A new study traces the origin of modern humans to the primitive Bushmen tribes of southern Africa. The finding upends a widely-held scientific belief that modern humans originated in east Africa.
The largest-ever genetic analysis of a remote tribe concludes that the Bushmen of southern Africa are the ancestral source of modern humans.
The study by researchers at Stanford University in California was led by evolutionary geneticist Marcus Feldman. He notes that migrations out of eastern Africa some 60 to 70,000 years ago led to the seeding of modern humans across Asia, Europe and the Americas.
"Who were the ancestors of those Africans? And I think we’ve proved with the data that the founding people in Africa were these click-speaking Bushmen from the southern part of Africa," said Feldman.
The Bushmen, whose unique spoken language includes a variety of tongue clicks, today number between 50,000 and 100,000 people, most of who live on the flat, dry and scrubby edge of the Kalahari Desert, on the fringes of human society.
Stanford researchers collected saliva specimens from 95 members of the Hadza and Sandawe tribes of Tanzania and the Khomani Bushmen of southern Africa. From these, scientists obtained 650,000 DNA variations.
The genetic variations, called single nucleotide polymorphisms, or SNPS, were compared with the DNA of tribal people in Kenya and Tanzania, as well as a group of individuals from Tuscany, Italy.
Scientists found the greatest genetic variation in the Bushmen, according to Feldman, who says as populations emerge, they become less genetically diverse.
Feldman says the finding suggests that the Bushmen are the source of all Homo sapiens, or early humans, dating back some 200,000 years. That includes those African tribes that migrated out of Africa from Sudan and the East African Highlands of Ethiopia to the rest of the world.
"The statistical analysis that we’ve done suggests that these are the most ancient people on the planet and that the rest of Africa derives from that group," he said.
While their numbers have dwindled to near-extinction levels, Feldman says it’s possible the Bush tribes did not always live in the sub-Saharan desert. Feldman says they might have been driven there by expansion of the more affluent or aggressive cattle-herding Bantu populations.
A new gene analysis of primitive southern Africa Bush tribes is published in the journal Proceedings of the National Academy of Sciences.
Modern Humans Traced to Southern African Bushmen
