Rajib Khan summarizes the recent research on

The genetic origin of Indians:
"What’s the biggest surprise from these results? For me I think it is the deep and incredibly thorough biological synthesis which characterizes the Indian subcontinent. We all know that there is a big difference between a Kashmiri Pandit and an Adivasi from South India. But about one third of the Pandit’s ancestry is “Ancestral South Indian,” which is almost absent outside of the subcontinent. And about one third of the Adivasi’s ancestry is “Ancestral North Indian,” which connects this individual with the populations which span the Atlantic, to the Urals, to the Sahara. The past is a strange and mysterious land. But the veil of ignorance is slowly lifting…."

Omar Ali gives links to other posts of Rajib Khan in Science sheds light on population history and living standards
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P.S. See also Rajib Khan's South Asian endogamy predates the British.