The maternal genetic history of the Angolan Namib Desert: a key region for understanding the peopling of southern Africa

Abstract

19 20 Southern Angola is a poorly studied region, inhabited by populations that have been associated with different 21 migratory movements into southern Africa. Besides the long-standing presence of indigenous Kx’a-speaking 22 foragers and the more recent arrival of Bantu-speaking pastoralists, ethnographic and linguistic studies have 23 suggested that other pre-Bantu communities were also present in the Namib desert, including peripatetic groups 24 like the Kwepe (formerly Kwadi speakers), Twa and Kwisi. Here we evaluate previous peopling hypotheses by 25 analyzing the relationships between seven groups from the Namib desert (Kuvale, Himba, Tjimba, Kwisi, Twa, 26 Kwepe) and Kunene Province (!Xun), based on newly collected linguistic data and 295 complete mtDNA 27 genomes. We found that: i) all groups from the Namib desert have genealogically-consistent matriclanic systems 28 that had a strong impact on their maternal genetic structure by enhancing genetic drift and population 29 differentiation; ii) the dominant pastoral groups represented by the Kuvale and Himba were part of a Bantu 30 proto-population that also included the ancestors of present-day Damara and Herero peoples from Namibia; iii) 31 Tjimba are closely related to the Himba; iv) the Kwepe, Twa and Kwisi have a divergent Bantu-related mtDNA 32 profile and probably stem from a single population that does not show clear signs of being a pre-Bantu 33 indigenous group. Taken together, our results suggest that the maternal genetic structure of the different groups 34 from the Namib desert is largely derived from endogamous Bantu peoples, and that their social stratification and 35 different subsistence patterns are not indicative of remnant groups, but reflect Bantu-internal variation and 36 ethnogenesis. 2 bioRxiv preprint doi: https://doi.org/10.1101/162230; this version posted July 11, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license. 37