Tripolje, Dereivka, and the Sredni Stog phenomenon (guest post)

This is another guest post by an anonymous contributor. Again, I don't necessarily agree with the author, but is he wrong? Feel free to let me know in the comments below.

The definition of Sredni Stog phenomenon (SSP) varies and is often a loosely applied term to refer to pretty much any individual in the Dnieper and Don regions between the ‘Neolithic’ and Yamnaya periods.

In order to elucidate the SSP, some brief remarks on the preceding Mariupol phenomenon are warranted. Understanding the Mariupol horizon is fairly straightforward – its development was catalysed by an intrusion of groups from somewhere west of the Dnieper, ~ 5500BC. The ‘proto-Mariupol’ group were genomic and economic ‘hunter-gatherers’, lacking any discernible EEF admixture, and with Y-hg I-L702 uniparental ‘trace-dye’. The Mariupol phenomenon predominantly impacted the lower reaches of the Dnieper and Azov steppe (Lower Dnieper- Azov group, ‘LDA’), but extended toward the Don, Volga and even the Kuban steppe in an attenuated form. The elevated levels of “Ukr N’ in Golubaya Krinitsa and the Y-hg I2a-L702 individual at Berezhnovka attest to this movement. The Mariupol phenomenon is associated with the development of formal cemeteries, linking them with Late Neolithic mixed farmer/HG groups in the northeast Balkans. Individuals were buried in a ‘supine straight-legged’ inhumation, with grave goods such as boar-tusk pendants for select males and adorning shell beads for females. This might signal the emergence of gender-differentiation in burials and the rise of local leaders or ‘chiefs’.

Data sets treat the ‘Neolithic’ in Ukraine as a monolithic phenomenon, however it is important to note that Dereivka stands apart – it is 200km north of other “Ukraine_N” sites such as Volnienski, Igren and Vovnigi, beyond the ‘Dnipro bend’. Moreover, male individuals from Dereivka are overwhelmingly assigned to Y-hg R1b-V88 and the burial pose (N-S) at Dereivka deviates from the more common E-W orientation seen elsewhere. Quite a few of the published ‘Sredni Stog’ individuals are from Dereivka, and often earlier than 4500BC, and N. Kotova assigns them to the Dnieper-Donets culture. Moreover, the recently published middle Don individuals, such as those from Golubaya Krinitsa and Vasilyevsky Cordon -17, are also not Sredni Stog, but can be thought of as ‘partially Mariupolised hunter-gatherers’. In another example, the (undated) ‘Sredni Stog’ individual I27930 from Igren was assigned to Y-hg Q and he can be modelled as a 2-way mix of EHG & WHG. This individual is actually from the Mesolithic.

So what occurred during the Sredni Stog period? In contrast to the Mariupol phase, the population dynamics associated with SSP are complex: at least three external flows can be highlighted (i) the advance of Tripolje communities from the Carpathians to the Dnieper (ii) arrival of South-Caucasian/CHG agro-pastoralists in the north Caucasus, and (iii) arrival of ‘central Asian’ populations in Volga-Caspian region (represented by “TTK individual’); in addition to intra-steppe shifts and flows. Notwithstanding, the ‘ideological background’ of SSP is rooted in the Mariupol horizon. The stereotypical SSP burials features individuals buried on their back, but increasingly with legs up-flexed. And we see the beginnings of kurgan constructions, which vary from stone cairns to soil-thrown barrows. Most are buried in simple pits, however some have more complex ‘catacomb’ pits.

What happened in the Dniester-Dnieper-Don region during the SSP? We can begin by orientating ourselves with a PCA to observe two main clines developing. One cline develops between ‘Ukr_N and EEF and a second cline pulls toward Lower-Volga Caucasus groups. The first cline mostly comprises of ‘Farmers’ from Tipolje and ‘hunter-gatherers’ from Dereivka. The second cline consists of individuals from Dereivka and the lower Dnieper-Azov group pulling toward Lower Volga-Caucasus groups.

Admixture analysis with qpAdm reveals 3 groups within the 2 broad clines. The first group can be thought of as ‘core Sredni Stog’. These individuals are 2-way mixes of ‘Ukr_N’ and ‘Steppe Eneolithic’ (sometimes Progress works, sometimes Remontoye or Berezhnovka). They are both males and females. In our examples, the females are from Kopachiv Yar (4000 BC) and Dereivka (3500BC). The males come from Dereivka (4300BC), Moluykhiv Bugor (4000BC), Vynohrado (4000BC); they are all derived for Y-hg I2a-L703+. These results represent a blending of social networks between the LDA and various lower Volga-Caucasus groups, and the subsequent expansion by LDA further West. The terminus ante quem of 4300 BC matches the corrected dating of the Kuban steppe sites such as Progress & Vojnuchka.

Another subset comprises of individuals from Dereivka and Verteba cave who situated on an ‘Ukr-N’ < - - > EEF cline. Many of the earlier Dereivka individuals are almost 100% Ukr_N. Verteba cave Tripolje can be modelled as 80% EEF + 20% Ukr_N. One individual from Dereikva (I3719) falls outside the Dereivka <-> Tripolje clin, as he plots further ‘south’ with Balkan-LBK farmers. Consistently, he comes out as ~100% EEF with qpAdm. Dating to ~4700BC, he precedes the arrival of Tipolje groups to the region by hundreds of years. FtDNA have assigned him to I2-Z161- FTH81, which is distinctive to the LDA haplotypes and is phylogenetically linked to a Czech LBK individual.

A third group consists of individuals with more complex 3-way ancestries, consisting of EEF, Ukr-N and Steppe_En and/or Maikop. These come from late Dereivka and late Tripolje groups, in archaeological literature often termed as ‘Soldanesti’, ‘Zhivotilovksa-Volchansk’, Cernavoda (Kartal). Once again, the males from Soldanesti and Cernavoda derive from LDA-related Y-hg I2a-L703 in some shape or form.

Conclusions:

1) Firstly, we note that the Dereivka group was subject to early EEF influence, as soon as eastern LBK groups reached Ukraine after 5000BC. However, their main interaction occurred with the younger, Tripolje group, which expanded toward the Dnieper after ~ 4300 BC.

2) In the LDA group we observe patrilineal continuity. These clans created expansive social-networks. They initially mixed with groups from the lower Volga-Caucasus area. Some then moved west, and ‘took over’ the Tripolje region and acquired high levels of EEF.

3) As a third conclusion, we can reject the commonly held notion that Tripolje was ‘conquered by Yamnaya pastoralists’. Our analysis instead highlights that their core structure fragmented as they became intertwined with powerful networks to their west (Trpolje) and east (Sredni Stog). The ‘take-over’ was due to the expansion of LDA/ SS groups. Mixed groups emerged such as Cernavoda and Soldanesti, which retained Tripolje ancestry and some cultural traditions. By the time Yamnaya groups reached the Dniester forest steppe, Tripolje had been long gone.

See also...

‘Proto-Yamnaya’ Eneolithic individuals from Kuban steppe c. 3700 BC ? (guest post)

On Maykop ancestry in Yamnaya

What Maykop ancestry in Yamnaya? There is none, or at least not enough worth discussing, except in one highly unusual female outlier from a burial in what is now eastern Ukraine. But apparently this is still up for debate? Well it shouldn't be.

To anyone with even a passing interest in the Yamnaya culture, it should be rather obvious that it formed during the tail end of the Eneolithic on the Pontic-Caspian steppe, as basically a direct offshoot of the earlier Repin culture, but perhaps also with significant influences from the earlier still Khvalynsk and Sredny Stog cultures. So why should its population history be much different from this?

It isn't, and this is fairly easy to demonstrate now despite the still rather poor sampling of Eneolithic remains from the Pontic-Caspian steppe.

Below is a series of qpAdm analyses in which I modeled several Yamnaya groups, as well as the closely related Afanasievo and Poltavka populations, exclusively and successfully as two- and three-way mixtures of a few Eneolithic singletons from various parts of the Pontic-Caspian steppe (obviously, I'd love to use homogeneous population sets instead, but, as per my point above, that's not possible yet). The models are sorted by their statistical fits, best to worst. Also note the large number and wide range of right pops or outgroups. I wanted to make sure that I wasn't missing anything.

Yamnaya_Samara
Dereivka_I_I4110 0.324±0.035
Progress_Eneolithic_PG2004 0.676±0.035
chisq 6.797
tail prob 0.976979
Full output

Afanasievo
Progress_Eneolithic_PG2004 0.638±0.038
Sredny_Stog_II_I6561 0.362±0.038
chisq 10.855
tail prob 0.818366
Full output

Yamnaya_Ukraine
Progress_Eneolithic_PG2001 0.655±0.073
Sredny_Stog_II_I6561 0.345±0.073
chisq 12.676
tail prob 0.696277
Full output

Poltavka
Dereivka_I_I4110 0.324±0.038
Progress_Eneolithic_PG2004 0.676±0.038
chisq 12.895
tail prob 0.680437
Full output

Yamnaya_Caucasus
Khvalynsk_Eneolithic_I0122 0.086±0.054
Sredny_Stog_II_I6561 0.221±0.070
Vonyuchka_Eneolithic_VJ1001 0.693±0.101
chisq 13.113
tail prob 0.593562
Full output

So, you might ask, is there any way to add Maykop to these models? Nope, it's pointless, because it doesn't improve the stats (for instance, see here, here and here). In other words, the situation is this: I already have awesome models, and I can't readily fit Maykop into my framework, so why do it? But if anyone out there wants to try, then by all means, and feel free to share the results with us in the comments.

Of course, the fact that most of these Yamnaya and Yamnaya-related populations are best modeled with somewhat different Eneolithic steppe singletons doesn't mean that they have radically different origins. In fact, they're all very closely related and they're basically like one Bronze Age steppe family. They just harbor somewhat different ratios of the same ancient ancestral components.

For the sake of being thorough, as per scientific literature, I pooled all of the above Afanasievo, Poltavka and Yamnaya samples into a Steppe_EMBA set and analyzed it with several genetically and geographically matching pairs of the Eneolithic singletons. This was one of the best fitting models, which I think is interesting, because the region roughly between the burial sites of these pairs of Eneolithic individuals was the home of the Repin culture.

Steppe_EMBA
North_Pontic_Eneolithic_I4110-I656 0.313±0.027
Progress_Eneolithic_PG2001-PG2004 0.687±0.027
chisq 15.378
tail prob 0.497157
Full output

Again, adding Maykop to this model makes no sense (see here, here and here). Clearly, I'd have to come up with a very different framework to successfully model Steppe_EMBA with a Maykop population. However, it's unlikely that such a model would make much sense in the context of various other types of genetic analyses and archeological data.

See also...

Yamnaya: home-grown

Big deal of 2018: Yamnaya not related to Maykop

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

Yamnaya: home-grown

I have some interesting news. It looks like Khvalynsk_Eneolithic I0434 can be used as essentially a perfect proxy for the Eneolithic steppe trio from Wang et al. 2018 when modeling the ancestry of the Yamnaya people of what is now the Samara region of Russia. Consider the qpAdm mixture models below, sorted by taildiff.

One of the best fitting models that also fairly closely matches archeological data, which suggest that Yamnaya was an amalgamation of the Khvalynsk, Repin and Sredny Stog cultures, is in bold. The worst fitting, and basically failed, models are listed below the dotted line. Note that almost all of these models feature reference populations from West and Central Asia.

Khvalynsk_I0434 + Iberia_ChL 0.681534184 > full output

Khvalynsk_I0434 + Globular_Amphora 0.525961242 > full output

Khvalynsk_I0434 + Iberia_Central_CA 0.515960444 > full output

Khvalynsk_I0434 + Sredny_Stog_I6561 0.485311962 > full output

Khvalynsk_I0434 + Varna 0.430411416 > full output

Khvalynsk_I0434 + Blatterhole_MN 0.328782809 > full output

Khvalynsk_I0434 + Baden_LCA 0.234307235 > full output

Khvalynsk_I0434 + Protoboleraz_LCA 0.231310724 > full output

Khvalynsk_I0434 + ALPc_MN 0.200002422 > full output

Khvalynsk_I0434 + Trypillia 0.193900977 > full output

Khvalynsk_I0434 + Balaton_Lasinja_CA 0.187031564 > full output

Khvalynsk_I0434 + Tiszapolgar_ECA 0.153940224 > full output

Khvalynsk_I0434 + Tisza_LN 0.145465993 > full output

Khvalynsk_I0434 + Balkans_ChL 0.111720163 > full output

...

Khvalynsk_I0434 + Armenia_EBA 0.0108890099 > full output

Khvalynsk_I0434 + Armenia_ChL 0.00882375703 > full output

Khvalynsk_I0434 + Levant_BA_North 0.0078751978 > full output

Khvalynsk_I0434 + Minoan_Lasithi 0.0675240088 > full output

Khvalynsk_I0434 + Peloponnese_N 0.046998906 > full output

Khvalynsk_I0434 + Hajji_Firuz_ChL 0.00269860335 > full output

Khvalynsk_I0434 + Shahr_I_Sokhta_BA1 0.00261908387 > full output

Khvalynsk_I0434 + Sarazm_Eneolithic 0.00120345503 > full output

Khvalynsk_I0434 + Seh_Gabi_ChL 0.00111898703 > full output

Khvalynsk_I0434 + Geoksiur_Eneolithic 0.000178295163 > full output

Khvalynsk_I0434 + Tepe_Hissar_ChL 0.000163698274 > full output

Khvalynsk_I0434 + Bustan_BA 0.000151088148 > full output

Why is this potentially important? Because unless Khvalynsk_Eneolithic I0434 was a recent migrant from the North Caucasus piedmont steppe, which is where the remains of the Eneolithic steppe trio were excavated, then Yamnaya's ethnogenesis might not have anything at all to do with Asia or even the Caucasus region. At least not within any reasonable time frame anyway. Here's a map showing the geographic locations of all of the populations relevant to the highlighted mixture model above.

I won't be fussed if it turns out that the majority of the ancestry of the Yamnaya, Corded Ware and other closely related ancient peoples was sourced from the Eneolithic populations of the North Caucasus piedmont steppe. But I think it's useful to make the point that there are still very few ancient samples available from the steppes between the Black and Caspian seas, so we don't yet have much of a clue how the groups living throughout this region during the Eneolithic and earlier fit into the grand scheme of things.

Update 24/12/2018: I decided to repeat the analysis, but this time with Caucasus Hunter-Gatherers (CHG) as one of the outgroups (or right pops). The reason I initially didn't include CHG in the outgroups was because I didn't want to discriminate, perhaps unfairly, against West and Central Asians with high levels of CHG-related ancestry, and in favor of Europeans with no or minimal CHG-related input. But in my opinion, the new results clearly make more sense, with Sredny Stog and Varna at the top of the list.

Khvalynsk_I0434 + Sredny_Stog_I6561 0.410719649 > full output

Khvalynsk_I0434 + Varna 0.394089365 > full output

Khvalynsk_I0434 + Iberia_ChL 0.16554258 > full output

Khvalynsk_I0434 + Globular_Amphora 0.128348823 > full output

Khvalynsk_I0434 + Iberia_Central_CA 0.126100242 > full output

Khvalynsk_I0434 + Trypillia 0.135306664 > full output

Khvalynsk_I0434 + Baden_LCA 0.0853031796 > full output

Khvalynsk_I0434 + Protoboleraz_LCA 0.0766892008 > full output

Khvalynsk_I0434 + Tisza_LN 0.0661622403 > full output

Khvalynsk_I0434 + Tiszapolgar_ECA 0.0626469042 > full output

Khvalynsk_I0434 + Balaton_Lasinja_CA 0.0536293042 > full output

Khvalynsk_I0434 + ALPc_MN 0.0505788809 > full output

...

Khvalynsk_I0434 + Minoan_Lasithi 0.0439451605 > full output

Khvalynsk_I0434 + Balkans_ChL 0.0436885241 > full output

Khvalynsk_I0434 + Blatterhole_MN 0.0329758292 > full output

Khvalynsk_I0434 + Peloponnese_N 0.0181930605 > full output

Khvalynsk_I0434 + Armenia_EBA 0.014715999 > full output

Khvalynsk_I0434 + Armenia_ChL 0.0060437014 > full output

Khvalynsk_I0434 + Levant_BA_North 0.00514574731 > full output

Khvalynsk_I0434 + Shahr_I_Sokhta_BA1 0.00350059625 > full output

Khvalynsk_I0434 + Hajji_Firuz_ChL 0.00228771991 > full output

Khvalynsk_I0434 + Seh_Gabi_ChL 0.00117061206 > full output

Khvalynsk_I0434 + Sarazm_Eneolithic 0.001118931 > full output

Khvalynsk_I0434 + Bustan_BA 0.00021203609 > full output

Khvalynsk_I0434 + Tepe_Hissar_ChL 0.000200643323 > full output

Khvalynsk_I0434 + Geoksiur_Eneolithic 0.000175941977 > full output

Update 17/02/2019: I basically managed to confirm my analysis with samples from the Wang et al. Caucasus paper. See here.

See also...

Big deal of 2018: Yamnaya not related to Maykop

"The Homeland: In the footprints of the early Indo-Europeans" time map

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