Khoisan hunter-gatherers have been the largest population throughout most of modern-human demographic history

• Main Authors: Kim, Hie Lim, Ratan, Aakrosh, Perry, George H., Montenegro, Alvaro, Miller, Webb, Schuster, Stephan C.
• Other Authors: Asian School of the Environment
• Language: English
• Published: 2018
• Subjects: Genomics; Population Genetics; DRNTU::Social sciences::Sociology
• Online Access: https://hdl.handle.net/10356/89544; http://hdl.handle.net/10220/46318
• Institution: Nanyang Technological University

The Khoisan people from Southern Africa maintained ancient lifestyles as hunter-gatherers or pastoralists up to modern times, though little else is known about their early history. Here we infer early demographic histories of modern humans using whole-genome sequences of five Khoisan individuals and one Bantu speaker. Comparison with a 420 K SNP data set from worldwide individuals demonstrates that two of the Khoisan genomes from the Ju/'hoansi population contain exclusive Khoisan ancestry. Coalescent analysis shows that the Khoisan and their ancestors have been the largest populations since their split with the non-Khoisan population ∼ 100-150 kyr ago. In contrast, the ancestors of the non-Khoisan groups, including Bantu-speakers and non-Africans, experienced population declines after the split and lost more than half of their genetic diversity. Paleoclimate records indicate that the precipitation in southern Africa increased ∼ 80-100 kyr ago while west-central Africa became drier. We hypothesize that these climate differences might be related to the divergent-ancient histories among human populations.