title: The Bantu expansion revisited: a new analysis of Y chromosome variation in Central Western Africa.
abstract: The current distribution of Bantu languages is commonly considered to be a consequence of a relatively recent population expansion (3-5kya) in Central Western Africa. While there is a substantial consensus regarding the centre of origin of Bantu languages (the Benue River Valley, between South East Nigeria and Western Cameroon), the identification of the area from where the population expansion actually started, the relation between the processes leading to the spread of languages and peoples and the relevance of local migratory events remain controversial. In order to shed new light on these aspects, we studied Y chromosome variation in a broad dataset of populations encompassing Nigeria, Cameroon, Gabon and Congo. Our results evidence an evolutionary scenario which is more complex than had been previously thought, pointing to a marked differentiation of Cameroonian populations from the rest of the dataset. In fact, in contrast with the current view of Bantu speakers as a homogeneous group of populations, we observed an unexpectedly high level of interpopulation genetic heterogeneity and highlighted previously undetected diversity for lineages associated with the diffusion of Bantu languages (E1b1a (M2) sub-branches). We also detected substantial differences in local demographic histories, which concord with the hypotheses regarding an early diffusion of Bantu languages into the forest area and a subsequent demographic expansion and migration towards eastern and western Africa.
authors.affiliation: Dipartimento di Biologia Ambientale, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Rome, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Montano
authors.forename: Gianmarco
authors.initials: G
authors.lastname: Ferri
authors.forename: Veronica
authors.initials: V
authors.lastname: Marcari
authors.forename: Chiara
authors.initials: C
authors.lastname: Batini
authors.forename: Okorie
authors.initials: O
authors.lastname: Anyaele
authors.forename: Giovanni
authors.initials: G
authors.lastname: Destro-Bisol
authors.forename: David
authors.initials: D
authors.lastname: Comas
mesh_terms: D000350:Africa, Central; D000354:Africa, Western; D000704:Analysis of Variance; D041322:Chromosomes, Human, Y / Q000235:genetics*; D003710:Demography; D004641:Emigration and Immigration; D014644:Genetic Variation / Q000235:genetics*; D005828:Genetics, Population; D006239:Haplotypes; D006801:Humans; D007802:Language; D008297:Male