for National Geographic News
A 36,000-year-old skull from South Africa provides the first fossil evidence that modern humans left Africa 70,000 to 50,000 years ago to colonize Eurasia, new research suggests.
"Up until a few years ago, this was largely just a theory based on some genetics," said Ted Goebel, an anthropologist at Texas A&M University who was not involved in the study.
"We're beginning to accumulate evidence from archaeology, from genetics, from physical anthropology that support this model or theory that modern humans spread out of Africa 60,000 or 70,000 years ago," he said.
Scientists today can only theorize about how anatomically modern humans, who appeared in East Africa by 195,000 years ago, spread across the continent to the Middle East, Asia, Australia, and Europe.
(See an interactive map of early human migration.)
The mystery endures in large part due to the scarcity of human fossils in sub-Saharan Africa dating to 70,000 to 15,000 years ago, Goebel says.
The "out of Africa" theory holds that modern humans left East Africa only relatively recently, pushing into southern Africa, the Middle East, Eurasia, and Australia sometime between 70,000 to 50,000 years ago.
This theory is bolstered not only by this latest discovery but also by a separate find in Russia, in which human teeth and artifacts have been dated to around the same age as the South Africa skull.
The results of both discoveries appear in the current issue of the journal Science.
The skull study was led by Frederick E. Grine, an anthropologist and anatomist at Stony Brook University on Long Island, New York.
The fossil was originally unearthed from a riverbed near Hofmeyr, South Africa, in 1952 but was never accurately dated.
SOURCES AND RELATED WEB SITES