Over the past week or so, since the publication of new Corded Ware samples in Narasimhan, Patterson et al. (2019) and after finding out that the R1a-M417 star-like phylogeny may have started ca. 3000 BC, I have been ruminating the relevance of contradictory data about the Ukraine_Eneolithic_o sample from Alexandria, its potential wrong radiocarbon date, and its implications for the Indo-European question.
How many other similar ‘controversial’ samples are there which we haven’t even considered? And what mechanisms are in place to control that the case of Hajji_Firuz_CA I2327 is not repeated?
Ukraine Eneolithic outlier I6561
It was not the first time that I (or many others) have alternatively questioned its subclade or its date, but the contradictory data seem to keep piling up. We can still explain all these discrepancies by assuming that the radiocarbon date is correct – seeing how it is a direct and newly reported lab analysis – because it is an isolated individual from a poorly sampled region, so he may actually be the first one to show features proper of later Corded Ware-related samples.
The individual seems to be especially relevant for the Indo-European and Uralic homeland question. The last one to mention this sample in a publication was Anthony (2019), who considered it in common with two other Eneolithic samples from Dereivka to show how Anatolian farmer-related ancestry first appeared in the recently opened CHG mating network of the Pontic-Caspian steppes and forest-steppes during the Middle Eneolithic, after the expansion of Khvalynsk:
The currently oldest sample with Anatolian Farmer ancestry in the steppes in an individual at Aleksandriya, a Sredni Stog cemetery on the Donets in eastern Ukraine. Sredni Stog has often been discussed as a possible Yamnaya ancestor in Ukraine (Anthony 2007: 239- 254). The single published grave is dated about 4000 BC (4045–3974 calBC/ 5215±20 BP/ PSUAMS-2832) and shows 20% Anatolian Farmer ancestry and 80% Khvalynsk-type steppe ancestry (CHG&EHG). His Y-chromosome haplogroup was R1a-Z93, similar to the later Sintashta culture and to South Asian Indo-Aryans, and he is the earliest known sample to show the genetic adaptation to lactase persistence (I3910-T). Another pre-Yamnaya grave with Anatolian Farmer ancestry was analyzed from the Dnieper valley at Dereivka, dated 3600-3400 BC (grave 73, 3634–3377 calBC/ 4725±25 BP/ UCIAMS-186349). She also had 20% Anatolian Farmer ancestry, but she showed less CHG than Aleksandriya and more Dereivka-1 ancestry, not surprising for a Dnieper valley sample, but also showing that the old fifth-millennium-type EHG/WHG Dnieper ancestry survived into the fourth millennium BC in the Dnieper valley (Mathieson et al. 2018).
The main problem is that this sample has more than one inconsistent, anachronistic data compared to its reported precise radiocarbon date ca. 4045–3974 calBCE (5215±20BP, PSUAMS-2832). I summarized them on Twitter:
First known R1a-M417 sample, with subclade R1a-Y26 (Y2-), with formation date and TMRCA ca. 2750 BC (CI 95% ca. 3750–1950 BC), and proper of much later Steppe_MLBA bottlenecks. The closest available sample would be the Poltavka outlier of hg. R1a-Z94 (ca. 2700 BC), from a mixed cemetery that could belong to a later (likely Abashevo) layer; the closest related subclade is probably found in sample I12450 of Butkara_IA (ca. 800 BC).
NOTE. The formation date of upper clade R1a-Z93 is estimated ca. 3000 BC, with a CI 95% ca. 3550–2550 BC, suggesting that the actual TMRCA range for the subclade has most likely a lower maximum formation date than estimated with the available samples under Y3.
Ancestry and PCA cluster like Steppe_MLBA (see PCA below), different from neighbouring Sredni Stog samples of the roughly coetaneous Dereivka site (ca. 3600-3400 BC), and from a later Yamnaya sample from Dereivka (ca. 2800 BC), even more shifted toward WHG-related ancestry.
Allele for lactase persistence (I3910-T), found only much later among Bell Beakers, and still later in Sintashta and Steppe_MLBA samples. This suggests a strong selection in northern Europe and South Asia stemming from steppe-related (and not forest-steppe-related) peoples, postdating the age of massive Indo-European migrations.
My impression is that the Hajji_Firuz Chalcolithic outlier, initially dated ca. 5900-5500 BC, had much less reason to be questioned than this sample, since Pre-Yamnaya ancestry was (and apparently is still) believed by members of the Reich Lab to have come from south of the Caucasus, and to have arrived around that time or earlier to the North Caspian steppe, i.e. before the 5th millennium BC.
The formation date of its initially reported haplogroup, R1b-Z2103, is ca. 4100 BC (CI 95% 4800-3500 BC), which seems also roughly compatible with that date and site – at least as compatible as R1a-Y3(xY2) is for ca. 4000 BC -, so it could have been interpreted as a migrant from the South Caspian region, potentially related to Proto-Anatolians, especially before the description of the Caucasus genetic barrier in Wang et al (2018). For some reason, though, the Hajji_Firuz sample was questioned, but this one didn’t even merited an interrogation mark.
All in all, my guess is that genomic data of I6561 would have been a priori more compatible with a later period, during the expansion of East Corded Ware groups: at least Middle Dnieper culture, potentially Multi-Cordoned Ware culture, but most likely a Srubnaya-related one, given the most likely SNP mutation and TMRCA date, and the haplogroup variability found in the few samples available from that culture.
I tried to start a thread on the possibility that the radiocarbon date was wrong, and IF it were, how likely it would be that formal stats could actually show this, or how could we automatically prevent ancestry magicfiascos.
In other words: if this guy were a Srubnaya-related individual actually dated e.g. ca. 1700 BC, and someone would try to ‘prove’ – based on the current open source tools alone – that he was the ancestor of expanding peoples of the 4th and 3rd millennium BC (i.e. Balkan outliers, Yamnaya, Corded Ware, you name it), could these results be formally challenged?
I was hoping for some original brainstorming where people would propose crazy, essentially impossible to understand statistical models, say plotting dozens of well-studied mutations of different geographically related ancient samples with their reported dates, to visually highlight samples that don’t exactly fit with such a feature-based time series analysis; I mean, the kind of theoretical models I wouldn’t even be able to follow after the first two tweets or so. I didn’t receive an answer like that, but still:
Is it possible, with the currently available tools in population genomics, to tell whether this sample is ancestral to or derived from other Steppe-related populations, before the date is tested again? And how certain would these tests be…?
The question in this case is more theoretical, though. IF this case were wrongly 14C-dated, would it be possible to detect this e.g. by assessing the number of mutations (like LP and the subclade) and the type of ancestry that shouldn't be there? More or less as w/ I2327
Yfull dates are likely underestimated. I generally just multiply by 1.25. So, the subclade for this sample doesn't seem out of place. My opinion is that Sintashta and Andronovo don't come from CWC due to dated splits, etc., but formed in Eastern Europe.
I have nothing to add to these answers, because I agree that all contradictory data are circumstancial.
The current absolute lack of this kind of validity checks for ancestry models is disappointing, though, and leaves the so-called outliers in a dangerous limbo between “potentially very interesting samples” and “potentially wrongly dated samples”. Radiocarbon date is thus – together with compatibility of population source in terms of archaeological cultures and their potential relationship – a necessary variable to take into account in any statistical design: an error in one of these variables means a catastrophic error in the whole model.
For example, in these qpAdm models, I assumed Srubnaya, Ukraine_Eneolithic_outlier, and Bulgaria_MLBA samples were roughly coetaneous and potentially related to the Srubnaya-Sabatinovka–Noua cultural horizon, hence stemming from a source close to:
Abashevo-like individuals (whose best proxy to date should be Poltavka_outlier I0432) potentially admixed with Poltavka-like herders; or
Potapovka-like individuals potentially admixed with Catacomb-like peoples (whose best proxy until recently were probably Yamnaya_Kalmykia*).
Apart from the lack of more models for comparison (I’m not going to dedicate more time to this), the results can’t be interpreted without a proper sampling and context, either, because (1) Poltavka_o may actually be from a much later group closely related to Srubnaya; (2) Bulgaria_MLBA is only one sample; and (3) there are only two samples from Potapovka; so the models here presented are basically useless, as many similar models that have been tested looking just for a formal “best fit”.
So feel free to chime in and contribute with ideas as to how to detect in the future whether a sample is ancestral to or derived from others. I will post here informative answers from Twitter, too, if there are any. I don’t think a discussion about the potentially wrong date in this specific sample is very useful, because this seems impossible to prove or disprove at this point. Just what tools or data would you use to at least try and assess whether samples are compatible with its reported date or not – preferably in some kind of automated sieve that takes dozens or hundreds of samples into account.
On the bright side, there is so much more than formal stats to arrive to relevant inferences about prehistoric populations, their movements and languages. That’s why I6561 didn’t matter for the conclusion by Anthony (2019) that it was the R1b-rich Eneolithic Don-Volga-Caucasus region the most likely Indo-Anatolian and Late Proto-Indo-European homeland, due to the creation of a wide Eneolithic mating network with extended exogamy practices, where Y-chromosome bottlenecks seem to be one of the main genomic data to take into account from the Neolithic to the Middle Bronze Age.
And that is the same reason why it doesn’t matter that much for the Proto-Indo-European or Uralic question for me, either.
The latest papers from Ning et al. Cell (2019) and Anthony JIES (2019) have offered some interesting new data, supporting once more what could be inferred since 2015, and what was evident in population genomics since 2017: that Proto-Indo-Europeans expanded under R1b bottlenecks, and that the so-called “Steppe ancestry” referred to two different components, one – Yamnaya or Steppe_EMBA ancestry – expanding with Proto-Indo-Europeans, and the other one – Corded Ware or Steppe_MLBA ancestry – expanding with Uralic speakers.
NOTE. As in the Corded Ware ancestry maps, the selected reports in this case are centered on the prototypical Yamnaya ancestry vs. other simplified components, so everything else refers to simplistic ancestral components widespread across populations that do not necessarily share any recent connection, much less a language. In fact, most of the time they clearly didn’t. They can be interpreted as “EHG that is not part of the Yamnaya component”, or “CHG that is not part of the Yamnaya component”. They can’t be read as “expanding EHG people/language” or “expanding CHG people/language”, at least no more than maps of “Steppe ancestry” can be read as “expanding Steppe people/language”. Also, remember that I have left the default behaviour for color classification, so that the highest value (i.e. 1, or white colour) could mean anything from 10% to 100% depending on the specific ancestry and period; that’s what the legend is for… But, fere libenter homines id quod volunt credunt.
Anthony (2019) agrees with the most likely explanation of the CHG component found in Yamnaya, as derived from steppe hunter-fishers close to the lower Volga basin. The ultimate origin of this specific CHG-like component that eventually formed part of the Pre-Yamnaya ancestry is not clear, though:
The hunter-fisher camps that first appeared on the lower Volga around 6200 BC could represent the migration northward of un-admixed CHG hunter-fishers from the steppe parts of the southeastern Caucasus, a speculation that awaits confirmation from aDNA.
The typical EHG component that formed part eventually of Pre-Yamnaya ancestry came from the Middle Volga Basin, most likely close to the Samara region, as shown by the sampled Samara hunter-gatherer (ca. 5600-5500 BC):
After 5000 BC domesticated animals appeared in these same sites in the lower Volga, and in new ones, and in grave sacrifices at Khvalynsk and Ekaterinovka. CHG genes and domesticated animals flowed north up the Volga, and EHG genes flowed south into the North Caucasus steppes, and the two components became admixed.
To the west, in the Dnieper-Dniester area, WHG became the dominant ancestry after the Mesolithic, at the expense of EHG, revealing a likely mating network reaching to the north into the Baltic:
Like the Mesolithic and Neolithic populations here, the Eneolithic populations of Dnieper-Donets II type seem to have limited their mating network to the rich, strategic region they occupied, centered on the Rapids. The absence of CHG shows that they did not mate frequently if at all with the people of the Volga steppes (…)
After approximately 4500 BC the Khvalynsk archaeological culture united the lower and middle Volga archaeological sites into one variable archaeological culture that kept domesticated sheep, goats, and cattle (and possibly horses). In my estimation, Khvalynsk might represent the oldest phase of PIE.
(…) this middle Volga mating network extended down to the North Caucasian steppes, where at cemeteries such as Progress-2 and Vonyuchka, dated 4300 BC, the same Khvalynsk-type ancestry appeared, an admixture of CHG and EHG with no Anatolian Farmer ancestry, with steppe-derived Y-chromosome haplogroup R1b. These three individuals in the North Caucasus steppes had higher proportions of CHG, overlapping Yamnaya. Without any doubt, a CHG population that was not admixed with Anatolian Farmers mated with EHG populations in the Volga steppes and in the North Caucasus steppes before 4500 BC. We can refer to this admixture as pre-Yamnaya, because it makes the best currently known genetic ancestor for EHG/CHG R1b Yamnaya genomes.
Three individuals from the sites of Progress 2 and Vonyuchka 1 in the North Caucasus piedmont steppe (‘Eneolithic steppe’), which harbour EHG and CHG related ancestry, are genetically very similar to Eneolithic individuals from Khvalynsk II and the Samara region. This extends the cline of dilution of EHG ancestry via CHG-related ancestry to sites immediately north of the Caucasus foothills
NOTE. Unpublished samples from Ekaterinovka have been previously reported as within the R1b-L23 tree. Interestingly, although the Varna outlier is a female, the Balkan outlier from Smyadovo shows two positive SNP calls for hg. R1b-M269. However, its poor coverage makes its most conservative haplogroup prediction R-M343.
The formation of this Pre-Yamnaya ancestry sets this Volga-Caucasus Khvalynsk community apart from the rest of the EHG-like population of eastern Europe.
Anthony (2019) seems to rely on ADMIXTURE graphics when he writes that the late Sredni Stog sample from Alexandria shows “80% Khvalynsk-type steppe ancestry (CHG&EHG)”. While this seems the most logical conclusion of what might have happened after the Suvorovo-Novodanilovka expansion through the North Pontic steppes (see my post on “Steppe ancestry” step by step), formal stats have not confirmed that.
In fact, analyses published in Wang et al. (2019) rejected that Corded Ware groups are derived from this Pre-Yamnaya ancestry, a reality that had been already hinted in Narasimhan et al. (2018), when Steppe_EMBA showed a poor fit for expanding Srubna-Andronovo populations. Hence the need to consider the whole CHG component of the North Pontic area separately:
NOTE. Fits for WHG + CHG + EHG in Neolithic and Eneolithic populations are taken in part from Mathieson et al. (2019) supplementary materials (download Excel here). Unfortunately, while data on the Ukraine_Eneolithic outlier from Alexandria abounds, I don’t have specific data on the so-called ‘outlier’ from Dereivka compared to the other two analyzed together, so these maps of CHG and EHG expansion are possibly showing a lesser distribution to the west than the real one ca. 4000-3500 BC.
Anatolia Neolithic ancestry clearly spread to the east into the north Pontic area through a Middle Eneolithic mating network, most likely opened after the Khvalynsk expansion:
Regarding Y-chromosome haplogroups, Anthony (2019) insists on the evident association of Khvalynsk, Yamnaya, and the spread of Pre-Yamnaya and Yamnaya ancestry with the expansion of elite R1b-L754 (and some I2a2) individuals:
3. Early Bronze Age
Data from Wang et al. (2019) show that Corded Ware-derived populations do not have good fits for Eneolithic_Steppe-like ancestry, no matter the model. In other words: Corded Ware populations show not only a higher contribution of Anatolia Neolithic ancestry (ca. 20-30% compared to the ca. 2-10% of Yamnaya); they show a different EHG + CHG combination compared to the Pre-Yamnaya one.
Yamnaya Kalmykia and Afanasievo show the closest fits to the Eneolithic population of the North Caucasian steppes, rejecting thus sizeable contributions from Anatolia Neolithic and/or WHG, as shown by the SD values. Both probably show then a Pre-Yamnaya ancestry closest to the late Repin population.
EBA maps include data from Wang et al. (2018) supplementary materials, specifically unpublished Yamnaya samples from Hungary that appeared in analysis of the preprint, but which were taken out of the definitive paper. Their location among Yamnaya settlers from Hungary is speculative, although most uncovered kurgans in Hungary are concentrated in the Tisza-Danube interfluve.
The Y-chromosome bottleneck of elite males from Proto-Indo-European clans under R1b-L754 and some I2a2 subclades, already visible in the Khvalynsk sampling, became even more noticeable in the subsequent expansion of late Repin/early Yamnaya elites under R1b-L23 and I2a-L699:
Maps of CHG, EHG, Anatolia Neolithic, and probably WHG show the expansion of these components among Corded Ware-related groups in North Eurasia, apart from other cultures close to the Caucasus:
The following maps show the most likely distribution of Yamnaya ancestry during the Bell Beaker-, Balkan-, and Sintashta-Potapovka-related expansions.
4.1. Bell Beakers
The amount of Yamnaya ancestry is probably overestimated among populations where Bell Beakers replaced Corded Ware. A map of Yamnaya ancestry among Bell Beakers gets trickier for the following reasons:
Expanding Repin peoples of Pre-Yamnaya ancestry must have had admixture through exogamy with late Sredni Stog/Proto-Corded Ware peoples during their expansion into the North Pontic area, and Sredni Stog in turn had probably some Pre-Yamnaya admixture, too (although they don’t appear in the simplistic formal stats above). This is supported by the increase of Anatolia farmer ancestry in more western Yamna samples.
Later, Yamnaya admixed through exogamy with Corded Ware-like populations in Central Europe during their expansion. Even samples from the Middle to Upper Danube and around the Lower Rhine will probably show increasing contributions of Steppe_MLBA, at the same time as they show an increasing proportion of EEF-related ancestry.
To complicate things further, the late Corded Ware Espersted family (from ca. 2500 BC or later) shows, in turn, what seems like a recent admixture with Yamnaya vanguard groups, with the sample of highest Yamnaya ancestry being the paternal uncle of other individuals (all of hg. R1a-M417), suggesting that there might have been many similar Central European mating networks from the mid-3rd millennium BC on, of (mainly) Yamnaya-like R1b elites displaying a small proportion of CW-like ancestry admixing through exogamy with Corded Ware-like peoples who already had some Yamnaya ancestry.
NOTE. Terms like “exogamy”, “male-driven migration”, and “sex bias”, are not only based on the Y-chromosome bottlenecks visible in the different cultural expansions since the Palaeolithic. Despite the scarce sampling available in 2017 for analysis of “Steppe ancestry”-related populations, it appeared to show already a male sex bias in Goldberg et al. (2017), and it has been confirmed for Neolithic and Copper Age population movements in Mathieson et al. (2018) – see Supplementary Table 5. The analysis of male-biased expansion of “Steppe ancestry” in CWC Esperstedt and Bell Beaker Germany is, for the reasons stated above, not very useful to distinguish their mutual influence, though.
Based on data from Olalde et al. (2019), Bell Beakers from Germany are the closest sampled ones to expanding East Bell Beakers, and those close to the Rhine – i.e. French, Dutch, and British Beakers in particular – show a clear excess “Steppe ancestry” due to their exogamy with local Corded Ware groups:
Only one 2-way model fits the ancestry in Iberia_CA_Stp with P-value>0.05: Germany_Beaker + Iberia_CA. Finding a Bell Beaker-related group as a plausible source for the introduction of steppe ancestry into Iberia is consistent with the fact that some of the individuals in the Iberia_CA_Stp group were excavated in Bell Beaker associated contexts. Models with Iberia_CA and other Bell Beaker groups such as France_Beaker (P-value=7.31E-06), Netherlands_Beaker (P-value=1.03E-03) and England_Beaker (P-value=4.86E-02) failed, probably because they have slightly higher proportions of steppe ancestry than the true source population.
The exogamy with Corded Ware-like groups in the Lower Rhine Basin seems at this point undeniable, as is the origin of Bell Beakers around the Middle-Upper Danube Basin from Yamnaya Hungary.
To avoid this excess “Steppe ancestry” showing up in the maps, since Bell Beakers from Germany pack the most Yamnaya ancestry among East Bell Beakers outside Hungary (ca. 51.1% “Steppe ancestry”), I equated this maximum with BK_Scotland_Ach (which shows ca. 61.1% “Steppe ancestry”, highest among western Beakers), and applied a simple rule of three for “Steppe ancestry” in Dutch and British Beakers.
NOTE. Formal stats for “Steppe ancestry” in Bell Beaker groups are available in Olalde et al. (2018) supplementary materials (PDF). I didn’t apply this adjustment to Bk_FR groups because of the R1b Bell Beaker sample from the Champagne/Alsace region reported by Samantha Brunel that will pack more Yamnaya ancestry than any other sampled Beaker to date, hence probably driving the Yamnaya ancestry up in French samples.
The most likely outcome in the following years, when Yamnaya and Corded Ware ancestry are investigated separately, is that Yamnaya ancestry will be much lower the farther away from the Middle and Lower Danube region, similar to the case in Iberia, so the map above probably overestimates this component in most Beakers to the north of the Danube. Even the late Hungarian Beaker samples, who pack the highest Yamnaya ancestry (up to 75%) among Beakers, represent likely a back-migration of Moravian Beakers, and will probably show a contribution of Corded Ware ancestry due to the exogamy with local Moravian groups.
Despite this decreasing admixture as Bell Beakers spread westward, the explosive expansion of Yamnaya R1b male lineages (in words of David Reich) and the radical replacement of local ones – whether derived from Corded Ware or Neolithic groups – shows the true extent of the North-West Indo-European expansion in Europe:
There is scarce data on Palaeo-Balkan movements yet, although it is known that:
Yamnaya ancestry appears among Mycenaeans, with the Yamnaya Bulgaria sample being its best current ancestral fit;
Interestingly, Potapovka is the only Corded Ware derived culture that shows good fits for Yamnaya ancestry, despite having replaced Poltavka in the region under the same Corded Ware-like (Abashevo) influence as Sintashta.
Srubnaya ancestry shows a best fit with non-Pre-Yamnaya ancestry, i.e. with different CHG + EHG components – possibly because the more western Potapovka (ancestral to Proto-Srubnaya Pokrovka) also showed good fits for it. Srubnaya shows poor fits for Pre-Yamnaya ancestry probably because Corded Ware-like (Abashevo) genetic influence increased during its formation.
On the other hand, more eastern Corded Ware-derived groups like Sintashta and its more direct offshoot Andronovo show poor fits with this model, too, but their fits are still better than those including Pre-Yamnaya ancestry.
The bottleneck of Proto-Indo-Iranians under R1a-Z93 was not yet complete by the time when the Sintashta-Potapovka-Filatovka community expanded with the Srubna-Andronovo horizon:
At the end of the Afanasevo culture, at least three samples show hg. Q1b (ca. 2900-2500 BC), which seemed to point to a resurgence of local lineages, despite continuity of the prototypical Pre-Yamnaya ancestry. On the other hand, Anthony (2019) makes this cryptic statement:
Yamnaya men were almost exclusively R1b, and pre-Yamnaya Eneolithic Volga-Caspian-Caucasus steppe men were principally R1b, with a significant Q1a minority.
Since the only available samples from the Khvalynsk community are R1b (x3), Q1a(x1), and R1a(x1), it seems strange that Anthony would talk about a “significant minority”, unless Q1a (potentially Q1b in the newer nomenclature) will pop up in some more individuals of those ca. 30 new to be published. Because he also mentions I2a2 as appearing in one elite burial, it seems Q1a (like R1a-M459) will not appear under elite kurgans, although it is still possible that hg. Q1a was involved in the expansion of Afanasevo to the east.
Okunevo, which replaced Afanasevo in the Altai region, shows a majority of hg. Q1b, but also some R1b-M269 samples proper of Afanasevo, suggesting partial genetic continuity.
NOTE. Other sampled Siberian populations clearly show a variety of Q subclades that likely expanded during the Palaeolithic, such as Baikal EBA samples from Ust’Ida and Shamanka with a majority of Q1b, and hg. Q reported from Elunino, Sagsai, Khövsgöl, and also among peoples of the Srubna-Andronovo horizon (the Krasnoyarsk MLBA outlier), and in Karasuk.
(…) in contrast to the lack of identifiable admixture from Yamnaya and Afanasievo in the CentralSteppe_EMBA, there is an admixture signal of 10 to 20% Yamnaya and Afanasievo in the Okunevo_EMBA samples, consistent with evidence of western steppe influence. This signal is not seen on the X chromosome (qpAdm P value for admixture on X 0.33 compared to 0.02 for autosomes), suggesting a male-derived admixture, also consistent with the fact that 1 of 10 Okunevo_EMBA males carries a R1b1a2a2 Y chromosome related to those found in western pastoralists. In contrast, there is no evidence of western steppe admixture among the more eastern Baikal region region Bronze Age (~2200 to 1800 BCE) samples.
Haplogroup diversity seems to be common in Iron Age populations all over Eurasia, most likely due to the spread of different types of sociopolitical structures where alliances played a more relevant role in the expansion of peoples. A well-known example of this is the spread of Akozino warrior-traders in the whole Baltic region under a partial N1a-VL29-bottleneck associated with the emerging chiefdom-based systems under the influence of expanding steppe nomads.
Surprisingly, then, Proto-Tocharians from Shirenzigou pack up to 74% Yamnaya ancestry, in spite of the 2,000 years that separate them from the demise of the Afanasevo culture. They show more Yamnaya ancestry than any other population by that time, being thus a sort of Late PIE fossils not only in their archaic dialect, but also in their genetic profile:
The recent intrusion of Corded Ware-like ancestry, as well as the variable admixture with Siberian and East Asian populations, both point to the known intense Old Iranian and Old/Middle Chinese contacts. The scarce Proto-Samoyedic and Proto-Turkic loans in Tocharian suggest a rather loose, probably more distant connection with East Uralic and Altaic peoples from the forest-steppe and steppe areas to the north (read more about external influences on Tocharian).
Interestingly, both R1b samples, MO12 and M15-2 – likely of Asian R1b-PH155 branch – show a best fit for Andronovo/Srubna + Hezhen/Ulchi ancestry, suggesting a likely connection with Iranians to the east of Xinjiang, who later expanded as the Wusun and Kangju. How they might have been related to Huns and Xiongnu individuals, who also show this haplogroup, is yet unknown, although Huns also show hg. R1a-Z93 (probably most R1a-Z2124) and Steppe_MLBA ancestry, earlier associated with expanding Iranian peoples of the Srubna-Andronovo horizon.
All in all, it seems that prehistoric movements explained through the lens of genetic research fit perfectly well the linguistic reconstruction of Proto-Indo-European and Proto-Uralic.
We know that the Caucasus Mountains formed a persistent prehistoric barrier to cultural and population movements. Nevertheless, an even more persistent frontier to population movements in Europe, especially since the Neolithic, is the Pontic-Caspian steppe – forest-steppe ecotone.
Like the Caucasus, this barrier could certainly be crossed, and peoples and cultures could permeate in both directions, but there have been no massive migrations through it. The main connection between both regions (steppe vs. forest-steppe/forest zone) was probably through its eastern part, through the Samara region in the Middle Volga.
The chances of population expansions crossing this natural barrier anywhere else seem quite limited, with a much less porous crossing region in the west, through the Dnieper-Dniester corridor.
A Persistent ecological and cultural frontier
It is very difficult to think about any culture that transgressed this persistent ecological and cultural frontier: many prehistoric and historical steppe pastoralists did appear eventually in the neighbouring forest-steppe areas during their expansions (e.g. Yamna, Scythians, or Turks), as did forest groups who permeated to the south (e.g. Comb Ware, GAC, or Abashevo), but their respective hold in foreign biomes was mostly temporary, because their cultures had to adapt to the new ecological environment. Most if not all groups originally from a different ecological niche eventually disappeared, subjected to renewed demographic pressure from neighbouring steppe or forest populations…
Before the emergence of pastoralism, the cultural contacts of the Pontic region (i.e. forest-steppes) with the Baltic were intense. In fact, the connection of the north Pontic area with the Baltic through the Dnieper-Dniester corridor and the Podolian-Volhynian region is essential to understand the spread of peoples of post-Maglemosian and post-Swiderian cultures (to the south), hunter-gatherer pottery (to the north), TRB (to the south), Late Trypillian groups (north), GAC (south), or Comb Ware (south) (see here for Eneolithic movements), and finally steppe ancestry and R1a-Z645 with Corded Ware (north). After the complex interaction of TRB, Trypillia, GAC, and CWC during the expansion of late Repin, this traditional long-range connection is lost and only emerges sporadically, such as with the expansion of East Germanic tribes.
A barrier to steppe migrations into northern Europe
One may think that this barrier was more permeable, then, in the past. However, the frontier is between steppe and forest-steppe ecological niches, and this barrier evolved during prehistory due to climate changes. The problem is, before the drought that began ca. 4000 BC and increased until the Yamna expansion, the steppe territory in the north Pontic region was much smaller, merely a strip of coastal land, compared to its greater size ca. 3300 BC and later.
This – apart from the cultural and technological changes associated with nomadic pastoralism – justifies the traditional connection of the north Pontic forest-steppes to the north, broken precisely after the expansion of Khvalynsk, as the north Pontic area became gradually a steppe region. The strips of north Pontic and Azov steppes and Crimea seem to have had stronger connections to the Northern Caucasus and Northern Caspian steppes than with the neighbouring forest-steppe areas during the Upper Palaeolithic, Mesolithic, and Neolithic.
NOTE. We still don’t know the genetic nature of Mikhailovka or Ezero, steppe-related groups possibly derived from Novodanilovka and Suvorovo close to the Black Sea (which possibly include groups from the Pannonian plains), and how they compare to neighbouring typically forest-steppe cultures of the so-called late Sredni Stog groups, like Dereivka or partly Kvityana.
Despite the Pontic-Caspian steppes and forest-steppes neighbouring each other for ca. 2,000 km, peoples from forested and steppe areas had an obvious advantage in their own regions, most likely due to the specialization of their subsistence economy. While this is visible already in Palaeolithic and Mesolithic hunter-gatherers, the arrival of the Neolithic package in the Pontic-Caspian region incremented the difference between groups, by spreading specialized animal domestication. The appearance of nomadic pastoralism adapted to the steppe, eventually including the use of horses and carts, made the cultural barrier based on the economic know-how even stronger.
Even though groups could still adapt and permeate a different territory (from steppe to forest-steppe/forest and vice-versa), this required an important cultural change, to the extent that it is eventually complicated to distinguish these groups from neighbouring ones (like north-west Pontic Mesolithic or Neolithic groups and their interaction with the steppes, Trypillia-Usatovo, Scythians-Thracians, etc.). In fact, this steppe – forest-steppe barrier is also seen to the east of the Urals, with the distinct expansion of Andronovo and Seima-Turbino/Andronovo-like horizons, which seem to represent completely different ethnolinguistic groups.
As a result of this cultural and genetic barrier, like that formed by the Northern Caucasus:
1) No steppe pastoralist culture (which after the emergence of Khvalynsk means almost invariably horse-riding, chariot-using nomadic herders who could easily pasture their cows in the huge grasslands without direct access to water) has ever been successful in spreading to the north or north-west into northern Europe, until the Mongols. No forest culture has ever been successful in expanding to the steppes, either (except for the infiltration of Abashevo into Sintashta-Potapovka).
2) Corded Ware was not an exception: like hunter-gatherer pottery before it (and like previous population movements of TRB, late Trypillia, GAC, Comb Ware or Lublin-Volhynia settlers) their movements between the north Pontic area and central Europe happened through forest-steppe ecological niches due to their adaptation to them. There is no reason to support a direct connection of CWC with true steppe cultures.
3) The so-called “Steppe ancestry” permeated the steppe – forest-steppe ecotone for hundreds of years during the 5th and early 4th millennium BC, due to the complex interaction of different groups, and probably to the aridization trend that expanded steppe (and probably forest-steppe) to the north. Language, culture, and paternal lineages did not cross that frontier, though.
EDIT (4 FEB 2019): Wang et al. is out in Nature Communications. They deleted the Yamna Hungary samples and related analyses, but it’s interesting to see where exactly they think the trajectory of admixture of Yamna with European MN cultures fits best. This path could also be inferred long ago from the steppe connections shown by the Yamna Hungary -> Bell Beaker evolution and by early Balkan samples:
Because, if YFull‘s (and Iain McDonald‘s) estimation of the split of R1b-L23 in L51 and Z2103 (ca. 4100 BC, TMRCA ca. 3700 BC) was wrong, by as much as the R1a-Z645 estimates proved wrong, and both subclades were older than expected, then maybe R1b-L51 was not part of the Yamna expansion, but rather part of an earlier expansion with Suvorovo-Novodanilovka into central Europe.
That is, R1b-L51 and R1b-Z2103 would have expanded wih Khvalynsk-Novodanilovka migrants, and they would have either disappeared among local populations, or settled and expanded with successful lineages in certain regions. I think this may give rise to two potential models.
A hidden group in the European east-central steppes?
Here is what Heyd (2011), for example, has to say about the effect of the Khvalynsk-Novodanilovka expansion in the 4th millennium BC, with the first Kurgan wave that shuttered the social, economic, and cultural foundations of south-eastern Europe (before the expansion of west Yamna migrants in the region):
As the Boleraz and Baden tumuli cases in Serbia and Hungary demonstrate, there are earlier, 4th millennium cal. B.C. round tumuli in the Carpathian basin. There are also earlier north-Pontic steppe populations who infiltrated similar environments west of the Black Sea prior to the rise of the Yamnaya culture. This situation can be traced back to the 2nd half of the 5th millennium cal. B.C. to a group of distinct burials, zoomorphic maceheads, long flint blades, triangular flint points, etc., summarized under the term Suvurovo-Novodanilovka (Govedarica 2004; Rassamakin 2004; Anthony 2007; Heyd forthcoming 2011). They also erected round personalized tumuli, though smaller in size and height, above inhumations of single individuals. Suvorovo and Casimcea are the key examples in the lower Danube region of Romania. In northeast Bulgaria, the primary grave of Polska Kosovo (ochre-stained supine extended body position: information communicated by S. Alexandrov) can also be seen as such, as should the Targovishte-“Gonova mogila” primary grave 1 in the Thracian plain with a burial arranged in a supine position with flexed legs, southeast-northwest orientated, and strewed with ochre (Kanchev 1991 , p. 56- 57; Ivanova Gaydarska 2007). In addition to the many copper and shell beads, the 17.4cm long obsidian blade is exceptional, which links this grave to the Csongrád-“Kettoshalom” grave in the south Hungarian plain (Ecsedy 1979). It also yielded an obsidian blade ( 13.2cm long) and copper, shell and limestone beads.
However, no traces of a tumulus have been recorded above the Kettoshalom tomb. Conventionally, it is dated to the Bodrogkeresztur-period in east Hungary, shortly after 4000 cal. B.C., which would correspond very well with the suggested Cernavodă I (or its less known cultural equivalent in the Thracian plain) attribution for the “Gonova mogila” grave, a cultural background to which the Csongrád grave should have also belonged. Bodrogkeresztur and Cernavodă I periods are not the only examples of 4th millennium cal. B.C. tumuli and burials displaying this steppe connection. Indeed we can find this early steppe impact throughout the 4th millennium cal. B.C. These include adscriptions to the Horodiștea II (Corlateni-Dealul Stadole, grave I: Burtanescu l 998, p. 37; Holbocai, grave 34: Coma 1998, p. 16); to Gordinești-Cernavodă 11 (Liești-Movila Arbănașu, grave 22: Brudiu 2000); to Gorodsk-Usatovo (Corlăteni Dealul Cetăţii, grave I: Comșa 1998, p. 17- 18, in Romania; Durankulak, grave 982: Vajsov 2002, in Bulgaria); and to Cernavodă III(Golyama Detelina, tum. 4: Leshtakov, Borisov 1995), and early (end of 4th millennium cal. B.C.) Ezero in Ovchartsi, primary grave (Kalchev 1994, p. 134-138) and Golyama Detelina, tum. 2 (Kanchev 1991) in Bulgaria. Also the Boleráz and Baden tumuli of Banjevac-Tolisavac and Mokrin in the south Carpathian basin account for this, since one should perhaps take into account primary grave 12 of the Sárrédtudavari-Orhalom tumulus in the Hungarian Alfold: a left-sided crouched juvenile ( 15- 17 y) individual in an oval, NW-SE orientated grave pit 14C dated to 3350-3100 cal. B.C. at 2 sigma (Dani, Ncpper 2006). Neither the burial custom (no ochre strewing or depositing a lump of ochre has been recorded), nor date account for its ascription to the Yamnaya!
All of these tumuli and burials demonstrate, though, that there is already a constant but perhaps low-level 4th millennium cal. B.C. steppe interaction, linking the regions of the north of the Black Sea with those of the west, and reaching deep into the Carpathian basin. This has to be acknowledged. even if these populations remain small, bounded to their steppe habitat with an economy adapted to this special environment, and are not always visible in the record. Indirect hints may help in seeing them, such as the frequent occurrence of horse bones, regarded as deriving from domesticated horses, in Hungarian Baden settlements (Bokonyi 1978; Benecke 1998), and in those of the south German Cham Culture (Matuschik 1999, p. 80-82) and the east German Bernburg Culture (Becker 1999; Benecke 1999). These occur, however, always in low numbers, perhaps not enough to maintain and regenerate a herd. Does this point us towards otherwise archaeologically hidden horsebreeders in the Carpathian basin, before the Yamnaya? In any case, I hope to make one case clear: these are by no means Yamnaya burials in the strict definition! Attribution to the Yamnaya in its strict definition applies.
Also, about the expansion of Yamna settlers along the steppes:
However, it should have been made clear by the distribution map of the Western Yamnaya that they were confining themselves solely to their own, well-known, steppe habitat and therefore not occupying, or pushing away and expelling, the locally settled farming societies. Also, living solely in the steppes requires another lifestyle, and quite different economic and social bases, most likely very different to the established farming societies. Although surely regarded as incoming strangers, they may therefore not have been seen as direct competitors. This argument can be further enforced when remembering that the lowlands and the steppes in the southeast of Europe had already been populated throughout the 4th millennium cal. B.C., as demonstrated above, by societies with a similar north-Pontic steppe origin and tradition, albeit in lower numbers. It is only for these groups that the Yamnaya may have become a threat, but their common origin and perhaps a similar economic/ social background with comparable lifestyles would surely have assisted to allow rapid assimilation. More important, though, is that farming societies in this region may therefore have been accustomed to dealing and interacting with different people and ethnic strangers for a long time. (…)
When assessing farming and steppe societies’ interaction from a general point of view, attitudes can diverge in three main directions:
the violent one; with raids, fights, struggles, warfare, suppression and finally the superiority and exploitation of the one over the other;
the peaceful one; with a continuous exchange of gifts, goods, work, information and genes in a balanced reciprocal system, leading eventually to the merging of the two societies and creation of a new identity;
the neutral one; with the two societies ignoring each other for a long time.
What we see from trying to understand the record of the Yamnaya, based on their tumuli and burials, and the local and neighbouring contemporary societies, based on their settlements, hoards, and graves, is likely a mixture of all three scenarios, with the balance perhaps more towards exchange in a highly dynamic system with alterations over time. However, violence and raids cannot be ruled out; they would be difficult to see in the archaeological record; or only indirectly, such as the building of hill forts, particularly the defence-like chain of Vucedol hillforts along the south shore of the Danube on the Serbian/Croatian border zone (Tasic 1995a), and the retreat of people into them (Falkenstein 1998, p. 261-262), with other interpretations also possible. And finally, we are dealing here with very different local and neighbouring societies, as well as with more distant contemporary ones, looking, in reality, rather like a chequer board of societies and archaeological cultures (see Parzinger 1993 for the overview). These display different regional backgrounds and traditions leading to different social and settlement organizations, different economic bases and material cultures in the wide areas between Prut and Maritza rivers, and Black Sea and Tisza river. They surely found their individual way of responding to the incoming and settling Yamnaya people.
The best data we have about this potential non-Yamna origin of R1b-L51 – and thus in favour of its admixture in the Carpathian basin – lies in:
The majority of R1a-Z2103 subclades found to date among Yamna samples.
The limited presence of (ancient and modern) R1b-L51 in eastern Europe and India, whose isolated finds are commonly (and simplistically) attributed to ‘late migrations’.
The presence of R1b-L51 (xZ2103) in cultures related to the ‘Yamna package’, but supposedly not to Yamna settlers. So for example I7043, of haplogroup R1b-L151(xU106,xP312), ca. 2500-2200 BC from Szigetszentmiklós-Üdülősor, probably from the Bell Beaker (Csepel group), but maybe from the early Nagýrev culture.
The expansion of its subclades apparently only from a single region, around the Carpathian basin, in contrast to R1b-Z2103.
The already ‘diluted’ steppe admixture found in the earliest samples with respect to Yamna, which points to the appearance after the Yamna admixture with the local population.
Ukrainian archaeologists (in contrast to their Russian colleagues) point to the relevance of North Pontic cultures like Kvitjana and Lower Mikhailovka in the development of Early Yamna in the west, and some eastern European researchers also believe in this similarity.
If R1b-Z2103 and R1b-L51 had expanded with Suvorovo-Novodanilovka migrants to the west, and had admixed later as Hungary_LCA-LBA-like peoples with Yamna migrants during the long-term contacts with other ‘kurganized cultures’ ca. 2900-2500 BC in the Great Hungarian Plains, it could explain some peculiar linguistic traits of North-West Indo-European, and also why R1b-Z2103 appears in cultures associated with this earlier ‘steppe influence’ (i.e. not directly related to Yamna) such as Vučedol (with a R1b-Z2103 sample, see below). That could also explain the presence of R1b-L151(xP312, xU106) in similar Balkan cultures, possibly not directly related to Yamna.
A hidden group among north or west Pontic Eneolithic steppe cultures?
The expansion of Khvalynsk as Novodanilovka into the North Pontic area happened through the south across the steppe, near the coast, with the forest-steppe region working as a clear natural border for this culture of likely horse-riding chieftains, whose economy was probably based on some rudimentary form of mobile pastoralism.
Although archaeologists are divided as to the origin of each individual Middle Eneolithic group near the Black Sea after the end of the Khvalynsk-Novodanilovka period, it seems more or less clear that steppe cultures like Cernavodă, Lower Mikhailovka, or Kvitjana are closer (or “more archaic”) in their steppe features, which connects them to Volga–Ural and Northern Caucasus cultures, like Northern Caucasus, Repin or Khvalynsk.
On the other hand, forest-steppe cultures like Dereivka (including Alexandria) show innovative traits and contacts with para- or sub-Neolithic cultures to the north, like Comb-Pit Ware groups, apart from corded decoration influenced by Trypillian groups to the west, especially in their later (‘Proto-Corded Ware‘) stage after ca. 3500 BC.
If Ukrainian researchers like Rassamakin are right, Early Yamna expanded not only from Repin settlers, but also from local steppe cultures adopting Repin traits to develop an Early Yamna culture, similar to how eastern (Volga–Ural groups) seem to have synchronously adopted Early Yamna without massive affluence of Repin settlements.
Furthermore, local traits develop in southern groups, like anthropomorphic stelae (shared with Kemi-Oba, direct heir of Lower Mikhailovka), and rich burials featuring wagons. These traits are seen in west Yamna settlers.
Problems of this model include:
On the North Pontic area – in contrast to the Volga–Ural region – , there was a clear “colonization” wave of Repin settlers, also supported by Ukrainian researchers, based on the number of new settlements and burials, and on the progressive retreat of Dereivka, Kvitjana, as well as (more recent) Maykop- and Trypillia-related groups from the North Pontic area ca. 3350/3300 BC. It seems unlikely that these expansionist, semi-nomadic, cattle-breeding, patrilineally-related steppe clans that were driving all native populations out of their territories suddenly decided, at some point during their spread into the North Pontic area ca. 3300-3100 BC, to join forces with some foreign male lineages from the area, and then continue their expansion to the west…
Similar to the fate of R1b-P297 subclades in the Baltic after the expansion of Corded Ware migrants, previous haplogropus of the North Pontic region – such as R1a, R1b-V88, and I2 subclades basically disappeared from the ancient DNA record after the expansion of Khvalynsk-Novodanilovka, and then after the expansion of Yamna, as is clear from Yamna, Afanasevo, and Bell Beaker samples obtained to date. This, in combination with what we know about Y-chromosome bottlenecks in post-Neolithic expansions, leaves little space to think that a big enough territorial group with a majority of “native” haplogroups could survive later expansions (be it R1b-L51 or R1a-Z645).
Supporting an expansion of the same male (and partly female) population, the Yamna admixture from east to west is quite homogeneous, with the only difference found in (non-significant) EEF-like proportion which becomes elevated in distant areas [apart from significant ‘southern’ contribution to certain outlier samples]. Based on the also homogeneous Y-DNA picture, the heterogeneity must come, in general, from the female exogamy practiced by expanding groups.
There is a short period, spanning some centuries (approximately 3300-2700 BC), in which the North Pontic area – especially the forest-steppe territories to the west of the Dnieper, i.e. the Upper Dniester, Boh, and Prut-Siret areas – are a chaos of incoming and emigrating, expanding and shrinking groups of different cultures, such as late Trypillian groups, Maykop-related traits, TRB, GAC, (Proto-)Corded Ware, and Early Yamna settlements. No natural geographic frontier can be delimited between these groups, which probably interacted in different ways. Nevertheless, based on their cultural traits, admixture, and especially on their Y-DNA, it seems that they never incorporated foreign male lineages, beyond those they probably had during their initial expansion trends.
The further expansionist waves of Early Yamna seen ca. 3100 BC, from the Danube Delta to the west, give an overall image of continuously expanding patrilineal clans of R1b-M269 subclades since the Khvalynsk-Novodanilovka migration, in different periodic steps, mostly from eastern Pontic-Caspian nuclei, usually overriding all encountered cultures and (especially male) populations, rather than showing long-term collaboration and interaction. Such interaction is seen only in exceptional cases, e.g. the long-term admixture between Abashevo and Poltavka, as seen in Proto-Indo-Iranian peoples and their language.
We are living right now an exemplary ego-, (ethno-)nationalism-, and/or supremacy-deflating moment, for some individuals of eastern and northern European descent who believed that R1a or ‘steppe ancestry proportions’ meant something special. The same can be said about those who had interiorized some social or ethnolinguistic meaning for the origin of R1b in western Europe, N1c in north-eastern Europe, as well as Greeks, Iranians, Armenians, or Mediterranean peoples in general of ‘Near Eastern’ ancestry or haplogroups, or peoples of Near Eastern origin and/or language.
These people had linked their haplogroups or ancestry with some fantasy continuity of ‘their’ ancestral populations to ‘their’ territories or languages (or both), and all are being proven wrong.
Apart from teaching such people a lesson about what simplistic views are useful for – whether it is based on ABO or RH group, white skin, blond hair, blue eyes, lactase persistence, or on the own ancestry or Y-DNA haplogroup -, it teaches the rest of us what can happen in the near future among western Europeans. Because, until recently, most western Europeans were comfortably settled thinking that our ancestors were some remnant population from an older, Palaeolithic or Mesolithic population, who acquired Indo-European languages by way of cultural diffusion in different periods, including only minor migrations.
Judging by what we can see now among some individuals of Northern and Eastern European descent, the only thing that can worsen the air of superiority among western Europeans is when they realize (within a few years, when all these stupid battles to control the narrative fade) that not only are they the cultural ‘heirs’ of the Graeco-Roman tradition that began with the Roman Empire, but that most of them are the direct patrilineal descendants of Khvalynsk, Yamna, Bell Beaker, and European Bronze Age peoples, and thus direct descendants of Middle PIE, Late PIE, and NWIE speakers.
The finding of R1b-L51 and R1b-Z2103 among expanding Suvorovo-Novodanilovka chieftains, with pockets of R1b-L51 remaining in steppe-like societies of the Balkans and the Carpathian Basin, would have beautifully complemented what we know about the East Yamna admixture with R1a-Z93 subclades (Uralic speakers) ca. 2600-2100 BC to form Proto-Indo-Iranian, and about the regional admixtures seen in the Balkans, e.g. in Proto-Greeks, with the prevalent J subclades of the region.
It would have meant an end to any modern culture or nation identifying themselves with the ‘true’ Late PIE and Yamna heirs, because these would be exclusively associated with the expansion of R1b-Z2103 subclades with late Repin, and later as the full-fledged Late PIE with Yamna settlers to south-east and central Europe, and to the southern Urals. The language would have had then obviously undergone different language changes in all these territories through long-lasting admixture with other populations. In that sense, it would have ended with the ideas of supremacy in western Europe before they even begin.
The most likely future
However limited the evidence, it seems that R1b-L51 expanded with Yamna, though, based on the estimates for the haplogroups involved, and on marginal hints at the variability of L23 subclades within Yamna and neighbouring populations. If R1b-L51 expanded with West Repin / Early Yamna settlers, this is why they have not yet been found among Yamna samples:
The subclade division of Yamna settlers needs not be 50:50 for L51:Z2103, either in time or in space. I think this is the simplistic view underlying many thoughts on this matter. Many different expanding patrilineal clans of L23 subclades may have been more or less successful in different areas, and non-Z2103 may have been on the minority, or more isolated relative to Z2103-clans among expanding peoples on the steppe, especially on the east. In fact, we usually talk in terms of “Z2103 vs. L51” as if
these two were the only L23 subclades; and
both had split and succeeded (expanding) synchronously;
that is, as if there had not been multiple subclades of both haplogroups, and as if there had not been different expansion waves for hundreds of years stemming from different evolving nuclei, involving each time only limited (successful) clans. Many different subclades of haplogroups L23 (xZ2103, xL51), Z2103, and L51 must have been unsuccessful during the ca. 1,500 years of late Khvalynsk and late Repin-Early Yamna expansions in which they must have participated (for approximately 60-75 generations, based on a mean 20-25 years).
If we want to imagine a pocket of ‘hidden’ L51 for some region of the North Pontic or Carpathian region, the same can be imagined – and much more likely – for any unsampled territory of expanding late Repin/Early Yamna settlers from the Lower Don – Lower Volga region (probably already a mixed society of L51 and Z2103 subclades since their beginning, as the early Repin culture, ca. 3800 BC), with L51 clans being probably successful to the west.
The Repin culture expanded only in small, mobile settlements from the Lower Don – Lower Volga to the north, east, and south, starting ca. 3500/3400 BC, in the waves that eventually gave a rather early distant offshoot in the Altai region, i.e. Afanasevo. Starting ca. 3300 BC in the archaeological record, the majority of R1b-Z2103 subclades found to date in Afanasevo also supports either
a mixed Repin society, with Z2103-clans predominating among eastern settlers; or
a Repin society marked by haplogroup L51, and thus a cultural diffusion of late Repin/Early Yamna traits among neighbouring (Khvalynsk, Samara, etc.) groups of essentially the same (early Khvalynsk-Novodanilovka) genetic stock in the Volga–Ural region.
Both options could justify a majority of Z2103 in the Lower Volga–Ural region, with the latter being supported by the scattered archaeological remains of late Repin in the region before the synchronous emergence of Early Yamna findings in the whole Pontic-Caspian steppe.
Most Z2103 from Yamna samples to date are from around 3100 BC (in average) onward, and from the right bank of the Lower Don to the east, particularly from the Lower Volga–Ural area (especially the Samara region), which – based on the center of expansion of late Repin settlers – may be depicting an artificially high Z2103-distribution of the whole Yamna community.
Yamna sample I0443, R1b-L23 (Y410+, L51-), ca. 3300-2700 BCE from Lopatino II, points to an intermediate subclade between L23 and L51, near one of the supposed late Repin sites (based on kurgan burials with late Repin cultural traits) in the Samara region.
Other Balkan cultures potentially unrelated to the Yamna expansion also show Z2103 (and not only L51) subclades, like I3499 (ca. 2884-2666 calBC), of the Vučedol culture, from Beli Manastir-Popova zemlja, which points to the infiltration of Yamna peoples in other cultures. In any case, the appearance of R1b-L23 subclades in the region happens only after the Yamna expansion ca. 3100 BC, probably through intrusions into different neighbouring regions, if these Balkan cultures are not directly derived from Yamna settlements (which is probably the case of the Csepel Bell Beaker or early Nagýrev sample, see above).
The diversity of haplogroups found in or around the Carpathian Basin in Late Chalcolithic / Early Bronze Age samples, including L151(xP312, xU106), P312, U106, Z2103, makes it the most likely sink of Yamna settlers, who spread thus with expanding family clans of different R1b-L23 subclades.
Even though some Yamna vanguard groups are known to have expanded up to Saxony-Anhalt before ca. 2700 BC, haplogroup Z2103 seems to be restricted to more eastern regions, which suggests that R1b-L51 was already successful among expanding West Yamna clans in Hungary, which gave rise only later to expanding East Bell Beakers (overwhelmingly of L151 subclades). The source of R1b-L51 and L151 expansion over Z2103 must lie therefore in the West Yamna period, and not in the Bell Beaker expansion.
The R1b-Z2103 found in Poltavka, Catacomb, and to the south point to a late migration displacing the western R1b-L51, only after the late Repin expansion. This is also seen in the steppe ancestry and R1b-Z2103 south of the Caucasus, in Hajji Firuz, which points to this route as a potential source of the supposed “Earliest Proto-Indo-Iranian” (the mariannu term) of the Near East. A similar replacement event happened some centuries later with expanding R1a-Z93 subclades from the east wiping out haplogroup R1b-Z2103 from the Pontic-Caspian steppe.
Many ancient samples from Khvalynsk, Northern Caucasus, Yamna, or later ones are reported simply as R1b-M269 or L23, without a clear subclade, so the simplistic ‘Yamna–Z2103’ picture is not real: if one takes into account that Z2103 might have been successful quite early in the eastern region, it is more likely to obtain a successful Y-SNP call of a Z2103 subclade in the Volga–Ural region than a xZ2103 one.
‘Western’ features described by archaeologists for West Yamna settlers, associated with Kemi Oba and southern Yamna groups in the North Pontic area – like rich burials with anthropomorphic stelae and wagons – are actually absent in burials from settlers beyond Bulgaria, which does not support their affiliation with these local steppe groups of the Black Sea. Also, a mix with local traditions is seen accross all Early Yamna groups of the Pontic-Caspian steppe, and still genetics and common cultural traits point to their homogeneization under the same patrilineal clans expanding continuously for centuries. The maintenance of local traditions (as evidenced by East Bell Beakers in Iberia related to Iberian Proto-Beakers) is often not a useful argument in genetics, especially when the female population is not replaced.
Middle Proto-Indo-European expanded with Khvalynsk-Novodanilovka after ca. 4800 BC, with the first Suvorovo settlements dated ca. 4600 BC.
Archaic Late Proto-Indo-European expanded with late Repin (or Volga–Ural settlers related to Khvalynsk, influenced by the Repin expansion) into Afanasevo ca. 3500/3400 BC.
Late Proto-Indo-European expanded with Early Yamna settlers to the west into central Europe and the Balkans ca. 3100 BC; and also to the east (as Pre-Proto-Indo-Iranian) into the southern Urals ca. 2600 BC.
North-West Indo-European expanded with Yamna Hungary -> East Bell Beakers, from ca. 2500 BC.
Proto-Indo-Iranian expanded with Sintashta, Potapovka, and later Andronovo and Srubna from ca. 2100 BC.
It seems that the subclades from Khvalynsk ca. 4250-4000 BC were wrongly reported – like those of Narasimhan et al. (2018). However, even if they are real and YFull estimates have to be revised, and even if the split had happened before the expansion of Suvorovo-Novodanilovka, the most likely origin of R1b-L51 among Bell Beakers will still be the expansion of late Repin / Early Yamna settlers, and that is what ancient DNA samples will most likely show, whatever the social or political consequences.
The only relevance of the finding of R1b-L51 in one place or another – especially if it is found to be a remnant of a Middle PIE expansion coupled with centuries of admixture and interaction in the Carpathian Basin – is the potential influence of an archaic PIE (or non-IE) layer on the development of North-West Indo-European in Yamna Hungary -> East Bell Beaker. That is, more or less like the Uralic influence related to the appearance of R1a-Z93 among Proto-Indo-Iranians, of R1a-Z284 among Pre-Germanic peoples, and of R1a-Z282 among Balto-Slavic peoples.
I think there is little that ancient DNA samples from West Yamna could add to what we know in general terms of archaeology or linguistics at this point regarding Late PIE migrations, beyond many interesting details. I am sure that those who have not attributed some random 6,000-year-old paternal ancestor any magical (ethnic or nationalist) meaning are just having fun, enjoying more and more the precise data we have now on European prehistoric populations.
As for those who believe in magical consequences of genetic studies, I don’t think there is anything for them to this quest beyond the artificially created grand-daddy issues. And, funnily enough, those who played (and play) the ‘neutrality’ card to feel superior in front of others – the “I only care about the truth”-type of lie, while secretly longing for grandpa’s ethnolinguistic continuity – are suffering the hardest fall.
The main objects of study in Corded Ware origins are necessarily the region where the oldest Corded Ware vessels appeared, Lesser Poland, as well as the adjacent (traditionally considered Proto-Corded Ware regions) Volhynia, Podolia, and upper Dniester river basin. These are some relevant points, continuing where I left the Eneolithic steppe developments (following Szmyt 1999, Rassamakin 1999, Kadrow 2008, Furholt 2014):
More frequent contacts were seen ca. 3500-3000 BC, with an interaction showing multidirectional migrations of larger human groups in the centuries around 3000 BC, involving a significant part of the population of central-east Europe.
The easternmost area of the Funnel Beaker culture had become more Baden-like with the expansion of the Baden culture in its western area ca. 3300-2900 BC (with findings up to 2600 BC), and these younger groups with Baden features moved increasingly into the western part of Volhynia.
The influence of the neighbouring Trypillian culture is seen in the eastern parts of Volhynia, from ca. 3000 BC, either from a younger phase CII (cf. Troyaniv, Koshilivtsy, Brînzeni, Zhvaniets, or Vychvatintsy) or later groups (cf. Gorodsk, Kasperivtsy, Sofievka, Horodiştea-Folteşti, Usatovo).
In the forest-steppe zone, herding and hunting activities intensified, while agricultural traditions were preserved, as shown by the Sofievka, Kasperivtsy, and Gorodsk groups. From the end of the 4th millennium BC mobile parts of the late Trypillian populations moved to the steppe zone, absorbing more and more steppe elements; among others, cord ornamentation (in Vykhvatintsy, Troyaniv, and Gorodsk groups), pottery forms (Vykhvatintsy, which served as prototype for the Thuringian Apmphorae, dispersed along the Dniester river, too), flat burials with bodies in contracted position on the left or right side (Vykhvatintsy, reminding of Polgár culture different male-female position, and later Corded Ware burials, and also Lower Mikhailovka, under a mound without stone constructions). At the end of the Trypillia culture, its agricultural system collapsed completely.
Slash and burn techniques of agriculture – especially those practiced by Trypillian and Funnel Beaker populations – must have intensified effects of natural growth of humidity (ca. 3400-2400), increasing fluvial activities in west Ukrainian river valleys, and increasing deforestation processes, which favoured pastoralism and nomadisation of the settlement system, and a consequent change of the social structure
At the same time, Yamna communities expanded along the lower and central Danube to the west, while the populations of the late phase of the Baden culture took the opposite direction and reached as far as Kiev in the north-east, contributing to the culture of the Sofievka group.
Globular Amphora communities migrated from the north-west, from eastern Poland, towards the Danube Delta and as far as the Dnieper in the east, destroying the primary structures of the communities in the supposed cradle territories of the Corded Ware culture. These communities found refuge and conditions for further development in south-eastern margin zone of the Funnel Beaker culture territories, penetrating at first the upper parts of the loess uplands like typical Funnel Beaker sites, but on the margins of their range, and also on areas avoided by Funnel Beaker settlement agglomerations. They brought with them the so-called Thuringian amphora up to Lesser Poland, borrowed from the late Trypillian Usatovo group. This resulted in the Złota culture, which eventually gave rise to the A-Amphorae.
In the end, we are left with this information about the oldest CWC (Furholt 2014):
The earliest radiocarbon-dated groups associated with the Corded Ware culture come from new single graves from Jutland in Denmark and Northern Germany, ca. 2900 BC. This Early Single Grave culture is associated with the appearance of individual graves (some time after the decline of the megalithic constructions), composed of a small round barrow and a new gender-differentiated burial practice emphasising male individuals orientated west-east (with regional exceptions), combined with the internment with new local battle-axe types (A-Axe). However, there is no single type of burial or burial custom in Corded Ware:
In southern Sweden the prevailing orientation is north-east – south-west, and south-north, contrary to the supposed rule male individuals are regularly deposited on their left and females on their right side.
In the Danish Isles and north-eastern Germany, the Final Neolithic / Single Grave Period is characterized by a majority of megalithic graves, with only some single graves from typical barrows. In south Germany, west-east and collective burials prevail, while in Switzerland no graves are found.
In Kujawia (south-eastern Poland), Hesse (Germany), or the Baltic, west-east orientation and gender differentiation cannot be proven statistically.
The oldest Corded Ware vessels (the A-Amphorae, which define the A-Horizon of the CWC) come probably from the Złota (or a related) group in Lesser Poland, where a mixed archaeological culture connecting Funnel Beaker, Baden, Globular Amphorae and Corded Ware appears ca. 2900-2600 BC. No cultural (typological) break is seen between earlier Globular Amphorae and the first Corded Ware Amphorae, but rather a continuum of traits and characteristics among the recovered vessels. This strengthens the connection of Corded Ware with Globular Amphorae peoples. The A-horizon expanded thus probably from Lesser Poland ca. 2800-2600, as seen in local contexts.
And of course we have a third way of defining Corded Ware individuals, which is the presence of herding, and thus a transition from hunter-gatherers to agropastoralists. This is how some Baltic Late Neolithic individuals with no archaeological data have been classified as members of the Corded Ware culture: Even though no cultural remains were extracted with the two ‘outlier’ individuals, their haplogroup and ancestry point to a direct origin in or around the steppe and forest-steppe region (yes, that risks circular reasoning).
Ukraine Neolithic cultures – mainly from Dereivka – show haplogroups R1b-V88, R1a1, and R1b-L754 (xP297, xM269), which is similar to the haplogroup distribution found in Ukraine Mesolithic, but apparently with an expanding group marked by haplogroup I2a2a1b1 (possibly I2a2a1b1b).
The first thing that stands out about Ukraine Eneolithic samples is that only two of them can be said to be really Ukraine Eneolithic (i.e. from “Sredni Stog”-related groups):
Corded Ware samples from Mittnik et al. (2018) offer very wide radiocarbon dates, so it is unclear which of them may be the oldest one. Most of them cluster closely to the older Ukraine Eneolithic sample I5876, but also to later steppe_MLBA samples i.e. Sintashta, Potapovka, and especially Srubna and Andronovo). This points to a genetic continuity from Pre-Corded Ware to Classic and late Corded Ware peoples. Therefore, much like Khvalynsk-Yamna and apparently many other Neolithic cultures, these peoples did not really admix; at least not with the male population.
Lucky for us, even though the culture remains undefined, haplogroup R1a-Z645 seems like a unifying trait, as I said long ago, so we only have to wait for more samples to trace their origin. Nevertheless, it is clear that Corded Ware may not have been as genetically homogeneous as Khvalynsk, Yamna and Yamna-related cultures, further supporting its archaeological complexity:
Jagodno1 and Jagodno2 (Silesia), dated ca. 2800 BC, show haplogroup G? and I/J? – compatible with an origin of CWC in common with Trypillia (which shows 3 samples of haplogroup G2a2b2a, and one E) and Ukraine Neolithic (showing the expansion of I2a2a1b1 subclades).
I7272, from Brandýsek (Czech Republic), dated ca. 2900-2200 BC shows haplogroup I2a2a2 (compatible with an origin in Ukraine Neolithic peoples – this haplogroup is also found in Yamna Kalmykia and in the Yamna Bulgaria outlier, i.e. late western samples from the Early Yamna culture).
NOTE. This precise subclade is only present to date in Chalcolithic samples from Iberia, which points (possibly like the Esperstedt family) to local Central European haplogroups integrated in a mixed Proto-Corded Ware population. The upper subclade I2a2a is found in Neolithic samples from Iberia, the British Isles, Hungary (Koros EN, ALPc), and also south-east European Mesolithic and Neolithic samples.
RISE1, from Oblaczkowo (Greater Poland), ca. 2865-2578 BC, shows haplogroup R1b1.
The Esperstedt family samples have been analysed as R1a-M417 (xZ645), although the supposed ‘xZ645’ has not been confirmed – not even in the risky new Y-calls from Wang et al. (2018) supplementary materials.
Maybe this heterogeneity is a problem of better defining the culture, but from what we can see the oldest CWC regions and the unifying ‘Corded Ware province’ – formed after ca. 2700 BC by Jutland and Northern Germany, the Netherlands, Saale, Bohemia, Austria and the Upper Danube regions – are for the moment not the most genetically homogeneous groups.
Homogeneity comes later – which we may tentatively identify with the expansion of the A-horizon from the northern Dnieper-Dniester and Lesser Poland area – , as seen around the Baltic (like the Battle Axe culture) with R1a-Z283 subclades, and around Sintashta (i.e. probably Abashevo – Balanovo) with R1a-Z93 subclades, which is compatible with the late spread of different Z645 groups (and potentially a unifying language) .
His recent studies include important sites (for Archaeology and recently also for Genomics) such us Dereivka and Alexandria, part of the North Pontic steppe and southern steppe-forest zone, on the Left Bank of the Dnieper river. According to him, many of these sites seem to form part of a common and distinct cultural group.
The author discusses the issues of chronology of the known burial grounds. In this article, first of all, the location of a series of burials at Ihren 8 cemetery is revised and the earlier proposed point of view of the author himself is refined. An important moment for that was a revision of a paired bi-ritual burial 7-8 from the excavations in 1932 with the Trypillian painted cup of the second half of the Trypillia B/2. The author presents the arguments for the assumption that the two burials were made not at the same time. As a whole, singled out are the Early Chalcolithic burials with the peculiar for them position on a back with bended knees, accompanied by flint products, first of all tools made on long blades. The second later group is represented by two supine burials which date is determined by a Trypillian cup. Concerning Oleksandriia burial ground, the author confirms his earlier expressed position on the Early Chalcolithic age of the burials with long flint blades, presenting additional arguments, one of which is a publication of a new radiocarbon date for one of the burials. Based on the author’s terminology, graves of the both burial grounds are considered within the borders of the so called Skelianska culture existence, while in Ihren burial ground several burials could be made in the period of so called «hiatus» when there were the Stohivska group sites in the Dnipro River region.
A new burial complex is publishing by authors. This burial complex finds analogies among the Early Eneolithic burials of the Siversky Donets basin according to the rite and inventory (long flint blade). In addition, a set of specific flint products (long blades, triangular «spear heads» and flat adzes) finds analogies at the Aleksandriia settlement, where Skelia-type ceramics are represented. Therefore, there is a reason to combine in the same cultural and chronological context the relevant materials of the Aleksandriia settlement and the Early Eneolithic burials, and consider their as a part of the phenomenon that one of the authors conventionally calls Skelia culture.
It remains to bee seen how this new data is interpreted with more complex anthropological models, of potential cultural-historical groups that might have shaped posterior migrations.