In Southern Africa, Human Genetics Tied to Environment

Ancestries of nearly two dozen indigenous groups in the region reveal a close link between the genetic clustering of populations and the Kalahari Desert’s ecogeography.

Sep 7, 2016
Jef Akst

FLICKR, FRANK VASSENInvestigating the genomes of 22 groups of KhoeSan people, hunter-gather and pastoralist tribes indigenous to Southern Africa who speak in “click” languages, researchers found that the variation among the groups depended on geography: groups living along the outer rim of the Kalahari Desert showed little evidence of interbreeding, while KhoeSan groups that lived in the Kalahari basin tended to interbreed more frequently.

The KhoeSan groups are genetically distinct from all other African populations, and are believed to be one of the “first groups to diverge from the ancestors of all humans,” according to a press release. In the new study, Brenna Henn of Stony Brook University in New York and colleagues identified five primary ancestries among the 22 groups. The genetic differences between these five groups correlated with their linguistic histories, and both genetics and language were linked with geography.

The results, published last week (September 1) in Genetics, suggest that ecology and geography may account for more of the genetic differences between groups than language differences or method of subsistence, Henn noted in the release. “There are a lot of threads of information to bring together—linguistics, subsistence, geography, genetics, archaeology. They don’t always reconcile easily.”