DNA hints at earlier human exodus from Africa
SCIENCE PHOTO LIBRARY
Hints of an early exodus of modern humans from Africa may have been detected in living humans, the BBC reports.
Present-day people outside Africa were thought to descend from a group that left their homeland 60,000 years ago.
Now, analysis of nearly 500 human genomes appears to have turned up the weak signal of an earlier migration.
But the results suggest this early wave of Homo sapiens all but vanished, so it does not drastically alter prevailing theories of our origins.
Writing in the academic journal Nature, Luca Pagani, Mait Metspalu and colleagues describe hints of this pioneer group in their analysis of DNA in people from the Oceanian nation of Papua New Guinea.
After evolving in Africa 200,000 years ago, modern humans are thought to have crossed through Egypt into the Arabian Peninsula some 60,000 years ago.
Until now, genetic evidence has shown that every non-African alive today could trace their origins to this fateful dispersal.
Yet we had known for some time that groups of modern humans made forays outside their “homeland” before 60,000 years ago.