New India Y-chromosome paper

A new Y-chromosome study comes at the heels of the Sengupta paper. It does not appear to be in the PNAS site yet, but here is a story from National Geographic.

India Acquired Language, not Genes, From West

Most modern Indians descended from South Asians, not invading Central Asian steppe dwellers, a new genetic study reports. The Indian subcontinent may have acquired agricultural techniques and languages—but it absorbed few genes—from the west, said Vijendra Kashyap, director of India's National Institute of Biologicals in Noida.

Based on my readings so far, I believe that the Proto-Indo-Iranians and hence the ancestors of the first speakers of Indic speakers belonged primarily to haplogroups J2a and R1a1. Today, J2a is found approximately 4% of Hindus, and primarily in the upper castes where the signal of the founders of the caste system would be most evident.

R1a1 is found across the caste hierarchy and in tribals and is more diverse in tribals and lower castes than in the upper castes. I suspect though, that the lack of informative subclades of R1a1 may mask multiple origins. Most of it is doubtlessly pre-Indo-European and probably pre-Neolithic, but some yet-undetected clade will be discovered that is of more recent origin. This will reflect the genetic contribution of Eurasian steppe groups which were themselves Indo-Europeanized at an earlier time from J2a-bearing populations that spread from Anatolia through the Balkans into Eastern Europe.

So, Hindus are indeed primarily descended from Pre-Indo-European populations, but they may still possess the signal of the arrival of the first Indic speakers. This will become even clearer once informative SNPs are discovered in haplogroup R1a1.

More to follow once I get a copy of the paper.