Our closest relative the chimpanzee is capable of sophisticated cooperative behaviour and even rudimentary altruism, two new studies reveal. The discovery suggests that some of the underpinnings of human sociality may have been present millions of years ago. "At least some of [those behaviours] are already present in rudimentary forms in chimps â and maybe in the common ancestor of chimps and humans," says Alicia Melis of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. "Humans are biologically prepared to develop these kinds of skills." To study the cooperative ability of chimps, Melis and colleagues put individual chimps at a sanctuary in Uganda in a test cage with a heavy tray of food in plain sight but out of reach through the bars of the cage. A rope threaded through eyelets on the left and right sides of the tray allowed the animal to pull the food within reach â but only by pulling on both ends of the rope simultaneously. Otherwise, the rope merely snaked through the eyelets, leaving the tray in place. When they could retrieve the food themselves, the eight juvenile chimps tested almost always did so and ignored a second chimp locked in an adjoining cage. But when the tray was widened â and the two ends of the rope became too far apart for a single chimp to grab both ends simultaneously â all the animals quickly learned to unbar the door and let the second chimp in to help. A friend in need Then Melis repeated the experiment but gave each test chimp a choice of two potential helpers: a subordinate chimp who was well-practised at the cooperative task, and a dominant male who was not. The test chimps at first chose the dominant male, perhaps out of deference, but quickly learned to pick the better helper. Researchers have reported cooperative behaviour in chimpanzees before â in surrounding prey, for example â or in forming social alliances. However, Melis's experiments are the first to show clearly that chimps understand when they need help and can recognise and choose the best helper. The chimps in this experiment always had selfish motives for cooperating, but chimps will sometimes help others even when they gain no benefit from doing so, as a second study, by Felix Warneken and Michael Tomasello at the same institute reveals. No reward The researchers studied what three captive-raised young chimps would do when a familiar human caretaker dropped an object out of her reach. All three chimps were more likely to pick up the object and hand it to the caretaker when she reached for the object than when she merely looked at the object. Click here to see a video of a helpful chimp in action. This suggests that the chimps understood the human's goal and tried to help, says Warneken â even though they received no reward or praise. Human infants also helped in this way (click here to see a toddler help) and performed other, more complex helping tasks. They would open a cabinet door, for example, to help an adult whose hands were full, while a chimp would not. "This suggests that a tiny bit of helping behaviour is already present in chimpanzees, but they're not as flexible as human infants are," says Warneken. Such altruistic helping behaviour is common in humans, but had never been documented in other animals before. Researchers now need to understand how often, and under what conditions, it occurs, says Joan Silk, an evolutionary anthropologist at the University of California at Los Angeles, US. In earlier studies, Silk found that chimps are as likely to choose a food reward for themselves alone as for themselves and a companion.
Doh! http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=379134&in_page_id=1770 The time-warp family who walk on all fours by BEN FARMER, Daily Mail An extraordinary family who walk on all fours are being hailed as the breakthrough discovery which could shed light on the moment Man first stood upright. Scientists believe that the five brothers and sisters found in Turkey could hold unique insights into human evolution. The Kurdish siblings, aged between 18 and 34 and from the rural south, 'bear crawl' on their feet and palms. Study of the five has shown the astonishing behaviour is not a hoax and they are largely unable to walk otherwise. Researchers have found a genetic condition which accounts for their extraordinary movement. And it could provide invaluable information on how humans evolved from a four-legged hominid into a creature walking on two feet. Two of the daughters and a son have only ever walked on two palms and two feet, but another son and daughter sometimes manage to walk upright. The five can stand upright, but only for a short time, with both knees and head flexed. Their remarkable story is told in a television documentary, to be screened next week, which shows scientists studying their movement, but also their struggle to fit in with modern society. Professor Nicholas Humphrey, evolutionary psychologist at the London School of Economics, visited the family twice. He said: "It's amazing as an example of a strange, strange aberration of human development. But their interest is how they can live in the modern world." The five are all mentally retarded. Their mother and father, who are closely related are believed to have handed down a unique combination of genes which result in the behaviour. Some researchers argue the genetic fault has caused the brothers and sisters to regress to a form of 'backward evolution'. Others believe it has led to brain damage which has allowed them to develop the walk. Rather than walking on their knuckles, like gorillas or chimpanzees, they walk on the palms of their hands, with their fingers spread upwards. Scientists believe this may be the way hominids moved to protect their fingers for more delicate movements. Prof Humphrey said he thought the family had reverted to an instinctive form of behaviour encoded deep in the brain but abandoned during evolution. He said: "I do not think they were destined to be quadrupeds by their genes, but their unique genetic make-up allowed them to be. 'It has produced an extraordinary window on our past. It is physically possible, which no one would have guessed from the modern human skeleton." Study of their hands has shown they are heavily callused and have been walking like this for years. Prof Humphrey said: "However they arrived at this point, we have adult human beings walking like ancestors several million years ago." The five siblings spend most of their time sitting outside the family's basic rural home. However, one brother travels to the local village where he engages in basic interactions with people. The documentary, to be shown on BBC2 on Friday, March 17, is called The Family That Walks On All Fours.