It looks like Outlook India is the first out of the gates to start reporting on the results from Rakhigarhi in northwest India, We Are All Harrapans. This is a “mature phase” Harrapan site that dates to about 2250 BC or so. Media reports have always been garbled on this topic, so anything that is coming not out of a paper needs to be treated cautiously. But I’ve heard some of the same things from independent sources from a while back, so I believe that this reporting is broadly on the mark.
Basically, the individual(s) they got DNA out of did not have any Eurasian steppe ancestry. This seems to confirm again that Eurasian steppe ancestry, which is found in fractions as high as ~30% in twice-born varna in Northern India (e.g., Rajputs, Tiwari Brahmins), arrived after 2000 BC. That is, after the peak period of the Indus Valley Civilization.
Again, one has to be wary of anything from the media because I’ve heard so many confusing things, including claims of garbled quotes, but here’s one of the authors of the forthcoming paper being quoted:
We did some analysis to figure out the exact date of the admixture. We have prepared a model in which all these stats fit together very tightly and that model suggests the Central Asian admixture happened about 1500-1000 BC…. Significant mixing happened around 1000 BC, also at 800 BC and 600 BC.
This is totally in line with the results from the March preprint discussed in the piece. That is, the Swat Valley samples show admixture and genetic change after 1200 BC. And the semi-historical understanding that we have of India during the period between 1000 BC and the rise of Mauryas is that it was a society in flux. But the only way the dating was changed by the Rakhigarhi results is if the genome is high enough quality that it allowed them to narrow down the parameters on some of the estimates of admixture.
One thing to keep in mind is that it is unlikely that the “Harappan people” were one single people genetically. There was probably a lot of variation in admixture with the indigenous South Asian substrate. And, I believe that the inflated steppe & AASI (“Ancient Ancestral South Indian”) ancestry you see in some North Indian Brahmin groups compared to Sindhis (who are more “Iranian”) is evidence that the Indo-Aryan intrusion resulted in an expansion of people with West Eurasian ancestry much deeper into South Asia than was the case with the Harappans.
And of the Harappans, some of the Indian scholars have asserted that their descendants are still present in the region. I think this is right, insofar as some of the jati groups, often scheduled caste, in the northwestern region of South Asia share a lot more affinity with populations to the south and east.
Related: Michael Witzel has commentary from a more linguistic perspective. If the “Para-Munda” hypothesis is right, I think what Witzel is seeing is the substrate language on which Munda was overlain, because Munda people are clearly intrusive from Southeast Asia in the period between 2000 and 1000 BC.
Addendum: If a relatively late intrusion (after 1500 BC) of Indo-Aryans to South Asia is supported by the evidence, it would be interesting in light of the high likelihood that Indo-Aryans were present in the region of upper Mesopotamia before 1500 BC. I believe that these “Indo”-Aryans actually probably never had any contact with South Asia, but descended from the horizon of cultures of which Sintashta and Andronovo were constituents. The Indo-Aryans who arrived in South Asia were probably from a different branch, and likely had interactions with other peoples in what is today eastern Iran and Afghanistan.