Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
, 27 (R2), R209-R218

African Genetic Diversity Provides Novel Insights Into Evolutionary History and Local Adaptations

Affiliations
Review

African Genetic Diversity Provides Novel Insights Into Evolutionary History and Local Adaptations

Ananyo Choudhury et al. Hum Mol Genet.

Abstract

Genetic variation and susceptibility to disease are shaped by human demographic history and adaptation. We can now study the genomes of extant Africans and uncover traces of population migration, admixture, assimilation and selection by applying sophisticated computational algorithms. There are four major ethnolinguistic divisions among present day Africans: Hunter-gatherer populations in southern and central Africa; Nilo-Saharan speakers from north and northeast Africa; Afro-Asiatic speakers from north and east Africa; and Niger-Congo speakers who are the predominant ethnolinguistic group spread across most of sub-Saharan Africa. The enormous ethnolinguistic diversity in sub-Saharan African populations is largely paralleled by extensive genetic diversity and until a decade ago, little was known about detailed origins and divergence of these groups. Results from large-scale population genetic studies, and more recently whole genome sequence data, are unravelling the critical role of events like migration and admixture and environmental factors including diet, infectious diseases and climatic conditions in shaping current population diversity. It is now possible to start providing quantitative estimates of divergence times, population size and dynamic processes that have affected populations and their genetic risk for disease. Finally, the availability of ancient genomes from Africa provides historical insights of unprecedented depth. In this review, we highlight some key interpretations that have emerged from recent African genome studies.

Figures

Figure 1.
Figure 1.
Major early African population splits showing our understanding prior to and after the availability of WGS data and novel analysis approaches. The events of the past ∼5000 years, prior to the Bantu expansion are not shown and therefore the African regions (South, Central, East and West) reflect the groups that predominated in these regions at ∼5000 years ago (kya). Both trees are rooted to the most recent common ancestor (MRCA) and the estimated major splits are shown in kya. (A) shows our understanding prior to ∼2016 when the MRCA was estimated to be ∼150 kya and (B) following further analyses that place the MRCA at ∼300 kya, with revised estimates of major splits shown in blue. The length of the branches are not to scale. The dotted line shows the recently proposed deep split of a western African ancestry population ∼250 kya. #1Skoglund et al. (12); #2Schlebusch et al. (9); #3Hsieh et al. (10). KS: Khoesan; RFF: Rain Forest Foragers.
Figure 2.
Figure 2.
Hunter-gatherer (HG) and Eurasian admixture in African populations showing possible sources and timing of events. (A) shows HG admixture events while (B) shows Eurasian admixture events. Blue dotted arrows indicate the route of the Bantu expansion (reflecting the late split), while the colours of the stars and crosses correspond to the suggested timing of admixture events (kya) as shown on the scale at the bottom of the diagram. Populations are labelled as identified in the literature.

Similar articles

See all similar articles

Cited by 3 articles

Publication types

Feedback