Population structure analyses using a Bayesian cluster analysis (STRUCTURE) showed a clear distinction between the continental population groups when the number of clusters was defined at 4 (K=4). The 128 In4 set consistently identified diverse individuals corresponding to European, West African, Amerindian, and East Asian population groups (Fig. 1a, Table 2). Adding an additional cluster (K=5), also allowed the identification of individuals from another genetically distinguishable population, that corresponding to a South Asian sub-continental group (Fig. 1b).
