Oldest Human Skeleton Offers New Clues To Evolution

Oldest human skeleton offers new clues to evolution By By Azadeh Ansari | CNN

The oldest-known hominid skeleton was a 4-foot-tall female who walked upright more than 4 million years ago and offers new clues to how humans may have evolved, scientists say.

Scientists believe that the fossilized remains, which were discovered in 1994 in Ethiopia and studied for years by an international team of researchers, support beliefs that humans and chimpanzees evolved separately from a common ancestor.

"This is not an ordinary fossil. It's not a chimp. It's not a human. It shows us what we used to be," said project co-director Tim White, a paleontologist at the University of California, Berkeley.

Ardipithecus ramidus, nicknamed "Ardi," is a hominid species that lived 4.4 million years ago in what is now Aramis, Ethiopia. That makes Ardi more than a million years older than the celebrated Lucy, the partial ape-human skeleton found in Africa in 1974.

Ardi's 125-piece skeleton includes the skull, teeth, pelvis, hands and feet bones. Scientists say the data collected from Ardi's bone fragments over the past 17 years push back the story of human evolution further than previously believed.

"In fact, what Ardipithecus tells us is that we as humans have been evolving to what we are today for at least 6 million years," C. Owen Lovejoy, an evolutionary biologist at Kent State University and project anatomist, said Thursday.

Analysis of Ardi's skeleton reveals that she weighed about 110 pounds, had very long arms and fingers, and possessed an opposable big toe that would have helped her grasp branches while moving through trees. Read more.