Researchers report genetic analyses of African populations that trace different genetic adaptations to common selective pressures. Little is known about the demographics and movement patterns in Africa between the time modern humans developed, around 300,000 years ago, and the time groups began leaving Africa, 80,000-40,000 years ago. Sarah Tishkoff and colleagues analyzed variation in genetic data from 840 Africans from across the continent and across multiple linguistic groups and societal subsistence lifestyles, including hunter-gatherer societies. Language groups were correlated with genetic diversity, as were geography and subsistence lifestyle. For example, the results suggested that four hunter-gatherer groups whose language contains clicks, including the Hadza and Sandawe from Tanzania, Dahalo from Kenya, and the Sabue from Ethiopia, whose language is unclassified, displayed genetic similarity to each other, despite geographic separation. Most other hunter-gatherer societies were genetically similar to neighboring agricultural or pastoral societies. Next, the authors examined the genes most likely to be associated with genetic variation among African groups, and found that many genes were involved in immune function and adaptation to diverse climates and diets. These included genes associated with malaria resistance and carbohydrate and lipid metabolism. According to the authors, although selective pressures are widespread across Africa, genetic variation among Africans suggests that the genes that enable response to selective pressures may vary across populations.
Article #18-17678: "Genomic evidence for shared common ancestry of East African hunting-gathering populations and insights into local adaptation," by Laura Scheinfeldt et al.
MEDIA CONTACT: Sarah A. Tishkoff, University of Pennsylvania, Philadelphia, PA; tel: 215-746-2670, 484-343-4919; e-mail: tishkoff@pennmedicine.upenn.edu; Laura Scheinfeldt, Coriell Institute for Medical Research, Camden, NJ; tel: 215-620-2719, e-mail: laura.scheinfeldt@gmail.com
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