Proceedings of the Royal Society B: Biological Sciences
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Bringing together linguistic and genetic evidence to test the Bantu expansion

Cesare de Filippo

Cesare de Filippo

Max Planck Research Group on Comparative Population Linguistics, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany

Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany

[email protected]

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Koen Bostoen

Koen Bostoen

Ghent University, KONGOKING Research Group, Rozier 44, 9000 Ghent, Belgium

Université libre de Bruxelles, 50 avenue F. D. Roosevelt, 1050 Brussels, Belgium

Royal Museum for Central Africa, Leuvensesteenweg 13, 3080 Tervuren, Belgium

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Mark Stoneking

Mark Stoneking

Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany

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Brigitte Pakendorf

Brigitte Pakendorf

Max Planck Research Group on Comparative Population Linguistics, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany

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    The expansion of Bantu languages represents one of the most momentous events in the history of Africa. While it is well accepted that Bantu languages spread from their homeland (Cameroon/Nigeria) approximately 5000 years ago (ya), there is no consensus about the timing and geographical routes underlying this expansion. Two main models of Bantu expansion have been suggested: The ‘early-split’ model claims that the most recent ancestor of Eastern languages expanded north of the rainforest towards the Great Lakes region approximately 4000 ya, while the ‘late-split’ model proposes that Eastern languages diversified from Western languages south of the rainforest approximately 2000 ya. Furthermore, it is unclear whether the language dispersal was coupled with the movement of people, raising the question of language shift versus demic diffusion. We use a novel approach taking into account both the spatial and temporal predictions of the two models and formally test these predictions with linguistic and genetic data. Our results show evidence for a demic diffusion in the genetic data, which is confirmed by the correlations between genetic and linguistic distances. While there is little support for the early-split model, the late-split model shows a relatively good fit to the data. Our analyses demonstrate that subsequent contact among languages/populations strongly affected the signal of the initial migration via isolation by distance.

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