A note on Steppe Maykop

I'm reading a new book titled Dispersals and Diversification: Linguistic and Archaeological Perspectives on the Early Stages of Indo-European (see here). One of the chapters is authored by archeologist David Anthony, in which he makes the following claims:

A previously unknown genetic population actually was identified in Wang et al. (2019), but it was a peculiar relict-seeming group related to Paleo Siberians and American Indians (Kennewick) that had survived isolated somewhere in the Caspian steppes or perhaps in the North Caucasus Mountains. The Maykop people did admix with this previously isolated Siberian/Kennewick population in graves labeled "Steppe Maykop" in Wang et al. (2019).

But this just makes it clearer that a cultural choice motivated the Maykop people to exclude marriages with Yamnaya and pre-Yamnaya people specifically, even while exchanges of material goods, ideas, technologies continued. Neither the Maykop nor the North Caucasus/Siberian/Kennewick population can be the source of most of the CHG [Caucasus hunter-gatherer] ancestry in Yamnaya. In order to narrow down when and where CHG ancestry entered the steppes, we must widen our geographic frame beyond the Caucasus.

Unfortunately, this is way off the mark. Especially unsound is his inference that the CHG-related ancestry in the Yamnaya population may have come from beyond the Caucasus.

In fact, the chances that the Steppe Maykop people were derived from a relict Siberian/Kennewick-related group that survived into the Maykop era in the Caspian steppes or the North Caucasus are exactly zero.

The real story was surely more complicated. In my opinion, it initially involved the migration during the Eneolithic or earlier of a people rich in CHG ancestry from the southernmost steppes into the Volga Delta and surrounds, and then the back-migration during the Early Bronze Age (EBA) of their descendants with around 50% admixture from Central Asian foragers. If so, these foragers were very similar to indigenous West Siberians and also relatively closely related to Native Americans.

I don't know why such an exotic people migrated into the North Caucasus steppes to form the bulk of the Steppe Maykop population, but I'm certain they did, and one interesting possibility is that they were recruited by Maykop chiefs to create a buffer zone against hostile Yamnaya-related groups trying to push into the Caucasus, possibly from the lower Don region.

Of course, the same ancient northward migration of the CHG-rich population that may have eventually given rise to the Steppe Maykop people might also explain the deep origins of the Yamnaya people.

The key sample in all of this is VJ1001 from the Wang et al. paper. This female comes from an Eneolithic (4332-4238 calBCE) kurgan burial in the North Caucasus steppes. But despite her early date, she's genetically very similar to most Yamnaya individuals. And she's also a perfect proxy for half of the ancestry of three out of the six Steppe Maykop individuals. Here's a mixture model that I put together using the Broad MIT/Harvard software qpAdm:

RUS_Steppe_Maykop (3/6)
RUS_Eneolithic_steppe_VJ1001 0.452±0.023
RUS_Tyumen_HG 0.548±0.023
chisq 7.494
tail prob 0.874914
Full output

Indeed, these Steppe Maykop samples don't harbor any Maykop ancestry. They're simply a two-way mixture between a population closely resembling VJ1001 and another one similar to hunter-gatherers from Tyumen, West Siberia.

Importantly, a couple of Steppe Maykop-related populations were inadvertently discovered by Narasimhan et al. northeast of the Caspian Sea in what is now Kazakhstan. One of these groups is labeled Kumsay_EBA, after the location of its cemetery. It's roughly contemporaneous with Steppe Maykop and basically identical to the aforementioned Steppe Maykop trio.

KAZ_Kumsay_EBA
RUS_Eneolithic_steppe_VJ1001 0.440±0.022
RUS_Tyumen_HG 0.560±0.022
chisq 10.573
tail prob 0.646513
Full output

I suppose it's possible that Kumsay_EBA represents the migration of Steppe Maykop people into the Kazakh steppes. But even if this is true, then there had to have been an earlier migration of a group from the Kazakh steppes or West Siberia that mixed with the VJ1001-related natives of the North Caucasus steppes to give rise to Steppe Maykop.

I'm assuming that the Yamnaya-like VJ1001 and her people were the indigenous population of the North Caucasus steppes because there are no indications that they or their ancestors migrated there within any reasonable time frame from anywhere else, and certainly not from as far afield as, say, what is now Iran.

The other three Steppe Maykop individuals, who are genetic outliers in varying degrees from the main Steppe Makyop cluster, show variable levels of Maykop ancestry, with an average of about 50%. But they too harbor significant VJ1001-related ancestry. So despite the fact that there was some irregular mixing between the Maykop and Steppe Maykop peoples, this is not what created the typical Steppe Maykop genetic profile.

RUS_Steppe_Maykop_o
RUS_Eneolithic_steppe_VJ1001 0.234±0.074
RUS_Maykop_Novosvobodnaya 0.461±0.046
RUS_Tyumen_HG 0.305±0.033
chisq 7.378
tail prob 0.831667
Full output

And, of course, it should be obvious by now that the ancestry of the vast majority of Yamnaya individuals is better modeled without any input whatsoever from the Maykop or Steppe Maykop samples.

In fact, early indications are that the Yamnaya people flooded into Steppe Maykop territory from the north and completely replaced its population (see here). Despite this, in Dispersals and Diversification archeologist Kristian Kristiansen makes the following claim: "steppe Maykop expanded north, leading to the formation of the Yamnaya Culture and Proto-Indo-European". Not a chance in hell Professor.

See also...

A final note for the year

The PIE homeland controversy: August 2019 status report

Some myths die hard

An exceptional burial indeed, but not that of an Indo-European