Catacomb > Armenia_MLBA

It should be obvious by now, thanks to ancient DNA, that Transcaucasia and surrounds were affected by multiple, and at times significant, population movements from Eastern Europe during the Eneolithic and Bronze Age periods. Based on the ancient samples from what is now Armenia, I’d say that this process peaked during the Middle Bronze Age. But who exactly were the people who perhaps swarmed south of the Caucasus at this time?
The most likely suspects are the various groups that occupied the southernmost parts of the Pontic-Caspian steppe throughout the Bronze Age. They were associated with the so called Catacomb, Kubano-Tersk and Yamnaya archeological cultures. Below is a Principal Component Analysis (PCA) that compares samples from these cultures with those from Middle to Late Bronze Age Armenia (labeled Armenia_MLBA). The relevant datasheet is available here.

Note that Armenia_MLBA forms a cline that appears to be stretching out towards the Catacomb, Kubano-Tersk, Yamnaya and other Bronze Age steppe groups, and this suggests that it harbors significant and probably recent steppe-related ancestry. But PCA plots based on just two dimensions of genetic variation can be misleading at times, so let’s check this out with some formal mixture models using qpAdm.

Catacomb 0.234±0.028
Kura-Araxes_Kaps 0.766±0.028
chisq 10.723
tail prob 0.826248
Full output
Kubano-Tersk 0.254±0.030
Kura-Araxes_Kaps 0.746±0.030
chisq 13.535
tail prob 0.633284
Full output
Kura-Araxes_Kaps 0.768±0.028
Yamnaya_Kalmykia 0.232±0.028
chisq 14.454
tail prob 0.564954
Full output
Kura-Araxes_Kaps 0.762±0.029
Yamnaya_Caucasus 0.238±0.029
chisq 15.916
tail prob 0.458816
Full output

All of these models are statistically very sound, and even though I ranked the results by «tail prob», there’s nothing in the output that clearly points to any one of the southern steppe groups as the obvious source of the steppe-related ancestry in Armenia_MLBA. But, interestingly, Catacomb tops the ranking, and it probably also makes the most sense based simply on Carbon-14 chronology. So, for now, I’m going with Catacomb.
I didn’t get a chance yet to investigate this issue in detail with the Global25. Does it contradict the results from my PCA and qpAdm analyses? If anyone reading this would like to take a close look that’d be great. Feel free to post your findings in the comments below. And if the answer is indeed Catacomb, then what language did these Catacomb-derived migrants, or perhaps invaders, speak? If not proto-Armenian then what?
By the way, please be aware that the Kubano-Tersk samples in my analyses are the same individuals as those featured in Wang et al. 2019 under the label «North Caucasus».
On a related note, here are a couple of intriguing qpAdm models that I came up with recently for the five Hittite era Anatolians in my dataset (aka Anatolia_MLBA). I don’t have a clue why these models work so well and what they mean exactly. They do suggest, however, that the Hittite era Anatolians harbor steppe-related ancestry, which may have been mediated via populations from the Caucasus similar to Armenia_MBA. But, then again, this might just be an artifact of trying to model several streams of ancestry, coming from various directions, with just two and three potential mixture sources. Any thoughts?

Anatolia_EBA_Ovaoren 0.651±0.109
Armenia_MBA 0.174±0.063
Peloponnese_N 0.175±0.058
chisq 8.321
tail prob 0.91027
Full output
Anatolia_EBA_Isparta 0.831±0.053
Armenia_MBA 0.169±0.053
chisq 16.170
tail prob 0.441163
Full output

See also…
Steppe ancestry in Chalcolithic Transcaucasia (aka Armenia_ChL explained)
Likely Yamnaya incursion(s) into Northwestern Iran
Late PIE ground zero now obvious; location of PIE homeland still uncertain, but…