Steppe Maykop: a buffer zone?

Unfortunately, the ancient data from the Wang et al. preprint still haven't been released online. As I've already pointed out many times, the manuscript conclusion looks horribly contrived (for instance, see here), but the data are awesome, and most of the preprint is quite solid.

One thing that I'd really like to do is to compare in detail each of the ancient populations from the preprint to groups of present-day and ancient speakers of Indo-European and Caucasian languages. What's the bet that, by and large, Eneolithic steppe will show strong links to Indo-Europeans, while Eneolithic Caucasus and Maykop to Caucasians?

But pending the release of the data, all I can do is look at what the authors have done with it.

Intriguingly, their analyses suggest that the Eneolithic steppe genotype may have vanished from the steppes abutting the Caucasus by at least 3500 BC. It seems to have been replaced there by a more heterogeneous gene pool, with both more easterly and southerly genetic affinities, associated with the Steppe Maykop archeological culture.

So who were the Steppe Maykop people and why did they show up, rather suddenly, in the North Caucasus steppes to seemingly clear out the Eneolithic steppe population from the region? I have a theory about that.

Both archeological and ancient DNA data show that the North Caucasus was being colonized by groups from Transcaucasia during the Eneolithic. But apparently this wasn't an entirely smooth and safe process, because these southern settlers were forced to build elaborate fortifications to keep the natives at bay. Indeed, at the site of Meshoko, in the Northwest Caucasus, there is evidence of such a fort being overrun and its community replaced, probably by a nearby indigenous group (see here).

On the other hand, during the Bronze Age Maykop period, the relations between the settlers from the south and the steppe peoples were apparently much more peaceful. So much so, in fact, that Maykop settlements weren't fortified. However, this was also the period when the North Caucasus steppes were home to the Steppe Maykop people.

So here's my theory: either by chance or design, Steppe Maykop territory was a buffer zone between Maykop and the potentially aggressive natives of the steppes to the north. I'm not necessarily suggesting that the Steppe Maykop people were foreign mercenaries hired by Maykop chiefs, but, in any case, they may have benefited economically in a variety of ways by keeping Maykop settlements safe.

Around 3000 BC, both Maykop and Steppe Maykop disappeared. The latter was replaced by the Yamnaya culture. I don't know much about this process. It may have been mostly driven by environmental impacts from climate change. But the fact that the Steppe Maykop population didn't contribute much, if any, ancestry to the Yamnaya people in the region suggests to me that it was a hostile takeover by Yamnaya.

Interestingly, the spread of Yamnaya into the North Caucasus steppes saw the return of the Eneolithic steppe genotype to the region, albeit in a modified form, with admixture from Middle Neolithic European farmers (see here).

See also...

Yamnaya: home-grown

A potentially violent end to the Kura-Araxes Culture (Alizadeh et al. 2018)