Charles Darwin,whose research in the 19th century paved the way for the science ofevolution, was cautious about the last common ancestor between humansand apes.
The story of humankind is reaching back another million years asscientists learn more about “Ardi,” a hominid who lived 4.4 millionyears ago in what is now Ethiopia. The 110-pound, 4-foot female roamedforests a million years before the famous Lucy, long studied as theearliest skeleton of a human ancestor.
This older skeleton reverses the common wisdom of human evolution, said anthropologist C. Owen Lovejoy of Kent State University.
Ratherthan humans evolving from an ancient chimp-like creature, the new findprovides evidence that chimps and humans evolved from some long-agocommon ancestor — but each evolved and changed separately along the way.
“This is not that common ancestor, but it’s the closest we have ever been able to come,” said Tim White, director of the Human Evolution Research Center at the University of California, Berkeley.
The lines that evolved into modern humans and living apes probablyshared an ancestor 6 million to 7 million years ago, White said in atelephone interview.
But Ardi has many traitsthat do not appear in modern-day African apes, leading to theconclusion that the apes evolved extensively since we shared that last common ancestor.