On Gamkrelidze-Ivanov's dubious map skills and then some

I've put together a new D-stats sheet that might be useful in the Indo-European homeland debate (see here). It features new samples from the EGDP dataset, with most of the stats based on over 750K SNPs. The stats are of the form D(Chimp,Ancient)(Mbuti,X).

The idea that Indo-Iranian languages arrived in Central and South Asia from the Armenian Plateau and/or eastern Anatolia during the Bronze Age, as per Gamkrelidze and Ivanov (check out their article here and, if you don't have access, crazy map here), is still popular with a lot of people. But it's most certainly a dud.

There's too much Bronze Age steppe ancestry in this part of the world, particularly among the more isolated Indo-Iranian populations like Pamir Tajiks and the Kalasha, as well as upper caste Indians, to ignore. At the same time, there is no hard data linking any of these groups to Bronze Age Armenia or Anatolia.

Also, some people in the comments here are still having problems comprehending the relationship between Eastern European Hunter-Gatherers (Eastern_HG or EHG) and Yamnaya, and how this relates to the issue of the Indo-European expansion from the Pontic-Caspian Steppe into other parts of Eastern Europe.

By and large the vast majority of EHG ancestry among present-day Europeans was mediated via Yamnaya or closely related groups from the steppe. How do I know? Because of the very close relationship between EHG and Yamnaya signals in present-day Europeans, and specifically Indo-European speaking Europeans, including those living in Eastern Europe.

Indeed, most of the EHG in Eastern Europe arrived there from the steppe as a package with Caucasus Hunter-Gatherer (Caucasus_HG or CHG) ancestry. Again, this is especially true for Indo-European speaking Northern and Eastern Europeans, who are generally hugging the line of best fit in these graphs for that reason. Note also that EHG and Yamnaya produce essentially the same results when plotted against CHG.

On the other hand, groups from far Northeastern Europe, where Uralic languages are currently spoken or were spoken until recently, appear to harbor inflated affinity to EHG and deflated affinity to CHG, putting them well above the line of best fit. These are also the same groups that show inflated East Eurasian, and more specifically Siberian, admixture, which is basically lacking in most Indo-Europeans. So I'm guessing that proto-Uralic speakers were mostly a mixture of EHG and East Eurasian, maybe with minor CHG.

Also worth noting is that Southern Europeans show inflated affinity to CHG and deflated affinity to EHG, putting them well below the line of best fit. This is because of their inflated Near Eastern ancestry (relative to Northern and Eastern Europeans) from the Neolithic and later periods, probably including CHG admixture that arrived in Southern Europe independently of EHG and Yamnaya/Yamnaya-related groups.

However, the ubiquitous presence of CHG across Europe today does not confirm Gamkrelidze and Ivanov's Armenian Plateau Indo-European homeland theory. That's because, unlike what their wacky map that I linked to above suggests, Eastern Europeans do not show any signs of ancestry from the South Caspian region (see here), which they clearly should if their Indo-European ancestors migrated en masse from Transcaucasia to the Pontic-Caspian steppe in an anti-clockwise direction around the Caspian Sea.

Rather, it appears that CHG gene flow diffused onto the Eastern European steppe with migrants coming directly from the Caucasus (see here). And, judging by the affinities of CHG and ancient groups in large part of CHG origin, these people were more likely the speakers of Caucasian languages than of Proto-Indo-European.

See also...

Hurrians and the others