Africa's East Coast Netted Ancient Humans
Bower, B., Science News
Modern humans lived on the African coast of the Red Sea about 125,000 years ago, pushing back the date for the earliest seaside settlement by at least 10,000 years, a new study finds. The discovery raises the possibility that ancient humans left Africa by following the Red Sea coast into southern Asia as well as by trekking up the eastern Mediterranean coast into central Asia.
The excavation, directed by geologist Robert C. Walter of Mexico's Centro de Investigacion Cientifica de Educacion Superior in Ensenada, has unearthed stone tools and shellfish remains in an exposed reef that straddles Eritrea's Red Sea shore. To assign a date to the artifacts, the scientists measured radioactive isotopes in fossil coral surrounding them.
Until now, the oldest coastal occupations by modern Homo sapiens--located at two South African cave sites--dated to between 115,000 and 100,000 years ago. Those discoveries include bone fragments from early H sapiens, whereas the Eritrean site has so far yielded no human skeletal remains.
Still, fossil finds elsewhere suggest that modern H. sapiens lived in eastern Africa by about 130,000 years ago, Walter says.
Global warming around 150,000 years ago may have dried out inland water sources and sent humans scurrying to the coast, where they learned to make a living from the sea, the researchers propose in the May 4 NATURE.
"The eventual dispersal of humans out of Africa was due to increased human competition for marine resources, possibly during hyper-arid conditions," they conclude. …