Fossil Dug Up From Africa, Paint Messy Picture of Evolution
http://www.time.com/time/health/article/0,8599,1650972,00.html?xid=feed-cnn-topics
(WASHINGTON)—Surprising fossils dug up in Africa are creating messy kinks in the iconic straight line of human evolution with its knuckle-dragging ape and briefcase-carrying man. The new research by famed paleontologist Maeve Leakey in Kenya shows our family tree is more like a wayward bush with stubby branches, calling into question the evolution of our ancestors.
The old theory was that the first and oldest species in our family tree, Homo habilis, evolved into Homo erectus, which then became us, Homo sapiens. But those two earlier species lived side-by-side about 1.5 million years ago in parts of Kenya for at least half a million years, Leakey and colleagues report in a paper published in Thursday's journal Nature.
In 2000 Leakey found an old H. erectus complete skull within walking distance of an upper jaw of the H. habilis, and both dated from the same general time period. That makes it unlikely that H. erectus evolved from H. habilis, researchers said. It's the equivalent of finding that your grandmother and great-grandmother were sisters rather than mother-daughter, said study co-author Fred Spoor, a professor of evolutionary anatomy at the University College in London.
The two species lived near each other, but probably didn't interact with each other, each having their own "ecological niche," Spoor said. Homo habilis was likely more vegetarian and Homo erectus ate some meat, he said. Like chimps and apes, "they'd just avoid each other, they don't feel comfortable in each other's company," he said.
They have some still-undiscovered common ancestor that probably lived 2 million to 3 million years ago, a time that has not left much fossil record, Spoor said. Overall what it paints for human evolution is a "chaotic kind of looking evolutionary tree rather than this heroic march that you see with the cartoons of an early ancestor evolving into some intermediate and eventually unto us," Spoor said in a phone interview from a field office of the Koobi Fora Research Project in northern Kenya.
Click link up top for more of this article.
