http://www.theaustralian.news.com.au/story/0,25197,26156782-2703,00.html
Human ancestors walked tall October 03, 2009 Article from: The Australian WASHINGTON: Move over, Lucy. A 1.3m-tall female nicknamed Ardi, who lived 4.4 million years ago in Africa, has replaced you as the earliest best known ancestor of the human species. Ardi's nearly complete skeleton is one million years older than Lucy's, pushing back the point when hominids (pre-human primates) are known to have split from the evolutionary line that led to chimpanzees and gorillas, an international scientific team said yesterday. "Ardi is not a chimp. It's not a human. It's what we used to be," said paleontologist Tim White of the University of California, Berkeley. He and his colleagues spent 15 years recovering and studying Ardi's bones. Ardi is "on our side of the family tree, not the chimpanzee side", Dr White told a news conference in Washington sponsored by the journal Science. Ardi is named for her genus and species, Ardipithecus ramidus, a distant cousin of Lucy's line, Australopithecus afarensis. The discovery sheds new light on human evolution during a previously little known epoch. Scientists believe that humans and apes both descended from a "last common ancestor", an even more primitive primate that lived between seven million and nine million years ago. The Ardi fossils suggest that the common ancestor - still undiscovered - resembled a chimp much less than researchers previously believed. The finds show that what seems most ancient about modern chimps and apes - such as canine fangs, long limbs with hooked fingers for swinging in trees, and hands designed for knuckle-walking - may be more recent developments. Ardi was not the last common ancestor, Dr White said, but "it's the closest we've come". A few older hominid skulls and teeth have been discovered, but nothing as complete as Ardi or Lucy. The first of Ardi's bones, a single tooth, was discovered in 1992, not far from where Lucy's skeleton was buried in the fossil-rich Afar Rift of Ethiopia. Later, more than 100 other pieces, including bits of a skull, hand, foot and pelvis, were carefully eased out of the volcanic soil. The fossils offer a detailed look at a species of sturdy, small-brained creatures that dwelled in an ancient African glade of hackberry, fig and palm trees, by a river that long ago turned to stone. Dr White called the project to assemble Ardi, which involved 47 scientists from 10 countries, "a scientific mission into the very deep past ... It was like discovering a time capsule from a period and place we knew nothing about". Owen Lovejoy, an evolutionary biologist at Ohio's Kent State University, said Ardi was "an image of what our early ancestors must have looked like". Ardi's hands, feet, pelvis and teeth are more like the bones of modern humans than of apes. For example, her pelvis is modified for walking upright on the ground, as well as climbing trees. "Ardi was not a knuckle-walker (like apes)," Dr Lovejoy said. Ardi was a woodland creature, with a small brain, long arms and short legs. Her discovery disproves the earlier theory that pre-humans learned to walk when they came down from trees to live on open savannas, Dr White said. She probably ate fruit, berries, mushrooms, birds, bats and other small mammals, judging by her teeth and the remains found where she was discovered. Scientists say she was female because of the shape of her canine teeth and her pelvis. AP [Non-text portions of this message have been removed]
