by Helen Fields The average adult human's brain weighs about 1.3 kilograms, has 100 billion or so neurons, and sucks up 20% of the oxygen we breathe. It's much bigger than an animal our size needs. According to a new computer model, the brains of humans and related primates are so large because we evolved to be social creatures. If we didn't play well with others, our brains would be puny. The idea behind the so-called social intelligence hypothesis is that we need pretty complex computers in our skulls to keep track of all the complex relationships we have with each other—who's a friend, who's an enemy, who's higher in the social ranks. Some studies have supported this idea, showing for example that bigger-brained primates tend to live in bigger social groups. The same appears to hold true for dolphins. But these studies only identified associations between brain and group size; they don't show how evolution might have worked. Since they didn't have a few million years of time on their hands, Ph.D. student Luke McNally and colleagues at Trinity College Dublin simulated evolution on a computer. They started with 50 simple brains. Each had just three to six neurons. The researchers then made each brain challenge the others to one of two classic games: the prisoner's dilemma or the snowdrift game. In the prisoner's dilemma, two people have been taken in for questioning by the police. If both keep their mouths shut, they'll both be set free. If one sells out the other, the snitch will get off and the other will do a long stint in jail. If they tell on each other, both get shorter sentences. © 2010 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 16640 - Posted: 04.12.2012

By Bruce Bower An ancient member of the human evolutionary family has put what’s left of a weird, gorillalike foot forward to show that upright walking evolved along different paths in East Africa. A 3.4 million-year-old partial fossil foot unearthed in Ethiopia comes from a previously unknown hominid species that deftly climbed trees but walked clumsily, say anthropologist Yohannes Haile-Selassie of the Cleveland Museum of Natural History and his colleagues. Their report appears in the March 29 Nature. To the scientists’ surprise, this creature lived at the same time and in the same region as Australopithecus afarensis, a hominid species best known for a partial skeleton dubbed Lucy. Another recent fossil discovery in Ethiopia suggests that Lucy’s kind walked much as people do today (SN: 7/17/10, p. 5). “For the first time, we have evidence of another hominid lineage that lived at the same time as Lucy,” says anthropologist and study coauthor Bruce Latimer of Case Western Reserve University in Cleveland. “This new find has a grasping big toe and no arch, suggesting [the species] couldn’t walk great distances and spent a lot of time in the trees.” Lucy’s flat-footed compatriot adds to limited evidence that some hominids retained feet designed for adept tree climbing several million years after the origin of an upright gait, writes Harvard University anthropologist Daniel Lieberman in a comment published in the same issue of Nature. © Society for Science & the Public 2000 - 2012

Keyword: Evolution
Link ID: 16583 - Posted: 03.29.2012

OUR intelligence, more than any particular behaviour or anatomical feature, is what distinguishes humans from the myriad other species with which we share our planet. It is a key factor in everything from our anatomy to our technology. To ask why we are intelligent is to ask why we are human; it admits no discrete answer. But let's ask it here anyway. Why are we, alone in nature, so smart? Perhaps we are not. Maybe our anthropocentric conceit prevents us from fully appreciating the intelligence of other animals, be they ants, cephalopods or cetaceans. As Douglas Adams put it: "Man had always assumed that he was more intelligent than dolphins because he had achieved so much - the wheel, New York, wars and so on - whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man - for precisely the same reasons." So let's rephrase the question. There is a cluster of abilities that seems unique to humans: language, tool use, culture and empathy. Other animals may have rudimentary forms of these abilities, but they do not approach humans' sophistication and flexibility. Why not? Some come closer than others. German psychologists say they have identified a chimp whose mental abilities far surpass those of its peers (see "Chimp prodigy shows signs of human-like intelligence"). Intriguingly, they go on to suggest that this might be because Natasha, the simian prodigy, exhibits strong social-reasoning skills, such as learning from others. These are the same skills to which the explosive development of human intelligence is increasingly attributed. © Copyright Reed Business Information Ltd.

Keyword: Intelligence; Evolution
Link ID: 16580 - Posted: 03.27.2012

By Tina Hesman Saey Reading the genetic instruction books of gorillas and chimpanzees has provided more insight into what sets humans apart from their closest primate relatives. The two new studies also provide details about how these primate species may have evolved. Comparing a newly compiled genetic blueprint, or genome, of a western lowland gorilla named Kamilah with the genomes of humans and chimpanzees has revealed that the three species didn’t make a clean break when splitting from a common ancestor millions of years ago. Although humans are more closely related to chimps over about 70 percent of the human genome, about 15 percent of the human genome bears a closer relationship to gorillas. An international group of researchers reports the findings, which come from the first gorilla genome to be deciphered, in the March 8 Nature. A separate study of western chimpanzees, published online March 15 in Science, also has implications for understanding the human-chimp split. The new work shows that humans and chimps have different strategies for shuffling their genetic decks before dealing genes out to their offspring. Neither humans nor chimps shuffle genetic material randomly across the genome. Instead, both species have what are called hot spots, locations in the genetic material where matching sets of chromosomes recombine most often, Gil McVean, a statistical geneticist at the University of Oxford in England and colleagues report. © Society for Science & the Public 2000 - 2012

Keyword: Evolution; Genes & Behavior
Link ID: 16528 - Posted: 03.17.2012

by Michael Marshall DON'T be offended, but you have the brain of a worm. Clusters of cells that are instrumental in building complex brains have been found in a simple worm that barely has a brain at all. The discovery suggests that, around 600 million years ago, primitive worms had the machinery to develop complex brains. They may even have had complex brains themselves - which were later lost. Vertebrates, such as humans and fish, have the biggest and most complex brains in the animal kingdom. Yet all their closest non-vertebrate relatives, such as the eel-like lancelets and sea squirts, have simple brains that lack the dozens of specialised nerve centres typical of complex brains. As a result, evolutionary biologists have long thought that complex brains only evolved after animals with backbones appeared. Not so, says Christopher Lowe of Stanford University in California. His team studies a species of acorn worm, Saccoglossus kowalevskii, which has a rudimentary nervous system made up of two nerve cords and nerves spread out in its skin. The worms live in burrows in the seabed and pull in passing particles of food. Lowe found that young S. kowalevskii have three clusters of cells identical to the ones vertebrates use to shape their brains. In developing vertebrate brains, these clusters - called signalling centres - make proteins that orchestrate the formation of specialised brain regions. The acorn worm, Lowe found, produces the same proteins, and they spread through its developing body in patterns similar to those they follow in the developing vertebrate brain (Nature, DOI: 10.1038/nature10838). © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 16518 - Posted: 03.15.2012

by Elizabeth Pennisi Ever since the human genome was sequenced a decade ago, researchers have dreamed about deciphering DNA from our three great ape cousins as well. Now the final remaining genome, that of the gorilla, is in hand, and it reveals interesting connections between us and them. Surprisingly, parts of our genome are more similar to the gorilla's than they are to the chimp's, and a few of the same genes previously thought key to our unique evolution are key to theirs, too. Today there are four groups of great apes: chimps and bonobos, humans, gorillas, and orangutans. The genome of the chimp—our closest relative—was published in 2005; the orangutan sequence came out in early 2011. Now researchers have analyzed the DNA of a western lowland gorilla named Kamilah, who lives at the San Diego Zoo. In addition, they sequenced DNA from three other gorillas, including one eastern lowland gorilla, a rare species estimated at only 20,000 individuals. "It's essential to have all of the great ape genomes in order to understand the features of our own genome that make humans unique," says Gregory Wray, an evolutionary biologist at Duke University in Durham, North Carolina, who was not involved in the study. Adds paleoanthropologist David Begun of the University of Toronto in Canada: "It will allow us to begin to identify genetic changes specific to humans since our divergence from chimps." Humans and apes are nearly identical in the vast majority of base pairs, or letters of the genetic code: The human genome is 1.37% different from the chimp's; 1.75% different from the gorilla's; and 3.4% different from the orangutan's, researchers from the Wellcome Trust Sanger Institute in Hinxton, U.K., and their colleagues report today in Nature. Although chimps and humans are indeed closest kin, 15% of the human genome more closely matches the gorilla's. Those genes' activity patterns are similar too, says Sanger evolutionary genomicist and lead author of the study Aylwyn Scally: "Some of our functional biology is more gorillalike than chimplike." © 2010 American Association for the Advancement of Science.

Keyword: Evolution; Genes & Behavior
Link ID: 16491 - Posted: 03.08.2012

By NATALIE ANGIER You may think you’re pretty familiar with your hands. You may think you know them like the back of your hand. But as the following exercises derived from the latest hand research will reveal, your pair of bioengineering sensations still hold quite a few surprises up their sleeve. • Make a fist with your nondominant hand, knuckle side up, and then try to extend each finger individually while keeping the other digits balled up tight. For which finger is it extremely difficult, maybe even impossible, to comply? • Now hold your hand palm up, fingers splayed straight out, and try curling your pinky inward without bending the knuckles of any other finger. Can you do it? • Imagine you’re an expert pianist or touch-typist, working on your chosen keyboard. For every note or letter you strike, how many of your fingers will move? • You’re at your desk and, without giving it much thought, you start reaching over for your water bottle, or your pen. What does your hand start doing long before it makes contact with the desired object? And a high-five to our nearest nonhuman kin: • What is the most important difference between a chimpanzee’s hands and our own? (a) the chimpanzee’s thumbs are not opposable; (b) the chimpanzee’s thumbs are shorter than ours; or (c) the chimpanzee’s thumbs are longer than ours. © 2012 The New York Times Company

Keyword: Evolution; Muscles
Link ID: 16443 - Posted: 02.28.2012

By Robin Anne Smith Recently while visiting the National Museum of Natural History in Washington, D.C., I found myself pondering the noggins of some very, very, old apes. Along one wall of the Hall of Human Origins — an exhibit on human evolution that opened in 2010 — were 76 fossil skulls from 15 species of early humans. Looking at these skulls, one thing was clear: millions of years of evolution have given us much bigger brains. In the 8 million to 6 million years since the ancestors of humans and chimps went their separate ways, the human brain more than tripled in size. If the earliest humans had brains the size of oranges, today’s human brains are more akin to cantaloupes. As for our closest primate relatives, the chimps? Their brains haven’t budged. With our big brains we compose symphonies, write plays, carve sculptures and do math. But our big brains came at a cost, some scientists say. In two recent studies, researchers from Duke University suggest the human brain boost may have been powered by a metabolic shift that meant more fuel for brains, and less fuel for muscles. Co-author Olivier Fedrigo told me the full story one morning over coffee near his home in Durham, North Carolina. The human brain isn’t just big, he explained. It’s also hungry. © 2012 Scientific American

Keyword: Evolution
Link ID: 16421 - Posted: 02.23.2012

by Lisa Grossman Clint Eastwood might sound an unlikely candidate to help investigate the evolution of the brain, but he has lent a helping hand to researchers doing just that. It turns out that brain regions that do the same job in monkeys and humans aren't always found in the same part of the skull. Previous studies comparing brains across species tended to assume that human brains were just blown-up versions of monkey brains and that functions are carried out by anatomically similar areas. To test this idea, Wim Vanduffel of Harvard Medical School in Boston and the Catholic University of Leuven (KUL) in Belgium, and colleagues scanned the brains of 24 people and four rhesus monkeys while they watched The Good, The Bad and The Ugly. They compared the brain responses of each individual to the same sensory stimulation, and identified which brain areas had similar functions. The majority of the human and monkey brain maps lined up, but some areas with a similar function were in completely different places. The team say the discovery is crucial to building more accurate models of our evolution. "You can't assume that because A and B are close together in the monkey brain, they need to be close together in the human brain," Vanduffel says. Journal reference: Nature Methods, DOI: 10.1038/nmeth.1868 © Copyright Reed Business Information Ltd.

Keyword: Evolution; Attention
Link ID: 16355 - Posted: 02.07.2012

By Bruce Bower A chimpanzee in need gets help indeed, on two conditions. Another chimp must both see his or her predicament and receive a blatant help request from the needy animal, a new study finds. Observations in the wild and in previous experiments indicate that chimps seldom help others (SN: 8/27/11, p. 10), but that’s not because the chimps don’t understand their peers’ motivations, as some researchers suspect, says primatologist Shinya Yamamoto of Kyoto University in Japan. In a series of lab tests, chimps who saw one of their relatives unsuccessfully reach for a juice box and then request help picked out a useful tool and passed it to their kin, Yamamoto and colleagues report online February 6 in the Proceedings of the National Academy of Sciences. “Chimpanzees can understand others’ goals from obvious cues and then provide help,” Yamamoto says. This ability to grasp that another individual has a goal in mind based on his or her behavior represents one element of what psychologists call theory of mind — an ability to attribute beliefs, desires, pretending and other mental states to oneself and others. Until now, scientists had studied chimps’ understanding of other chimps’ goals only in competitive situations, such as clashes over food and mates. That fueled suspicion that chimps discern others’ goals only in the heat of such struggles. © Society for Science & the Public 2000 - 2012

Keyword: Evolution; Consciousness
Link ID: 16351 - Posted: 02.07.2012

Brian Switek The largest mammals to walk Earth evolved from shrew-like creatures that proliferated after the dinosaurs died out, 65 million years ago. But the change from pipsqueak to behemoth took a while: 24 million generations. Researchers led by Alistair Evans, an evolutionary biologist at Monash University in Clayton, Australia, investigated how maximum body mass increased among 28 orders of mammals on multiple continents during the past 70 million years. By comparing the sizes of the largest members of mammal groups at different points in time, and using modern mammals to estimate the length of a generation for each group, Evans and colleagues tracked the speed at which mammals expanded. Their work is published online in the Proceedings of the National Academy of Sciences1 today. The top speed of mammal inflation was slower than had been thought. Previous estimates of the time it takes for a mouse-sized mammal to grow to the size of an elephant — a 100,000-fold size increase — had been based on observations of much smaller, 'microevolutionary' changes in mice, and ranged from 200,0002 to 2 million generations. “This tells us how much slower so-called macroevolution is compared to microevolution,” says Evans, explaining that small size changes can occur quickly, but larger-scale alterations require more time. To put this into perspective, “if we wiped out everything above the size of a rabbit, it would take at least 5 million generations to get to elephant-sized animals”, a 1,000-fold increase. That translates to about 20 million years. Bucking the trend But not all groups followed the same rule. Whales, the largest mammals ever, grew much more quickly than land-dwelling mammals, needing only about 3 million generations for a 1,000-fold size increase. Evans says that the difference was probably the result of different evolutionary constraints of life in the sea, such as the need to retain body heat, which is easier with a larger body mass. © 2012 Nature Publishing Group

Keyword: Evolution
Link ID: 16326 - Posted: 01.31.2012

By NATALIE ANGIER Meet the African crested rat, or Lophiomys imhausi, a creature so large, flamboyantly furred and thickly helmeted it hardly seems a member of the international rat consortium. Yet it is indeed a rat, a deadly dirty rat, its superspecialized pelt permeated with potent toxins harvested from trees. As a recent report in the journal Proceedings of the Royal Society B makes clear, the crested rat offers one of the most extreme cases of a survival strategy rare among mammals: deterring predators with chemical weapons. Venoms and repellents are hardly rare in nature: Many insects, frogs, snakes, jellyfish and other phyletic characters use them with abandon. But mammals generally rely, for defense or offense, on teeth, claws, muscles, keen senses or quick wits. Every so often, however, a mammalian lineage discovers the wonders of chemistry, of nature’s burbling beakers and tubes. And somewhere in the distance a mad cackle sounds. Skunks and zorilles mimic the sulfurous, anoxic stink of a swamp. The male duck-billed platypus infuses its heel spurs with a cobralike poison. The hedgehog declares: Don’t quite get the point of my spines? Allow me to sharpen their sting with a daub of venom I just chewed off the back of a Bufo toad. © 2012 The New York Times Company

Keyword: Evolution; Chemical Senses (Smell & Taste)
Link ID: 16324 - Posted: 01.31.2012

By Ferris Jabr As a dung beetle rolls its planet of poop along the ground it periodically stops, climbs onto the ball and does a little dance. Why? It's probably getting its bearings. A series of experiments published in the January 18 issue of PLoS ONE shows that the beetles are much more likely to perform their dance when they wander off course or encounter an obstacle. Until now, no one had any idea what a jitterbugging dung beetle was up to. Emily Baird of Lund University in Sweden and her colleagues study how animals with tiny brains—such as bees and beetles—perform complex mental tasks, like navigating the world. The dung beetle intrigues Baird because it manages to roll its dung ball in a perfectly straight line, even though it pushes the ball with its back legs, its head pointed at the ground in the opposite direction. If the six-legged Sisyphus can't see where it's going, how does it stay on its course? Every now and then, a dung beetle stops rolling, mounts its ball and pirouettes. Baird noticed that dung beetles do not dance as often in the lab, where they roll around on flat surfaces, as they do in the field, where the terrain is rough and rocks and clumps of grass often obstruct the beetles' paths. She guessed that by climbing onto a ball of dung four or five times its height, a beetle gets a pretty good vantage point from which to correct any navigational mistakes. But it was only an intuition—she needed evidence. © 2012 Scientific American

Keyword: Animal Migration; Evolution
Link ID: 16274 - Posted: 01.21.2012

By Devin Powell A boa constrictor knows to stop squeezing a juicy rat by sensing the heartbeat of its prey, easing up only when the pulse stops, a new study finds. Detecting heartbeats may give snakes like the boa constrictor an edge for hunting iguanas and other large cold-blooded animals that can cling to life for a long time when cut off from oxygen, researchers report online January 18 in Biology Letters. Taking the pulse of such creatures would be a surefire way to know when to let go. To pinpoint the snake’s sensitivity to this particular vital sign, researchers at Dickinson College in Carlisle, Pa., started with rat corpses lacking any signs of life. The scientists then implanted pressure sensors and artificial hearts, small bulbs pumped with fluid that produce the illusion of a regular pulse. Wild boa constrictors attacked the carcasses with or without the simulated heartbeat. But the snakes hugged harder and for about twice as long when the pulse was switched on. If the pulse stopped, the squeezing also stopped. Lab-raised snakes never exposed to live prey responded the same way, suggesting the behavior is innate, not learned. © Society for Science & the Public 2000 - 2012

Keyword: Evolution
Link ID: 16271 - Posted: 01.19.2012

By Michelle Clement I like video games (I will rip up some Assassin’s Creed whenever I get a long weekend, do NOT get me started). My cat likes video games too, even though she doesn’t understand that she’s playing them. On a whim not too long ago, I downloaded a “games for cats” app on my iPad that simulates a dancing laser pointer or a skittering mouse, and my cat gets so into the game that she’ll push my iPad all the way across the floor in her excitement. Here’s a video of someone else’s kitten playing the same game: The phenomenon isn’t restricted to domesticated cats, either: Cats aren’t the only animals that are mentally stimulated by flashing and dancing lights, though. As it turns out, researchers at Wageningen University, in the course of their research on ethical livestock farming, noticed that pigs like to play with dancing lights as well. European regulations currently require that pig farmers provide mentally-stimulating activity for their pigs in order to reduce boredom, which leads to aggression and biting, and researchers at Wageningen University, in collaboration with the Utrecht School of the Arts, are currently developing a video game called “Pig Chase” for livestock pigs that is not unlike my cat’s iPad app. The key difference, however, is that this game would be an interspecies two-player game. [EDIT: I was contacted this afternoon by Nate at Hiccup, and he informed me that Game For Cats has also recently incorporated interspecies functionality. I didn't know that, so thanks for the update!] © 2012 Scientific American,

Keyword: Evolution; Learning & Memory
Link ID: 16235 - Posted: 01.10.2012

by Jeff Warren What if we merged brains with other species? Would we have very different psychology? Or wordlessly swap intimate feelings? I'VE spent years thinking about consciousness and my current obsession is whether we can know anything about what it is like is to be a dog, a dolphin, or a bat. The most influential answer came from philosopher Thomas Nagel in his 1974 paper, "What is it like to be a bat?" Unlike some of the era's behaviourists, who saw animals as little more than automatons that respond to stimulus, Nagel didn't doubt bats had experience, that it was "like something" being a nimble, echo-locating mammal swooping through the night. But he doubted our ability to say anything true about it beyond projection or imagination. Nagel may be right, but for me the human-to-animal mind question is simply an extreme form of the human-to-human mind question: we can't know another's experience, but there are deep points of overlap we can expand. What follows is from a conversation with two of the smartest people I know in the field: Lori Marino, a comparative neuroanatomist at Emory University in Atlanta, Georgia, and Ben Goertzel, a mathematician, and a former research director of the Singularity Institute for Artificial Intelligence in San Francisco. JEFF: Imagine that in front of us are the disarticulated brains of a human, a dog and a dolphin. What might we learn by combining the pieces of the animals in unusual ways? LORI: Something similar is going on in Leipzig. For example, researchers inserted a human gene into a mouse brain, causing it to grow human-like neurons in the language area: the mouse's vocalisations were deeper. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Attention
Link ID: 16191 - Posted: 12.27.2011

By Susan Milius Pigeons, who aren’t even distant uncles to a monkey, have matched primates in a test of learning an abstract numerical concept. Trained on one-two-three, the pigeons then had to put pairs of numbers up to nine in order, says comparative psychologist Damian Scarf of the University of Otago in New Zealand. Pigeons rivaled rhesus monkeys tested earlier at the same task, Scarf and his colleagues report in the Dec. 23 Science. The results “suggest that despite completely different brain organization and hundreds of millions of years of evolutionary divergence, pigeons and monkeys solve this problem in a similar way,” says Elizabeth Brannon of Duke University, a coauthor of the original study of numerical order in monkeys. Humankind may be pretty proud of its numerical prowess, but numbers — four succulent fruits versus eight, one lurking lion versus three — matter very much in animal life, too. Research is uncovering various kinds of number-related abilities in animals as diverse as the honeybee, mosquitofish, grey parrot, Plethodon salamanders and a waterbird called a coot. So pigeons could be compared with other species, Scarf used Brannon’s numerical-order test, which baboons and lemurs as well as some monkeys have passed. For training, pigeons saw computer screens displaying sets of three images, each with one, two or three shapes. The shapes varied so that a bird couldn’t get the number order right just by pecking at increasing surface area. Scarf then rewarded birds for pecking in one-shape, two-shapes, three-shapes order. © Society for Science & the Public 2000 - 2011

Keyword: Evolution
Link ID: 16178 - Posted: 12.23.2011

by Peter Aldhous Itsy bitsy spiders have a big problem: where to store their bulging brains. For Anapisona simoni and other arachnid lightweights, the problem is so acute that their brains have literally spilled out of their body cavities and into their legs. Tiny creatures' brains and microelectronics have something in common, it turns out: ultimately, attempts to miniaturise the circuitry will hit a wall. Once the axons that transmit neural signals get down to 0.1 micrometre in diameter, for instance, channels that move ions across cell membranes get so "noisy" that signalling becomes unreliable. What's more, nervous tissue demands a lot of energy, and if nerve cells get too small they simply don't contain enough mitochondria – organelles that act as cellular power plants – to meet their needs. As a result, animals face a trade-off as natural selection pushes them towards the minuscule: either dumb down, or lug around brains that are much bigger, proportionate to body size, than those needed by a larger creatures with similar smarts. Weaving websMovie Camera is not for dullards, so tiny spiders haven't taken the evolutionary road to stupidity. In 2007, William Eberhard of the Smithsonian Tropical Research Institute in Panama and the University of Costa Rica found that the smallest spiders weave webs that are just as complex as those made by larger relatives. "There was no correlation between the size of the spider and the precision with which it built the sticky spiral in the web," he says. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 16150 - Posted: 12.15.2011

By Bruce Bower Culturally speaking, ancient East Africans were a stone’s throw away from southern Arabia. Stone tools collected at several sites along a plateau in Oman, which date to roughly 106,000 years ago, match elongated cutting implements previously found at East African sites from around the same time, say archaeologist Jeffrey Rose of the University of Birmingham, England, and his colleagues. New finds also include cores — or rocks from which tools were pounded off with a hammer stone — that correspond to East African specimens, the researchers report online November 30 in PLoS ONE. East African sites that have yielded these distinctive stone artifacts extend southward along the Nile River to the Horn of Africa. “In the mountain of papers speculating about human dispersal out of Africa, a link between southern Arabia and the Nile Valley has never been considered,” Rose says. Either Africans crossed the Red Sea and trekked into southern Arabia well before an African exodus around 60,000 years ago, or ancient people from Arabia influenced African toolmaking, the scientists suggest. “The finds in Oman are rather spectacular,” comments archaeologist Michael Petraglia of the University of Oxford, England. “They have a date that is earlier than similar African artifacts, which could imply a migration back to Africa, or at least a flow between African and Arabian populations.” © Society for Science & the Public 2000 - 2011

Keyword: Evolution
Link ID: 16141 - Posted: 12.13.2011

by Rowan Hooper WHAT was the basis for the earliest friendships? If wild chimps are any guide: support in a fight, borrowing a valued tool, and a bite to eat now and then. Quite similar to our friendships today, in fact. Indeed, some chimps are so modern they have relationships that we would classify as friends with benefits. Primatologists are reassessing the complexity of chimpanzee society in the light of new findings that also suggest answers to a long-standing question: why share things with non-relatives? For the first time wild chimps in Senegal have been observed taking plant foods and tools from other chimps, who don't react to the intrusion. The chimps donating their stuff don't get paid, but neither do they protest. Instead, the trade appears to help build social cohesion. What's more, in another west African study, this time in Ivory Coast, a "market" has been described where chimps exchange commodities in the shape of both social behaviours including grooming and sex, and resources such as meat. Christophe Boesch of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, says we have only recently begun to appreciate the time and energy chimps invest in reciprocal relationships, and he compares chimp relationships to friendship. "These findings have prompted primatologists to use some terms that have in the past been reserved for humans." © Copyright Reed Business Information Ltd.

Keyword: Evolution; Aggression
Link ID: 16119 - Posted: 12.08.2011