branch of the family that survived a cataclysmic asteroid strike 65 million years ago.

That initial controversy has largely vanished, thanks to a series of astonishing discoveries over the past 20 years or so—for example, that many dinosaur species sported feathers, and that the bone structures of birds and dinos are similar in all sorts of ways. “We now know birds are a subgroup of dinosaurs, like humans are a subgroup of apes,” says paleontologist Michael Lee, of the South Australian Museum, in Adelaide.

Now a new report in Science by Lee and several colleagues has laid out in unprecedented detail the exact bird branch of the dinosaur tree that sprouted and evolved over some 50 million years—and how that evolution may have saved birds from extinction when the asteroid struck.

The study is based on a cross-species analysis of more than 1,500 anatomical features across 120 species of early birds and therapod dinosaurs—the branch that includes velociraptors and T. Rex, and which is most closely related to birds. Of all the evolutionary changes that reshaped the bird lineage, says Michael Benton, a paleontologist at the University of Bristol in the UK, writing in a commentary on the new paper that also appears in Science, “The key seems to be miniaturization.”

Starting about 200 million years ago, the paper shows, one group of therapods began to shrink rapidly, from an average weight of more than 350 lb. to less than two. Not only that, says Lee, but, “It turns out that birds and their direct ancestors evolved about four times faster than other dinosaurs over that time.”

It’s not unusual to see different rates of evolution in related species, he says. “Rodents are the most successful mammals by far, for example,” Lee says, “and one reason is that they have the most rapidly evolving DNA.” Rapid evolution could be one reason there are now 10,000 species of birds, but only a few dozen species of crocodiles, even though both are equally ancient.

Shrinkage isn’t the only change that transformed therapods into birds, says Benton. “There was miniaturization, but also modifications to the eyes, the elaboration of feathers, the development of wings out of the small, silly-looking forelimbs therapods have.”

These changes might have been driven by their helpfulness in letting birds adapt to living in trees—previously uninhabited ecological niche. It’s still just a hypothesis, says Benton, but “there might have been an opportunity to conquer a new habitat by getting smaller, developing the ability to climb and to glide, developing better vision so you don’t go banging into branches.”

The changes could also have given birds a huge advantage over other dinosaurs when the asteroid finally struck. “Birds obviously didn’t evolve knowing in advance that it would hit,” says Lee, “but the adaptations might have incidentally helped them survive—they could warm themselves with feathers [when dust from the asteroid cooled the Earth], fly long distances for food.”

What most people don’t realize, says Lee, is that birds didn’t show up just as the other dinosaurs were dying out. “They shared the world for 100 million years.” The quintessential proto-bird, Archaeopteryx, lived 150 million years ago, he points out. But the terrifying T. Rex wouldn’t show up until many tens of millions of years later.

 

TIME Friendship

Study: BFFs May Have Similar DNA

RyanJLane—Getty Images

Really close friends might be as genetically similar as fourth cousins

Next time someone says “You would really like my friend, she’s just like you,” try to refrain from giving her the side eye. It turns out she might have some science to back her up. According to a new study from Yale University and the University of California at San Diego, good friends are often genetically similar, and can share as much as 1% of the same gene variants. In genetic terms, that’s a lot. As close as, say, fourth cousins.

“This gives us a deeper accounting of the origins of friendship,” says Nicholas Christakis, professor of sociology, evolutionary biology, and medicine at Yale, who co-authored the study with James Fowler, professor of medical genetics and political science at UC San Diego. “Not only do we form ties with people superficially like ourselves, we form ties with people who are like us on a deep genetic level. They’re like our kin, though they’re not.”

To do their study, which was published in July in the Proceedings of the National Academy of Sciences, Christakis and Fowler looked at 1.5 million gene variants from the Framingham Heart Study, a dataset which has details on the friendships and genetics of its participants. Most of the participants were of European descent. Researchers genetically compared pairs of friends with pairs of strangers from among the same 1,932 subjects they studied. None of the pairs were related to each other.

The study found that, oddly, close friends are often genetically similar in their sense of smell. But it also concluded that friendship may play a role in evolution. The genes that were shared by friends saw the most “evolutionary activity”, or have evolved the fastest over the past 30,000 years. Whether the friendship or the genetic similarity came first is up for debate. Do we seek out genetically similar friends or do our friendships and mating affect what genes get passed on

“Human beings are one of the few species who form long-term, non-reproductive relationships with other members of our species,” says Fowler. “This role of affiliation is important. It ties into the success of our species.”

TIME behavior

These Goosebump Sensors Can Read Your Emotions

The Goose Bump Detector is a goose bump monitoring sensor attached to the arm. Young-Ho Cho/KAIST

Sounds crazy right? Read on

South Korean researchers are developing a technology that can measure your goosebumps—which are activated when you’re cold, sure, but also when you’re scared, moved or otherwise emotionally aroused. It sounds weird until you consider the potential applications for such a thing, some of which are fascinating while others seem unsettling when it comes to emotional privacy.

A team of scientists at KAIST in Daejeon, South Korea have developed a very thin sticker-like sensor that can easily be applied to the skin. The wearable 20mm x 20mm polymer sensor measures goosebumps, and the researchers believe it provides insight into human’s emotional states.

Although the sensors are still in early development, the team believes they could provide insight into physical and emotional responses so that they can determine how people experience and react to the world around them. This could help lead the way to personalized music streams and advertising, the researchers suggest in a statement. “In the future, human emotions will be regarded like any typical biometric information, including body temperature or blood pressure,” study author Young-Ho Cho said.

Social media sites like Facebook are already tapping into what the site perceives as your interests in order to curate advertising targeted just for you. Analyzing your emotions would take that kind of monitoring to a whole new level. Emotion sensing is something retailers are interested in, and companies like 3VR are rolling out initiatives like “big data video-mining,” which uses video cameras that can estimate the age, gender, and mood shoppers as they pass through a given store.

But what can goosebumps tell us? The obvious reason we get goosebumps is that it’s a biological method to combat chills. Goosebumps occur when tiny muscles attached to each of our hairs contract, and the areas surrounding that contraction rises. In animals with a lot of fur, this retains heat. We don’t have a lot of fur, so it doesn’t exactly serve the same purpose for us—but it does clue us into when our bodies are at an uncomfortable level.

When it comes to getting goosebumps while watching a sad or inspiring movie, it’s a little more evolutionarily confusing, but researchers think it’s because we release the stress hormone adrenaline when we feel strong emotions, and that hormone can trigger goosebumps to rise. “This response is an evolutionary holdover from our primate ancestors. Those ancestors had long hair that stood out when those tiny muscles contracted, making the individual look larger and usually more fierce when something threatening or scary occurred,” says Dr. Rick Potts, director of the human origins program at the Smithsonian Institution. “There was an evolutionary advantage for our ancestors, but for us, the advantage has disappeared—though we retain the impulse of those tiny muscles contracting just beneath the skin.”

The research is published in the journal Applied Physics Letters and it’s still preliminary. But knowing there’s a market for understanding your emotions is enough to give us goosebumps.

TIME Science

Diving Beetles Could One Day Help Scuba Divers

A large Diving Beetle plunges into the water. Barrett & MacKay—Getty Images/All Canada Photos

It's all about the suction-cup pads on the male beetle's legs

Male diving beetles have adhesive plungers on their forelegs that allow them to hold onto their female mating partners, a recent study published in Journal of the Royal Society Interface reports. And the effectiveness of those plungers could point ways forward for the design of human underwater equipment.

The team of researchers from Taiwan saw that female underwater beetles in the dystiscidae family squirmed to avoid copulation with an undesirable suitor, triggering a need for the adaptation in the males’ legs.

The team of scientists, led by Dr Kai-Jung Chi from National Chung Hsing University, compared the gripping features of two species of male aquatic beetles — one that had spatula-shaped bristles and a more evolved diving beetle that had suction-cup-shaped pads. Researchers found that the primitive beetles released a glue-like secretion, but the beetles with the circular plungers on their legs were able to withstand seven times more force than the others — proving that the suction cup posed a sexual advantage.

Scientists hope that the success of the male aquatic beetles’ adhesive legs will help inspire innovations in aquatic equipment such as the attachments used by underwater rescuers or scuba divers.

TIME Research

We Evolved To Withstand Getting Punched in The Face

University of Utah
University of Utah An artist's impression of how human faces may have evolved to minimise injury from punches.

"When modern humans fight hand to hand, the face is usually the primary target," a researcher says

Humans evolved to minimize injury incurred by punches to the face, a new study suggests.

Researchers at the University of Utah observed that the fossils of australopiths—bi-peds that lived 4-5 million years ago and directly preceded the human genus Homo—had robust cheek, jaw, eye and nose features. Scientists had previously thought that the australopiths’ strong facial features were an evolutionary adaptation to their hardy diet, but the study published in the journal Biological Reviews suggests that they were likely eating softer foods like fruit.

Dr. David Carrier, the lead researcher in the study, told the Guardian that the australopiths’ hands had adapted to form a fist, allowing them to engage in hand-to-hand combat. “When modern humans fight hand to hand, the face is usually the primary target,” Carrier said. Carrier and his team found that the bones that had evolved to be more robust were typically the features that suffer the greatest impact in a fight.

The study also shows that while the faces, hands and up-right nature of australopiths evolved to allow for improved fighting, modern-day humans have less robust facial features. Carrier told BBC that humans have less of a need to protect themselves because violence is no longer a driving evolutionary factor. “There’s a temporal correlation,” Carrier said.

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