Tony Joseph writes in The Hindu:
The thorniest, most fought-over question in Indian history is slowly but surely getting answered: did Indo-European language speakers, who called themselves Aryans, stream into India sometime around 2,000 BC – 1,500 BC when the Indus Valley civilisation came to an end, bringing with them Sanskrit and a distinctive set of cultural practices? Genetic research based on an avalanche of new DNA evidence is making scientists around the world converge on an unambiguous answer: yes, they did.
The paper that put all of the recent discoveries together into a tight and coherent history of migrations into India was published just three months ago in a peer-reviewed journal called ‘BMC Evolutionary Biology’. In that paper, titled “A Genetic Chronology for the Indian Subcontinent Points to Heavily Sex-biased Dispersals”, 16 scientists led by Prof. Martin P. Richards of the University of Huddersfield, U.K., concluded: “Genetic influx from Central Asia in the Bronze Age was strongly male-driven, consistent with the patriarchal, patrilocal and patrilineal social structure attributed to the inferred pastoralist early Indo-European society. This was part of a much wider process of Indo-European expansion, with an ultimate source in the Pontic-Caspian region, which carried closely related Y-chromosome lineages… across a vast swathe of Eurasia between 5,000 and 3,500 years ago”.