Mozambican genetic variation provides new insights into the Bantu expansion

Abstract

The Bantu expansion, which started in West Central Africa around 5,000 BP, constitutes a major migratory movement involving the joint spread of peoples and languages across sub-Saharan Africa. Despite the rich linguistic and archaeological evidence available, the genetic relationships between different Bantu-speaking populations and the migratory routes they followed during various phases of the expansion remain poorly understood. Here, we analyze the genetic profiles of southwestern and southeastern Bantu-speaking peoples located at the edges of the Bantu expansion by generating genome-wide data for 200 individuals from 12Mozambican and 3 Angolan populations using ~1.9 million autosomal single nucleotide polymorphisms.Incorporating a wide range of available genetic data, our analyses confirm previous results favoring a "late split" between West and East Bantu speakers, following a joint passage through the rainforest. In addition, we find that Bantu speakers from eastern Africa display genetic substructure, with Mozambican populations forming a gradient of relatedness along a North-South cline stretching from the coastal border between Kenya and Tanzania to South Africa. This gradient is further associated with a southward increase in genetic homogeneity, and involved minimum admixture with resident populations. Together, our results provide the first genetic evidence in support of a rapid North-South dispersal of Bantu peoples along the Indian Ocean Coast, as inferred from the distribution and antiquity of Early Iron Age assemblages associated with the Kwale archaeological tradition.

Unraveling African diversity from a cross‐disciplinary perspective

“…It started in west‐central Africa 5,000–3,000 years ago, and evolutionary genetics demonstrated that mass human migration was the main underlying force of this expansion . New cross‐disciplinary research projects will elucidate long‐distant spread of farming practices and the interaction of migrating farmers with autochthonous groups, to shed additional light of when, where, and how early Bantu‐speaking populations settled in wider regions from central, eastern, and southern Africa …”

“…20 It started in westcentral Africa 5,000-3,000 years ago, and evolutionary genetics demonstrated that mass human migration was the main underlying force of this expansion. 21,22 New cross-disciplinary research projects 23 On both sides of the African continent, recent mass migrations contributed to one of the humanity's darkest chapters, the slave trade.…”