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Chloe Tenn Whether they’re predicting the outcomes of sports games or opening jars, the intelligence of octopuses and their cephalopod kin has fascinated avid sports fans and scientists alike (not that the two groups are mutually exclusive). However, insights into the animals’ brains have been limited, as structural data has come from low-tech methods such as dissection. Wen-Sung Chung, a University of Queensland Brain Institute neurobiologist who focuses on marine species, explains that octopuses have “probably the biggest centralized brain in invertebrates,” with multiple layers and lobes. Some species have more than 500 million neurons, he adds—compared to around 70 million in lab mice—making cephalopods especially intriguing as models for neuroscience. Chung and his colleagues decided to bring cephalopod neuroscience into the 21st century: using cutting-edge MRI, they probed the brains of four cephalopod species. They were especially interested in exploring whether cephalopod brain structures reflect the environments they live in. Indeed, the team reports numerous structural differences between species that live on reefs and those that dwell in deeper waters in a November 18 Current Biology paper. Giovanna Ponte, an evolutionary marine biologist at Stazione Zoologica Anton Dohrn Napoli in Italy who was not involved with the work, tells The Scientist that while this isn’t the first study to look for neurological correlates underlying ecological differences in cephalopods, it offers a new technological approach to investigating these animals’ brain morphology and diversity, and most importantly, “is the first time that there is . . . a comparative approach between different species.” © 1986–2022 The Scientist.

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 28166 - Posted: 01.22.2022

By Carl Zimmer Edward O. Wilson, a biologist and author who conducted pioneering work on biodiversity, insects and human nature — and won two Pulitzer Prizes along the way — died on Sunday in Burlington, Mass. He was 92. His death was announced on Monday by the E.O. Wilson Biodiversity Foundation. When Dr. Wilson began his career in evolutionary biology in the 1950s, the study of animals and plants seemed to many scientists like a quaint, obsolete hobby. Molecular biologists were getting their first glimpses of DNA, proteins and other invisible foundations of life. Dr. Wilson made it his life’s work to put evolution on an equal footing. “How could our seemingly old-fashioned subjects achieve new intellectual rigor and originality compared to molecular biology?” he recalled in 2009. He answered his own question by pioneering new fields of research. As an expert on insects, Dr. Wilson studied the evolution of behavior, exploring how natural selection and other forces could produce something as extraordinarily complex as an ant colony. He then championed this kind of research as a way of making sense of all behavior — including our own. As part of his campaign, Dr. Wilson wrote a string of books that influenced his fellow scientists while also gaining a broad public audience. “On Human Nature” won the Pulitzer Prize for general nonfiction in 1979; “The Ants,” which Dr. Wilson wrote with his longtime colleague Bert Hölldobler, won him his second Pulitzer, in 1991. © 2021 The New York Times Company

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:None
Link ID: 28125 - Posted: 12.29.2021

Rafael Yuste Michael Levin In the middle of his landmark book On the Origin of Species, Darwin had a crisis of faith. In a bout of honesty, he wrote, “To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I confess, absurd in the highest degree.” While scientists are still working out the details of how the eye evolved, we are also still stuck on the question of how intelligence emerges in biology. How can a biological system ever generate coherent and goal-oriented behavior from the bottom up when there is no external designer? In fact, intelligence—a purposeful response to available information, often anticipating the future—is not restricted to the minds of some privileged species. It is distributed throughout biology, at many different spatial and temporal scales. There are not just intelligent people, mammals, birds and cephalopods. Intelligent, purposeful problem-solving behavior can be found in parts of all living things: single cells and tissues, individual neurons and networks of neurons, viruses, ribosomes and RNA fragments, down to motor proteins and molecular networks. Arguably, understanding the origin of intelligence is the central problem in biology—one that is still wide open. In this piece, we argue that progress in developmental biology and neuroscience is now providing a promising path to show how the architecture of modular systems underlies evolutionary and organismal intelligence. © 2021 Scientific American

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28118 - Posted: 12.18.2021

By Bruce Bower Evidence that cross-continental Stone Age networking events powered human evolution ramped up in 2021. A long-standing argument that Homo sapiens originated in East Africa before moving elsewhere and replacing Eurasian Homo species such as Neandertals has come under increasing fire over the last decade. Research this year supported an alternative scenario in which H. sapiens evolved across vast geographic expanses, first within Africa and later outside it. The process would have worked as follows: Many Homo groups lived during a period known as the Middle Pleistocene, about 789,000 to 130,000 years ago, and were too closely related to have been distinct species. These groups would have occasionally mated with each other while traveling through Africa, Asia and Europe. A variety of skeletal variations on a human theme emerged among far-flung communities. Human anatomy and DNA today include remnants of that complex networking legacy, proponents of this scenario say. It’s not clear precisely how often or when during this period groups may have mixed and mingled. But in this framework, no clear genetic or physical dividing line separated Middle Pleistocene folks usually classed as H. sapiens from Neandertals, Denisovans and other ancient Homo populations. “Middle Pleistocene Homo groups were humans,” says paleoanthropologist John Hawks of the University of Wisconsin–Madison. “Today’s humans are a remix of those ancient ancestors.” © Society for Science & the Public 2000–2021.

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 28111 - Posted: 12.15.2021

By Bruce Bower A child’s partial skull found in a remote section of a South African cave system has fueled suspicion that an ancient hominid known as Homo naledi deliberately disposed of its dead in caves. An international team led by paleoanthropologist Lee Berger of University of the Witwatersrand, Johannesburg pieced together 28 skull fragments and six teeth from a child’s skull discovered in a narrow opening located about 12 meters from an underground chamber where cave explorers first found H. naledi fossils (SN: 9/10/15). Features of the child’s skull qualify it as H. naledi, a species with an orange-sized brain and skeletal characteristics of both present-day people and Homo species from around 2 million years ago. “The case is building for deliberate, ritualized body disposal in caves by Homo naledi,” Berger said at a November 4 news conference held in Johannesburg. While that argument is controversial, there is no evidence that the child’s skull was washed into the tiny space or dragged there by predators or scavengers (SN: 4/19/16). Berger’s group describes the find in two papers published November 4 in PaleoAnthropology. In one, Juliet Brophy, a paleoanthropologist at Louisiana State University in Baton Rouge and colleagues describe the youngster’s skull. In the other, paleoanthropologist Marina Elliott of Canada’s Simon Fraser University in Burnaby and colleagues detail new explorations in South Africa’s Rising Star cave system. © Society for Science & the Public 2000–2021.

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:None
Link ID: 28068 - Posted: 11.09.2021

By Laura Sanders Brains are like sponges, slurping up new information. But sponges may also be a little bit like brains. Sponges, which are humans’ very distant evolutionary relatives, don’t have nervous systems. But a detailed analysis of sponge cells turns up what might just be an echo of our own brains: cells called neuroids that crawl around the animal’s digestive chambers and send out messages, researchers report in the Nov. 5 Science. The finding not only gives clues about the early evolution of more complicated nervous systems, but also raises many questions, says evolutionary biologist Thibaut Brunet of the Pasteur Institute in Paris, who wasn’t involved in the study. “This is just the beginning,” he says. “There’s a lot more to explore.” The cells were lurking in Spongilla lacustris, a freshwater sponge that grows in lakes in the Northern Hemisphere. “We jokingly call it the Godzilla of sponges” because of the rhyme with Spongilla, say Jacob Musser, an evolutionary biologist in Detlev Arendt’s group at the European Molecular Biology Laboratory in Heidelberg, Germany. Simple as they are, these sponges have a surprising amount of complexity, says Musser, who helped pry the sponges off a metal ferry dock using paint scrapers. “They’re such fascinating creatures.” © Society for Science & the Public 2000–2021.

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28065 - Posted: 11.06.2021

By Trishla Ostwal Juan Negro crouched in the shadows just outside a cave, wearing his headlamp. For a brief moment, he wasn’t an ornithologist at the Spanish National Research Council’s Doñana Biological Station in Seville. He was a Neandertal, intent on catching dinner. As he waited in the cold, dark hours of the night, crowlike birds called choughs entered the cave. The “Neandertal” then stealthily snuck in and began the hunt. This idea to role-play started with butchered bird bones. Piles of ancient tool- and tooth-nicked choughs bones have been found in the same caves that Neandertals frequented, evidence suggesting that the ancient hominids chowed down on the birds. But catching choughs is tricky. During the day, they fly far to feed on invertebrates, seeds and fruits. At night though, their behavior practically turns them into sitting ducks. The birds roost in groups and often return to the same spot, even if they’ve been disturbed or preyed on there before. So the question was, how might Neandertals have managed to catch these avian prey? To find out, Negro and his colleagues decided to act like, well, Neandertals. Wielding bare hands along with butterfly nets and lamps — proxy for nets (SN: 04/09/20) and fire (SN: 2/20/14) that Neandertals may have had at hand— teams of two to 10 researchers silently snuck into caves and other spots across Spain, where the birds roost to see how many choughs they could catch. a person inside a building attempting to catch a bird © Society for Science & the Public 2000–2021

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:None
Link ID: 28026 - Posted: 10.09.2021

By Carl Zimmer Ancient human footprints preserved in the ground across the White Sands National Park in New Mexico are astonishingly old, scientists reported on Thursday, dating back about 23,000 years to the Ice Age. The results, if they hold up to scrutiny, would rejuvenate the scientific debate about how humans first spread across the Americas, implying that they did so at a time when massive glaciers covered much of their path. Researchers who have argued for such an early arrival hailed the new study as firm proof. “I think this is probably the biggest discovery about the peopling of America in a hundred years,” said Ciprian Ardelean, an archaeologist at Autonomous University of Zacatecas in Mexico who was not involved in the work. “I don’t know what gods they prayed to, but this is a dream find.” For decades, many archaeologists have maintained that humans spread across North and South America only at the end of the last ice age. They pointed to the oldest known tools, including spear tips, scrapers and needles, dating back about 13,000 years. The technology was known as Clovis, named for the town of Clovis, N.M., where some of these first instruments came to light. The age of the Clovis tools lined up neatly with the retreat of the glaciers. That alignment bolstered a scenario in which Siberian hunter-gatherers moved into Alaska during the Ice Age, where they lived for generations until ice-free corridors opened and allowed them to expand southward. But starting in the 1970s, some archaeologists began publishing older evidence of humanity’s presence in North America. Last year, Dr. Ardelean and his colleagues published a report of stone tools in a mountain cave in Mexico dating back 26,000 years. © 2021 The New York Times Company

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:None
Link ID: 28006 - Posted: 09.25.2021

By Jonathan Lambert Vampire bats may be bloodthirsty, but that doesn’t mean they can’t share a drink with friends. Fights can erupt among bats over gushing wounds bit into unsuspecting animals. But bats that have bonded while roosting often team up to drink blood away from home, researchers report September 23 in PLOS Biology. Vampire bats (Desmodus rotundus) can form long-term social bonds with each other through grooming, sharing regurgitated blood meals and generally hanging out together at the roost (SN: 10/31/19). But whether these friendships, which occur between both kin and nonkin, extend to the bats’ nightly hunting had been unclear. “They’re flying around out there, but we didn’t know if they were still interacting with each other,” says Gerald Carter, an evolutionary biologist at Ohio State University in Columbus. To find out, Carter and his colleague Simon Ripperger of the Museum für Naturkunde in Berlin, built on previous research that uncovered a colony’s social network using bat backpacks. Tiny computer sensors glued to 50 female bats in Tolé, Panama, continuously registered proximity to other sensors both within the roost and outside, revealing when bats met up while foraging. Two common vampire bats feed on a cow near La Chorrera, Panama. It can take 10 to 40 minutes for a bat to bite a small, diamond-shaped wound into an animal’s flesh, and fights can sometimes break out over access to wounds. But researchers found that bats who are friendly back at the roost likely feed together in the field, potentially saving time and energy. © Society for Science & the Public 2000–2021

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 15: Language and Lateralization
Link ID: 28005 - Posted: 09.25.2021

By Carl Zimmer Sign up for Science Times Get stories that capture the wonders of nature, the cosmos and the human body. Get it sent to your inbox. For half a billion years or so, our ancestors sprouted tails. As fish, they used their tails to swim through the Cambrian seas. Much later, when they evolved into primates, their tails helped them stay balanced as they raced from branch to branch through Eocene jungles. But then, roughly 25 million years ago, the tails disappeared. Charles Darwin first recognized this change in our ancient anatomy. But how and why it happened has remained a mystery. Now a team of scientists in New York say they have pinpointed the genetic mutation that may have erased our tails. When the scientists made this genetic tweak in mice, the animals didn’t grow tails, according to a new study that was posted online last week. This dramatic anatomical change had a profound impact on our evolution. Our ancestors’ tail muscles evolved into a hammock-like mesh across the pelvis. When the ancestors of humans stood up and walked on two legs a few million years ago, that muscular hammock was ready to support the weight of upright organs. Although it’s impossible to definitively prove that this mutation lopped off our ancestors’ tails, “it’s as close to a smoking gun as one could hope for,” said Cedric Feschotte, a geneticist at Cornell who was not involved in the study. Darwin shocked his Victorian audiences by claiming that we descended from primates with tails. He noted that while humans and apes lack a visible tail, they share a tiny set of vertebrae that extend beyond the pelvis — a structure known as the coccyx. “I cannot doubt that it is a rudimentary tail,” he wrote. © 2021 The New York Times Company

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 28001 - Posted: 09.22.2021

By Priyanka Runwal Brain tissue is innately squishy. Unlike bones, shells or teeth, it is rich in fat and rots quickly, seldom making an appearance in the fossil record. So when Russell Bicknell, an invertebrate paleontologist at the University of New England in Australia, noticed a pop of white near the front of a fossilized horseshoe crab body where the animal’s brain would have been, he was surprised. A closer look revealed an exceptional imprint of the brain along with other bits of the creature’s nervous system. Unearthed from the Mazon Creek deposit in northeastern Illinois, and dating back 310 million years, it’s the first fossilized horseshoe crab brain ever found. Dr. Bicknell and his colleagues reported the find last month in the journal Geology. “These kinds of fossils are so rare that if you happen to stumble upon one, you’d generally be in shock,” he said. “We’re talking a needle-in-a-haystack level of wow.” The find helps fill a gap in the evolution of arthropod brains and also shows how little they have changed over hundreds of millions of years. Soft-tissue preservation requires special conditions. Scientists have found brains encased in fossilized tree resin, better known as amber, that were less than 66 million years old. They have also found brains preserved as flattened carbon films, sometimes replaced or overlaid by minerals in shale deposits that are more than 500 million years old. Such deposits include corpses of ocean-dwelling arthropods that sank to the seafloor, were rapidly buried in mud and remained shielded from immediate decay in the low-oxygen environment. However, the fossilized brain of Euproops danae, which is kept in a collection at the Yale Peabody Museum of Natural History, required a different set of conditions to be preserved. © 2021 The New York Times Company

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:None
Link ID: 27956 - Posted: 08.21.2021

By Cara Giaimo Giraffes seem above it all. They float over the savanna like two-story ascetics, peering down at the fray from behind those long lashes. For decades, many biologists thought giraffes extended this treatment to their peers as well, with one popular wildlife guide calling them “aloof” and capable of only “the most casual” associations. Sign up for Science Times Get stories that capture the wonders of nature, the cosmos and the human body. Get it sent to your inbox. But more recently, as experts have paid closer attention to these lanky icons, a different social picture has begun to emerge. Female giraffes are now known to enjoy yearslong bonds. They have lunch buddies, stand guard over dead calves and stay close with their mothers and grandmothers. Females even form shared day care-like arrangements, called crèches, in which they take turns babysitting and feeding each others young. Observations like these have reached a critical mass, said Zoe Muller, a wildlife biologist who completed her Ph.D. at the University of Bristol in England. She and Stephen Harris, also at Bristol, recently reviewed hundreds of giraffe studies to look for broader patterns. Their analysis, published on Tuesday in the journal Mammal Review, suggests that giraffes are not loners, but socially complex creatures, akin to elephants or chimpanzees. They’re just a little more subtle about it. Dr. Muller’s sense of giraffes as secret socialites began in 2005, when she was researching her master’s thesis in Laikipia, Kenya. There to collect data on antelopes, she found herself drawn to the ganglier ungulates. “They are so weird to look at,” she said. “If somebody described them to you, you wouldn’t believe they even really existed.” After noticing that the same giraffes tended to spend time together — they looked “like teenagers hanging out,” she said — Dr. Muller started to read up on their lifestyles. “I was really surprised to see that all the scientific books said that they were completely non-sociable,” she said. “I thought, ‘Well, hang on. That’s not what I see at all.’” © 2021 The New York Times Company

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 27945 - Posted: 08.11.2021

By Jaime Chambers Wiggles and wobbles and a powerful pull toward people — that’s what 8-week-old puppies are made of. From an early age, dogs outpace wolves at engaging with and interpreting cues from humans, even if the dogs have had less exposure to people, researchers report online July 12 in Current Biology. The result suggests that domestication has reworked dogs’ brains to make the pooches innately drawn to people — and perhaps to intuit human gestures. Compared with human-raised wolf pups, dog puppies that had limited exposure to people were still 30 times as likely to approach a strange human, and five times as likely to approach a familiar person. “I think that is by far the clearest result in the paper, and is powerful and meaningful,” says Clive Wynne, a canine behavioral scientist at Arizona State University in Tempe who was not involved in the study. Wolf pups are naturally less entranced by people than dogs are. “When I walked into the [wolf] pen for the first time, they would all just run into the corner and hide,” says Hannah Salomons, an evolutionary anthropologist studying dog cognition at Duke University. Over time, Salomons says, most came to ignore her, “acting like I was a piece of furniture.” But dogs can’t seem to resist humans’ allure (SN: 7/19/17). They respond much more readily to people, following where a person points, for example. That ability may seem simple, but it’s a skill even chimpanzees — humans’ close relatives — don’t show. Human babies don’t learn how to do it until near their first birthday. © Society for Science & the Public 2000–2021

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 27906 - Posted: 07.14.2021

By Veronique Greenwood Captive cuttlefish require entertainment when they eat. Dinner and a show — if they can’t get live prey, then they need some dancing from a dead shrimp on a stick in their tank. When the food looks alive, the little cephalopods, which look like iridescent footballs with eight short arms and two tentacles, are more likely to eat it. Because a person standing before them has to jiggle it, the animals start to recognize that mealtime and a looming human-shaped outline go together. As soon as a person walks into the room, “they all swim to the front of the tank saying, give me food!” said Trevor Wardill, a biologist at the University of Minnesota who studies cuttlefish vision. You may get a squirt of water from a cuttlefish’s siphon if you don’t feed them, though. Alexandra Schnell, a comparative psychologist at the University of Cambridge, recalled some who sprayed her if she was even a little slow with the treats. It’s the kind of behavior that researchers who’ve worked with cuttlefish sometimes remark on: The critters have character. But they do not have the name recognition of their cousins — the octopus and the squid. Even Tessa Montague, a neuroscientist who today studies cuttlefish at Columbia University, hadn’t really heard of them until an aquarium visit during graduate school. “Octopus are obviously part of lots of children’s story books,” she notes. Cuttlefish were not present. During the last week of a course at the Marine Biological Laboratory in Woods Hole, Mass., though, she heard a talk by Bret Grasse, whom she called a “cephalopod guru.” “He said they have three hearts, green blood and one of the largest brains among invertebrates,” she said. “And they can regenerate their limbs, they can camouflage. Within about 30 seconds, I had basically planned out my entire life. That lunchtime I went to the facility where he was culturing all these animals. My entire scientific career flashed in front of me. I was like, this is it, this is what I’ve been looking for.” © 2021 The New York Times Company

Related chapters from BN: Chapter 17: Learning and Memory; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 27903 - Posted: 07.10.2021

Rebecca Hersher Big bodies are good for cold places. That's the gist of a foundational rule in ecology that has been around since the mid-1800s: Animals that live in colder places tend to have larger bodies, especially birds and mammals that need to regulate their body temperatures. For example, some of the largest whale and bear species have evolved in the coldest reaches of the planet. The rule applies broadly to modern humans too. Populations that evolved in colder places generally have bigger bodies. That's also true of human ancestors, a new study finds. The research offers conclusive evidence that human body size and climate are historically connected. In general, our ancient relatives got much larger as they evolved. "Over the last million years, you see that body size changes by about 50% and brain size actually triples, which is a lot," explains Andrea Manica, an evolutionary ecologist at the University of Cambridge. "And there have been all sorts of theories about what might have underpinned those two big changes in size." Article continues after sponsor message Manica and a team of paleontologists and climate scientists in Germany and the United Kingdom set out to test one of those theories: that the local climate was driving brain and body growth. They examined about 300 fossils of human ancestors collected in Europe, Asia and Africa, and they used the same basic climate data that scientists use to predict future climate change to estimate instead temperature and precipitation over the last million years. © 2021 npr

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:None
Link ID: 27901 - Posted: 07.10.2021

By Bruce Bower A fossil skull nicknamed “Dragon Man” has surfaced in China under mysterious circumstances, with big news for Neandertals. Dragon Man belonged to a previously unrecognized Stone Age species that replaces Neandertals as the closest known relatives of people today, researchers say. A nearly complete male skull now housed in the Geoscience Museum of Hebei GEO University in Shijiazhuang, China, represents a species dubbed Homo longi by Hebei GEO paleoanthropologist Xijun Ni and his colleagues. The scientists describe the skull, which dates to at least 146,000 years ago, and analyze its position in Homo evolution in three papers published June 25 in The Innovation. Qiang Ji, a paleontologist also at Hebei GEO, received the skull in 2018 from a farmer who said the fossil had been dug up by a coworker of his grandfather’s in 1933. During bridge construction over a river in Harbin, China, the worker allegedly scooped the skull out of river sediment. Whether or not that story is true, this fossil could help answer questions about a poorly understood period of human evolution. “The Harbin cranium presents a combination of features setting it apart from other Homo species,” Ji says. The name H. longi derives from a Chinese term for the province where it was found, which translates as “dragon river.” That term inspired the nickname Dragon Man. As in H. sapiens, the Harbin skull held a large brain situated atop a relatively short face and small cheek bones. But traits such as a long, low braincase, thick brow ridges, large molars and almost square eye sockets recall several extinct Homo populations or species, including Neandertals and H. heidelbergensis (SN: 4/1/20). © Society for Science & the Public 2000–2021

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:None
Link ID: 27878 - Posted: 06.26.2021

By Christa Lesté-Lasserre In the animal kingdom, killer whales are social stars: They travel in extended, varied family groups, care for grandchildren after menopause, and even imitate human speech. Now, marine biologists are adding one more behavior to the list: forming fast friendships. A new study suggests the whales rival chimpanzees, macaques, and even humans when it comes to the kinds of “social touching” that indicates strong bonds. The study marks “a very important contribution to the field” of social behavior in dolphins and whales, says José Zamorano-Abramson, a comparative psychologist at the Complutense University of Madrid who wasn’t involved in the work. “These new images show lots of touching of many different types, probably related to different kinds of emotions, much like the complex social dynamics we see in great apes.” Audio and video recordings have shown how some marine mammals maintain social structures—including male dolphins that learn the “names” of close allies. But there is little footage of wild killer whales—which hunt and play in open water. Although the whales only swim at about 6 kilometers per hour, it’s hard to fully observe them from boats, and they might not act naturally near humans, Zamorano-Abramson says. That’s where drone technology came swooping in. Michael Weiss, a behavioral ecologist at the Center for Whale Research in Friday Harbor, Washington, teamed up with colleagues to launch unmanned drones from their 6.5-meter motorboat and from the shores of the northern Pacific Ocean, flying them 30 to 120 meters above a pod of 22 southern resident killer whales. That was high enough to respect federal aviation requirements—and not bother the whales. They logged 10 hours of footage over a 10-day period, marking the first time drones have been used to study friendly physical contacts in any cetacean. © 2021 American Association for the Advancement of Science.

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 27864 - Posted: 06.19.2021

By Richard Sima An elephant’s trunk is a marvel of biology. Devoid of any joints or bone, the trunk is an appendage made of pure muscle that is capable of both uprooting trees and gingerly plucking individual leaves and also boasts a sense of smell more powerful than a bomb-sniffing dog’s. Elephants use their trunks in a variety of ways. They use it to drink, store and spray water, and they also blow air through it to communicate — their 110-decibel bellows can be heard for miles. “It’s like a muscular multitool,” said Andrew Schulz, a mechanical engineering doctoral student at the Georgia Institute of Technology. In a study published Wednesday in The Journal of the Royal Society Interface, Mr. Schulz and his colleagues reported on how elephants can use their trunks for yet another function: applying suction to grab food, a behavior previously thought to be exclusive to fishes. Despite the ubiquity of elephants in children’s books and nature documentaries, there are numerous gaps in scientific knowledge about the biomechanics of their trunks that the new study helps fill. For example, the most recent detailed account of elephant trunk anatomy is a hand-drawn monograph that was published in 1908, Mr. Schulz said. Contrary to popular belief, the trunk does not act like a straw. “What they do is actually drink water into their trunk and they store it,” Mr. Schulz said. “So the elephant trunk is actually like a trunk.” Mr. Schulz completed his research in the lab of David Hu, which studies how animals move and function with an eye toward applying the discoveries toward human engineering problems. He said one reason elephants’ anatomy is poorly understood is because they are difficult to work with. © 2021 The New York Times Company

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 27840 - Posted: 06.02.2021

By Natalie Angier Julia, her friends and family agreed, had style. When, out of the blue, the 18-year-old chimpanzee began inserting long, stiff blades of grass into one or both ears and then went about her day with her new statement accessories clearly visible to the world, the other chimpanzees at the Chimfunshi wildlife sanctuary in Zambia were dazzled. Pretty soon, they were trying it, too: first her son, then her two closest female friends, then a male friend, out to eight of the 10 chimps in the group, all of them struggling, in front of Julia the Influencer — and hidden video cameras — to get the grass-in-the-ear routine just right. “It was quite funny to see,” said Edwin van Leeuwen of the University of Antwerp, who studies animal culture. “They tried again and again without success. They shivered through their whole bodies.” Dr. van Leeuwen tried it himself and understood why. “It’s not a pleasant feeling, poking a piece of grass far enough into the ear to stay there,” he said. But once the chimpanzees had mastered the technique, they repeated it often, proudly, almost ritualistically, fiddling with the inserted blades to make sure others were suitably impressed. Julia died more than two years ago, yet her grassy-ear routine — a tradition that arose spontaneously, spread through social networks and skirts uncomfortably close to a human meme or fad — lives on among her followers in the sanctuary. The behavior is just one of many surprising examples of animal culture that researchers have lately divulged, as a vivid summary makes clear in a recent issue of Science. Culture was once considered the patented property of human beings: We have the art, science, music and online shopping; animals have the instinct, imprinting and hard-wired responses. But that dismissive attitude toward nonhuman minds turns out to be more deeply misguided with every new finding of animal wit or whimsy: Culture, as many biologists now understand it, is much bigger than we are. © 2021 The New York Times Company

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:None
Link ID: 27809 - Posted: 05.08.2021

By Charles Choi Even after ancient humans took their first steps out of Africa, they still unexpectedly may have possessed brains more like those of great apes than modern humans, a new study suggests. For decades, scientists had thought modern humanlike organization of brain structures evolved soon after the human lineage Homo arose roughly 2.8 million years ago (SN: 3/4/15). But an analysis of fossilized human skulls that retain imprints of the brains they once held now suggests such brain development occurred much later. Modernlike brains may have emerged in an evolutionary sprint starting about 1.7 million years ago, researchers report in the April 9 Science. What sets modern humans apart most from our closest living relatives, the great apes, is most likely our brain. To learn more about how the modern human brain evolved, the researchers analyzed replicas of the brain’s convoluted outer surface, re-created from the oldest known fossils to preserve the inner surfaces of early human skulls. The 1.77-million to 1.85-million-year-old fossils are from the Dmanisi archaeological site in the modern-day nation of Georgia and were compared with bones from Africa and Southeast Asia ranging from roughly 2 million to 70,000 years old. The scientists focused on the brain’s frontal lobes, which are linked with complex mental tasks such as toolmaking and language. Early Homo from Dmanisi and Africa still apparently retained a great ape–like organization of the frontal lobe 1.8 million years ago, “a million or so years later than previously thought,” says paleoanthropologist Philipp Gunz at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who did not take part in this study. © Society for Science & the Public 2000–2021.

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior
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Link ID: 27768 - Posted: 04.10.2021