How relevant is Arslantepe to the PIE homeland debate?

Below is an abstract of a presentation from the recent 11th International Congress on the Archaeology of the Ancient Near East (see here). It was discussed on at least a couple of DNA forums, and hailed by some as potentially pivotal to the Proto-Indo-European (PIE) homeland debate. Emphasis is mine:

Palaeogenetic and Anthropological Perspectives on late Chalcolithic and Early Bronze Age Arslantepe

Skourtanioti, Eirini - Max Planck Institute for the Science of Human History, Jena
Selim, Erdal Yilaz - Department of Anthropology, Hacettepe University, Ankara

While Anatolia was highlighted as the genetic origin of early Neolithic European farmers, the genetic substructure in Anatolia itself as well as the demographic and cultural changes remain unclear. In eastern Anatolia, the archaeological record reflects influences from North-Central Anatolia, the northeastern sectors of Fertile Crescent and the Caucasus, and suggests that some of these were brought along with the movement of people. Central to this question is the archaeological site of Arslantepe (6 th -1 st millennium BC), strategically located at the Upper Euphrates, the nexus of all three regions. Arslantepe also developed one of the first state societies of Anatolia along with advanced metal-technologies. Archaeological research suggests that conflicts with surrounding groups of pastoralists affiliated to the Caucasus might have contributed to the collapse of its palatial system at the end of the Chalcolithic period (4 th millennium BC). To test if these developments were accompanied by genetic changes, we generated genome-wide data from 18 ancient individuals spanning from the Late Chalcolithic period to the Early Bronze Age of Arslantepe. Our results show no evidence for a major genetic shift between the two time periods. However, we observe that individuals from Arslantepe are very heterogeneous and differentiated from other ancient western and central Anatolians in that they have more Iran/Caucasus related ancestry. Our data also show evidence for an ongoing but also recent confluence of Anatolian/Levantine and Caucasus/Iranian ancestries, highlighting the complexity of the Chalcolithic and Bronze Age periods in this region.

Actually, I think it's likely that the good people at Max Planck will try to weave these results into their southern PIE homeland theory.

If so, they'll probably claim that since there's no discernible steppe ancestry in any of the 18 ancient Anatolians, then it's unlikely that there were any migrations from the Pontic-Caspian steppe into Anatolia during the Chalcolithic and Bronze Age periods. Ergo, they're likely to conclude that the PIE homeland was located south of the steppe, perhaps in Transcaucasia or what is now Iran, because this is where some of the Arslantepe ancients appear to source a lot of their recent ancestry from. But that would be a mistake.

First of all, the best way to link Arslantepe to the Proto-Indo-Europeans is probably via the massive Arslantepe Royal Tomb, which shows a close archaeological relationship with kurgan burials in the North Caucasus. Here's an abstract from a paper on the topic from 2011 (freely available here). Emphasis is mine:

The first appearance of the Kurgan funerary tradition in the Northern Caucasus (Majkop‐Novosvobodnaya) dates to the second half of the fourth millennium and records an impressive display and accumulation of wealth in the grave goods (mainly metal objects) which stress the emergence of radical social transformations in the communities of the region. But kurgans also signal a new approach to territory and a different conception of the landscape. The Arslantepe Royal Tomb (in the Upper Euphrates Valley, eastern Anatolia), which is dated to 3100-2900 B.C., shows that far-reaching influences from the Northern Caucasus were already crossing the Greater Caucasus range and that they were being assimilated by the Anatolian power groups. The set of traits that the Arslantepe Royal Tomb shares with the funerary representations of the northern Caucasian Kurgans (ritual, grave goods and eventually the location chosen for the burial) was the result of a symbolic and ideological selection performed by a local community. It aimed at legitimizing and justifying the current historical and political contingencies and the emergence of new images and power rules. What can be grasped of the general sense and cultural values of the phenomenon of the northern Caucasian Kurgans by means of an interpretation performed by an external (and distant) community?

So we can still argue that the PIE homeland was on the steppe, with Anatolian languages splitting from the rest of PIE in the North Caucasus, and then making their way south to Anatolia along with people of fully Caucasian genetic structure. As far as I can tell, that's essentially the theory proposed recently by Damgaard et al. in their linguistic supplement (see here).

But I'm not a huge fan of this solution. Clearly, the archaeological and genetic changes at Arslantepe from the Chalcolithic to the Bronze Age were in large part caused by the arrival of groups associated with the Kura-Araxes archaeological culture, and they were probably speakers of early Hurra-Urutian languages. If there were any migrants directly from the North Caucasus at Arslantepe, then I'd say that they probably spoke Caucasian languages.

Indo-Europeans certainly arrived at Arslantepe during the Late Bronze Age, with the expansion of the Hittite Empire into the region. But it's impossible to say how much, if any, PIE ancestry they brought with them, because obviously language shifts are a complex phenomenon, and this is especially true in state societies, like the Hittite Empire, in which cultural and political domination can lead to widespread language change without any accompanying gene flow.

See also...

Ahead of the pack

Genetic borders are usually linguistic borders too

Yamnaya isn't from Iran just like R1a isn't from India