A discovery in Africa has shaken up the argument of one direct line of human evolution. The old theory ran that Homo habilis evolved into Homo erectus. Which evolved into us. The homo sapiens.
But the new study found remains of the first two links in the same place and time, informs WDEF.
Surprising research based on two African fossils suggests our family tree is more like a wayward bush with stubby branches, challenging what had been common thinking on how early humans evolved.
The discovery by Meave Leakey, a member of a famous family of paleontologists, shows that two species of early human ancestors lived at the same time in Kenya. That pokes holes in the chief theory of man's early evolution - that one of those species evolved from the other.
And it further discredits that iconic illustration of human evolution that begins with a knuckle-dragging ape and ends with a briefcase-carrying man.
The old theory is that the first and oldest species in our family tree, Homo habilis, evolved into Homo erectus, which then became human, Homo sapiens. But Leakey's find suggests 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. She and her research colleagues report the discovery in a paper published in Thursday's journal Nature, The Jerusalem Post reports.
The Koobi Fora Research Project group, led by the famous mother and daughter team of Meave and Louise Leakey, discovered the two fossils in 2000. One is an upper jaw bone of Homo habilis, which dates from 1.44 million years ago, and the other is "an exquisitely preserved" skull of Homo erectus, dated to about 1.55 million years ago, the paper's lead author, Fred Spoor, said.
"What is truly striking about this fossil is its size," Spoor, a professor of evolutionary anatomy at University College London, said in a statement.
"It is the smallest Homo erectus found thus far anywhere in the world," Australian Life Scientist reports.