Researchers find signs of western Eurasian genes in southern African Khoisan tribes

(Phys.org) —A team of researchers with representatives from the U.S., Germany and France has found evidence of western Eurasian genes in Khoisan tribes living in southern Africa. This suggests, the researchers conclude in a paper they've had published in Proceedings of the National Academy of Sciences, that a migration from the Middle East back to Africa occurred approximately 3000 years ago.

Scientists believe humans evolved from ancestral primates in Africa several hundred thousand years ago, but it wasn't until approximately 65,000 years ago that they made their way out of Africa and into the Middle East and eventually the rest of the world. Until recently, that migration has been viewed by most scientists as a one-way trip. Gene studies over the past several years has turned that thinking around, however, as its been found that many people in several parts of Africa have European or Asian gene segments in their DNA. In this latest study, the researchers have found evidence of Eurasian genes in tribespeople who were thought to have a purely African ancestry.

The Khoisan tribespeople of today still live much as their ancestors did—they are hunter-gathers who are also pastoralists—they are most familiar to westerners as the people who speak with distinctive clicking noises. Until now, they were believed to have the purest African gene pool due to their thousands of years of isolationist practices....