Genomic Variation in Seven Khoe-San Groups Reveals Adaptation and Complex African History

• Published in: Science (American Association for the Advancement of Science) 2012-10, Vol.338 (6105), p.374-379
• Main Authors: Schlebusch, Carina M., Skoglund, Pontus, Sjödin, Per, Gattepaille, Lucie M., Hernandez, Dena, Jay, Flora, Li, Sen, De Jongh, Michael, Singleton, Andrew, Blum, Michael G. B., Soodyall, Himla, Jakobsson, Mattias
• Format: Article
• Language: English
• Subjects: Adaptation; Adaptation, Biological; Adaptation, Biological - genetics; African Continental Ancestry Group; African Culture; African history; Animals; Biological and medical sciences; Biological Evolution; Black People - genetics; Blends; Botswana; Chromosomes, Human, Pair 10; Chromosomes, Human, Pair 10 - genetics; Chromosomes, Human, Pair 6; Chromosomes, Human, Pair 6 - genetics; Diverse techniques; Evolutionary biology; Fundamental and applied biological sciences. Psychology; Genetic diversity; Genetic variation; Genetics; Genetics of eukaryotes. Biological and molecular evolution; Genome, Human; Genome, Human - genetics; Genomes; Genomics; Globes; Haplotypes; Homozygote; Human; Humans; Life Sciences; Metagenomics; Molecular and cellular biology; Muscle, Skeletal; Muscle, Skeletal - physiology; Online; Pan troglodytes; Polymorphism, Single Nucleotide; Population; Population - genetics; Population genetics, reproduction patterns; Population geography; Population structure; Populations; Populations and Evolution; Stratification
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1227721

The history of click-speaking Khoe-San, and African populations in general, remains poorly understood. We genotyped ~2.3 million single-nucleotide polymorphisms in 220 southern Africans and found that the Khoe-San diverged from other populations ≥100,000 years ago, but population structure within the Khoe-San dated back to about 35,000 years ago. Genetic variation in various sub-Saharan populations did not localize the origin of modern humans to a single geographic region within Africa; instead, it indicated a history of admixture and stratification. We found evidence of adaptation targeting muscle function and immune response; potential adaptive introgression of protection from ultraviolet light; and selection predating modern human diversification, involving skeletal and neurological development. These new findings illustrate the importance of African genomic diversity in understanding human evolutionary history.