Evidence for a genetic link between eastern and southern African populations is published in Nature Communications this week. The research addresses discrepancies between fossil evidence suggesting that modern humans originated in east Africa and genetic studies that point towards a southern heritage.
Hunter-gatherer populations in Africa preserve unique information about human history, but the genetic substructures of these populations remain unclear. Joseph Pickrell and colleagues conducted the most comprehensive study to date of genetic diversity in Southern Africa. Looking at data from 21 southern African and two eastern African groups, they examined more than 500,000 SNPs to look for similarities and differences between the populations.
Their data suggests that click-language-speaking east-African hunter-gatherers share a quarter of their ancestry with southern click-language-speaking populations despite their geographical isolation. They believe that genetic differences between forager populations in the northwestern and southeastern Kalahari began up to 30,000 years ago. Finally they show a genetic signature of population mixture between these indigenous populations and migrants from the north beginning 1,200 years ago.