Maykop ancestry in Copper Age Arslantepe

At least four individuals from the Late Chalcolithic (LC) burial site of Arslantepe show ancestry typical of the population associated with the contemporaneous Maykop culture in the North Caucasus. They are ART018, ART020, ART027 and ART039 from the recent Skourtanioti et al. paper. I've labeled them TUR_Arslantepe_LC_Maykop in my qpAdm mixture model below:

TUR_Arslantepe_LC_Maykop
RUS_Maykop_Novosvobodnaya 0.318±0.041
TUR_Arslantepe_LC 0.682±0.041
chisq 9.969
tail prob 0.533159
Full output

Considering the tight statistical fit, I think it's even possible that some of these people harbor direct ancestry from Maykop Novosvobodnaya. Here's a Principal Component Analysis (PCA) showing why my qpAdm model works so well. It was produced with the data in the text file here and the Vahaduo PCA tools here.

Moreover, one of the Arslantepe males, ART038, belongs to Y-haplogroup R1b-V1636 (R1b1a2). This is clearly a marker of paternal steppe ancestry, because it's been reported in two Eneolithic samples from the southernmost part of the Pontic-Caspian steppe near the North Caucasus foothills (see here). These individuals are dated to ~4,200 calBCE, so they lived about a thousand years earlier than ART038.

ART038 probably lacks steppe and Maykop-related ancestries on his autosomes. Nevertheless, my point about his Y-haplogroup stands, because autosomal admixture can be bred out and disappear completely within a couple hundred years, or about 6 to 8 generations.

Interestingly, Skourtanioti et al. argued against the possibility of significant steppe and Maykop-related ancestries in the Arslantepe LC samples. They also didn't see R1b-V1636 as an obvious signal of paternal steppe ancestry. I find this very puzzling indeed, because to me it seems way off the mark. From the paper:

However, R1b-V1636 and R1b-Z2103 lineages split long before (~17 kya) and therefore there is no direct evidence for an early incursion from the Pontic steppe during the main era of Arslantepe. Lineage L2-L595 found in ALA084 (Alalakh) has previously been reported in one individual from Chalcolithic Northern Iran (Narasimhan et al., 2019) and in three males from the Late Maykop phase in the North Caucasus (Wang et al., 2019). These three share ancestry from the common Anatolian/Iranian ancestry cline described here, which indicates a widespread distribution that also reached the southern margins of the steppe zone north of the Caucasus mountain range.

See also...

Perhaps a hint of things to come

An early Mitanni?

How relevant is Arslantepe to the PIE homeland debate?

A significant finding

At least five individuals from Neolithic burial sites in what is now Ukraine harbor ancestry that is normally associated with much later steppe populations. Labeled UKR_N_admixed in the plot below, these samples were part of the Mathieson et al. 2018 dataset and most were radiocarbon dated to well before 5,000 BCE. An interactive version of the plot is available here.

Their unusual ancestry probably explains why they form a cluster that appears to be pulling away from the ancient European hunter-gatherer cline towards the part of the plot home to RUS_Progress_En (from the Progress-2 Eneolithic burial site in the North Caucasus piedmont region). But, of course, there's more to this. For instance, consider the formal statistics-based qpAdm mixture models below:

UKR_N_admixed
RUS_Progress_En 0.083±0.021
UKR_N 0.917±0.021
chisq 7.461
tail prob 0.589238
Full output

UKR_N_admixed
RUS_Progress_En 0.172±0.021
SRB_Iron_Gates_HG 0.332±0.024
UKR_Meso 0.495±0.035
chisq 9.255
tail prob 0.321282
Full output

UKR_N_I1738
RUS_Progress_En 0.196±0.035
SRB_Iron_Gates_HG 0.414±0.039
UKR_Meso 0.390±0.056
chisq 7.913
tail prob 0.442006
Full output

Ergo, as much as a quarter of the genome of individual I1738, dated to 5473-5326 calBCE, might be derived from a population very similar to RUS_Progress_En. This is a big deal, because it's still widely believed that this type of ancestry didn't exist until the Eneolithic, and that it didn't spread significantly until the migrations of steppe pastoralists associated with the Early Bronze Age Yamnaya culture.

I'm confident, nay, certain, that my findings will be confirmed directly with more Neolithic samples from present-day Ukraine and surrounds.

See also...

Understanding the Eneolithic steppe

Ancient DNA vs Ex Oriente Lux

Mixed marriages on the early Eneolithic steppe

Understanding the Eneolithic steppe

Archeologist David Anthony has teamed up with Harvard's David Reich Lab to work on a paper about the Eneolithic period on the Pontic-Caspian steppe.

A couple of other labs are also preparing papers on similar topics, and they've already sequenced and analyzed many of their ancient samples (for instance, see here). However, I don't have a clue when these papers will be published. My guess is that we'll have to wait a year or so.

Needless to say, knowing what happened on the Pontic-Caspian (PC) steppe and surrounds during the Eneolithic is crucial to understanding the origins of the present-day European gene pool. It's also likely to be highly relevant to the debate about the location of the Proto-Indo-European (PIE) homeland.

In this blog post I'll explain what I've learned about the Eneolithic peoples of the PC steppe based on already published data.

If we ignore Steppe Maykop samples, the currently available Eneolithic individuals from the eastern part of the PC steppe form an essentially perfect cline in my Principal Component Analysis (PCA) of ancient West Eurasian genetic variation.

The cline runs from the Mesolithic hunter-fishers of the Eastern European forest zone to those of the Eneolithic sites of Progress 2 and Vonyuchka in the North Caucasus foothills. Let's call this the Khvalynsk cline, because three of the samples are from a burial site in the Volga River valley associated with the Khvalynsk culture. The relevant datasheet is available here.

The reason that these samples form the cline is because they carry different ratios of admixture related to Caucasus hunter-gatherers (CHG) from what is now Georgia. Moreover, the Khvalynsk individuals appear to be relatively recent mixtures between sources rich and poor in this type of ancestry.

I also marked a Maykop cline on the plot. This cline is made up of individuals associated with the Maykop and Steppe Maykop cultures from the Caucasus Mountains and nearby parts of the PC steppe, respectively. The Maykop culture is dated to the Early Bronze Age (EBA) period, but the PC steppe was still part of the Eneolithic world at the time.

The Maykop cline is more complicated than the Khvalynsk cline, because some of the Maykop individuals carry genetic components that the others lack. These genetic components are closely related to the aforementioned CHG, as well as Anatolian Neolithic farmers (ANF) and Western Siberian hunter-gatherers (WSHG).

Note that the two clines intersect, but this isn't because any of the Khvalynsk cline samples harbor Maykop-related ancestry. It's largely because the Steppe Maykop individuals carry high levels of Vonyuchka-related ancestry.

So unless we're dealing here with a remarkable string of coincidences, then the Vonyuchka hunter-fisher must be a decent proxy for the people who spread significant levels of CHG-related ancestry north of the Caucasus.

The important question, therefore, is where and when exactly did this population form? And it's a question that the authors of the aforementioned upcoming papers should be aiming to answer comprehensively.

In my view, it was the result of interactions between the hunter-fishers of the North Caucasus and the southernmost parts of the PC steppe during the Neolithic period, perhaps around 6,000 BCE, just before significant ANF-related ancestry spread across the Caucasus during the Eneolithic. That's because the Progress 2/Vonyuchka samples lack ANF-related ancestry, or at least an obvious signal of it, and are dated to ~4,200 BCE. And when I say Neolithic in this context, I don't mean the Near Eastern type of Neolithic with well developed farming, but rather the local type of Neolithic still based on hunting and fishing.

Now, obviously, the people of the Corded Ware and Yamnaya cultures were the children of the Eneolithic PC steppe. So you might be wondering how they fit into all of this. I still don't know, and apparently neither do the scientists at Harvard (see here). However, I'd say that the Maykop cline isn't relevant to this question. The Khvalynsk cline might be relevant, but even if it is, this doesn't necessarily mean that the Yamnaya people are by and large derived from the Khvalynsk people.

Here's the same PCA plot as above, but this time with early Corded Ware and Yamnaya samples also highlighted. Note that, apart from a few outliers, they form a rather tight cluster that is shifted slightly away from the Khvalynsk cline, but probably not in the direction of the Maykop cline.

A couple of the Yamnaya outliers are shifted towards the "eastern" end of the Khvalynsk cline, and thus near the Progress 2/Vonyuchka samples. This isn't surprising because these Yamnaya individuals are from burial sites close to the North Caucasus and probably harbor significant levels of local ancestry.

The most extreme Yamnaya outlier, from a site in what is now Ukraine, is clearly shifted towards the Maykop cline, and even towards the Caucasus Maykop cluster. However, this is a female with no grave goods and she may have been a foreign bride or captive, possibly from a late Maykop settlement. It's also possible that her 3095-2915 calBCE dating is wrong.

I'm pretty sure that when we find out why the Yamnaya cluster is so deliberately shifted away from the Khvalynsk cline, we'll also discover how the early Corded Ware and Yamnaya populations formed. For now, I strongly suspect that this has something to do with gene flow from the western edge of the PC steppe and the ethnogenesis of the Sredny Stog culture, which was located just west of the Khvalynsk culture.

By and large, the PC steppe is still seen by historical linguists and archeologists as the most sensible place to put the PIE homeland.

However, a theory that the PIE homeland was located somewhere south of the Caucasus, and that instead the PC steppe was the late or nuclear PIE dispersal point, has gained popularity in recent years, largely thanks to the apparent lack of PC steppe ancestry in a handful of samples from Hittite era Anatolia. In this scheme, the Maykop culture took PIE into Eastern Europe and the Yamnaya culture subsequently spread late/nuclear PIE from the PC steppe, while Proto-Anatolian, the ancestor of Hittite, was introduced into Anatolia from the east along with Maykop-related ancestry.

This is possible, in the sense that almost anything is possible, but it doesn't strike me as the most parsimonious interpretation of the facts.

Even before ancient DNA, it was known that the Maykop culture colonized parts of the PC steppe, at least for a short time, and probably had contacts with the Yamnaya people and/or their antecedents. But it was generally seen as the vector for Caucasian and other non-Indo-European influences in PIE.

Moreover, not only were the Maykop and Yamnaya populations of fundamentally different genetic origins, but apparently the Yamnaya people didn't absorb any perceptible Maykop ancestry as they expanded into the North Caucasus region at the tail end of the Maykop period.

That's really difficult to explain if we assume that these groups were close linguistic relatives, and much easier to reconcile with the assumption that they were derived from different worlds culturally and linguistically.

Another important question is what happened to the Steppe Maykop people, because right now it looks like they vanished almost without a trace, essentially as if they were pushed out or even erased by the Yamnaya expansion. If they were indeed pushed out or erased, then it's likely that their language was as well.

As for the lack of PC steppe ancestry in Hittite era Anatolians, I honestly can't see this is as a significant obstacle to a PIE homeland on the steppe, especially if we consider that the most widely accepted Indo-European phylogenies show the Anatolian family as the most basal node.

In the opinion of the vast majority of experts, it's the most basal node because the Proto-Anatolian speakers were the first to leave the PIE homeland. And if they were indeed the first to leave the homeland, then why should we expect their descendants to harbor significant ancestry from the homeland? In my view, such an assumption would contradict the most widely accepted Indo-European phylogenies.

See also...

The Caucasus is a semipermeable barrier to gene flow

Ancient DNA vs Ex Oriente Lux

In recent years you may have read academic papers, books and press articles claiming that the Early Bronze Age Yamnaya culture of the Pontic-Caspian steppe was founded by migrants from the Caucasus, Mesopotamia or even Central Asia.

Of course, none of this is true.

The Yamnaya herders and closely related groups, such as the people associated with the Corded Ware culture, expanded from the steppe between the Black and Caspian seas, and, thanks to ancient DNA, it's now certain that they were overwhelmingly derived from a population that had existed in this region since at least the mid-5th millennium BCE (see here).

So rather than being culturally advanced colonists from some Near Eastern civilization, the ancestors of the Yamnaya herders were a relatively primitive local people who still largely relied on hunting and fishing for their subsistence. They also sometimes buried their dead with flint blades and adzes, but hardly ever with metal objects, despite living in the Eneolithic epoch or the Copper Age.

As far as I know, this group doesn't have a specific name. But in recent scientific literature it's referred to as Eneolithic steppe, so let's use that.

It's not yet clear how the Yamnaya people became pastoralists. Some scholars believe that they were basically an offshoot of the cattle herding Maykop culture of the North Caucasus. However, the obvious problem with this idea is that the Yamnaya and Maykop populations probably didn't share any recent ancestry. In fact, ancient DNA shows that the former wasn't derived from the latter in any important or even discernible way (see here).

On the other hand, Yamnaya samples do harbor a subtle signal of recent gene flow from the west that appears to be most closely associated with Middle to Late Neolithic European agropastoralists (see here). Therefore, it's possible that herding was adopted by the ancestors of the Yamnaya people as a result of their sporadic contacts with populations living on the western edge of the Pontic-Caspian steppe.

Eneolithic steppe is currently represented by just three samples in the ancient DNA record, and all of these individuals are from sites on the North Caucasus Piedmont steppe (two from Progress 2 and one from Vonyuchka 1).

As a result, it might be tempting to argue that cultural, if not genetic, impulses from the Caucasus did play an important role in the formation of the Yamnaya and related peoples. However, it's important to note that the North Caucasus Piedmont steppe was the southern periphery of Eneolithic steppe territory.

Below is a map of Eneolithic steppe burial sites featured in recent scientific literature. It's based on data from Gresky et al. 2016, a paper that focused on a specific and complex type of cranial surgery or trepanation often practiced by groups associated with this archeological culture (see here).

Incredibly, one of the skeletons from Vertoletnoe pole has been radiocarbon dated to the mid-6th millennium BCE. My suspicion, however, is that this result was blown out by the so called reservoir effect (see here). In any case, the academic consensus seems to be that the roots of Eneolithic steppe should be sought in the Lower Don region, rather than in the Caucasus foothills (see page 36 here).

Considering that nine Eneolithic steppe skulls from the Lower Don were analyzed by Gresky et al., I'd say it's only a matter of time before we see the publication of genome-wide data for at least of couple of these samples. Indeed, the paper's lead author is from the Deutsches Archäologisches Institut, which is currently involved in a major archaeogenetic project on the ancient Caucasus and surrounds. Unfortunately, the study is scheduled to be completed in about four years (see here).

But whatever happens, the story of Eneolithic steppe deserves to be investigated in as much detail as possible, because it obviously had a profound impact on Europe and its people.

In my estimation, at least a third of the ancestry of present-day Northern Europeans, all the way from Ireland to the Ural Mountains in Russia, is ultimately derived from Eneolithic steppe groups. It's also possible that R1a-M417 and R1b-L51, the two most frequent Y-chromosome haplogroups in European males today, derive from a couple of Eneolithic steppe founders. If so, that's a very impressive effort for such an obscure archeological culture from what is generally regarded as a peripheral part of Europe.

See also...

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

Not too many people have been buried sitting on wagons. The most famous case is that of an Early Bronze Age man who, considering his injuries, may have died in a high-speed crash - high-speed for its time anyway - on the Pontic-Caspian steppe in Eastern Europe.

It's likely that this guy was one of the very first wagon-drivers in human history, because his four-wheeled wooden model is dated to 3336-3105 calBCE, which makes it the oldest wagon discovered thus far. His genotype data, under the label Steppe Maykop SA6004, were published recently along with Wang et al. 2019.

Early wagons are very important for a couple of reasons: they revolutionized human transport and warfare, and they're often closely associated with the prehistoric expansions of Indo-European languages.

So I'm pretty sure that many of you must be thinking right now that wagon-driver SA6004 was an early Indo-European, or even a Proto-Indo-European! I bet that's what Wang et al. thought too, considering the conclusion in their paper. But, alas, the chances of this are slim to none.

Steppe Maykop samples show rather peculiar genetic structure considering their geographic origin, with a large proportion of their ancestry deriving from a source closely related to western Siberian hunter-gatherers (aka West_Siberia_N in the ancient DNA record). Indeed, SA6004 basically looks like a 50/50 mix between West_Siberia_N and Piedmont_Eneolithic. Here's a map with all of the relevant details.

Thus, clearly, the Steppe Maykop population wasn't ancestral or even directly related to the steppe and steppe-derived groups generally regarded to have been Indo-European speaking, such as those associated with the Yamnaya, Corded Ware, and Bell Beaker cultures. That's because these groups lack any discernible West_Siberia_N-related ancestry.

It also wasn't ancestral or directly related to any present-day or currently sampled ancient Indo-European speaking populations, again because these populations basically lack West_Siberia_N-related ancestry.

On the other hand, Yamnaya, Corded Ware and other closely related groups show an exceptionally strong genetic relationship with Indo-European speakers, especially those from across Northern Europe, which experienced massive migrations from the Pontic-Caspian steppe during the late Neolithic period, and hardly anything from elsewhere since then.

Case in point, the samples from Wang et al. labeled Yamnaya Caucasus were recovered from the same area of the Pontic-Caspian as their Steppe Maykop samples, and yet, take a look at this linear model based on outgroup f3-statistics. Steppe Maykop does show high genetic affinity to Indo-European speakers (no doubt mediated via its Piedmont_Eneolithic-related ancestry), but, unlike Yamnaya Caucasus, it also shows unusually high affinity for a West Eurasian population to Native Americans and Siberians. The relevant datasheet is available here.

So the only way that the Steppe Maykop population was Indo-European-speaking, was if it inherited its Indo-European speech from its Piedmont_Eneolithic-related ancestors. And even if it was Indo-European-speaking, it probably spoke an extinct Indo-European language not closely related to any extant Indo-European languages. In other words, the possibility that Steppe Maykop passed on its language to Yamnaya, along with its wagons, is close to zero. More likely, Yamnaya stole a few wagons from Steppe Maykop, and the rest is history.

See also...

The Steppe Maykop enigma

On Maykop ancestry in Yamnaya

Late PIE ground zero now obvious; location of PIE homeland still uncertain, but...