Domestication spread probably via the North Pontic steppe to Khvalynsk… but not horse riding

Interesting paper Excavation at the Razdolnoe site on the Kalmius river in 2010, by N. Kotova, D. Anthony, D. Brown, S. Degermendzhy, P. Crabtree, In: Archaeology and Palaeoecology of the Ukrainian Steppe / IA NAS of Ukraine, Kyiv 2017.

Nothing new probably to those who have read Anthony (2007), but this new publication of his research on the North Pontic region seems to contradict recent papers which cast doubts on the presence of early forms of domestication in the North Pontic steppe, and would reject thus also the arrival of domestication to Khvalynsk from a southern route.

Interesting excerpts discussing recent research and results of this one (emphasis mine):

A brief comment about the fauna is required. A separate international archaeological project studied sites dated to the mid — 6th millennium BC in the Severskiy Donets basin (Starobelsk I, Novoselovka III) northeast of Razdolnoe, and found that they had hunting and gathering economies that made use of Unio shellfish, fish, and turtles, like the Neolithic occupation at Razdolnoe. But the Donets sites had no domesticated animal species. The author argued that the cultures of the Donets and lower Don basins in the 6th millennium BC probably had no domesticated animals, and that the domesticated sheep-goat bones identified at Semenovka, west of Razdolnoe, and dated to 5500 calBC, probably were mis-identified and actually came from wild saiga antelope (Motuzaite- Matuzeviciute 2012: 14). This suggestion was made on the basis of a single bone identified as sheep-goat at Semenovka by O.P. Zhuravlev (not N.S. Kotova as Motuzaite-Matuzeviciute wrote) and sent out for radiocarbon dating, that was re-examined by Cambridge University archaeozoologists.

Regardless of which identification is correct, a single bone is insufficient to cast doubt on sheep-goat bones identified at Sredni Stog 1, Sobachki, and other Neolithic sites in the Dnieper valley. Nevertheless, yet another international collaboration that studied the economy of Dereivka in the Dnieper valley argued that the economy of Eneolithic Dereivka site, which they dated to about 3500 calBC (ignoring 10 radiocarbon dates between 4200—3700 calBC), was still at an «initial phase of animal domestication» and that the Dereivka occupants of 3500 calBC were still largely dependent on hunting and fishing (Mileto et al. 2017: 67—68).

The dated Bos calf in the lower occupation level at Razdolnoe shows that domesticated animals were present in the Kalmius river valley in the Azov steppes in 5500 calBC, at a time when the cultures of the Donets valley were still hunters and gatherers just 200 km to the northeast of Razdolnoe. Sheep-goat and Bos bones were found in all Neolithic and Eneolithic levels at Razdolnoe. Because it was a small excavation, this evidence should not be over-interpreted. We cannot say how important domesticated animals were in the daily diet. But domesticated sheep-goat and cows had reached the Azov steppes by 5500 calBC. The appearance of cattle and sheep-goat as sacrificial animals in graves of the Khvalynsk Culture on the Volga by the early 5th millennium BC probably was a continuation of the spread of animal herding eastward from the Azov steppes.

Most likely route of expansion of horse domestication and horse riding (including Suvorovo-Novodanilovka chiefs) from Khvalynsk into the North Pontic steppe and the Balkans.

Re-reading the papers on this subject – in which researchers seem to be fighting among each other for a radical interpretation of few animal bones – , I would suggest that the key concept they should be emphasizing is probably not the ‘presence’ vs. ‘absence’ of domestication in North Pontic steppe cultures in absolute terms.

Since there were clearly domesticated animals to the east and west of North Pontic cultures in the Neolithic, and thus the finding there of domesticated animals is more than likely, what is of great interest is the relative measure in which domesticated animals were relied upon by forest-steppe economies, compared to the use of available natural resources.

After all, many researchers currently agree that the North Pontic steppe and forest-steppe peoples formed communities of mainly hunter-fishers and gatherers, and findings of this paper do not seem to contradict this.

NOTE. In fact, there was a more recent paper I referenced which argues in such general terms with detail – probably written at the same time as this one -, by one of the authors they discuss, Mileto et al. (2018).

Also, as the paper states,

we want to emphasize that even a small excavation in the steppe zone, where only scanty number of the Neolithic and Eneolithic sites have been known yet, is very important and always gives very interesting materials.

Hence by confirming Anthony’s account of early domestication spreading eastwards during the Neolithic expansion, and without horses’ remains in any of the periods investigated (including Sredni Stog I-III), it also supports his hypothesis of horse riding emerging in Khvalynsk and expanding westward.

The Razdolnoe site lies near modern-day Donetsk, and its latest layer investigated (ca. 4300-4150 BC) represents thus the eastern variant of Sredni Stog III, being consequently the one more in contact with expanding early Khvalynsk.

Given the absence of horse remains in all layers, these results would also suggest that Novodanilovka and Suvorovo horse-riding chiefs (emerging ca. 4400-4200 BC to the west of this region) were indeed unrelated to the surrounding Sredni Stog population, and most likely migrants from the horse-riding Khvalynsk culture.

Featured image: Expansion of domestication in the Pontic-Caspian steppe, according to Anthony (2007).


Decline of genetic diversity in ancient domestic stallions in Europe

Open access research article Decline of genetic diversity in ancient domestic stallions in Europe, by Wutke et al., Science (2018), 4(4):eaap9691.

Abstract (emphasis mine):

Present-day domestic horses are immensely diverse in their maternally inherited mitochondrial DNA, yet they show very little variation on their paternally inherited Y chromosome. Although it has recently been shown that Y chromosomal diversity in domestic horses was higher at least until the Iron Age, when and why this diversity disappeared remain controversial questions. We genotyped 16 recently discovered Y chromosomal single-nucleotide polymorphisms in 96 ancient Eurasian stallions spanning the early domestication stages (Copper and Bronze Age) to the Middle Ages. Using this Y chromosomal time series, which covers nearly the entire history of horse domestication, we reveal how Y chromosomal diversity changed over time. Our results also show that the lack of multiple stallion lineages in the extant domestic population is caused by neither a founder effect nor random demographic effects but instead is the result of artificial selection—initially during the Iron Age by nomadic people from the Eurasian steppes and later during the Roman period. Moreover, the modern domestic haplotype probably derived from another, already advantageous, haplotype, most likely after the beginning of the domestication. In line with recent findings indicating that the Przewalski and domestic horse lineages remained connected by gene flow after they diverged about 45,000 years ago, we present evidence for Y chromosomal introgression of Przewalski horses into the gene pool of European domestic horses at least until medieval times.

The frequencies of Y chromosome haplotypes started to change during the Late Bronze Age (1600–900 BCE).
Inferred temporal trajectories of haplotype frequencies. Each haplotype is displayed by a different color. The shaded area represents the 95% highest-density region. The trajectories were constructed taking the median values across frequencies from the simulations of the Bayesian posterior sample. The small chart represents the stacked frequencies; the amplitude of each colored area is proportional to the median haplotype frequencies (normalized) at a given time. The x and y axes of the small chart match those in the large one. Ka, thousands of years.

Interesting excerpts:

The first record of the modern domestic Y chromosome haplotype stems from two Bronze Age samples of similar age. Notably, both samples were found in two distantly located regions: present-day Slovakia (2000–1600 BCE, dated by archaeological context) and western Siberia (14C-dated: 1609–1436 cal. BCE). Although a very recent study proposes an oriental origin of this haplotype (14), we cannot determine the geographical origin of Y-HT-1 with certainty, because this haplotype has not been found thus far in predomestic or wild stallions. There are two possible scenarios: (i) Y-HT-1 emerged within the domestic population by mutation and (ii) Y-HT-1 was already present in wild horses and entered the domestic population either at the beginning of domestication (but initially restricted to Asian horses) or later by introgression (from wild Y-HT-1 carrying studs during the Iron Age). Crosses between domestic animals and their wild counterparts have been observed in several domestic species (15–18); thus, the simplest explanation would be that we missed Y-HT-1 in older samples because of limited geographical sampling. However, the estimated haplotype age is contemporary (Fig. 4) with the assumed starting point of horse domestication ~4000–3500 BCE (19), rendering it likely that Y-HT-1 originated within the domestic horse gene pool. Still, we cannot rule out definitively that it appeared before domestication.

Independent of its geographical origin, Y-HT-1 progressively replaced all other haplotypes—except for one additional lineage that is restricted to Yakutian horses (11). Considering our data, this trend in paternal diversity toward dominance of the modern lineage appears to start in the Bronze Age and becomes even more pronounced during the Iron Age. The Bronze Age was a time of large-scale human migrations across Eurasia (20–22), movements that were undoubtedly facilitated by the spread of horses as a means of transport and warfare. At that time, the western Eurasian steppes were inhabited by highly mobile cultures that largely relied on horses (20, 21, 23, 24). The genetic admixture of northern and central European humans with Caucasians/eastern Europeans did correlate with the spread of the Yamnaya culture from the Pontic-Caspian steppe (25), an area that has repeatedly been suggested as the center of horse domestication (19, 26, 27). Given the importance of domestic horses, it appears that deliberate selection/rejection of certain stallions by these people might have contributed to the loss of paternal diversity. The spread of humans out of this region might also have resulted in the spread of Y-HT-1 from Asia to Europe. This scenario also agrees with recent findings that the low male diversity of extant horses is not caused by recruiting only a limited number of stallions during early domestication (13).

Decline of paternal diversity began in Asia.
Maps displaying age, locality, and haplotype (different colors) of each successfully genotyped sample.

The presence of the Y chromosome haplotype carried by present-day Przewalski horses (Y-HT-2) in early domestic stallions and a European wild horse (Pie05; table S2) could be the result of introgression of Przewalski stallions. Although the original distribution of the Przewalski horse is unknown, it was probably much larger than that of the relict population in Mongolia that produced modern Przewalski horses and might even have extended into Central Europe. However, it is also possible that either Przewalski horses were among the initially domesticated horses or that Y-HT-2 occurred both in Przewalski horses and in those wild horses that are the ancestors of domestic horses, based on autosomal DNA data (30). Regardless of how Y-HT-2 entered the domestic gene pool, it was eventually lost, as were all haplotypes except Y-HT-1. In our sample set, Y-HT-2 was undetectable as early as the third time bin. However, it is possible that Y-HT-2 may have been present during this time period, but with a frequency below 0.11 (with 95% probability). The inferred time trajectories for Y-HT-2 frequencies suggest that it could nevertheless have persisted at very low frequencies until the Middle Ages (Fig. 3). On the basis of these simulations, this finding could be interpreted as a relic of this haplotype’s formerly higher frequency in the domestic horse gene pool. It is also possible that the presence of this haplotype could be the result of mating a wild stallion with a domestic mare, a frequently reported breeding practice when wild horses were still widely distributed. However, a significant contribution of the Przewalski horse to the gene pool of modern domestic horses has been almost ruled out by recent genomic studies (13, 31, 32).

Stallion lineages through time.
Temporal haplotype network of the four detected Y chromosome haplotypes. Age of the samples indicated by multiple layers separated by color; vertical lines connecting the haplotypes of consecutive layers/ages represent which haplotype was transferred into a later/younger period. Numbers constitute the respective number of individuals showing this particular haplotype for that period. Prz, Przewalski; Dom, domestic.


North Pontic steppe Eneolithic cultures, and an alternative Indo-Slavonic model

I am not a fan of continuity theories – that much should be clear for anyone reading this blog. However, most of such proposals’ supremacist (or rather fear-of-inferiority) overtones don’t mean they have to be wrong. It just means that most of them, most of the time, most likely are.

While reading Tommenable’s comments, I thought about a potential alternative model, where one could a priori accept an identification of North Pontic cultures as ‘Indo-Slavonic’, which seems to be the Eastern European R1a continuist trend right now.

NOTE. To accept this model, one should first (not a posteriori) accept an Indo-Slavonic linguistic group on theoretical grounds, of course, and take the steppe ancestral component (and not archaeological data) as the most meaningful aspect to consider for language expansion and exchange (which we know is not the most intelligent approach to cultural or language change).

Thinking about how Genomics could challenge what mainstream Linguistics and Archaeology accepts, the only situation I can think of (using simplistic phylogeography) regarding late Khvalynsk-Sredni Stog contacts (until ca. 3300 BC) is:

  1. That the community of R1b-L51 lineages was in fact an isolated group , and not a western one – i.e. to the east within the Volga-Ural groups, or maybe to the south within the North Caucasian groups .
  2. That the R1b-Z2103 community was a huge one dominating over much of the steppe, from the Dnieper area to the Volga-Ural region (where we know they were).
  3. That R1a-M417 subclades (and especially subclade R1a-Z645) with steppe ancestry, as found in Corded Ware migrants,were only found in the North Pontic area (i.e. in Sredni Stog) during the fourth millennium (until at least 3300 BC, when Yamna substitutes it), and did not form other communities in the forest-steppe or Forest Zone (from where Corded Ware eventually expanded), as it is quite likely.
  4. That both the R1b-Z2103 and R1a-Z645 communities shared obvious genetic connections (whatever they were) around the Dnieper, that could justify a common, shared language.
Diachronic map of Eneolithic migrations in eastern Europe ca. 4000-3100 BC

Only then, if a widespread Graeco-Aryan-speaking community happened to be spread from west to east in the Pontic-Caspian steppe, with close contacts with North Pontic cultures, and having an isolated Northern Late PIE community somewhere different than West Yamna, it could leave for me a reasonable doubt of a cultural connection (maybe “Indo-Slavonic” in nature) of the North Pontic steppe. But then we would probably be stuck – yet again – with some sort of cultural diffusion event, impossible to demonstrate.

Since it is known (in Linguistics, and also in Y-DNA lineages, due to the early expansion of Z2103 subclades) that Graeco-Aryan groups separated early, this model would not be impossible.

Also a priori in favour of that model would be the early expansion of a (Northern IE-speaking) Pre-Tocharian population to the east. On the other hand, from an archaeological point of view, the group reaching Afanasevo seems to have expanded from Repin, just like the community expanding Yamna to the west of the Dnieper.

I really doubt there can be any serious discussion though, apart from amateur geneticists with a personal interest on this, because:

  • Graeco-Aryan is a Late PIE dialect, and Late PIE guesstimates are more recent than that.
  • Dialectal separation within a Late Proto-Indo-European language must have happened late, gradually, and in close contact, allowing for common innovations to spread through dialectal groups.
  • It does not make sense in terms of prehistoric cultures, since there is no direct connection or migration among steppe cultures but for the Novodanilovka and the Yamna expansions.
  • Indo-Slavonic is only supported by a handful of linguists, and not in the way or timing described in this model.

NOTE. You can read Kortlandt’s works in (also on his personal website) if you are really interested in knowing more about an Indo-Slavonic proposal, from an expert Balticist and Slavicist. However, if your intent is to demonstrate some ancient ethnic link of “your” people (whatever that means) to mythical Proto-Indo-Europeans, you would not need actual knowledge or sound theories to do that, so you can skip that part. Also, Kortlandt would probably support a later model of Indo-Slavonic expansion in the steppe, related to East Yamna, and later Sintashta, Srubna, etc…

Migration Yamna -> Corded Ware -> Bell Beaker as claimed by articles published in Nature (2015). From materials of the UAB.

If you think about it, if most modern Slavs were mainly of R1b-L23 lineages instead of R1a-Z645 (a replacement which, as it is clear know, is the consequence of a simple resurge of previous lineages in East-Central Europe, coupled with a later gradual replacement through founder effects, so no big migration history here), and Finnic speakers were mainly of R1a-Z645 lineages (whose replacement by N1c lineages seems also the consequence of quite late consecutive founder effects), I doubt we would be having this reticence to accept sound anthropological models.

So, we are speculating here for the sake of an unnecessary, naïve compromise…Just hoping to find some common ground to move on, now that the picture is clearer for everyone.

NOTE. The change of narratives where certain languages must have accompanied R1a-Z645 and N1c lineages, but in alternative ways not previously described, is obviously unjustified, if linguistic and archaeological data tell a different story. As unjustified as it is to change Yamna for “Neolithic Steppe” as homeland of Late Indo-European, to fit it with the steppe ancestry concept

See also: