Northeast Indian Passageway as Barrier or Corridor for Human Migrations: An Evaluation through distinctiveness of Y-chromosome and Mt-DNA gene pools

Abstract

Northeast India is the homeland of different ethnic groups with a variety of cultures and speaking different languages and dialects. Though many scholars consider the region as melting pot of diverse races, castes, religions, languages and cultures; the northeast Indian passageway connecting the Indian subcontinent to East/Southeast Asia is thought to have been a major corridor for human migrations. Since it is also an important linguistic contact zone, it is predicted that northeast India has witnessed extensive population interactions, thus, leading to high genetic diversity within groups and heterogeneity among groups. To test this prediction, various scientific evidences were collected and analysed in due course of time. A review of such studies was conducted and contrary to the prediction, the results provide strong evidence for a genetic discontinuity between northeast Indian groups and other Indian groups. Therefore, it can be conclude that the northeast Indian passageway acted as a geographic barrier rather than as a corridor for human migrations between the Indian subcontinent and East/Southeast Asia, at least within the past millennia and possibly for several tens of thousands years, as suggested by the overall distinctiveness of the Indian and East Asian Y-chromosome and mt-DNA gene pools.