Humanity's forgotten return to Africa revealed in DNA

Call it humanity's unexpected U-turn. One of the biggest events in the history of our species is the exodus out of Africa some 65,000 years ago, the start of Homo sapiens' long march across the world. Now a study of southern African genes shows that, unexpectedly, another migration took western Eurasian DNA back to the very southern tip of the continent 3000 years ago.

According to conventional thinking, the Khoisan tribes of southern Africa, have lived in near-isolation from the rest of humanity for thousands of years. In fact, the study shows that some of their DNA matches most closely people from modern-day southern Europe, including Spain and Italy.

Because Eurasian people also carry traces of Neanderthal DNA, the finding also shows – for the first time – that genetic material from our extinct cousin may be widespread in African populations.

The Khoisan tribes of southern Africa are hunter-gatherers and pastoralists who speak unique click languages. Their extraordinarily diverse gene pool split from everyone else's before the African exodus.

http://www.newscientist.com/article/dn24988-humanitys-forgotten-return-to-africa-revealed-in-dna.html#.UvEkY2J_vfI