Evolutionary event has not only transformed the genetic structure of human populations but also associated with social and cultural transformation. South Asian populations were formed as a result of such evolutionary events of migration and admixture of genetically and culturally distinct groups. Most of the genetic studies pointed to large-scale admixture event between Ancestral North Indian (ANI) and Ancestral South Indian (ASI) groups, also additional layers of recent admixture. In the present study we have analyzed 213 individuals inhabited in South West coast India with traditional warriors and feudal lord status and historically associated with recent migrations events and possible admixture with Indo-Scythians, Saka, Huns and Kushans, whose genetic links are still missing. Analysis of autosomal SNP markers suggests that these groups possibly derived their ancestry from some groups of North West India having additional Middle Eastern genetic component and also their separation history suggests very early separation from North West Indian and Gangetic plain Indo-Europeans during late bronze or Iron age, most probably following central India and Godavari basin to South West coast. Higher distribution of west Eurasian mitochondrial haplogroups also points to admixture through maternal lineage. Selection screen using genome wide genealogy approach revealed genetic signatures related to their long-term coastal food habits. Thus, our study suggests that the South West coastal groups with traditional warriors and feudal lords’ status are of a distinct lineage compared to Dravidian and Gangetic plain Indo-Europeans and are remnants of very early migrations from North West India following Godavari basin to Karnataka and Kerala.
If you do a west-to-east transect there is more “ANI” ancestry in the west of the subcontinent. This is true in the north, obviously (Punjabis to Bengalis), but less appreciated is that the same seems true in the peninsula south of the Vindhya Range. To some extend this is due to more steppe ancestry in groups like Nairs because of “gene flow” from Namboothiri Brahmins and such. But, that’s not all. As noted in this paper some of these western coastal groups clearly have an excess of “Middle Eastern” ancestry. That’s not surprising for the Jews of Cochin or even the Nasrani Christians. But what about Bunts and Nairs? There are two main ways you can explain this in my opinion:
1) A pre-steppe IVC and post-IVC era migration of “Iranian” peoples associated with the Ashmound culture has a significant impact that is most preserved in the western part of the peninsula
2) Later connections between West Asian (Arab and pre-Arab) people who were integrated into the local cultures over time (due to the matrilineal nature, at least originally, of some of these southwestern groups one can imagine how easy it would be to integrate sailors from other societies, or at least their offspring)