Rakhigarhi

I woke up this morning to a bombshell announcement: they published the Rakhigarhi genome.

Rakhigarhi is one of the sites of the ancient civilization of the Indus 3300-1300 BC. Of these, Harappa and Mohenjo-Daro have been more famous – although, maybe not in future, because now Rakhigarhi has DNA. We still don’t know the cities’ names; the language remains undeciphered.

Razib is all over this story. So’s LiveScience.

By now we know the sites trend “cosmopolitan”; think, that polyglot “Place of Reeds” called Teo[ti]huacan in Nahuatl. The cultures in these towns already differed internally such that – per Mark Kenoyer – they differed in burial practices. Many locals did cremation. Good luck getting DNA from that. But at least one group was doing burial, like those in this cemetery, so that’s whence the DNA.

Getting the DNA even from a burial is hard enough in hot, humid India. And the Rakhigarhi sample is female so, we can’t know who daddy was.

Even in segregated neighbourhoods there should be SOME intermixture after millennia. And so they find at this burial. But… the mixture is special. It’s a small bit parallel to Andaman Islander and a large bit some sort of west Eurasian farmer. It all looks like “Peripheral Indus”; we already have eleven other samples of that. Which is fortunate; this can fill in the gaps from the Rakhigarhi burial.

I don’t know if the Indus peoples were already doing caste; I’ve not seen the evidence for endogamy found in modern Pakistan or India. But there’s not much mixture with anything else beyond Peripheral Indus.

Mark Kenoyer notes that the Peripheral Indus remains found in Turan (now Iran and Turkmenistan) are atypical of the peripheries in which they are found. Indeed, they are peripheral. The best model is that these other eleven came from the Indus and moved north.

That this genome is not linked to many outside populations implies that it’s autochthonous to the Indus. Their split from other West Eurasians is Ice Age. This is a STARK contrast with Europe: the Indus locals (like Anatolians) learnt to farm whilst Europe imported farmers.

Another implication is that the west-to-east route – “the Iranian plateau” – was blocked, until (I am guessing) the domestications of camel and horse. Iran is rugged and full of deserts, and those parts that weren’t were inhabited by Iranian farmers, who (we now know) were alien to the Indus. During the Neolithic and Early Bronze, the route to the Indus instead went north-to-south. That’s the road the Aryans would take: from Bactria and Ferghana, through the Kush.