Evolutionary Comparison Finds Shocking History for Vertebrates

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Wired UK (Oct, 12. 2011) - Evolutionary biologists from Cornell University have discovered that just about every vertebrate on Earth — including humans — descended from an ancient ancestor with a sixth sense: the ability to detect electrical fields in water.

About 500 million years ago there was probably a predatory marine fish with good eyesight, powerful jaws and sharp teeth roaming the oceans, sporting a lateral line system for detecting water movements and a well-developed electroreceptive system to sense predators and prey around it. The vast majority of the 65,000 or so living vertebrate species are its descendants.

A few hundred million years ago, there was a major fork in the evolutionary tree. One lineage led to the ray-finned fishes, or actinopterygians, and they’ve kept a weak electroreceptive system to this day. Sturgeon have receptors in the skin of their heads, for example, and the North American paddlefish has 70,000 receptors in its snout and head.

The other lineage led to lobe-finned fishes, or sarcopterygians, which in turn gave rise to land vertebrates. Some land vertebrates, including salamanders like the Mexican axolotl, still have electroreception. But in the change to terrestrial life, the lineage leading to reptiles, birds and mammals lost that electrosense and the lateral line.

The researchers took the axolotl (to represent the evolutionary lineage leading to land animals) and the paddlefish (as a model for the branch leading to ray-finned fishes) to find out the history of this sense. They found that electrosensors develop in precisely the same pattern from the same embryonic tissue in the developing skin, confirming that this is an ancient sensory system.

Also, the electrosensory organs develop immediately adjacent to the lateral line, providing compelling evidence “that these two sensory systems share a common evolutionary heritage,” said Willy Bemis, Cornell professor of ecology and evolutionary biology and a senior author of the paper.

Bemis and his colleagues will now be able to build a better picture of what the common ancestor of these two lineages looked like.

Clever Test Shows Meerkat Voices Are Personal

"Alan! Alan! Alan!
...oh it's not Alan. Jeff!!"

Wired Science (Oct, 12. 2011) - By using audio trickery to present meerkats with a puzzling situation, biologists have demonstrated that the adorable African critters recognize each other by voice.

The findings are based on tests in which calls from the same individual were played near-simultaneously in two different locations. The implications go beyond meerkats.

Humans and many primates clearly recognize individual voices, a capacity considered fundamental for rich social lives. Some mammals, such as dolphins, have demonstrated the ability in captive settings. But while recognizing voices seems obvious — how else could Meerkat Manor make sense? — it’s been surprisingly difficult to design quantitative studies for truly wild animals other than primates, leaving an important aspect of animal social life in empirical shadow.

“Understanding how animals experience the individuals within their social worlds is key to deciphering the evolution of social and communicative capacities,” write researchers led by University of Zurich ethologist Simon Townsend in their new meerkat study, published Oct. 11 in Biology Letters.

Of course, many animals clearly recognize individuals by scent and sight. But those abilities are considered less cognitively-demanding than vocalizations, which can be highly complex and imply mental representations of other individuals. The late, great ethologist Donald Griffin called vocalizations a window into animal minds.

For primates, the best-studied vocalizers, social relationships are often so complex and self-evident that it’s possible to play recordings of individual voices, then see how animals respond. A chimp will, for example, react differently to the voice of each different member of his group.

As for other mammals, experiments in natural settings have tended to involve tests of whether individuals respond to their kin, as with leopard seals recognizing their pups’ cries, or to general social categories.

In one unpublished study, meerkats responded differently to the voices of a group’s dominant female, but it wasn’t clear whether they recognized the individual or simply some categorical sign of dominance.

But Townsend’s team came up with a deceptively simple test that posed a physically impossible scenario to any meerkat capable of recognizing individual voices.

Using hidden speakers, they played recorded calls from one individual on one side of a target meerkat, and then from the other. The situation was similar to hearing a friend shout from the kitchen, then from the second-floor bathroom just a second later.

The meerkats reacted with a prolonged vigilance, paying much closer attention than they did to other recorded calls. The situation didn’t compute.

According to Townsend, the methodology could be applied to other animals that haven’t yet been studied, producing an animal kingdom-wide picture of individual voice recognition. That picture could help show what makes humans special — or, conversely, what seemingly special abilities are actually widespread.

“You see this ability in primates, which you’d expect,” said Townsend. “But the fact that we can show this in non-primate social mammals suggests the skill is omnipresent. It suggests that humans aren’t so unique.”

Children Like Teamwork More Than Chimps Do

LiveScience (Oct, 13. 2011) - Chimpanzees and humans are fairly close cousins, evolutionarily speaking. But a new study finds they lack something that we have (besides written language and hairlessness): a desire to work together.

When all other things are equal, 3-year-old children prefer to do a task collaboratively rather than alone, while chimpanzees show no such preference, said study researcher Yvonne Rekers, a cognitive scientist at the Max Planck Institute for Evolutionary Anthropology in Germany.

"We expected that difference between human and chimpanzee cooperation, because we can see it nowadays," Rekers told LiveScience. "Humans collaborate in a larger variety of contexts and in more complex forms."

However, that leaves the question: Why these differences in cooperation? Cognitive abilities may be at the root of some of them, Rekers said, but motivation could matter as well.

Working together

To investigate the motivations of both species, the researchers chose a task that both groups would willingly undertake: pulling a rope to get a food reward. The children in the study got gummy frogs as their treat, while the chimpanzees got bananas.

Fifteen chimps and 24 children were introduced to the same experimental set-up: a room containing both a single end of rope and a doubled-over rope with two available ends. The 3-year-olds and the chimps were all taught that by pulling both ends of the doubled-over rope at the same time, they could draw a food-laden board toward them, delivering a batch of gummy frogs or bananas.

Pulling the single rope would produce the identical food reward, but only with the help of another child or chimp in the room next door, who had to pull the opposite end of the rope at the same time. (The child or chimp acting as the potential partner in the experiment wasn't being tested; he or she had only the single end to pull. The potential partners were, however, highly motivated to pull that rope, because they too knew that a food reward would be coming their way.)

Cooperating kids

Despite the fact that the chimps got their food four to five seconds faster when they pulled the single end and worked with a partner than when they pulled both ends of the doubled rope by themselves, they were just as likely to choose the doubled rope, the researchers said. The chimps chose the single-ended rope 58 percent of the time, a number not significantly different than chance.

The 3-year-old children, by contrast, chose to pull the collaborative single rope in 78 percent of trials, even though it did not produce snacks any faster.

The children had all practiced the game beforehand and so knew how it worked. They, like the chimps, could see their potential partner through a opening between the two rooms. But to make their experience more like that of the chimps, the kids were encouraged not to speak during the experiment.

In order to keep all factors constant, a snack went to the cooperating child (the one not being tested) regardless of whether he or she was called upon to pull. That set-up, however, led Rekers and her colleagues to worry that perhaps the tested children were picking the collaborative work to prevent their partners from getting gummy frogs for doing nothing.

The researchers set up a second experiment with 12 new children in which the potential partner never received a reward — at least not within the sight of the tested child. The results were essentially unchanged, with 81 percent of kids choosing to work together. That finding suggested that the original result was not influenced by any desire to prevent freeloaders.

Rekers and her colleagues aren't sure whether this preference for cooperation is innate in humans or not, but one theory is that evolutionary pressures at some point nudged humans, but not chimps, into becoming cooperative foragers. The next step, Rekers said, is to study other primate species, such as bonobos.

She said she also plans to look into what children get out of working together.

"Is it just that they enjoy doing stuff together?" she said. "Or are they following other strategies or goals?"

Alison Gopnik: What do babies think?

TED (Oct, 10. 2011) - "Babies and young children are like the R&D division of the human species," says psychologist Alison Gopnik. Her research explores the sophisticated intelligence-gathering and decision-making that babies are really doing when they play.

Psychologists Decipher Brain’s Clever Autofocus Software

Wired Science (Oct, 10. 2011) - It’s something we all take for granted: our ability to look at an object, near or far, and bring it instantly into focus. The eyes of humans and many animals do this almost instantaneously and with stunning accuracy. Now researchers say they are one step closer to understanding how the brain accomplishes this feat.

Wilson Geisler and Johannes Burge, psychologists at the Center for Perceptual Systems at the University of Texas, Austin, have developed a simple algorithm for quickly and accurately estimating the focus error from a single blurry image-something they say is key to understanding how biological visual systems avoid the repetitive guess-and-check method employed by digital cameras. The discovery may advance our understanding of how nearsightedness develops in humans or help engineers improve digital cameras, the researchers say.

In order to see an object clearly, an accurate estimate of blur is important. Humans and animals instinctively extract key features from a blurry image, use that information to determine their distance from an object, then instantly focus the eye to the precise desired focal length, Geisler explains. “In some animals, that’s the primary way they sense distance,” he says. For example, the chameleon relies on this method to pinpoint the location of a flying insect and snap its tongue to that exact spot. Altering the amount of blur by placing a lens in front of its eye causes the chameleon to misjudge the distance in a predictable way.

But scientists didn’t know how biological visual systems estimate blur so well. Many researchers had thought the brain used a system of guessing and checking to get to the answer, much like the way a camera’s auto-focus system works. Basically, the camera changes the focal distance, measures the contrast in the image it sees, and repeats the process until it has maximized the contrast, Burge says.

“This search procedure is slow, often begins its search in the wrong direction, and relies on the assumption that maximum contrast equals best focus—which is not strictly true,” Burge says.

In an attempt to resolve the question of how humans and animals might use blur to accurately estimate distance, Geisler and Burge used well-known mathematical equations to create a computer simulation of the human visual system. They presented the computer with digital images of natural scenes similar to what a person might see, such as faces, flowers, or scenery, and observed that although the content of these images varied widely, many features of the images—patterns of sharpness and blurriness and relative amounts of detail—remained the same.

The duo then attempted to mimic how the human visual system might be processing these images by adding a set of filters to their model designed to detect these features. When they blurred the images by systematically changing the focus error in the computer simulation and tested the response of the filters, the researchers found that they could predict the exact amount of focus error by the pattern of response they observed in the feature detectors. The researchers say this provides a potential explanation for how the brains of humans and animals can quickly and accurately determine focus error without guessing and checking. Their research appears online this week in the Proceedings of the National Academy of Sciences.

“They’ve provided proof that there is enough information in a static image to determine if an object is too close or too far away,” says Larry Thibos, a professor of optometry and vision researcher at Indiana University, Bloomington. “We’ve known for 50 or 60 years that people are very good at knowing whether or not something is in focus. It’s taken this paper to show us how the visual system might accomplish this feat.”

The researchers also added common visual imperfections to their simulations and found that when it comes to judging focus, flaws are actually a good thing.

“What we discovered is that the imperfections in the eye—things like astigmatism and chromatic aberration—actually help it to focus,” Geisler explains. That may help explain why people who have had their astigmatism corrected through laser eye surgery often have trouble focusing for several weeks afterward, Geisler says.

That sort of understanding may have an impact on medical decisions, Thibos says. “People might be tempted to try and perfect nature,” he says, “when maybe it’s better to be a little bit imperfect.”

Problem solving Elephant

UPI.com (Oct, 8. 2011) -- An elephant at the National Zoo in Washington devised a problem-solving strategy to reach a branch with his trunk and grab a treat, zoo officials said.

Kandula, the zoo's youngest elephant, figured out how to roll a large cube underneath the branch and stand on it to secure his meal.

Scientists said that sort of spontaneous problem-solving had never been seen in elephants before, even though they can recognize themselves in mirrors, drop logs to collapse fences to get to food and even dig wells, The Washington Post reported.

"We knew elephants were intelligent," said Diana Reiss, who studies animal intelligence at City University of New York. But although as intelligent as dolphins and chimpanzees in some ways, researchers said, all attempts to get elephants to spontaneously solve a problem had previously failed.

In a study published in the journal PLoS One, researchers described hanging bamboo and fruit just out of reach of elephants at the National Zoo, placing a cube or aluminum tub nearby.

In the seventh session, researchers said, Kandula "just suddenly did it." And in the next session, Kandula rolled the cube all over the elephant compound, using it to reach a flower he wanted to sniff and to play with a toy hung from a tree, they said.

Monkeys Use Mind Control

ScienceNOW (Oct, 6. 2011) - By implanting electrodes into both the motor and the sensory areas of the brain, researchers have created a virtual prosthetic hand that monkeys control using only their minds, and that enables them to feel virtual textures.

Neuroscientist Miguel Nicolelis of Duke University in Durham, N.C., whose group has been developing so-called brain-machine interfaces, says that one of the pitfalls in these systems is that “no one’s been able to close the loop” between controlling a limb and feeling a physical touch. So he and a group of researchers decided to create a “brain-machine-brain” interface using a virtual system. The researchers implanted two sets of tiny electrodes into a monkey’s brain: one set in the motor control center, and the other in the part of the somatosensory cortex that processes the sensation of physical touch from the left hand. Using the first set, the monkey could control a virtual monkey arm on a computer screen and sweep the hand over virtual disks with different “textures.” Meanwhile, the second set of electrodes fed a series of electrical pulses into the touch center of its brain. A low frequency of pulses indicated a rough texture, whereas high frequency indicated a fine texture (see video), and the monkeys quickly learned to tell the difference.

By giving the monkey rewards when it identified the right texture, the researchers discovered that it took as few as four training sessions for the animal to consistently distinguish the textures from one another, even when the researchers switched the order of the visually identical disks on the screen. The researchers then implanted the electrodes into the sensory region that receives tactile sensations from the foot in a different monkey; this monkey, too, acted as if the virtual appendage (in this case, the foot) was its own, moving it to correctly identify the textures, the team reports online today in Nature.

Although the monkeys are all adults, the motor and sensory regions of their brains are amazingly plastic, Nicolelis says: the combination of seeing an appendage that they control and feeling a physical touch tricks them into thinking that the virtual appendage is their own “within minutes.” And throughout this experiment, the monkey’s own general sense of touch didn’t seem to be affected. “The brain,” Nicolelis says, “is creating a sixth sense.”

“It’s definitely a milestone in brain-computer interfaces,” says neuroscientist Sliman Bensmaia of the University of Chicago, who is developing touch-feedback systems for human prosthetics. Too many of the robotic arms now being developed, even very advanced ones, he says, ignore the importance of touch. “Sensory feedback is critical to doing anything,” he says. Even mundane tasks like picking up a cup require a great deal of concentration so the wearer does not drop or crush it.

The new work is still an early step, however, he says. A biological arm receives countless inputs not only from texture but also from temperature and its position in space.

Nicolelis says his group is currently working on fine-tuning the sensory feedback as well as exploring ways to link the brain and computer wirelessly. After many years of working on brain-computer interfaces, he says, “We’re getting very close to where they may be clinically useful” for paralyzed patients, not just in the lab, and for doctors as well. Touch feedback may allow surgeons, for instance, to perform microscopic surgery or countless other applications. “The brain,” Nicolelis says, “has evolved capabilities that go way beyond the body.”

Ben Goldacre: Battling Bad Science

TED TALKS (Filmed July 2011, Posted Sept 2011) Every day there are news reports of new health advice, but how can you know if they're right? Doctor and epidemiologist Ben Goldacre shows us, at high speed, the ways evidence can be distorted, from the blindingly obvious nutrition claims to the very subtle tricks of the pharmaceutical industry.

Richard Dawkins Interview

An interview with the evolutionary biologist, best-selling author and outspoken atheist.

Archaeologists find ancient 'child cave art' in the Dordogne

BBC Science (Sept. 30, 2011) - Jessica Cooney, an archaeologist from Cambridge University, talks about paintings found in a cave "nursery" in France.

One of the pieces of art, discovered in the cave of Rouffignac in the Dordogne, is thought to be a 13,000-year-old finger painting created by two and three-year-olds.

Jessica Cooney, speaking to the BBC's David Sillito, explains that the most prolific artist is thought to be a five-year-old girl.

Watch the video "Archaeologists find ancient 'child cave art' in the Dordogne" >>

'Once in a lifetime' rare white whale calf spotted off Australia

The Telegraph.co.uk (Sept. 29, 2011) - An extremely rare white humpback whale calf has been spotted near Australia's Great Barrier Reef in an event witnesses described Thursday as a "once in a lifetime experience".

Believed to be just a few weeks old, the baby humpback was seen at Cid Harbour in the famous reef's Whitsunday Islands area by local man Wayne Fewings, who was with his family in a boat when he spotted a whale pod.

"We were just drifting when I noticed the smaller whale in the pod was white. I couldn't believe my eyes, and I just grabbed my camera," Fewings said.

"Then the white calf approached my boat, seeming to want to check us out. I was just so amazed at seeing this animal, it made me think how truly astounding the Great Barrier Reef is," he added of the sighting on Saturday.

"I feel very lucky to have witnessed this, it's a once in a lifetime experience."

Reef official Mark Read said white whales were highly unusual, with only 10-15 believed to exist among the 10,000-15,000 humpbacks living along Australia's east coast, and purely white ones – like the calf spotted on Saturday – rarer still.

Its parents could both have been dark humpbacks carrying the recessive white whale gene, but Read said one or either may also have been white themselves, raising speculation it was the offspring of famous white humpback Migaloo.

Migaloo – the name is an Aboriginal word meaning "whitefella" – is the world's best-known all-white humpback and has built up a loyal following in Australia since first being sighted in 1991.

Humpback whales are currently on their southern migration and Mr Read said the baby white would be feeding heavily from its mother as it laid down fat stores for the "cold Antarctic waters."

Its sex was unknown and Read said there were no plans to bestow the young mammal with a name of its own.

"We'd be pretty comfortable for him or her just to simply remain anonymous and just live out its life in relative peace and harmony," Read said.

Australia's east coast humpback population has been brought back from the brink of extinction following the halting of whaling in the early 1960s, he added, describing it as a "conservation success story."

Australian koalas' loud noises 'made by human-style voice boxes'

The Telegraph.co.uk (Sept. 29, 2011) - Male koalas in Australia bellow so loud during mating season because their voice boxes are akin to those found in humans, scientists have discovered.

Despite the tree-dwelling mammal having a cute and furry appearance, a 15 pound koala is as loud as a cow weighing more than a tonne, a study found.

Researchers discovered the marsupial emitted a louder sound as a way of attracting sexual partners during mating season.

The team of Australian and Austrian scientists, writing in The Journal of Experimental Biology, also found their cries were a way of boasting about their body size and intimidate rival lovers.

Using complex medical imaging they discovered the sounds were louder because their larynx had “descended” and sat deeper in their throat and chest than other species.

This was similar to human development because as a person grows up, their larynx also becomes lower, and deeper, as they learn more complex language and speech.

"A lot of times people in the bush might hear a Koala calling… you have this cute fluffy animal but on the other hand (hear) this booming voice which jolts them a bit,” said Dr Bill Ellis, a co-author of the study.

"There are some interesting parallels in the structure of the actual vocal tract. This descendant of larynx koalas have is similar to that in some of the big cats but also in humans.”

“In adult humans we have really complex speech we should expect that similarly in koalas - it might be complex as well.”

Dr Ellis, the director of the Koala Ecology Group at the University of Queensland, added: "To our ear, we can't actually hear much difference between a large and not so large koala, but it seems koalas can tell.”

During their research, the scientists recorded 140 of the animals at the Lone Pine Koala Sanctuary in Queensland and measured their heads and body lengths.

They also carried out a medical scan on one male koala, which disclosed the marsupial's strange vocal anatomy.

An analysis of the recordings found the difference was not in the pitch but in “vocal tract resonance”. The bellows gave the impression their vocal tract was nearly 20 inches long or almost entire length of their body.

Dr Ben Charlton, from the University of Vienna, Austria, who led the study, said: “A permanently descended larynx hasn't been documented in marsupials before.

"It was believed that only humans had (this)… and that it was an essential adaptation for the creation of vowel sounds."

Dr Ellis said their noises were a way of “making themselves sound a lot bigger than they are".

They also found that as a female searched for a mating partner, they identified who issued the loudest bellows and calculated how big they were.

Previous studies using GPS tracking, specialists listening devices and DNA technology found larger males had better breeding success than their smaller rivals.

“It's quite apparent that there are some attributes that are closely correlated between the size and that one male can tell how big another male is,” Dr Ellis said.

"There are a number of strategies that koalas use for breeding and ... it isn't like an arms race to be the biggest koala.”

Earlier this year the Australian government warned koalas were facing serious risk of extinction, thanks to predators, climate change and rampant human development.

 

Sexy snacks: Study finds female mate searching evolves when mating gifts are important

PHYSORG.com (Sept. 28, 2011) - In the animal world, males typically search for their female partners. The mystery is that in some species, you get a reversal -- the females search for males.

A new study of katydids in the latest issue of the journal Proceedings of the Royal Society B -- co-authored by U of T Mississauga professor Darryl Gwynne -- supports a theory that females will search if males offer a lot more than just sperm.

"In this beast [in this study], it's a big cheesy, gooey substance that the male ejects when he copulates," says Gwynne. "It's attached to his sperm packet, so while she's being inseminated, she can reach back and grab this mating gift and eat it."

Gwynne met the lead author of the study, Jay McCartney, while on sabbatical at Massey University in New Zealand. Since part of his own research expertise covered the mating behaviours of these types of insects, Gwynne was asked to act as a co-supervisor of the project and suggested that the data could provide clues into the diversity in nature of how animals search for mates.

"Males mostly do the searching, because the Darwinian sexual selection process is typical stronger in males; they're competitive," says Gwynne." As a consequence of their eagerness to get to the females, the females just hang out waiting for the males to come to them."

In the insects that Gwynne works with, some males sing to advertise that they have a safe burrow to offer the females, while in other species, they offer the females a nutritional perk. In the katydids, where a female searched for a male, she stood to gain the largest nutritional gift.

And from the male's perspective, a large food gift not only potentially benefits his offspring, but distracts the female long enough to ensure that he has time for a full insemination. Otherwise, says Gwynne, "she's hungry…if he didn't give her this gift, she'd just pull off the sperm packet and snack on that like a little hors d'oeuvre." Gwynne says that female searching behaviour exists elsewhere in the animal kingdom -- for example, in singing animals like frogs -- and deserves further study.

Monkeys at typewriters 'close to reproducing Shakespeare'

The Telegraph (Sept. 26, 2011) - Millions of virtual monkeys have almost typed out the entire works of Shakespeare by bashing random keys on simulated typewriters.

The virtual monkeys, created by an American programmer, have already typed up the whole of the poem A Lover's Complaint and are 99.99 per cent of the way through the Bard's complete works.

The experiment attempts to prove the theory that an infinite number of monkeys sitting at an infinite number of typewriters would eventually reproduce the works of Shakespeare by chance.

Jesse Anderson, the programmer behind the project, said he was inspired by an episode of The Simpsons which spoofs the famous problem.

Mr Anderson set up millions of small computer programmes, or virtual monkeys, using Amazon's SC2 cloud computing system, and programmed them to churn out random sequences of nine characters.

If the nine-letter sequence appears anywhere in one of Shakespeare's writings, it is matched against the relevant passage in a copy of the Bard's complete works, and is checked off the list.

The monkeys, which started typing on August 21, have already completed more than five trillion of the 5.5 trillion possible nine-letter combinations, but have so far only finished one whole work.

But the experiment is an imperfect reproduction of the infinite monkey theorem because it saves correct sections of text while discarding future wrong guesses, experts said.

Dr Ian Steward, emeritus professor of mathematics at Warwick University, said that for the monkeys to type up the complete works in the correct order without mistakes would take much longer than the age of the universe.

He told the BBC: "Along the way there would be untold numbers of attempts with one character wrong; even more with two wrong, and so on.

"Almost all other books, being shorter, would appear (countless times) before Shakespeare did."

Writing on his blog, Mr Anderson said: "This is the largest work ever randomly reproduced. It is one small step for a monkey, one giant leap for virtual primates everywhere.

"I understand the definition of infinite and infinite monkey theorem and I realise that this project does not have infinite resources.

"No monkeys were harmed during the making of this code. This project is my attempt to find a creative way to attain an answer without infinite resources."

In 2003 the Arts Council for England paid £2,000 for a real-life test of the theorem involving six Sulawesi crested macaques, but the trial was abandoned after a month.

The monkeys produced five pages of text, mainly composed of the letter S, but failed to type anything close to a word of English, broke the computer and used the keyboard as a lavatory.

New study says birds learn how to build nests

BBC News (Sept. 26, 2011) New study has found birds learn the art of nest-building, rather than it being just an instinctive skill.

Researchers from Edinburgh, Glasgow and St Andrews Universities studied film of southern masked weavers recorded by scientists in Botswana.

This colourful species was chosen because individual birds build many complex nests in a season.

Dr Patrick Walsh of Edinburgh University said the study revealed "a clear role for experience".

The research has been published in the Behavioural Processes journal.

Individual birds varied their technique from one nest to the next and there were instances of birds building nests from left to right as well as from right to left.

Even for birds, practise makes perfect”Dr Patrick WalshUniversity of Edinburgh

As birds gained more experience, they dropped blades of grass less often.

"If birds built their nests according to a genetic template, you would expect all birds to build their nests the same way each time. However this was not the case," added Dr Walsh.

"Southern Masked Weaver birds displayed strong variations in their approach, revealing a clear role for experience.

"Even for birds, practise makes perfect."

Painting Pachyderm

Oli Scarff/Getty Images (Sept. 20, 2011) - DUNSTABLE, UK.  Karishma, a 13 year old female Asian elephant, paints at an easel in her enclosure at ZSL Whipsnade Zoo on September 20, 2011 in Dunstable, England. A selection of Karishma’s artwork will go on display at the Zoo this weekend to celebrate Elephant Appreciation Day.

Unlike Humans, Chimpanzees Don’t Enjoy Collaborating

Wired Science (Sept. 22, 2011) - When it benefits them, chimpanzees willingly work together. Otherwise, they can’t be bothered.

For humans, collaboration is rewarding for its own sake, a behavioral split that may underlie key differences between human and chimpanzee societies.

Primate researchers, working with semi-free ranging chimpanzees at a sanctuary in Uganda, found chimpanzees recruit a helping partner only if it gets them more food than they’d get alone. The study, described in Animal Behavior, Sept. 7, is part of a current trend in primatology to unpick how motivation and mental state affects an animal’s interactions.

“It looks like motivation plays a very important role in how we behave,” said Anke Bullinger, primary author. “And it gives a hint that even though species might be cognitively capable of doing certain things, they might not show the behavior, because they just don’t want to.”

The extent of human cooperation is unique, but not cooperation itself. Chimpanzees, bonobos, elephants and many birds work together for joint rewards.

“The interesting thing is that there isn’t much research on the motivational aspects of this,” Bullinger said. “I suspect that motivation plays a role in many aspects of cognition, not just in cooperative behavior, but also in social learning, in communication.”

For the study, Bullinger and her colleagues set food boards out of the chimpanzee’s direct reach. To bring the banana bearing platforms close, the chimps pulled on a rope resting on the ground. Chimpanzees had two options. One board they could pull close solo. On another board, loose rope threaded between loops. To get these boards, both ends had to be pulled, so the chimpanzee had to go get their partner, waiting in an adjoining room.

When Bullinger placed two banana pieces on the single board, and four pieces on the partner board, amounting to the same payoff for each chimpanzee, the animals chose to work alone the vast majority of the time. If another banana piece for each was added to the partner board, the chimpanzees overwhelmingly choose to collaborate.

“We were a bit surprised that just one more piece made such a difference,” Bullinger said.

The study implies that chimpanzees view others as social tools, as a means of maximizing their own rewards.

Continue reading: "Unlike Humans, Chimpanzees Don’t Enjoy Collaborating"

Former Trainer Says Killer Whale Captivity Causes Attacks

Wired Science (Sept. 20, 2011) - On Sept. 19, a federal hearings began on the safety of keeping killer whales in captivity. Convened by the Occupational Health and Safety Administration in the aftermath of two fatal attacks on trainers, the hearings won’t consider the safety of killer whales — but according to former SeaWorld trainer Jeff Ventre, the two issues are inseparable.

An animal-loving Florida kid who majored in biology and rose to trainer stardom in Shamu Stadium before being fired, Ventre says the attacks that killed Dawn Brancheau at SeaWorld and Alexis Martinez at Loro Parque are manifestations of stress, even madness, in animals forced into miserable, unnatural conditions.

“Killer whales don’t attack humans in the wild,” said Ventre. “What we’ve seen in these injuries to people is a direct byproduct of the stress associated with captivity.”

Ventre was fired in 1995. SeaWorld says it was for being careless; Ventre says it’s because he’d become critical of the industry. Wired recently talked to Ventre, who has since become a medical doctor and cetacean advocate, about his work.

Wired: When did your feelings about keeping killer whales in captivity begin to change?

Jeff Ventre: When I started, I was just happy to have the job. It was amazing to see dolphins and sea lions and killer whales, despite the fact that they were in captivity. I thought there was going to be a lot of science, too. I’d grown up with Jacques Cousteau programming. Over time I found out there wasn’t much science going on. It was just a different version of the circus. Over time, that wears on you.

I did two different tours of duty at Shamu Stadium. The first time I was there, I was an apprentice. I did a lot of bucket-scrubbing, blue-collar type work, and had only a little water experience. Then I went around to the other stadiums, where they had dolphins, belugas and false killer whales, and honed my waterwork abilities. Then I was brought back to Shamu Stadium in 1994, where I spent my last two years. It was that second tour of duty that was somewhat enlightening.

By that time I’d learned enough about killer whales that I began to realize that what we were telling students coming in for education shows was at odds with what was true.

Wired: Give me an example.

Ventre: We were telling people that the animals lived to maybe 20 years old. But in reality, I knew that females lived to be 50, and males to be 30. That was a red flag. I also began to realize that all the killer whales in captivity had broken teeth. That seemed odd to me, because we were feeding them dead fish.

It’s because, when you put on a live public performance, or do a training session, you have to separate the killer whales with steel gates. These have horizontal bars on them. If you’ve ever seen two dogs on the opposite side of a fence barking, this is two orcas on the opposite side of a gate. Sometimes they charge the gate and bite down on the bars.

This knocks off the enamel and exposes the pulp of the tooth. This fleshy pulp is then drilled out by a veterinarian. What you have is a hollow tooth, creating a corridor down into the jaw itself. So for the rest of that animal’s life, they need to get their teeth flushed two or three times a day. In humans, it’s known that poor dentition leads to heart disease, kidney disease and stroke. These orcas are essentially left with a diseased mouth.

Wired: What are other ways in which killer whales are poorly suited for captivity?

Continue reading: "Former Trainer Says Killer Whale Captivity Causes Attacks" >>

How Far Will Dolphins Go to Relate to Humans?

New York Times Science (Sept. 19, 2011) - OFF THE BAHAMAS — In a remote patch of turquoise sea, Denise L. Herzing splashes into the water with a pod of 15 Atlantic spotted dolphins. For the next 45 minutes, she engages the curious creatures in a game of keep-away, using a piece of Sargassum seaweed like a dog’s chew toy.

Dr. Herzing is no tourist cavorting with marine mammals. As the world’s leading authority on the species, she has been studying the dolphins for 25 years as part of the Wild Dolphin Project, the longest-running underwater study of its kind.

“I’m kind of an old-school naturalist,” she said. “I really believe in immersing yourself in the environment of the animal.”

Immerse herself she has. Based in Jupiter, Fla., she has tracked three generations of dolphins in this area. She knows every animal by name, along with individual personalities and life histories. She has captured much of their lives on video, which she is using to build a growing database.

And next year Dr. Herzing plans to begin a new phase of her research, something she says has been a lifetime goal: real-time two-way communication, in which dolphins take the initiative to interact with humans.

Up to now, dolphins have shown themselves to be adept at responding to human prompts, with food as a reward for performing a task. “It’s rare that we ask dolphins to seek something from us,” Dr. Herzing said.

But if she is right, the dolphins will seek to communicate with humans, and the reward will be social interaction itself, with dolphins and humans perhaps developing a crude vocabulary for objects and actions.

Other scientists are excited by the project. “ ‘Mind-blowing’ doesn’t do justice to the possibilities out there,” said Adam Pack, a cetacean researcher at the University of Hawaii at Hilo and an occasional collaborator with Dr. Herzing. “You’ve got crystal-clear warm water, no land in sight and an interest by this community of dolphins of engaging with humans.”

How far will dolphins go to engage?

“The key is going to be coming up with a system in which the dolphins want to communicate,” said Stan Kuczaj, director of the Marine Mammal Behavior and Cognition Laboratory at the University of Southern Mississippi. “If they don’t care, it won’t work.”

Dr. Kuczaj developed an early two-way communication system while working at a captive lab in Orlando in the late 1980s. The system relied on visual symbols, not sound, and used a large stationary keyboard that proved to be too cumbersome.

But he says that the effort gave him confidence that such a system could work and that Dr. Herzing is “definitely the closest to getting there.”

“If it works,” he said, “it’ll be a huge step forward.”

Continue reading: "How Far Will Dolphins Go to Relate to Humans?" >>

Exposing the Impact of Our Choices on Nonhuman Animals

Care2 by Zoe Weil (Sept. 19, 2011)

In 1985, I was fascinated by what I’d read about Sarah, a chimpanzee who could use a symbolic language to communicate, so I contacted Dr. David Premack, the principal researcher working with Sarah and other chimps at the University of Pennsylvania primate research lab, to volunteer. I’ll never forget meeting Sarah. When I was brought to her cage, I was warned to stay away from the bars because Sarah was strong enough, and often aggressive enough, to grab me and cause severe injury.

Sarah lived alone in her cage. The four other chimps at the lab were only three years old, and I was told that Sarah might harm them, so this social animal was confined permanently in solitude. She had long since refused to continue with her language training, so her life consisted largely of watching soap operas on a TV on the other side of her cage or sitting in her small outdoor enclosure. It was the new young chimps, who were the subjects in the ongoing language acquisition studies who lived together and had a huge outdoor space in which to play.

Sarah threw what was described as a temper tantrum when introduced to new people, and I was no exception. She screamed and bounded from wall to wall, but I felt determined to have a positive relationship with her. Every time I volunteered I made a point of visiting Sarah. One day I said to her, “Sarah, turn around and I’ll scratch your back.” I rotated my right index finger in the air as I said “turn around” in case she didn’t understand my words. Sure enough, Sarah turned around, sank down to sit on the floor and pressed her back against the bars of the cage. I was unafraid as I went up to her and scratched her back.

I didn’t volunteer for very long. One of the young chimps bit my hand when I was paying too much attention to another who had climbed onto my shoulders. Even a three-year-old chimp can administer quite a bite, and it came just a week before my father died, and I needed to be gone for some time. I realized I didn’t really want to go back. Once I’d seen behind the scenes of something that had initially seemed so benign – teaching chimpanzees language – I realized just how much suffering was being inflicted on these cousins of ours.

For years I felt haunted by Sarah. Was she to live out her days in isolation and misery? All I could do was tell her story and, as a humane educator, teach, so that we might make different societal choices in relationship to others, whether people or nonhuman animals. Fifteen years later, I learned that Sarah had found a final home at Chimp Haven, a chimpanzee sanctuary that houses chimps formerly used in medical research, entertainment and as pets. My eyes filled with tears of relief at this good news.

Continue reading: "Exposing the Impact of Our Choices on Nonhuman Animals" >>

Crows Use Mirrors To Find Food

BBC Nature (Sept. 20, 2011) Clever New Caledonian crows can use mirrors to find food, according to scientists.

Researchers from the University of Auckland, New Zealand, tested wild-caught crows' reactions to mirrors.

The crows did not recognise themselves but found cached food items by studying their reflections.  The results put the birds in an elite group of species - which includes primates and elephants - known to be able to process mirror information.

New Caledonian crows (Corvus moneduloides) are known for their intelligent and innovative use of tools, such as twigs, which they use to fish nutritious insects out of holes and crevices.

Mirror experiments with other members of the same family of birds, the corvids, have found that magpies recognise their reflections but jungle crows do not.

In this study, published in the journal Animal Behaviour, psychologists examined the recognition skills of the notoriously clever New Caledonian crows.

Scientists captured 10 wild birds and placed them in large cages in order to record their behaviour in response to mirrors.

All the crows reacted to seeing their reflections as if they were encountering another crow; the birds made rapid head movements, raised their tails and even attacked the reflection.

Lead researcher Felipe S Medina Rodriguez said the crows' antagonistic reaction to their mirror image "was not surprising". He explained that an animal usually had extensive exposure to mirrors before it began to display an understanding that the image it was seeing was itself.

When the crows moved away from the mirror and lost sight of their reflection, they frequently searched behind the mirror to locate the "other" bird.

The researchers think that the behaviour was probably caused by the birds' lack of experience of mirrors; similar reactions have been recorded in primate infants and two-year-old children.

The second part of the experiment, though, revealed some surprising findings.

The scientists devised a task to test whether the crows could use mirrors to locate cubes of meat that were hidden from direct view.

All of the crows tested appeared to understand how the meat's reflection correlated to its location.

Continue reading: "Crows Use Mirrors To Find Food" >>

Escaped Pet Birds Are Teaching Wild Birds to Speak English

Treehugger (Sept. 15, 2011) Across parts of Australia, reports have been pouring in of strange voices chattering high in the treetops -- mysterious, non-sensical conversations in English. But while this phenomenon is certainly quite odd, its explanation isn't paranormal. It turns out that escaped pet birds, namely parrots and cockatoos, have begun teaching their wild bird counterparts a bit of the language they picked up from their time in captivity -- and, according to witnesses, that includes more than a few expletives.

Jaynia Sladek, an ornithologist from the Australian Museum, says that some birds are just natural mimickers, able to acquire new sounds based on things they hear around them. For birds kept as pets, these sounds tend to mirror human language -- but that influence doesn't cease even after said birds escape or are released back into the wild.

Once back in their natural environments, these chatty ex-pets eventually join with wild birds who, in turn, start picking up the new words and sounds. The remnants of that language also eventually gets passed along to the escaped birds' offspring, much like it does for humans.

"There's no reason why, if one comes into the flock with words, [then] another member of the flock wouldn't pick it up as well," Sladek said in an interview with Australian Geographic.

According to the report, 'Hello cockie' is one of the most commonly heard phrases feral birds are teaching in the wild, along with a host of expletives -- perhaps the last words those escapees heard after their frantic owners realized they were making a break for freedom.

Zoo Death Stirs Debate About Keeping Dolphins in Captivity

Wired Science (Sept. 14, 2011) - The death of a young bottlenose dolphin at a Chicago zoo was accidental, but some biologists say it shows why dolphins shouldn’t be kept in captivity for entertainment.

The dolphin, a 4-year-old named Nea, died on the afternoon of Sept. 5 at the Brookfield Zoo. According to a zoo press release, trainers heard “a loud pop” from the pool, apparently the sound of two dolphins colliding. Nobody reported seeing the collision, but it’s thought to have happened in the air as the animals jumped. Nea died minutes later from a fractured skull.

Zoo officials described it as a “freak incident,” ascribing it to typical roughhousing gone awry. But crowding dolphins into small, unnatural environments makes accidents more likely, said Wild Dolphin Project biologist Denise Herzing.

“Dolphins whack each other in the wild. That’s part of their aggressiveness. But in captivity, there’s less room,” said Herzing. “This isn’t the first time dolphins have had an accident in the air. Certainly there have been dolphins jumping out of tanks. The restricted lives of dolphins jumping in a pool can impact their ability to do what they normally do.”

Continue Reading “Zoo Death Stirs Debate About Keeping Dolphins in Captivity” »

Mother Tongue Comes from Your Prehistoric Father

ScienceDaily (Sep. 17, 2011) — Language change among our prehistoric ancestors came about via the arrival of immigrant men -- rather than women -- into new settlements, according to new research.

The claim is made by two University of Cambridge academics, Peter Forster and Colin Renfrew, in a report to be published in Science on September 9.

They studied the instances of genetic markers (the male Y chromosome and female mtDNA) from several thousand individuals in communities around the world that seem to show the emergence globally of sex-specific transmission of language.

From Scandinavian Vikings who ferried kidnapped British women to Iceland -- to African, Indian and Polynesian tribes, a pattern has emerged which appears to show that the arrival of men to particular geographic locations -- through either agricultural dispersal or the arrival of military forces -- can have a significant impact on what language is spoken there.

Professor Renfrew said: "It may be that during colonisation episodes by emigrating agriculturalists, men generally outnumber women in the pioneering groups and take wives from the local community.

"When the parents have different linguistic backgrounds, it may often be the language of the father which is dominant within the family group."

Dr Forster, of Murray Edwards College, also pointed to the fact that men have a greater variance in offspring than women -- they are more likely to father children with different mothers than vice versa. This has been recorded both in prehistoric tribes such as the 19th and 20th century Polar Eskimos from Greenland and in historic figures like Genghis Khan, who is believed to have fathered hundreds of children.

Indeed, his Y chromosome is carried by 0.5 per cent of the world's male population today.

Perhaps the most striking example of sex-biased language change however comes from a genetic study on the prehistoric encounter of expanding Polynesians with resident Melanesians in New Guinea and the neighbouring Admiralty Islands. The New Guinean coast contains pockets of Polynesian-speaking areas separated by Melanesian areas. The Polynesian mtDNA level (40-50%) is similar in these areas regardless of language, whereas the Y chromosome correlates strongly with the presence of Polynesian languages.

Past studies have shown similar findings in the Indian subcontinent among the speakers of Tibeto-Burman and among the immigrant Indo-European languages as opposed to indigenous Dravidian languages.

In the Americas, too, language replacement in the course of postulated farming dispersal has also been found to correlate for the Uto-Aztecan language family.

Added Forster: "Whether in European, Indian, Chinese or other languages, the expression 'mother tongue' and its concept is firmly embedded in popular imagination -- perhaps this is the reason why for so many years the role of fathers, or more likely, specific groups of successful males, in determining prehistoric language switches has not been recognised by geneticists."

"Prehistoric women may have more readily adopted the language of immigrant males, particularly if these newcomers brought with them military prowess or a perceived higher status associated with farming or metalworking."

Journal Reference:
P. Forster, C. Renfrew. Mother Tongue and Y Chromosomes. Science, 2011; 333 (6048): 1390 DOI:10.1126/science.1205331

Orangutans Play With iPads

Source: kotaku.com.au 
Orangutans, it turns out, love the iPad and its games just as much as some humans do.

A budding program at the Milwaukee County Zoo is working to place iPads into the giant, gentle palms of their orangutans. Two of the zoo's orangutans already look forward to weekly sessions with an iPad. They even have favorite apps, shows and games, but they haven't yet been given free rein with the Apple device because keepers worry they might get frustrated and simply snap one in half.

"One of the biggest hurdles we face is that an orangutan can snap an iPad like you or I could rip cardboard," said Richard Zimmerman, executive director of Orangutan Outreach, which hopes to extend Milwaukee's iPad enrichment program to zoos around the country. "Even the little guys like Mahal are incredibly strong. A big male could take it apart in about five seconds."

Before extending the program, allowing the orangutan's to have personal iPads, Zimmerman and his group needs to find an orangutan-proof case. But the program is still making strides in its infancy in Milwaukee.

It started as an April Fool's joke, Scott Engel, the iPad Enrichment Coordinator at the zoo, tells me.

"A friend of a friend who is a gorilla keeper at the zoo was half-joking about getting an iPad to use with gorillas after seeing a story in the UK Sun," he said.

While the Sun's story was an April Fool's Day joke, Engel thought, 'Why not?' So he contacted Milwaukee County Zoo to float the idea of using his old iPad to work with orangutans. Now Engel spends 20 minutes three-to-four days a week working with MJ and Mahal.

Engel started by showing the two the device through the glass where visitors usually stand. The first thing he did was turn on his iPad 2's camera and let the two use the device as a sort of mirror.

"It was amazing to see how they welcomed this strange device into their area," he said.

Once they were used to the iPad, the keepers started using the device in a back area where the orangutans could reach through a cage door and touch it. Last week, the two had their first chance to go completely hands and feet on with the device, though it still isn't allows in the enclosure with them.

The orangutans both have their favorite apps, often spending quite a bit of time finger-painting with DrawFree, watching television shows and even playing games. They've tried iFishPond,Flick Kick Football and seem to really love the interactive book The Fantastic Flying Books of Morris Lessmore.

"I'll show [Morris Lessmore] to them through the glass and they love the combination of movement, sound, and color," Engel said. "They will sit for about 20 minutes, listening to the story . In fact, MJ and I finished the book in one session."

The orangutans also seem particularly enchanted with videos.

"We'll show the orangutans videos of themselves, videos of wild orangutans, and other animals that reside at the zoo," Engel said. "This has been very successful and really seems to hold their interest. In fact I think orangutan MJ has a crush on David Attenborough. Whenever he comes on to narrate a scene, her eyes light up and she just stares."

The notion of enrichment at zoos is incredibly important, especially with orangutans which are highly intelligent creatures that require mental stimulation to keep from growing bored or depressed, Zimmerman said.

"Orangutans are very tactile and their natural curiosity is perfect for a device like an iPad," he said. "They are open to all types of enrichment and we think that the touchscreen 'games' will be really good for them— especially during the winter months in northern climates when they spend long periods of time indoors. Orangutans love painting with their fingers as well as brushes, and they seem to take quickly to using their fingers to paint on the touchscreen. We have a lot of different ideas we want to try with them and a lot of interest in the zoo community around the country."

Zimmerman hopes to extend the iPad program to Zoo Atlanta next, where they already have touchscreens built into an "enrichment tree" in the orangutan enclosure. Keepers there are ready to kick off the program, he said. Zoos in Toronto, Phoenix, Honolulu, Memphis and Florida are also on board with the idea.

"As long as the orangutans are the decision-makers, the enrichment can be great for them," Zimmerman said. "If the iPad games can help alleviate any boredom they might otherwise feel, we are all for it! And if zoo visitors can see this in practice and then go home with a better appreciation for the orangutans as sentient, intelligent beings who need to be protected in the wild, then everybody wins!"

Once the program is more established, and once the have a solution for protecting iPads from the incredible strength of an orangutan, Zimmerman hopes to kick off a second phase of the program.

"One of our goals is to be able to have the orangutans interact and communicate amongst themselves... essentially being able to go online and see who else is online... and contacting them to be able to 'play'," he said. "We've been calling it 'Primate Playdate'."

And the hope isn't just that orangutans will go online to play video games with each other, from zoo to zoo, Zimmerman thinks it's possible that zoo visitors could download the same apps and play with and against the primates with their own iPhones and iPads.

"Play is a huge component of this type of enrichment and I've found that a simple app like the camera app on the iPad is wonderful," Engel said. "The awesome thing is that when I arrive at the orangutan area, Mj and Mahal come over to see me and they seem to look forward to our enrichment sessions. The super amazing thing about the whole experience is that they don't get any reward for this - no food or treats, they just get to play. They chose to greet me and let me hang out with them. That is the best thing about it. They get to decide something. I'm just along for the ride."Be sure to click through the gallery for more images and video of the orangutans playing with their iPads for the first time. Don't forget to click on the bottom right expand button to see them full size.

Evolution of the Evolutionarily Minded - Does evolutionary psychology need a rethink?

Source: Science Daily

In the century and a half since Charles Darwin's publication of The Origin of Species, evolutionary theory has become the bedrock of modern biology, yet its application to the understanding of the human mind remains controversial. For the past 30 years, evolutionary interpretation of human cognition has been dominated by the field of evolutionary psychology. One view of this field is that human minds are composed of a list of dedicated programmes, each fashioned by natural selection to solve specific problems faced by our Stone Age ancestors, with all humans possessing the same universal architecture irrespective of geography or upbringing. However, this characterization of the human mind has been subject to criticism, in particular that some interpretations were so speculative they amounted to 'evolutionary stories.'

In an article published July 19 in the online, open access journal PLoS Biology, a team of biologists, psychologists and philosophers from the University of Utrecht in the Netherlands, the University of Cincinnati in America, and the University of St Andrews in Scotland, suggest a new framework for the evolutionary analysis of the mind that draws on recent work from a variety of related subjects.

Professor Johan Bolhuis and colleagues describe how the field of evolutionary psychology had been dominated by a set of widely held assumptions -- e.g., that human behavior is unlikely to be adaptive in modern environments, that human cognition is task-specific, and that there is a universal human nature. However, new findings and approaches from genetics, neuroscience and evolutionary biology now question these assumptions. For example, many human genes have been subject to recent selection in the past few thousand years, which means that humans cannot accurately be portrayed as being adapted only to a Stone Age environment. Experimental and theoretical findings also suggest that humans play an active, constructive role in co-directing their own development and evolution. How humans think and behave varies from individual to individual and place to place. Moreover, experimental evidence suggests that human minds frequently utilize very general learning rules rather than a more modular account of cognition.

Senior author Professor Kevin Laland, former president of the European Human Behaviour and Evolution Association, states: "The current evolutionary psychology paradigm made sense in the 1980s, when modularity of mind was all the rage and everyone thought that evolution was slow. However, with the benefit of hindsight we can see that these assumptions were questionable, and [it] is now clear that the field needs a broader, theoretical framework. Recent developments in evolutionary & developmental biology and cognitive science provide some very exciting new avenues for research. We enter a new phase in the discipline."

Journal Reference:

1. Johan J. Bolhuis, Gillian R. Brown, Robert C. Richardson, Kevin N. Laland. Darwin in Mind: New Opportunities for Evolutionary Psychology. PLoS Biology, 2011; 9 (7): e1001109 DOI: 10.1371/journal.pbio.1001109

Chimpanzees Are Spontaneously Generous After All, Study Shows

Source: Science Daily

Researchers at the Yerkes National Primate Research Center have shown chimpanzees have a significant bias for prosocial behavior. This, the study authors report, is in contrast to previous studies that positioned chimpanzees as reluctant altruists and led to the widely held belief that human altruism evolved in the last six million years only after humans split from apes.

The current study findings are available in the online edition of Proceedings of the National Academy of Sciences.

According to Yerkes researchers Victoria Horner, PhD, Frans de Waal, PhD, and their colleagues, chimpanzees may not have shown prosocial behaviors in other studies because of design issues, such as the complexity of the apparatus used to deliver rewards and the distance between the animals.

"I have always been skeptical of the previous negative findings and their over-interpretation, says Dr. de Waal. "This study confirms the prosocial nature of chimpanzees with a different test, better adapted to the species," he continues.

In the current study, Dr. Horner and colleagues greatly simplified the test, which focused on offering seven adult female chimpanzees a choice between two similar actions: one that rewards both the "actor," the term used in the paper for the lead study participant, and a partner, and another that rewards only the actor/chooser herself. Examples of the critically important simplified design aspects include allowing the study partners to sit close together and ensuring conspicuous food consumption, which the researchers achieved by wrapping pieces of banana in paper that made a loud noise upon removal.

In each trial, the chooser, which was always tested with her partner in sight, selected between differently colored tokens from a bin. One colored token could be exchanged with an experimenter for treats for both members of the pair (prosocial); the other colored token would result in a treat only for the chooser (selfish). All seven chimpanzees showed an overwhelming preference for the prosocial choice. The study also showed the choosers behaved altruistically especially towards partners who either patiently waited or gently reminded them that they were there by drawing attention to themselves. The chimpanzees making the choices were less likely to reward partners who made a fuss, begged persistently or spat water at them, thus showing their altruism was spontaneous and not subject to intimidation.

"We were excited to find female after female chose the option that gave both her and her partner food," says Dr. Horner. "It was also interesting to me that being overly persistent did not go down well with the choosers. It was far more productive for partners to be calm and remind the choosers they were there from time to time," she continues.

The authors say this study puts to rest a longstanding puzzle surrounding chimpanzee altruism. It is well-known these apes help each other in the wild and show various forms of empathy, such as reassurance of distressed parties. The negative findings of previous studies did not fit this image. These results, however, confirm chimpanzee altruism in a well-controlled experiment, suggesting human altruism is less of an anomaly than previously thought.

The study authors next plan to determine whether the altruistic tendency of the chimpanzees towards their partners is related to social interactions within the group, such as reciprocal exchanges of food or social support.

Journal Reference:

1. Victoria Horner, J. Devyn Carter, Malini Suchak, Frans B. M. de Waal. Spontaneous prosocial choice by chimpanzees. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1111088108