Chapter 6. Evolution of the Brain and Behavior

Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.


Links 1 - 20 of 2091

Nell Greenfieldboyce Parrots can perform impressive feats of intelligence, and a new study suggests that some of these "feathered apes" may also practice acts of kindness. African grey parrots voluntarily helped a partner get a food reward by giving the other bird a valuable metal token that could be exchanged for a walnut, according to a newly published report in the journal Current Biology. "This was really surprising that they did this so spontaneously and so readily," says Désirée Brucks, a biologist at ETH Zürich in Switzerland who is interested in the evolution of altruism. Children as young as 1 seem highly motivated to help others, and scientists used to think this kind of prosocial behavior was uniquely human. More recent research has explored "helping" behavior in other species, everything from nonhuman primates to rats and bats. To see whether intelligent birds might help out a feathered pal, Brucks and Auguste von Bayern of the Max Planck Institute for Ornithology in Germany tested African grey parrots. They used parrots that had previously been trained to understand that specific tokens, in the form of small metal rings, could be traded for a food treat through an exchange window. In their experiment, this exchange window was covered up and closed on one bird's cage, making it impossible for that bird to trade. The bird had a pile of tokens in its cage but no way to use them. Meanwhile, its neighbor in an adjacent cage had an open exchange window — but no tokens for food. © 2020 npr

Keyword: Emotions; Evolution
Link ID: 26948 - Posted: 01.10.2020

Kristen S. Morrow Human beings used to be defined as “the tool-maker” species. But the uniqueness of this description was challenged in the 1960s when Dr. Jane Goodall discovered that chimpanzees will pick and modify grass stems to use to collect termites. Her observations called into question homo sapiens‘ very place in the world. Since then scientists’ knowledge of animal tool use has expanded exponentially. We now know that monkeys, crows, parrots, pigs and many other animals can use tools, and research on animal tool use changed our understanding of how animals think and learn. Studying animal tooling – defined as the process of using an object to achieve a mechanical outcome on a target – can also provide clues to the mysteries of human evolution. Our human ancestors’ shift to making and using tools is linked to evolutionary changes in hand anatomy, a transition to walking on two rather than four feet and increased brain size. But using found stones as pounding tools doesn’t require any of these advanced evolutionary traits; it likely came about before humans began to manufacture tools. By studying this percussive tool use in monkeys, researchers like my colleagues and I can infer how early human ancestors practiced the same skills before modern hands, posture and brains evolved. Understanding wild animals’ memory, thinking and problem-solving abilities is no easy task. In experimental research where animals are asked to perform a behavior or solve a problem, there should be no distractions – like a predator popping up. But wild animals come and go as they please, over large spaces, and researchers cannot control what is happening around them. © 2010–2020, The Conversation US, Inc.

Keyword: Evolution
Link ID: 26947 - Posted: 01.10.2020

By Veronique Greenwood The cuttlefish hovers in the aquarium, its fins rippling and large, limpid eyes glistening. When a scientist drops a shrimp in, this cousin of the squid and octopus pauses, aims and shoots its tentacles around the prize. There’s just one unusual detail: The diminutive cephalopod is wearing snazzy 3-D glasses. Putting 3-D glasses on a cuttlefish is not the simplest task ever performed in the service of science. “Some individuals will not wear them no matter how much I try,” said Trevor Wardill, a sensory neuroscientist at the University of Minnesota, who with other colleagues managed to gently lift the cephalopods from an aquarium, dab them between the eyes with a bit of glue and some Velcro and fit the creatures with blue-and-red specs. The whimsical eyewear was part of an attempt to tell whether cuttlefish see in 3-D, using the distance between their two eyes to generate depth perception like humans do. It was inspired by research in which praying mantises in 3-D glasses helped answer a similar question. The team’s results, published Wednesday in the journal Science Advances, suggest that, contrary to what scientists believed in the past, cuttlefish really can see in three dimensions. Octopuses and squid, despite being savvy hunters, don’t seem to have 3-D vision like ours. Previous work, more than 50 years ago, had found that one-eyed cuttlefish could still catch prey, suggesting they might be similar. But cuttlefish eyes often focus in concert when they’re hunting, and there is significant overlap in what each eye sees, a promising combination for generating 3-D vision. Dr. Wardill, Rachael Feord, a graduate student at the University of Cambridge, and the team decided to give the glasses a try during visits to the Marine Biological Lab in Woods Hole, Mass. The logic went like this: With each eye covered by a different colored lens, two different-colored versions of a scene, just slightly offset from each other, should pop out into a three-dimensional image. By playing a video on the tank wall of a scuttling pair of shrimp silhouettes, each a different color and separated from each other by varying amounts, the researchers could make a shrimp seem closer to the cuttlefish or farther away. If, that is, the cuttlefish experienced 3-D vision like ours. © 2020 The New York Times Company

Keyword: Vision; Evolution
Link ID: 26945 - Posted: 01.09.2020

By Rodrigo Pérez Ortega Nearly 2600 years ago, a man was beheaded near modern-day York, U.K.—for what reasons, we still don’t know—and his head was quickly buried in the clay-rich mud. When researchers found his skull in 2008, they were startled to find that his brain tissue, which normally rots rapidly after death, had survived for millennia—even maintaining features such as folds and grooves (above). Now, researchers think they know why. Using several molecular techniques to examine the remaining tissue, the researchers figured out that two structural proteins—which act as the “skeletons” of neurons and astrocytes—were more tightly packed in the ancient brain. In a yearlong experiment, they found that these aggregated proteins were also more stable than those in modern-day brains. In fact, the ancient protein clumps may have helped preserve the structure of the soft tissue for ages, the researchers report today in the Journal of the Royal Society Interface. Aggregated proteins are a hallmark of aging and brain diseases like Alzheimer’s. But the team didn’t find any protein clumps typical of those conditions in the ancient brain. The scientists still aren’t sure what made the proteins aggregate, but they suspect it could have something to do with the burial conditions, which appeared to take place as part of a ritual. In the meantime, the new findings could help researchers gather information from proteins of other ancient tissues from which DNA cannot be easily recovered. © 2019 American Association for the Advancement of Science

Keyword: Brain imaging; Glia
Link ID: 26941 - Posted: 01.09.2020

A cousin of the starfish that resides in the coral reefs of the Caribbean and Gulf of Mexico lacks eyes but can still see, according to scientists who studied the creature. Researchers said on Thursday that the red brittle star, called Ophiocoma wendtii, joins a species of sea urchin as the only creatures known to be able to see without having eyes — known as extraocular vision. The red brittle star possesses this exotic capability thanks to light-sensing cells, called photoreceptors, covering its body and pigment cells, called chromatophores, that move during the day to facilitate the animal's dramatic colour change from a deep reddish-brown in daytime to a striped beige at night. Brittle stars, with five radiating arms extending from a central disk, are related to starfish (also called sea stars), sea cucumbers, sea urchins and others in a group of marine invertebrates called echinoderms. They have a nervous system but no brain. Looking for a safe hiding place The red brittle star — which measure up to about 35 centimetres (14 inches) from arm tip to arm tip — lives in bright and complex habitats, with high predation threats from reef fish. It stays hidden during daytime — making the ability to spot a safe place to hide critical — and comes out at night to feed on detritus. Its photoreceptors are surrounded during daytime by chromatophores that narrow the field of the light being detected, making each photoreceptor like the pixel of a computer image that, when combined with other pixels, makes a whole image. The visual system does not work at night, when the chromatophores contract. "If our conclusions about the chromatophores are correct, this is a beautiful example of innovation in evolution," said Lauren Sumner-Rooney, a research fellow at Oxford University Museum of Natural History, who led the study published in the journal Current Biology. ©2020 CBC/Radio-Canada.

Keyword: Vision; Evolution
Link ID: 26929 - Posted: 01.04.2020

By Eva Frederick One day in 2014, primatologist Yuko Hattori was trying to teach a mother chimpanzee in her lab to keep a beat. Hattori would play a repetitive piano note, and the chimp would attempt to tap out the rhythm on a small electronic keyboard in hopes of receiving a tasty piece of apple. Everything went as expected in the experiment room, but in the next room over, something strange was happening. Another chimpanzee, the mother’s son, heard the beat and began to sway his body back and forth, almost as if he were dancing. “I was shocked,” Hattori says. “I was not aware that without any training or reward, a chimpanzee would spontaneously engage with the sound.” Hattori has now published her research showing that chimps respond to sounds, both rhythmic and random, by “dancing.” “This study is very thought-provoking,” says Andrea Ravignani, a cognitive biologist at the Seal Rehabilitation and Research Centre who researches the evolution of rhythm, speech, and music. The work, she says, could shed light on the evolution of dancing in humans. For their the study, Hattori and her colleague Masaki Tomonaga at Kyoto University played 2-minute clips of evenly spaced, repetitive piano tones (heard in the video above) to seven chimpanzees (three males and four females). On hearing the sound, the chimps started to groove, swaying back and forth and sometimes tapping their fingers or their feet to the beat or making howling “singing” sounds, the researchers report today in the Proceedings of the National Academy of Sciences. All of the chimps showed at least a little bit of rhythmic movement, though the males spent much more time moving to the music than females. © 2019 American Association for the Advancement of Science.

Keyword: Evolution; Hearing
Link ID: 26916 - Posted: 12.26.2019

By Bruce Bower Homo erectus, a humanlike species that dispersed from Africa into parts of Europe and Asia roughly 2 million years ago, eventually reached the Indonesian island of Java before dying out. Scientists say they have now resolved a controversy over just how long ago the last known H. erectus inhabited the Southeast Asian island. New evidence narrows the timing of this hominid’s final stand on Java to between 117,000 and 108,000 years ago, says a team led by geochronologists Yan Rizal of Indonesia’s Bandung Institute of Technology and Kira Westaway of Macquarie University in Sydney. The scientists present their results December 18 in Nature. If the findings hold up to scrutiny, the fossils would be the last known occurrence of H. erectus anywhere in the world, and would show that the hominid was part of a complex interplay among different Homo species in Southeast Asia that started more than 100,000 years ago. Excavations at Java’s Ngandong site from 1931 to 1933 uncovered 12 skullcaps and two lower leg bones from H. erectus. Since then, uncertainty about how Ngandong sediment layers formed and confusion about the original location of the excavated fossils has led to dramatically contrasting age estimates for the finds. A 1996 report in Science dated the Ngandong specimens to between 53,000 and 27,000 years ago, suggesting that H. erectus had lived alongside Homo sapiens in Indonesia (SN: 12/14/96). But a more recent analysis greatly increased the estimated age of the Java fossils, dating them to around 550,000 years ago (SN: 4/16/10). © Society for Science & the Public 2000–2019

Keyword: Evolution
Link ID: 26905 - Posted: 12.19.2019

By Virginia Morell Dogs may not be able to count to 10, but even the untrained ones have a rough sense of how many treats you put in their food bowl. That’s the finding of a new study, which reveals that our canine pals innately understand quantities in much the same way we do. The study is “compelling and exciting,” says Michael Beran, a psychologist at Georgia State University in Atlanta who was not involved in the research. “It further increases our confidence that [these representations of quantity in the brain] are ancient and widespread among species.” The ability to rapidly estimate the number of sheep in a flock or ripened fruits on a tree is known as the “approximate number system.” Previous studies have suggested monkeys, fish, bees, and dogs have this talent. But much of this research has used trained animals that receive multiple tests and rewards. That leaves open the question of whether the ability is innate in these species, as it is in humans. In the new study, Gregory Berns, a neuroscientist at Emory University in Atlanta, and colleagues recruited 11 dogs from various breeds, including border collies, pitbull mixes, and Labrador golden retriever mixes, to see whether they could find brain activity associated with a sensitivity to numbers. The team, which pioneered canine brain scanning (by getting dogs to voluntarily enter a functional magnetic resonance imaging scanner and remain motionless), had their subjects enter the scanner, rest their heads on a block, and fix their eyes on a screen at the opposite end (see video, above). On the screen was an array of light gray dots on a black background whose number changed every 300 milliseconds. If dogs, like humans and nonhuman primates, have a dedicated brain region for representing quantities, their brains should show more activity there when the number of dots was dissimilar (three small dots versus 10 large ones) than when they were constant (four small dots versus four large dots). © 2019 American Association for the Advancement of Science.

Keyword: Attention; Evolution
Link ID: 26900 - Posted: 12.18.2019

Joshua Schrock You know what it’s like to be sick. You feel fatigued, maybe a little depressed, less hungry than usual, more easily nauseated and perhaps more sensitive to pain and cold. The fact that illness comes with a distinct set of psychological and behavioral features is not a new discovery. In medical terminology, the symptom of malaise encompasses some of the feelings that come with being ill. Animal behaviorists and neuroimmunologists use the term sickness behavior to describe the observable behavior changes that occur during illness. Health care providers often treat these symptoms as little more than annoying side effects of having an infectious disease. But as it turns out, these changes may actually be part of how you fight off infection. I’m an anthropologist interested in how illness and infection have shaped human evolution. My colleagues and I propose that all these aspects of being sick are features of an emotion that we call “lassitude.” And it’s an important part of how human beings work to recover from illness. The human immune system is a complex set of mechanisms that help you suppress and eliminate organisms – such as bacteria, viruses and parasitic worms – that cause infection. Activating the immune system, however, costs your body a lot of energy. This presents a series of problems that your brain and body must solve to fight against infection most effectively. Where will this extra energy come from? What should you do to avoid additional infections or injuries that would increase the immune system’s energy requirements even more? © 2010–2019, The Conversation US, Inc.

Keyword: Neuroimmunology; Emotions
Link ID: 26899 - Posted: 12.18.2019

Thomas R. Sawallis and Louis-Jean Boë Sound doesn’t fossilize. Language doesn’t either. Even when writing systems have developed, they’ve represented full-fledged and functional languages. Rather than preserving the first baby steps toward language, they’re fully formed, made up of words, sentences and grammar carried from one person to another by speech sounds, like any of the perhaps 6,000 languages spoken today. So if you believe, as we linguists do, that language is the foundational distinction between humans and other intelligent animals, how can we study its emergence in our ancestors? Happily, researchers do know a lot about language – words, sentences and grammar – and speech – the vocal sounds that carry language to the next person’s ear – in living people. So we should be able to compare language with less complex animal communication. And that’s what we and our colleagues have spent decades investigating: How do apes and monkeys use their mouth and throat to produce the vowel sounds in speech? Spoken language in humans is an intricately woven string of syllables with consonants appended to the syllables’ core vowels, so mastering vowels was a key to speech emergence. We believe that our multidisciplinary findings push back the date for that crucial step in language evolution by as much as 27 million years. The sounds of speech Say “but.” Now say “bet,” “bat,” “bought,” “boot.” The words all begin and end the same. It’s the differences among the vowel sounds that keep them distinct in speech. © 2010–2019, The Conversation US, Inc.

Keyword: Language; Evolution
Link ID: 26893 - Posted: 12.12.2019

By Eva Frederick Many human grandmothers love to spoil their grandchildren with attention and treats, and for good reason: Studies have shown that having a living grandmother increases a child’s chance of survival. Now, new research shows the same may be true for killer whales. By providing young animals with some freshly caught salmon now and then—or perhaps with knowledge on where to find it—grannies increase their grand-offspring’s chance of survival. The new study is the first direct evidence in nonhuman animals of the “grandmother hypothesis.” The idea posits that females of some species live long after they stop reproducing to provide extra care for their grandchildren. “It’s very cool that these long-lived cetaceans have what looks like a postfertile life stage,” says Kristen Hawkes, an anthropologist at the University of Utah in Salt Lake City who has dedicated much of her career to studying the grandmother effect; she was not involved in the new study. Women usually go through menopause between ages 45 and 55, even though they may live to age 80, 90, or older. Studies in modern-day hunter-gatherer communities as well as in populations in Finland and Canada show that older women can help increase the number of children their daughters have, and boost the survival rates of their grandchildren. Dan Franks, a computer scientist and biologist at the University of York in the United Kingdom, wanted to know whether this grandmother effect occurs in other species as well. © 2019 American Association for the Advancement of Science

Keyword: Sexual Behavior; Evolution
Link ID: 26887 - Posted: 12.10.2019

By Carolyn Gramling Exceptionally preserved skulls of a mammal that lived alongside the dinosaurs may be offering scientists a glimpse into the evolution of the middle ear. The separation of the three tiny middle ear bones — known popularly as the hammer, anvil and stirrup — from the jaw is a defining characteristic of mammals. The evolutionary shift of those tiny bones, which started out as joints in ancient reptilian jaws and ultimately split from the jaw completely, gave mammals greater sensitivity to sound, particularly at higher frequencies (SN: 3/20/07). But finding well-preserved skulls from ancient mammals that can help reveal the timing of this separation is a challenge. Now, scientists have six specimens — four nearly complete skeletons and two fragmented specimens — of a newly described, shrew-sized critter dubbed Origolestes lii that lived about 123 million years ago. O. lii was part of the Jehol Biota, an ecosystem of ancient wetlands-dwellers that thrived between 133 million and 120 million years ago in what’s now northeastern China. The skulls on the nearly complete skeletons were so well-preserved that they were able to be examined in 3-D, say paleontologist Fangyuan Mao of the Chinese Academy of Sciences in Beijing and colleagues. That analysis suggests that O. lii’s middle ear bones were fully separated from its jaw, the team reports online December 5 in Science. Fossils from an older, extinct line of mammals have shown separated middle ear bones, but this newfound species would be the first of a more recent lineage to exhibit this evolutionary advance. © Society for Science & the Public 2000–2019

Keyword: Hearing; Evolution
Link ID: 26880 - Posted: 12.07.2019

By Virginia Morell Say “sit!” to your dog, and—if he’s a good boy—he’ll likely plant his rump on the floor. But would he respond correctly if the word were spoken by a stranger, or someone with a thick accent? A new study shows he will, suggesting dogs perceive spoken words in a sophisticated way long thought unique to humans. “It’s a very solid and interesting finding,” says Tecumseh Fitch, an expert on vertebrate communication at the University of Vienna who was not involved in the research. The way we pronounce words changes depending on our sex, age, and even social rank. Some as-yet-unknown neural mechanism enables us to filter out differences in accent and pronunciation, helping us understand spoken words regardless of the speaker. Animals like zebra finches, chinchillas, and macaques can be trained to do this, but until now only humans were shown to do this spontaneously. In the new study, Holly Root-Gutteridge, a cognitive biologist at the University of Sussex in Brighton, U.K., and her colleagues ran a test that others have used to show dogs can recognize other dogs from their barks. The researchers filmed 42 dogs of different breeds as they sat with their owners near an audio speaker that played six monosyllabic, noncommand words with similar sounds, such as “had,” “hid,” and “who’d.” The words were spoken—not by the dog’s owner—but by several strangers, men and women of different ages and with different accents. © 2019 American Association for the Advancement of Science.

Keyword: Language; Evolution
Link ID: 26866 - Posted: 12.04.2019

Nicola Davis Dolphins, like humans, have a dominant right-hand side, according to research. About 90% of humans are right-handed but we are not the only animals that show such preferences: gorillas tend to be right-handed, kangaroos are generally southpaws, and even cats have preferences for a particular side – although which is favoured appears to depend on their sex. Now researchers have found common bottlenose dolphins appear to have an even stronger right-side bias than humans. “I didn’t expect to find it in that particular behaviour, and I didn’t expect to find such a strong example,” said Dr Daisy Kaplan, co-author of the study from the Dolphin Communication Project, a non-profit organisation in the US. Researchers studying common bottlenose dolphins in the Bahamas say the preference shows up in crater feeding, whereby dolphins swim close to the ocean floor, echolocating for prey, before shoving their beaks into the sand to snaffle a meal. Writing in the journal Royal Society Open Science, Kaplan and colleagues say the animals make a sharp and sudden turn before digging in with their beaks. Crucially, however, they found this turn is almost always to the left, with the same direction taken in more than 99% of the 709 turns recorded between 2012 and 2018. The researchers say the findings indicate a right-side bias, since a left turn keeps a dolphin’s right eye and right side close to the ocean floor. The team found only four turns were made to the right and all of these were made by the same dolphin, which had an oddly shaped right pectoral fin. However the Kaplan said it was unlikely this fin was behind the right turns: two other dolphins had an abnormal or missing right fin yet still turned left.

Keyword: Laterality; Evolution
Link ID: 26861 - Posted: 12.02.2019

Suzana Herculano-Houzel Here’s something new to consider being thankful for at the dinner table: the long evolutionary journey that gave you your big brain and your long life. Courtesy of our primate ancestors that invented cooking over a million years ago, you are a member of the one species able to afford so many cortical neurons in its brain. With them come the extended childhood and the pushing century-long lifespan that together make human beings unique. All these bequests of your bigger brain cortex mean you can gather four generations around a meal to exchange banter and gossip, turn information into knowledge and even practice the art of what-not-to-say-when. You may even want to be thankful for another achievement of our neuron-crammed human cortices: all the technology that allows people spread over the globe to come together in person, on screens, or through words whispered directly into your ears long distance. I know I am thankful. But then, I’m the one proposing that we humans revise the way we tell the story of how our species came to be. Back when I had just received my freshly minted Ph.D. in neuroscience and started working in science communication, I found out that 6 in 10 college-educated people believed they only used 10% of their brains. I’m glad to say that they’re wrong: We use all of it, just in different ways at different times. The myth seemed to be supported by statements in serious textbooks and scientific articles that “the human brain is made of 100 billion neurons and 10 times as many supporting glial cells.” I wondered if those numbers were facts or guesses. Did anyone actually know that those were the numbers of cells in the human brain? No, they didn’t. © 2010–2019, The Conversation US, Inc.

Keyword: Intelligence; Neurogenesis
Link ID: 26857 - Posted: 11.29.2019

By Veronique Greenwood A few years back, Ryan Herbison, then a graduate student in parasitology at the University of Otago, painstakingly collected about 1,300 earwigs and more than 2,500 sandhoppers from gardens and a beach in New Zealand. Then, he dissected and examined the insides of their heads. This macabre scavenger hunt was in search of worms that lay coiled within some of the insects. The worms are parasites that force earwigs and sandhoppers to march into bodies of water, drowning themselves so the worms’ aquatic offspring can thrive. “Like a back-seat driver, but a bit more sinister,” said Mr. Herbison, describing these mind-controlling parasites. “And sometimes they may just grab the steering wheel.” Just how they do that, though, has remained a bit of a mystery. But in a paper published Wednesday in Proceedings of the Royal Society B, Mr. Herbison and fellow researchers reported that the parasites seemed to be manipulating the production of host proteins involved in generating energy and movement in their unfortunate hosts. The analysis is limited, but the researchers speculated that the parasites may be affecting neuronal connections in the bugs’ brains and perhaps even interfering with memory in a way that puts the hosts at risk. Parasites use a variety of similar strategies. Some make cat urine suicidally attractive to mice, which are promptly eaten so that the parasites can go through the next phase of their life cycle in the cat. Others prompt ants to expose themselves on high tree branches, the better to be eaten by birds. And still others cause snails to hang out in open spaces, with swollen eyestalks pulsing like neon signs, for apparently the same reason. © 2019 The New York Times Company

Keyword: Learning & Memory; Evolution
Link ID: 26845 - Posted: 11.22.2019

By Susana Martinez-Conde The many evils of social media notwithstanding, millions of users agree that some of its most delightful aspects include viral illusions and cute cat videos. The potential for synergy was vast in retrospect—but only realized in 2013, when Rasmus Bååth, a cognitive scientist from Lund University in Sweden, blended both elements in a YouTube video of his kitten attacking a printed version of Akiyoshi Kitaoka’s famous “Rotating Snakes” illusion. The clip, which has been viewed more than 6 million times as of this writing, led to subsequent empirical research and an internet survey of cat owners, where 29% of respondents answered that their pets reacted to the Rotating Snakes. The results, published in the journal Psychology in 2014, indicated—though not conclusively—that cats experience illusory motion when they look at the Rotating Snakes pattern, much as most humans do. Now, a team of researchers from University of Padova, Italy, Queen Mary University of London in the UK, and the Parco Natura Viva—Garda Zoological Park in Bussolengo, Italy, has collected additional evidence that cats—in this case, big cats—find the Rotating Snakes Illusion fascinating. Advertisement Intrigued by the earlier study on house cats, Christian Agrillo of the University of Padova and his collaborators set out to determine whether lions at Parco Natura Viva were similarly susceptible to motion illusions, as well as explore the possibility that such patterns might serve as a source of visual enrichment for zoo animals. Their findings were published last month in Frontiers in Psychology. © 2019 Scientific American,

Keyword: Vision; Evolution
Link ID: 26826 - Posted: 11.18.2019

By Bruce Bower An ancient ape that was larger than a full-grown male gorilla has now revealed molecular clues to its evolutionary roots. Proteins extracted from a roughly 1.9-million-year-old tooth of the aptly named Gigantopithecus blacki peg it as a close relative of modern orangutans and their direct ancestors, say bioarchaeologist Frido Welker of the University of Copenhagen and his colleagues. Protein comparisons among living and fossil apes suggest that Gigantopithecus and orangutan forerunners diverged from a common ancestor between around 10 million and 12 million years ago, Welker’s group reports November 13 in Nature. Since it was first described in 1935, based on a molar purchased from a traditional Chinese drugstore in Hong Kong, G. blacki has stimulated debate over its evolutionary links to other ancient apes. Almost 2,000 isolated teeth and four partial jaws of G. blacki have since been found in southern China and nearby parts of Southeast Asia. G. blacki fossils date from around 2 million to almost 300,000 years ago. The sizes of individual teeth and jaws indicate that G. blacki weighed between 200 and 300 kilograms. Proteins preserve better in teeth and bones than DNA does, but both molecular forms break down quickly in hot, humid settings. “We were surprised to find any proteins this old at all, especially in a fossil from a subtropical environment,” Welker says. Proteins consisting of chains of amino acids can be used to sort out living and fossil species of various animals, including hominids (SN: 5/1/19). © Society for Science & the Public 2000–2019

Keyword: Evolution
Link ID: 26818 - Posted: 11.14.2019

By Karinna Hurley Part of the Museum of Natural History in Paris, the Jardin des Plantes, on the left bank of the Seine River, hosts a collection of galleries and gardens. A couple of miles away, the larger museum also includes the Museum of Mankind, which is, in part, an exploration of what it means to be human. There, like in many other museums worldwide, you can view a collection of stone tools used by the earliest humans. Tool use was long believed to be unique to our species—a defining feature, like language. Utilizing objects to achieve goals is not just a demonstration of advanced cognitive capabilities; it is largely through our symbolic and material tools that we share and transmit culture. In 1960 primatologist Jane Goodall observed wild chimpanzees making and using tools. A connection between humans and other animals, in how we think and learn, was captivating news. Since then, scientists have gone on to establish tool use in a relatively small number of other species. And observations of learning to use a tool from other group members, rather than instinctively, have been even more rare—until now. The Jardin des Plantes is also home to a special couple, Priscilla and Billie. Along with at least one of their daughters, these Visayan warty pigs—residents of the garden’s zoo—are the first in any pig species to be identified using tools and, even more remarkably, to apparently transmit this behavior through social learning. The discovery was made by chance by ecologist Meredith Root-Bernstein, who was watching the family from outside its enclosure. Priscilla, working on building a nest, picked up a piece of bark in her mouth and used it to aid her digging. For six weeks Root-Bernstein frequently returned to the zoo to try to again catch her in the act. Although she didn’t do so, she did notice the digging tool moved among different areas of the enclosure and always near a recently constructed nest. © 2019 Scientific American

Keyword: Evolution; Intelligence
Link ID: 26817 - Posted: 11.14.2019

By Elizabeth Preston A pack of baldheaded, boldly plumaged birds steps through the grass shoulder to shoulder, red eyes darting around. They look like middle schoolers seeking a cafeteria table at lunchtime. Perhaps they’re not so different. A study published Monday in Current Biology shows that the vulturine guineafowl of eastern Africa, like humans, have many-layered societies. In the past, scientists hypothesized that such social structures require a lot of brainpower. But the pea-brained guineafowl are revealing the flaws in that assumption. Damien Farine, who led the research and is an ornithologist at the Max Planck Institute of Animal Behavior who studies collective behavior, first worked in Kenya during his postdoctoral research on baboon societies. Baboons are a model for researchers trying to understand how human society evolved. Some kinds of baboons live in groups within groups, a structure that’s called a multilevel society. “Humans are the classic multilevel society,” Dr. Farine said. Imagine a human family living in a village: The family might be friendly with other families within the village, which in turn might have ties to neighboring villages, and so on. “People have long hypothesized that living in complex society is one of the reasons why we’ve evolved such large brains,” Dr. Farine said. Researchers have found evidence for multilevel societies in some other large-brained mammals, such as monkeys, elephants, giraffes and sperm whales. But as Dr. Farine studied baboons, he also watched the vulturine guineafowl wandering around his study site. “I was really struck by the social behavior that they exhibited,” he said. These hefty birds can fly, but rarely choose to. Instead, they stroll across the landscape in packs, often walking so closely that their bodies touch. They may chase each other or fight to maintain their strict hierarchies. But at other times they engage in friendly behaviors like sharing food. Their groups are unusually large for birds, sometimes including 60 or more individuals. And while most other social birds are very territorial, Dr. Farine says, groups of vulturine guineafowl don’t mind sharing turf. © 2019 The New York Times Company

Keyword: Evolution
Link ID: 26789 - Posted: 11.05.2019