Genetic diversity and demographic history of Sub-Saharan human populations based on genome-wide data
Résumé
It is widely accepted that anatomically modern humans (AMH) originated in Africa. Nevertheless, the early history of AMH remains largely unknown, as the extent of deep population structure and possible ancient admixture events within Africa before the “out of Africa” event have not been elucidated.
To reconstruct ancient AMH demographic history in Africa, we investigate genome-wide data from 14 sub-Saharan Africa populations, including hunting-gathering, pastoralists and agricultural populations. The ancestors of the hunting-gathering and pastoralist populations were the first to diverge from the rest of AMH, which make them relevant to investigate deep population structure.
We first describe the genetic diversity patterns and investigate the early demographic history of Sub-Saharan Africa. Specifically, we reconstruct the early history of population divergences, admixture, and changes in effective population sizes among sub-Saharan African hunter-gatherer populations, and between hunter-gatherer and other agropastoralist populations in Africa. Furthermore, we investigate more recent expansion of agriculture in Sub-Saharan Africa during the past 5000 years, having possibly influenced genetic diversity and recent admixture patterns among populations.
Finally, recently available ancient DNA data from Sub-Saharan Africa allows us to better frame our demographic inferences and distinguish unambiguous ancestral components, which provides promising new insights into the evolutionary history of African populations.