Everything Science Forum

http://www.everything-science.com/index.php?option=com_content&task=view&id=135&Itemid=1

The lure of a seafood diet may explain why early humans came out of Africa, according to research by the universities of Leeds and Glasgow published in Science this week.

Early modern humans in East Africa survived on an inland diet based on big game but by 70,000 years ago their diet had changed to a coastal one consisting largely of shellfish. However, dramatic climate change seems likely to have reduced the Red Sea's shellfish stocks. New DNA evidence suggests their taste for life beside the sea caused them to set off from Africa to find new, better fishing grounds.

The international project shows – contrary to previous thinking – that early modern humans spread across the Red Sea from the Horn of Africa, along the tropical coast of the Indian Ocean towards the Pacific, in just a few thousand years.

Leeds biologist Dr Martin Richards said: What’s more, those early settlers were the ancestors of all non-Africans alive today - including modern Europ. . .

I've followed this business for a long time. The debate goes on and on centering on two main theories-the "recently out of Africa" idea and the idea that modern humans evolved worldwide in a diverse multiregional fashion following much earlier migrations from Africa. Here's a short aricle from the National Geographic site.

http://news.nationalgeographic.com/news/2001/01/0111origins.html

Opposition to this theory comes from multiregionalists, anthropologists who see modern man arising from "a process of change within a species," said one of the theory’s architects, Milford Wolpoff.

Multiregionalists see modern humans arising from these changes in Africa, Eurasia, and Australia. The species that evolved, they say, gained traits held by all modern humans but remained racially diverse because of geographical adaptations and the distances between populations.

The modern traits were shared species-wide through interbreeding, maintains Wolpoff.

"The [Homo sapiens’] genes spread widely and were successful," he explained.

Wolpoff also argues for a much earlier date for the evolution of Homo sapiens than Out of Africa theorists postulate.

"There’s only been one species for a long time," he said.