Reconstructing the peopling of old-world South Asia: from modern to ancient genomes

Reconstructions of the past effectivepopulation size strongly suggest that South Asia has been populated almostsince the Early Upper Palaeolithic. One of the probable explanations ofthis pattern relates to the fact that South Asia was among the first geographicregions to be peopled by modern humans after their African exodus. Today,various ethnic groups of South Asia comprise tribes, castes, and populationsidentifying themselves by different religions, being largely endogamous andhence revealing complex, multilayered genetic differentiation. From such acomplex structure, several questions have stood out from our and other researchgroups analyses that could not be addressed a few years ago but can be nowusing the latest technology and resolution. The novelty of the approaches relylargely, though not solely, on extensive high-coverage sequencing ofspecifically targeted modern and ancient samples, autosomal SNP genotyping ofspecific populations, extensive Y chromosome resequencing of selectedpopulation groups (Tribal and caste populations from different geographicalarea) and statistical analysis of the results in the context of human genomicvariation worldwide. Here, I will discuss the complex population structure ofIndian Sub-continent and future research directions to understand the deepancestry components of South Asians at the Eurasian and global scales, patternsof admixture and migrations derived from studying ancient and modern genomes.