title: Genetic variation reveals large-scale population expansion and migration during the expansion of Bantu-speaking peoples.
abstract: The majority of sub-Saharan Africans today speak a number of closely related languages collectively referred to as 'Bantu' languages. The current distribution of Bantu-speaking populations has been found to largely be a consequence of the movement of people rather than a diffusion of language alone. Linguistic and single marker genetic studies have generated various hypotheses regarding the timing and the routes of the Bantu expansion, but these hypotheses have not been thoroughly investigated. In this study, we re-analysed microsatellite markers typed for large number of African populations that-owing to their fast mutation rates-capture signatures of recent population history. We confirm the spread of west African people across most of sub-Saharan Africa and estimated the expansion of Bantu-speaking groups, using a Bayesian approach, to around 5600 years ago. We tested four different divergence models for Bantu-speaking populations with a distribution comprising three geographical regions in Africa. We found that the most likely model for the movement of the eastern branch of Bantu-speakers involves migration of Bantu-speaking groups to the east followed by migration to the south. This model, however, is only marginally more likely than other models, which might indicate direct movement from the west and/or significant gene flow with the western Branch of Bantu-speakers. Our study use multi-loci genetic data to explicitly investigate the timing and mode of the Bantu expansion and it demonstrates that west African groups rapidly expanded both in numbers and over a large geographical area, affirming the fact that the Bantu expansion was one of the most dramatic demographic events in human history.
authors.affiliation: Department of Evolutionary Biology, Evolutionary Biology Centre, Norbyvägen 18D, Uppsala 752 36, Sweden Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, Copenhagen 2100, Denmark.
authors.forename: Sen
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Evolutionary Biology, Evolutionary Biology Centre, Norbyvägen 18D, Uppsala 752 36, Sweden.
authors.forename: Carina
authors.initials: C
authors.lastname: Schlebusch
authors.affiliation: Department of Evolutionary Biology, Evolutionary Biology Centre, Norbyvägen 18D, Uppsala 752 36, Sweden Science for Life Laboratory, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden mattias.jakobsson@ebc.uu.se.
authors.forename: Mattias
authors.initials: M
authors.lastname: Jakobsson
mesh_terms: D017954:Africa South of the Sahara; D004641:Emigration and Immigration; D051456:Gene Flow; D014644:Genetic Variation; D006801:Humans; D007802:Language; D018895:Microsatellite Repeats / Q000235:genetics; D008957:Models, Genetic; D011110:Polymorphism, Genetic
keywords: Africa; Bantu-speakers; approximate Bayesian computation; migration; population expansion