Genome-wide evidence of austronesian-bantu admixture and cultural reversion in a hunter-gatherer group of Madagascar

Linguistic and cultural evidence suggest that Madagascar was the final point of two major dispersals of Austronesian- and Bantuspeaking populations. Today, the Mikea are described as the lastknown Malagasy population reported to be still practicing a hunter-gatherer lifestyle. It is unclear, however, whether the Mikea descend from a remnant population that existed before the arrival of Austronesian and Bantu agriculturalists or whether it is only their lifestyle that separates them from the other contemporary populations of South Madagascar. To address these questions we have performed a genome-wide analysis of >700,000 SNP markers on 21 Mikea, 24 Vezo, and 24 Temoro individuals, together with 50 individuals from Bajo and Lebbo populations from Indonesia. Our analyses of these data in the context of data available from other Southeast Asian and African populations reveal that all three Malagasy populations are derived from the same admixture event involving Austronesian and Bantu sourc...