On the Ukraine Eneolithic outlier I6561 from Alexandria

sredni-stog-eneolithic-late

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.

ukraine-eneolithic-from-caucasus
PCA of ancient Eurasian samples. An interpretation of the evolution of the Pontic-Caspian steppe populations in the Eneolithic. See full PCA.

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.
  • Hajji Firuz Chalcolithic outlier

    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.

    There was already a similar situation with two samples (RISE568 and RISE569) initially reported as belonging to Czech Corded Ware groups, that turned out to be Early Slavs ca. 3,000 years younger, in turn more closely related to Bell Beaker-derived cultures of Central-East Europe. It seems little has changed since that case.

    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.

    ukraine-eneolithic-from-srubna
    PCA of ancient Eurasian samples. Marked I6561 sample within the cluster formed by Srubnaya samples. See full PCA.

    Compatibility checks

    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 magic fiascos.

    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:

    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.

    Formal stats

    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-SabatinovkaNoua cultural horizon, hence stemming from a source close to:

    1. Abashevo-like individuals (whose best proxy to date should be Poltavka_outlier I0432) potentially admixed with Poltavka-like herders; or
    2. Potapovka-like individuals potentially admixed with Catacomb-like peoples (whose best proxy until recently were probably Yamnaya_Kalmykia*).

    *To avoid adding more potential errors by merging different datasets, I have used only proxy samples available in the Reich Lab’s curated dataset of published ancient DNA.

    srubnaya-noua-sabatinovka-mlba
    Srubnaya and Noua-Sabatinovka cultural horizon during the MLBA. See full maps.

    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.

    Related

Yamnaya replaced Europeans, but admixed heavily as they spread to Asia

narasimhan-spread-yamnaya-ancestry

Recent papers The formation of human populations in South and Central Asia, by Narasimhan, Patterson et al. Science (2019) and An Ancient Harappan Genome Lacks Ancestry from Steppe Pastoralists or Iranian Farmers, by Shinde et al. Cell (2019).

NOTE. For direct access to Narasimhan, Patterson et al. (2019), visit this link courtesy of the first author and the Reich Lab.

I am currently not on holidays anymore, and the information in the paper is huge, with many complex issues raised by the new samples and analyses rather than solved, so I will stick to the Indo-European question, especially to some details that have changed since the publication of the preprint. For a summary of its previous findings, see the book series A Song of Sheep and Horses, in particular the sections from A Clash of Chiefs where I discuss languages and regions related to Central and South Asia.

I have updated the maps of the Preshistory Atlas, and included the most recently reported mtDNA and Y-DNA subclades. I will try to update the Eurasian PCA and related graphics, too.

NOTE. Many subclades from this paper have been reported by Kolgeh (download), Pribislav and Principe at Anthrogenica on this thread. I have checked some out for comparison, but even if it contradicted their analyses mine would be the wrong ones. I will upload my spreadsheets and link to them from this page whenever I find the time.

caucasus-cline-narasimhan
Ancestry clines (1) before and (2) after the advent of farming. Colour modified from the original to emphasize the CHG cline: notice the apparent relevance of forest-steppe groups in the formation of this CHG mating network from which Pre-Yamnaya peoples emerged.

Indo-Europeans

I think the Narasimhan, Patterson et al. (2019) paper is well-balanced, and unexpectedly centered – as it should – on the spread of Yamnaya-related ancestry (now Western_Steppe_EMBA) as the marker of Proto-Indo-European migrations, which stretched ca. 3000 BC “from Hungary in the west to the Altai mountains in the east”, spreading later Indo-European dialects after admixing with local groups, from the Atlantic to South Asia.

I. Afanasievo

I.1. East or West PIE?

I expected Afanasievo to show (1) R1b-L23(xZ2103, xL51) and (2) R1b-L51 lineages, apart from (3) the known R1b-Z2103 ones, pointing thus to an ancestral PIE community before the typical Yamnaya bottlenecks, and with R1b-L51 supporting a connection with North-West Indo-European. The presence of some samples of hg. Q pointed in this direction, too.

However, Afanasievo samples show overwhelmingly R1b-Z2103 subclades (all except for those with low coverage), all apparently under R1b-Z2108 (formed ca. 3500 BC, TMRCA ca. 3500 BC), like most samples from East Yamnaya.

This necessarily shifts the split and spread of R1b-L23 lineages to Khvalynsk/early Repin-related expansions, in line with what TMRCA suggested, and what advances by Anthony (2019) and Khokhlov (2018) on future samples from the Reich Lab suggest.

Given the almost indistinguishable ancestry between Afanasievo and Early Yamnaya, there seems to be as of yet little potential information to support in population genomics that Pre-Tocharians were more closely related to North-West Indo-Europeans than to Graeco-Aryans, as it is proposed in linguistics based on the few shared traits between them, and the lack of innovations proper of the Graeco-Aryan community.

NOTE. A new issue of Wekʷos contains an abstract from a relevant paper by Blažek on vocabulary for ‘word’, including the common NWIE *wrdʰo-/wordʰo-, but also a new (for me, at least) Northern Indo-European one: *rēki-/*rēkoi̯-, shared by Slavic and Tocharian.

The fact that bottlenecks happened around the time of the late Repin expansion suggests that we might be able to see different clans based on the predominant lineages developing around the Don-Volga area in the 4th millennium BC. The finding of Pre-R1b-L51 in Lopatino (see below), and of a Catacomb sample of hg. R1b-Z2103(Z2105-) in the North Caucasus steppe near Novoaleksandrovskij also support a star-like phylogeny of R1b-L23 stemming from the Don-Volga area.

NOTE. Interestingly, a dismissal of a common trunk between Tocharian and North-West Indo-European would mean that shared similarities between such disparate groups could be traced back to a Common Late PIE trunk, and not to a shared (western) Repin community. For an example of such a ‘pure’ East-West dialectal division, see the diagram of Adams & Mallory (2007) at the end of the post. It would thus mean a fatal blow to Kortlandt’s Indo-Slavonic group among other hypothetical groupings (remade versions of the ancient Centum-Satem division), as well as to certain assumptions about laryngeal survival or tritectalism that usually accompany them. Still, I don’t think this is the case, so the question will remain a linguistic one, and maybe some similarities will be found with enough number of samples that differentiate Northern Indo-Europeans from the East Yamna/Catacomb-Poltavka-Balkan_EBA group.

afanasievo-y-dna
Y-chromosome haplogroups of Afanasievo samples and neighbouring groups. See full maps.

I.2. Expansion or resurgence of hg. Q1b?

Haplogroup Q1b-Y6802(xY6798) seems to be the main lineage that expanded with Afanasievo, or resurged in their territory. It’s difficult to tell, because the three available samples are family, and belong to a later period.

NOTE. I have finally put some order to the chaos of Q1a vs. Q1b subclades in my spreadsheet and in the maps. The change of ISOGG 2016 to 2017 has caused that many samples reported as of Q1 subclades from papers prepared during the 2017-2018 period, and which did not provide specific SNP calls, were impossible to define with certainty. By checking some of them I could determine the specific standard used.

In favour of the presence of this haplogroup in the Pre-Yamnaya community are:

  • The statement by Anthony (2019) that Q1a [hence maybe Q1b in the new ISOGG nomenclature] represented a significant minority among an R1b-rich community.
  • The sample found in a Sintastha WSHG outlier (see below), of hg. Q1b-Y6798, and the sample from Lola, of hg. Q1b-L717, are thus from other lineage(s) separated thousands of years from the Afanasievo subclade, but might be related to the Khvalynsk expansion, like R1b-V1636 and R1b-M269 are.

These are the data that suggest multiple resurgence events in Afanasievo, rather than expanding Q1b lineages with late Repin:

  • Overwhelming presence of R1b in early Yamnaya and Afanasievo samples; one Q1(xQ1b) sample reported in Khvalynsk.
  • The three Q1b samples appear only later, although wide CI for radiocarbon dates, different sites, and indistinguishable ancestry may preclude a proper interpretation of the only available family.
    • Nevertheless, ancestry seems unimportant in the case of Afanasievo, since the same ancestry is found up to the Iron Age in a community of varied haplogroups.
  • Another sample of hg. Q1b-Y6802(xY6798) is found in Aigyrzhal_BA (ca. 2120 BC), with Central_Steppe_EMBA (WSHG-related) ancestry; however, this clade formed and expanded ca. 14000 BC.
  • The whole Altai – Baikal area seems to be a Q1b-L54 hotspot, although admittedly many subclades separated very early from each other, so they might be found throughout North Eurasia during the Neolithic.
  • One Afanasievo sample is reported as of hg. C in Shin (2017), and the same haplogroup is reported by Hollard (2014) for the only available sample of early Chemurchek to date, from Kulala ula, North Altai (ca. 2400 BC).
afanasievo-chemurchek-y-dna
Y-chromosome haplogroups of late Afanasievo – early Chemurchek samples and neighbouring groups. See full maps.

I.3. Agricultural substrate

Evidence of continuous contacts of Central_Steppe_MLBA populations with BMAC from ca. 2100 BC on – visible in the appearance of Steppe ancestry among BMAC samples and BMAC ancestry among Steppe pastoralists – supports the close interaction between Indo-Iranian pastoralists and BMAC agriculturalists as the origin of the Asian agricultural substrate found in Proto-Indo-Iranian, hence likely related to the language of the Oxus Civilization.

Similar to the European agricultural substrate adopted by West Yamnaya settlers (both NWIE and Palaeo-Balkan speakers), Tocharian shows a few substrate terms in common with Indo-Iranian, which can be explained by contacts in different dialectal stages through phonetic reconstruction alone.

The recent Hermes et al. (2019) supports the early integration of pastoralism and millet cultivation in Central Asia (ca. 2700 BC or earlier), with the spread of agriculture to the north – through the Inner Asian Mountain Corridor – being thus unrelated to the Indo-Iranian expansions, which might support independent loans.

However, compared to the huge number of parallel shared loans between NWIE and Palaeo-Balkan languages in the European substratum, Indo-Iranians seem to have been the first borrowers of vocabulary from Asian agriculturalists, while Proto-Tocharian shows just one certain related word, with phonetic similarities that warrant an adoption from late Indo-Iranian dialects.

chemurchek-sintashta-bmac
Y-chromosome haplogroups of Sintashta, Central Asia, and neighbouring groups in the Early Bronze Age. See full maps.

The finding of hg. (pre-)R1b-PH155 in a BMAC sample from Dzharkutan (to the west of Xinjiang) together with hg. R1b in a sample from Central Mongolia previously reported by Shin (2017) support the widespread presence of this lineage to the east and west of Xinjiang, which means it might have become incorporated to Indo-Iranian migrants into the Xiaohe horizon, to the Afanasievo-Chemurchek-derived groups, or the later from the former. In other words, the Island Biogeography Theory with its explanation of founder effects might be, after all, applicable to the whole Xinjiang area, not only during the Chemurchek – Tianshan-Beilu – Xiaohe interaction.

Of course, there is no need for too complicated models of haplogroup resurgence events in Central and South Asia, seeing how the total amount of hg. R1a-L657 (today prevalent among Indo-Aryan speakers from South Asia) among ancient Western/Central_Steppe_MLBA-related samples amounts to a total of 0, and that many different lineages survived in the region. Similar cases of haplogroup resurgence and Y-DNA bottleneck events are also found in the Central and Eastern Mediterranean, and in North-Eastern Europe. From the paper:

[It] could reflect stronger ecological or cultural barriers to the spread of people in South Asia than in Europe, allowing the previously established groups more time to adapt and mix with incoming groups. A second difference is the smaller proportion of Steppe pastoralist– related ancestry in South Asia compared with Europe, its later arrival by ~500 to 1000 years, and a lower (albeit still significant) male sex bias in the admixture (…).

Y-chromosome haplogroups of samples from the Srubna-Andronovo and Andronovo-related horizon, Xiaohe, late BMAC, and neighbouring groups. See full maps.

II. R1b-Beakers replaced R1a-CWC peoples

II.1. R1a-M417-rich Corded Ware

Newly reported Corded Ware samples from Radovesice show hg. R1a-M417, at least some of them xZ645, ‘archaic’ lineages shared with the early Bergrheinfeld sample (ca. 2650 BC) and with the coeval Esperstedt family, hence supporting that it eventually became the typical Western Corded Ware lineage(s), probably dominating over the so-called A-horizon and the Single Grave culture in particular. On the other hand, R1a-Z645 was typical of bottlenecks among expanding Eastern Corded Ware groups.

Interestingly, it is supported once again that known bottlenecks under hg. R1a-M417 happened during the Corded Ware expansion, evidenced also by the remarkable high variability of male lineages among early Corded Ware samples. Similarly, these Corded Ware samples from Bohemia form part of the typical ‘Central European’ cluster in the PCA, which excludes once again not only the ‘official’ Espersted outlier I1540, but also the known outlier with Yamnaya ancestry.

NOTE. The fact that Esperstedt is closely related geographically and in terms of ancestry to later Únětice samples further complicates the assumption that Únětice is a mixture of Bell Beakers and Corded Ware, being rather an admixture of incoming Bell Beakers with post-Yamnaya vanguard settlers who admixed with Corded Ware (see more on the expansion of Yamnaya ancestry). In other words, Únětice is rather an admixture of Yamnaya+EEF with Yamnaya+(CWC+EEF).

Y-chromosome haplogroups of samples from Catacomb, Poltavka, Balkan EBA, and Bell Beaker, as well as neighbouring groups. See full maps.

On Ukraine_Eneolithic I6561

If the bottlenecks are as straightforward as they appear, with a star-like phylogeny of R1a-M417 starting with the Pre-Corded Ware expansion, then what is happening with the Alexandria sample, so precisely radiocarbon dated to ca. 4045-3974 BC? The reported hg. R1a-M417 was fully compatible, while R1a-Z645 could be compatible with its date, but the few positive SNPs I got in my analysis point indeed to a potential subclade of R1a-Z94, and I trust more experienced hobbyists in this ‘art’ of ascertaining the SNPs of ancient samples, and they report hg. R1a-Z93 (Z95+, Y26+, Y2-).

Seeing how Y-DNA bottlenecks worked in Yamnaya-Afanasievo and in Corded Ware and related groups, and if this sample really is so deep within R1a-Z93 in a region that should be more strongly affected by the known Neolithic Y-chromosome bottlenecks and forest-steppe ecotone, someone from the lab responsible for this sample should check its date once again, before more people keep chasing their tails with an individual that (based on its derived SNPs’ TMRCA) might actually be dated to the Bronze Age, where it could make much more sense in terms of ancestry and position in the PCA.

EDIT (14 SEP 2019): … and with the fact that he is the first individual to show the genetic adaptation for lactase persistence (I3910-T), which is only found later among Bell Beakers, and much later in Sintashta and related Steppe_MLBA peoples (see comments below).

This is also evidenced by the other Ukraine_Eneolithic (likely a late Yamnaya) sample of hg. R1b-Z2103 from Dereivka (ca. 2800 BC) and who – despite being in a similar territory 1,000 years later – shows a wholly diluted Yamnaya ancestry under typically European HG ancestry, even more so than other late Sredni Stog samples from Dereivka of ca. 3600-3400 BC, suggesting a decrease in Steppe ancestry rather than an increase – which is supposedly what should be expected based on the ancestry from Alexandria…

Like the reported Chalcolithic individual of Hajji Firuz who showed an apparently incompatible subclade and Yamnaya ancestry at least some 1,000 years before it should, and turned out to be from the Iron Age (see below), this may be another case of wrong radiocarbon dating.

NOTE. It would be interesting, if this turns out to be another Hajji Firuz-like error, to check how well different ancestry models worked in whose hands exactly, and if anyone actually pointed out that this sample was derived, and not ancestral, to many different samples that were used in combination with it. It would also be a great control to check if those still supporting a Sredni Stog origin for PIE would shift their preference even more to the north or west, depending on where the first “true” R1a-M417 samples popped up. Such a finding now could be thus a great tool to discover whether haplogroup-based bias plays a role in ancestry magic as related to the Indo-European question, i.e. if it really is about “pure statistics”, or there is something else to it…

II.1. R1b-L51-rich Bell Beakers

The overwhelming majority of R1b-L51 lineages in Radovesice during the Bell Beaker period, just after the sampled Corded Ware individuals from the same site, further strengthen the hypothesis of an almost full replacement of R1a-M417 lineages from Central Europe up to southern Scandinavia after the arrival of Bell Beakers.

Yet another R1b-L151* sample has popped up in Central Europe, in the individual classified as Bilina_BA (ca. 2200-800 BC), which clusters with Bell Beakers from Bohemia, with the outlier from Turlojiškė, and with Early Slavs, suggesting once again that a group of central-east European Beakers represented the Pre-Proto-Balto-Slavic community before their spread and admixture events to the east.

The available ancient distribution of R1b-L51*, R1b-L52* or R1b-L151* is getting thus closer to the most likely origin of R1b-L51 in the expansion of East Bell Beakers, who trace their paternal ancestors to Yamnaya settlers from the Carpathian Basin:

NOTE. Some of these are from other sources, and some are samples I have checked in a hurry, so I may have missed some derived SNPs. If you send me a corrected SNP call to dismiss one of these, or more ‘archaic’ samples, I’ll correct the map accordingly. See also maps of modern distributionof R1b-M269 subclades .

r1b-l51-ancient-europe
Distribution of ‘archaic’ R1b-L51 subclades in ancient samples, overlaid over a map of Yamnaya and Bell Beaker migrations. In blue, Yamnaya Pre-L51 from Lopatino (not shown) and R1b-L52* from BBC Augsburg. In violet, R1b-L51 (xP312,xU106) from BBC Prague and Poland. In maroon, hg. R1b-L151* from BBC Hungary, BA Bohemia, and (not shown) a potential sample from BBC at Mondelange, which is certainly xU106, maybe xP312. Interestingly, the earliest sample of hg. R1b-U106 (a lineage more proper of northern Europe) has been found in a Bell Beaker from Radovesice (ca. 2350 BC), between two of these ‘archaic’ R1b-L51 samples; and a sample possibly of hg. R1b-ZZ11+ (ancestral to DF27 and U152) was found in a Bell Beaker from Quedlinburg, Germany (ca. 2290 BC), to the north-west of Bohemia. The oldest R1b-U152 are logically from Central Europe, too.

III. Proto-Indo-Iranian

Before the emergence of Proto-Indo-Iranian, it seems that Pre-Proto-Indo-Iranian-speaking Poltavka groups were subjected to pressure from Central_Steppe_EMBA-related peoples coming from the (south-?)east, such as those found sampled from Mereke_BA. Their ‘kurgan’ culture was dated correctly to approximately the same date as Poltavka materials, but their ancestry and hg. N2(pre-N2a) – also found in a previous sample from Botai – point to their intrusive nature, and thus to difficulties in the Pre-Proto-Indo-Iranian community to keep control over the previous East Yamnaya territory in the Don-Volga-Ural steppes.

We know that the region does not show genetic continuity with a previous period (or was not under this ‘eastern’ pressure) because of an Eastern Yamnaya sample from the same site (ca. 3100 BC) showing typical Yamnaya ancestry. Before Yamnaya, it is likely that Pre-Yamnaya ancestry formed through admixture of EHG-like Khvalynsk with a North Caspian steppe population similar to the Steppe_Eneolithic samples from the North Caucasus Piedmont (see Anthony 2019), so we can also rule out some intermittent presence of a Botai/Kelteminar-like population in the region during the Khvalynsk period.

It is very likely, then, that this competition for the same territory – coupled with the known harsher climate of the late 3rd millennium BC – led Poltavka herders to their known joint venture with Abashevo chiefs in the formation of the Sintashta-Potapovka-Filatovka community of fortified settlements. Supporting these intense contacts of Poltavka herders with Central Asian populations, late ‘outliers’ from the Volga-Ural region show admixture with typical Central_Steppe_MLBA populations: one in Potapovka (ca. 2220 BC), of hg. R1b-Z2103; and four in the Sintashta_MLBA_o1 cluster (ca. 2050-1650 BC), with two samples of hg. R1b-L23 (one R1b-Z2109), one Q1b-L56(xL53), one Q1b-Y6798.

central-steppe-pastoralists
Outlier analysis reveals ancient contacts between sites. We plot the average of principal component 1 (x axis) and principal component 2 (y axis) for the West Eurasian and All Eurasian PCA plots (…). In the Middle to Late Bronze Age Steppe, we observe, in addition to the Western_Steppe_MLBA and Central_Steppe_MLBA clusters (indistinguishable in this projection), outliers admixed with other ancestries. The BMAC-related admixture in Kazakhstan documents northward gene flow onto the Steppe and confirms the Inner Asian Mountain Corridor as a conduit for movement of people.

Similar to how the Sintashta_MLBA_o2 cluster shows an admixture with central steppe populations and hg. R1a-Z645, the WSHG ancestry in those outliers from the o1 cluster of typically (or potentially) Yamnaya lineages show that Poltavka-like herders survived well after centuries of Abashevo-Poltavka coexistence and admixture events, supporting the formation of a Proto-Indo-Iranian community from the local language as pronounced by the incomers, who dominated as elites over the fortified settlements.

The Proto-Indo-Iranian community likely formed thus in situ in the Don-Volga-Ural region, from the admixture of locals of Yamnaya ancestry with incomers of Corded Ware ancestry – represented by the ca. 67% Yamnaya-like ancestry and ca. 33% ancestry from the European cline. Their community formed thus ca. 1,000 years later than the expansion of Late PIE ca. 3500 BC, and expanded (some 500 years after that) a full-fledged Proto-Indo-Iranian language with the Srubna-Andronovo horizon, further admixing with ca. 9% of Central_Steppe_EMBA (WSHG-related) ancestry in their migration through Central Asia, as reported in the paper.

IV. Armenian

The sample from Hajji Firuz, of hg. R1b-Z2103 (xPF331), has been – as expected – re-dated to the Iron Age (ca. 1193-1019 BC), hence it may offer – together with the samples from the Levant and their Aegean-like ancestry rapidly diluted among local populations – yet another proof of how the Late Bronze Age upheaval in Europe was the cause of the Armenian migration to the Armenoid homeland, where they thrived under the strong influence from Hurro-Urartian.

middle-east-armenia-y-dna
Y-chromosome haplogroups of the Middle East and neighbouring groups during the Late Bronze Age / Iron Age. See full maps.

Indus Valley Civilization and Dravidian

A surprise came from the analysis reported by Shinde et al. (2019) of an Iran_N-related IVC ancestry which may have split earlier than 10000 BC from a source common to Iran hunter-gatherers of the Belt Cave.

For the controversial Elamo-Dravidian hypothesis of the Muscovite school, this difference in ancestry between both groups (IVC and Iran Neolithic) seems to be a death blow, if population genomics was even needed for that. Nevertheless, I guess that a full rejection of a recent connection will come down to more recent and subtle population movements in the area.

EDIT (12 SEP): Apparently, Iosif Lazaridis is not so sure about this deep splitting of ‘lineages’ as shown in the paper, so we may be talking about different contributions of AME+ANE/ENA, which means the Elamo-Dravidian game is afoot; at least in genomics:

I shared the idea that the Indus Valley Civilization was linked to the Proto-Dravidian community, so I’m inclined to support this statement by Narasimhan, Patterson, et al. (2019), even if based only on modern samples and a few ancient ones:

The strong correlation between ASI ancestry and present-day Dravidian languages suggests that the ASI, which we have shown formed as groups with ancestry typical of the Indus Periphery Cline moved south and east after the decline of the IVC to mix with groups with more AASI ancestry, most likely spoke an early Dravidian language.

india-steppe-indus-valley-andamanese-ancestry
Natural neighbour interpolation of qpAdm results – Maximum A Posteriori Estimate from the Hierarchical Model (estimates used in the Narasimhan, Patterson et al. 2019 figures) for Central_Steppe_MLBA-related (left), Indus_Periphery_West-related (center) and Andamanese_Hunter-Gatherer-related ancestry (right) among sampled modern Indian populations. In blue, peoples of IE language; in red, Dravidian; in pink, Tibeto-Burman; in black, unclassified. See full image.

I am wary of this sort of simplistic correlation with modern speakers, because we have seen what happened with the wrong assumptions about modern Balto-Slavic and Finno-Ugric speakers and their genetic profile (see e.g. here or here). In fact, I just can’t differentiate as well as those with deep knowledge in South Asian history the social stratification of the different tribal groups – with their endogamous rules under the varna and jati systems – in the ancestry maps of modern India. The pattern of ancestry and language distribution combined with the findings of ancient populations seem in principle straightforward, though.

Conclusion

The message to take home from Shinde et al. (2019) is that genomic data is fully at odds with the Anatolian homeland hypothesis – including the latest model by Heggarty (2014)* – whose relevance is still overvalued today, probably due in part to the shift of OIT proponents to more reasonable Out-of-Iran models, apparently more fashionable as a vector of Indo-Aryan languages than Eurasian steppe pastoralists?
*The authors listed this model erroneously as Heggarty (2019).

The paper seems to play with the occasional reference to Corded Ware as a vector of expansion of Indo-European languages, even after accepting the role of Yamnaya as the most evident population expanding Late PIE to western Europe – and the different ancestry that spread with Indo-Iranian to South Asia 1,000 years later. However, the most cringe-worthy aspect is the sole citation of the debunked, pseudoscientific glottochronological method used by Ringe, Warnow, and Taylor (2002) to support the so-called “steppe homeland”, a paper and dialectal scheme which keeps being referenced in papers of the Reich Lab, probably as a consequence of its use in Anthony (2007).

On the other hand, these are the equivalent simplistic comments in Narasimhan, Patterson et al. (2019):

The Steppe ancestry in South Asia has the same profile as that in Bronze Age Eastern Europe, tracking a movement of people that affected both regions and that likely spread the unique features shared between Indo-Iranian and Balto-Slavic languages. (…), which despite their vast geographic separation share the “satem” innovation and “ruki” sound laws.

mallory-adams-tree
Indo-European dialectal relationships, from Mallory and Adams (2006).

The only academic closely related to linguistics from the list of authors, as far as I know, is James P. Mallory, who has supported a North-West Indo-European dialect (including Balto-Slavic) for a long time – recently associating its expansion with Bell Beakers – opposed thus to a Graeco-Aryan group which shared certain innovations, “Satemization” not being one of them. Not that anyone needs to be a linguist to dismiss any similarities between Balto-Slavic and Indo-Iranian beyond this phonetic trend, mind you.

Even Anthony (2019) supports now R1b-rich Pre-Yamnaya and Yamnaya communities from the Don-Volga region expanding Middle and Late Proto-Indo-European dialects.

So how does the underlying Corded Ware ancestry of eastern Europe (where Pre-Balto-Slavs eventually spread to from Bell Beaker-derived groups) and of the highly admixed (“cosmopolitan”, according to the authors) Sintashta-Potapovka-Filatovka in the east relate to the similar-but-different phonetic trends of two unrelated IE dialects?

If only there was a language substrate that could (as Shinde et al. put it) “elegantly” explain this similar phonetic evolution, solving at the same time the question of the expansion of Uralic languages and their strong linguistic contacts with steppe peoples. Say, Eneolithic populations of mainly hunter-fisher-gatherers from the North Pontic forest-steppes with a stronger connection to metalworking

Related

Yamnaya ancestry: mapping the Proto-Indo-European expansions

steppe-ancestry-expansion-europe

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.

The following maps are based on formal stats published in the papers and supplementary materials from 2015 until today, mainly on Wang et al. (2018 & 2019), Mathieson et al. (2018) and Olalde et al. (2018), and others like Lazaridis et al. (2016), Lazaridis et al. (2017), Mittnik et al. (2018), Lamnidis et al. (2018), Fernandes et al. (2018), Jeong et al. (2019), Olalde et al. (2019), etc.

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.

Sections:

  1. Neolithic or the formation of Early Indo-European
  2. Eneolithic or the expansion of Middle Proto-Indo-European
  3. Chalcolithic / Early Bronze Age or the expansion of Late Proto-Indo-European
  4. European Early Bronze Age and MLBA or the expansion of Late PIE dialects

1. Neolithic

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.

neolithic-chg-ancestry
Natural neighbor interpolation of CHG ancestry among Neolithic populations. See full map.

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.

neolithic-ehg-ancestry
Natural neighbor interpolation of EHG ancestry among Neolithic populations. See full map.

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 (…)

neolithic-whg-ancestry
Natural neighbor interpolation of WHG ancestry among Neolithic populations. See full map.

North-West Anatolia Neolithic ancestry, proper of expanding Early European farmers, is found up to border of the Dniester, as Anthony (2007) had predicted.

neolithic-anatolia-farmer-ancestry
Natural neighbor interpolation of Anatolia Neolithic ancestry among Neolithic populations. See full map.

2. Eneolithic

From Anthony (2019):

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.

From Wang et al (2019):

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

eneolithic-pre-yamnaya-ancestry
Natural neighbor interpolation of Pre-Yamnaya ancestry among Neolithic populations. See full map. This map corresponds roughly to the map of Khvalynsk-Novodanilovka expansion, and in particular to the expansion of horse-head pommel-scepters (read more about Khvalynsk, and specifically about horse symbolism)

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.

eneolithic-ehg-ancestry
Natural neighbor interpolation of non-Pre-Yamnaya EHG ancestry among Eneolithic populations. See full map.

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:

eneolithic-chg-ancestry
Natural neighbor interpolation of non-Pre-Yamnaya CHG ancestry among Eneolithic populations. See full map. You can read more about population movements in the late Sredni Stog and closer to the Proto-Corded Ware period.

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.

eneolithic-whg-ancestry
Natural neighbor interpolation of WHG ancestry among Eneolithic populations. See full map.

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:

eneolithic-anatolia-farmer-ancestry
Natural neighbor interpolation of Anatolia Neolithic ancestry among Eneolithic populations. See full map.
eneolithic-iran-chl-ancestry
Natural neighbor interpolation of Iran Chl. ancestry among Eneolithic populations. See full map.

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:

eneolithic-early-y-dna
Y-DNA haplogroups in West Eurasia during the Early Eneolithic in the Pontic-Caspian steppes. See full map, and see culture, ADMIXTURE, Y-DNA, and mtDNA maps of the Early Eneolithic and Late Eneolithic.

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.

eneolithic-steppe-best-fits
Supplementary Table 13. P values of rank=2 and admixture proportions in modelling Steppe ancestry populations as a three-way admixture of Eneolithic steppe Anatolian_Neolithic and WHG using 14 outgroups.
Left populations: Test, Eneolithic_steppe, Anatolian_Neolithic, WHG.
Right populations: Mbuti.DG, Ust_Ishim.DG, Kostenki14, MA1, Han.DG, Papuan.DG, Onge.DG, Villabruna, Vestonice16, ElMiron, Ethiopia_4500BP.SG, Karitiana.DG, Natufian, Iran_Ganj_Dareh_Neolithic.

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.

wang-eneolithic-steppe-caucasus-yamnaya
Modelling results for the Steppe and Caucasus cluster. Admixture proportions based on (temporally and geographically) distal and proximal models, showing additional AF ancestry in Steppe groups and additional gene flow from the south in some of the Steppe groups as well as the Caucasus groups. See tables above. Modified from Wang et al. (2019). Within a blue square, Yamnaya-related groups; within a cyan square, Corded Ware-related groups. Green background behind best p-values. In red circle, SD of AF/WHG ancestry contribution in Afanasevo and Yamnaya Kalmykia, with ranges that almost include 0%.

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.

eba-yamnaya-ancestry
Natural neighbor interpolation of Pre-Yamnaya ancestry among Early Bronze Age populations. See full map. This map corresponds roughly with the known expansion of late Repin/Yamnaya settlers.

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:

chalcolithic-early-y-dna
Y-DNA haplogroups in West Eurasia during the Yamnaya expansion. See full map and maps of cultures, ADMIXTURE, Y-DNA, and mtDNA of the Early Chalcolithic and Yamnaya Hungary.

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:

NOTE. For maps with actual formal stats of Corded Ware ancestry from the Early Bronze Age to the modern times, you can read the post Corded Ware ancestry in North Eurasia and the Uralic expansion.

eba-chg-ancestry
Natural neighbor interpolation of non-Pre-Yamnaya CHG ancestry among Early Bronze Age populations. See full map.
eba-ehg-ancestry
Natural neighbor interpolation of non-Pre-Yamnaya EHG ancestry among Early Bronze Age populations. See full map.
eba-whg-ancestry
Natural neighbor interpolation of WHG ancestry among Early Bronze Age populations. See full map.
eba-anatolia-farmer-ancestry
Natural neighbor interpolation of Anatolia Neolithic ancestry among Early Bronze Age populations. See full map.
eba-iran-chl-ancestry
Natural neighbor interpolation of Iran Chl. ancestry among Early Bronze Age populations. See full map.

4. Middle to Late Bronze Age

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.
mlba-yamnaya-ancestry
Natural neighbor interpolation of Yamnaya ancestry among Middle to Late Bronze Age populations (Esperstedt CWC site close to BK_DE, label is hidden by BK_DE_SAN). See full map. You can see how this map correlated with the map of Late Copper Age migrations and Yamanaya into Bell Beaker expansion.

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.

olalde-iberia-chalcolithic

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:

chalcolithic-late-y-dna
Y-DNA haplogroups in West Eurasia during the Bell Beaker expansion. See full map and see maps of cultures, ADMIXTURE, Y-DNA, and mtDNA of the Late Copper Age and of the Yamnaya-Bell Beaker transition.

4.2. Palaeo-Balkan

There is scarce data on Palaeo-Balkan movements yet, although it is known that:

  1. Yamnaya ancestry appears among Mycenaeans, with the Yamnaya Bulgaria sample being its best current ancestral fit;
  2. the emergence of steppe ancestry and R1b-M269 in the eastern Mediterranean was associated with Ancient Greeks;
  3. Thracians, Albanians, and Armenians also show R1b-M269 subclades and “Steppe ancestry”.

4.3. Sintashta-Potapovka-Filatovka

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.

This proves that there was a period of admixture in the Pre-Proto-Indo-Iranian community between CWC-like Abashevo and Yamnaya-like Catacomb-Poltavka herders in the Sintashta-Potapovka-Filatovka community, probably more easily detectable in this group because of the specific temporal and geographic sampling available.

srubnaya-yamnaya-ehg-chg-ancestry
Supplementary Table 14. P values of rank=3 and admixture proportions in modelling Steppe ancestry populations as a four-way admixture of distal sources EHG, CHG, Anatolian_Neolithic and WHG using 14 outgroups.
Left populations: Steppe cluster, EHG, CHG, WHG, Anatolian_Neolithic
Right populations: Mbuti.DG, Ust_Ishim.DG, Kostenki14, MA1, Han.DG, Papuan.DG, Onge.DG, Villabruna, Vestonice16, ElMiron, Ethiopia_4500BP.SG, Karitiana.DG, Natufian, Iran_Ganj_Dareh_Neolithic.

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.

mlba-ehg-ancestry
Natural neighbor interpolation of non-Pre-Yamnaya EHG ancestry among Middle to Late Bronze Age populations. See full map.
mlba-chg-ancestry
Natural neighbor interpolation of non-Pre-Yamnaya CHG ancestry among Middle to Late Bronze Age populations. See full map.
mlba-anatolia-farmer-ancestry
Natural neighbor interpolation of Anatolia Neolithic ancestry among Middle to Late Bronze Age populations. See full map.
mlba-iran-chl-ancestry
Natural neighbor interpolation of Iran Chl. ancestry among Middle to Late Bronze Age populations. See full map.

NOTE For maps with actual formal stats of Corded Ware ancestry from the Early Bronze Age to the modern times, you should read the post Corded Ware ancestry in North Eurasia and the Uralic expansion instead.

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:

early-bronze-age-y-dna
Y-DNA haplogroups in West Eurasia during the European Early Bronze Age. See full map and see maps of cultures, ADMIXTURE, Y-DNA, and mtDNA of the Early Bronze Age.

4.4. Afanasevo

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.

middle-bronze-age-y-dna
Y-DNA haplogroups in West Eurasia during the Middle Bronze Age. See full map and see maps of cultures, ADMIXTURE, Y-DNA, and mtDNA of the Middle Bronze Age and the Late Bronze Age.

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.

From Damgaard et al. Science (2018):

(…) 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.

This Yamnaya ancestry has been also recently found to be the best fit for the Iron Age population of Shirenzigou in Xinjiang – where Tocharian languages were attested centuries later – despite the haplogroup diversity acquired during their evolution, likely through an intermediate Chemurchek culture (see a recent discussion on the elusive Proto-Tocharians).

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.

early-iron-age-y-dna
Y-DNA haplogroups in West Eurasia during the Early Iron Age. See full map and see maps of cultures, ADMIXTURE, Y-DNA, and mtDNA of the Early Iron Age and Late Iron Age.

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:

shirenzigou-afanasievo-yamnaya-andronovo-srubna-ulchi-han

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.

Related

Iron Age Tocharians of Yamnaya ancestry from Afanasevo show hg. R1b-M269 and Q1a1

New open access Ancient Genomes Reveal Yamnaya-Related Ancestry and a Potential Source of Indo-European Speakers in Iron Age Tianshan, by Ning et al. Current Biology (2019).

Interesting excerpts (emphasis mine, changes for clarity):

Here, we report the first genome-wide data of 10 ancient individuals from northeastern Xinjiang. They are dated to around 2,200 years ago and were found at the Iron Age Shirenzigou site. We find them to be already genetically admixed between Eastern and Western Eurasians. We also find that the majority of the East Eurasian ancestry in the Shirenzigou individuals is related to northeastern Asian populations, while the West Eurasian ancestry is best presented by ∼20% to 80% Yamnaya-like ancestry. Our data thus suggest a Western Eurasian steppe origin for at least part of the ancient Xinjiang population. Our findings furthermore support a Yamnaya-related origin for the now extinct Tocharian languages in the Tarim Basin, in southern Xinjiang.

Haplogroups

The dominant mtDNA lineages of the Shirenzigou people are commonly found in modern and ancient West Eurasian populations, such as U4, U5, and H, while they also have East Eurasian-specific haplogroups A, D4, and G3, preliminarily documenting admixed ancestry from eastern and western Eurasia.

The admixture profile is also shown on the paternal Y chromosome side that 4 out of 6 males in Shirenzigou (Figure S2) belong to the West Eurasian-specific haplogroup R1b (n = 2) and East Eurasian-specific haplogroup Q1a (n = 2), the former is predominant in ancient Yamnaya and nearly 100% in Afanasievo, different from the Middle and Late Bronze Age Steppe groups (Steppe_MLBA) such as Andronovo, [Potapovka], Srubnaya, and Sintashta whose Y chromosomal haplogroup is mainly R1a.

tocharians-y-dna-mtdna

Autosomal

We first carried out principal component analysis (PCA) to assess the genetic affinities of the ancient individuals qualitatively by projecting them onto present-day Eurasian variation (Figure 2). We observed a distinct separation between East and West Eurasians. Our ancient Shirenzigou samples and present-day populations from Central Asia and northwestern China form a genetic cline from East to West in the first PC. The distribution of Shirenzigou samples on the cline is relatively scattered with two major clusters, one being closer to modern-day Uygurs and Kazakhs and the other being closer to recently published ancient Saka and Huns from the Tianshan in Kazakhstan (…).

We applied a formal admixture test using f3 statistics in the form of f3 (Shirenzigou; X, Y) where X and Y are worldwide populations that might be the genetic sources for the Shirenzigou individuals. We observed the most significant signals of admixture in the Shirenzigou samples when using Yamnaya_Samara or Srubnaya as the West Eurasian source and some Northern Asians or Koreans as the East Eurasian source (Table S1). We also plotted the outgroup f3 statistics in the form of f3 (Mbuti; X, Anatolia_Neolithic) and f3 (Mbuti; X, Kostenki14) to visualize the allele sharing between population X and Anatolian farmers. As shown in Figure S3, the Steppe_MLBA populations including Srubnaya, Andronovo, and Sintashta were shifted toward farming populations compared with Yamnaya groups and the Shirenzigou samples. This observation is consistent with ADMIXTURE analysis that Steppe_MLBA populations have an Anatolian and European farmer-related component that Yamnaya groups and the Shirenzigou individuals do not seem to have. The analysis consistently suggested Yamnaya-related Steppe populations were the better source in modeling the West Eurasian ancestry in Shirenzigou.

tocharians-pca-admixture
PCA and ADMIXTURE for Shirenzigou Samples. Modified from the original to include in black squares samples related to Yamnaya.

Genetic Composition of Iron Age Shirenzigou Individuals

We continued to use qpAdm to estimate the admixture proportions in the Shirenzigou samples by using different pairs of source populations, such as Yamnaya_Samara, Afanasievo, Srubnaya, Andronovo, BMAC culture (Bustan_BA and Sappali_Tepe_BA) and Tianshan_Hun as the West Eurasian source and Han, Ulchi, Hezhen, Shamanka_EN as the East Eurasian source. In all cases, Yamnaya, Afanasievo, or Tianshan_Hun always provide the best model fit for the Shirenzigou individuals, while Srubnaya, Andronovo, Bustan_BA and Sappali_Tepe_BA only work in some cases. The Yamnaya_Samara or Afanasievo-related ancestry ranges from ∼20% to 80% in different Shirenzigou individuals, consistent with the scattered distribution on the East-West cline in the PCA

ancestry-tocharians

(…) we then modeled Shirenzigou as a three-way admixture of Yamnaya_Samara, Ulchi (or Hezhen) and Han to infer the source from the East Eurasia side that contributed to Shirenzigou. We found the Ulchi or Hezhen and Han-related ancestry had a complicated and unevenly distribution in the Shirenzigou samples. The most Shirenzigou individuals derived the majority of their East Eurasian ancestry from Ulchi or Hezhen-related populations, while the following two individuals M820 and M15-2 have more Han related than Ulchi/Hezhen-related ancestry.

One important question remains, though: how and when did these Proto-Tocharian speakers migrate from the Afanasevo culture in the Altai into the Tarim Basin? The traditional answer, now more likely than ever, is through the Chemurchek culture. See e.g. A re-analysis of the Qiemu’erqieke (Shamirshak) cemeteries, Xinjiang, China, by Jia and Betts JIES (2010) 38(4).

Also, given the apparent lack of (extra farmer ancestry that characterizes) Corded Ware ancestry, if the results were already suspicious before, how likely are now the published R1a(xZ93) and/or radiocarbon dates of the Xiaohe mummies from Li et al. (2010, 2015)? Because, after all, one should have expected in such a late date a generalized admixture with neighbouring Srubna/Andronovo-like populations.

Related

Złota a GAC-CWC transitional group…but not the origin of Corded Ware peoples

koszyce-gac-zlota-cwc

Open access Unraveling ancestry, kinship, and violence in a Late Neolithic mass grave, by Schroeder et al. PNAS (2019).

Interesting excerpts of the paper and supplementary materials, about the Złota group variant of Globular Amphora (emphasis mine):

A special case is the so-called Złota group, which emerged around 2,900 BCE in the northern part of the Małopolska Upland and existed until 2,600-2,500 BCE. Originally defined as a separate archaeological “culture” (15), this group is mainly defined by the rather local introduction of a distinct form of burial in the area mentioned. Distinct Złota settlements have not yet been identified. Nonetheless, because of the character of its burial practices and material culture, which both retain many elements of the GAC and yet point forward to the Corded Ware tradition, and because of its geographical location, the Złota group has attracted significant archaeological attention (15, 16).

The Złota group buried their dead in a new, distinct type of funerary structure; so-called niche graves (also called catacomb graves). These structures featured an entrance shaft or pit and, below that, a more or less extensive niche, sometimes connected to the entrance area by a narrow corridor. Local limestone was used to seal off the entrance shaft and to pave the floor of the niche, on which the dead were usually placed along with grave goods. This specific and relatively sophisticated form of burial probably reflects contacts between the northern Małopolska Upland and the steppe and forest-steppe communities further to the east, who also buried their dead in a form of catacomb graves. Individual cases of the use of ochre and of deformation of skulls in Złota burials provide further indications of such a connection (15). At the same time, the Złota niche grave practice also retains central elements of the GAC funerary tradition, such as the frequent practice of multiple burials in one grave, often entailing redeposition and violation of the anatomical order of corpses, and thus differs from the catacomb grave customs found on the steppes which are strongly dominated by single graves. Nonetheless, at Złota group cemeteries single burial graves appear, and even in multiple burial graves the identity of each individual is increasingly emphasized, e.g. by careful deposition of the body and through the personal nature of grave goods (16).

globular-amphorae-corded-ware-zlota-amphorae
Correspondence analysis of amphorae from the Złota-graveyards reveals that there is no typological break between Globular Amphorae and Corded Ware Amphorae, including ‘Strichbündelamphorae’ (after Furholt 2008)

Just like its burial practices, the material culture and grave goods of the Złota group combine elements of the GAC, such as amber ornaments and central parts of the ceramic inventory, with elements also found in the Corded Ware tradition, such as copper ornaments, stone shaft-hole axes, bone and shell ornaments, and other stylistic features of the ceramic inventory. In particular, Złota group ceramic styles have been seen as a clear transitional phenomenon between classical GAC styles and the subsequent Corded Ware ceramics, probably playing a key role in the development of the typical cord decoration patterns that came to define the latter (17).

As briefly summarized above, the Złota group displays a distinct funerary tradition and combination of material culture traits, which give the clear impression of a cultural “transitional situation”. While the group also appears to have had long-distance contacts directed elsewhere (e.g. to Baden communities to the south), it is the combination of Globular Amphora traits, on the one hand, and traits found among late Yamnaya or Catacomb Grave groups to the east as well as the closely related Corded Ware groups that emerged around 2,800 BCE, on the other hand, that is such a striking feature of the Złota group and which makes it interesting when attempting to understand cultural and demographic dynamics in Central and Eastern Europe during the early 3rd millennium BCE.

catacomb-grave-ksiaznice
Catacomb grave no. 2a/06 from Książnice, Złota culture (acc. to Wilk 2013). Image from Włodarczak (2017)

Książnice (site 2, grave 3ZC), Świętokrzyskie province. This burial, a so-called niche grave of the Złota type (with a vertical entrance shaft and perpendicularly situated niche), was excavated in 2006 and contained the remains of 8 individuals, osteologically identified as three adult females and five children, positioned on limestone pavement in the niche part of the grave. Radiocarbon dating of the human remains indicates that the grave dates to 2900-2630 BCE, 95.4% probability (Dataset S1). The grave had an oval entrance shaft with a diameter of 60 cm and depth of 130 cm; the depth of the niche reached to 170 cm (both measured from the modern surface), and it also contained a few animal bones, a few flint artefacts and four ceramic vessels typical of the Złota group. Książnice is located in the western part of the Małopolska Upland, which only has a few Złota group sites but a stronger presence of other, contemporary groups (including variants of the Baden culture).

Wilczyce (site 90, grave 10), Świętokrzyskie province. A rescue excavation in 2001 uncovered a niche grave of the Złota type, which had a round entrance shaft measuring 90 cm in diameter. The grave was some 60-65 cm deep below the modern surface and the bottom of the niche was paved with thin limestone plates, on which remains of three individuals had been placed; two adults, one female and one male, and one child. Four ceramic vessels of Złota group type were deposited in the niche along with the bodies. Wilczyce is located in the Sandomierz Upland, an area with substantial presence of both the Globular Amphora culture and Złota group, as well as the Corded Ware culture from 2800 BCE.

zlota-gac-cwc
Genetic affinities of the Koszyce individuals and other GAC groups (here including Złota) analyzed in this study. (A) Principal component analysis of previously published and newly sequenced ancient individuals. Ancient genomes were projected onto modern reference populations, shown in gray. (B) Ancestry proportions based on supervised ADMIXTURE analysis (K = 3), specifying Western hunter-gatherers, Anatolian Neolithic farmers, and early Bronze Age steppe populations as ancestral source populations. LP, Late Paleolithic; M, Mesolithic; EN, Early Neolithic; MN, Middle Neolithic; LN, Late Neolithic; EBA, Early Bronze Age; PWC, Pitted Ware culture; TRB, Trichterbecherkultur/Funnelbeaker culture; LBK, Linearbandkeramik/Linear Pottery culture; GAC, Globular Amphora culture; Złota, Złota culture. Image modified to outline in red GAC and Złota groups.

To further investigate the ancestry of the Globular Amphora individuals, we performed a supervised ADMIXTURE (6) analysis, specifying typical western European hunter-gatherers (Loschbour), early Neolithic Anatolian farmers (Barcın), and early Bronze Age steppe populations (Yamnaya) as ancestral source populations (Fig. 2B). The results indicate that the Globular Amphora/Złota group individuals harbor ca. 30% western hunter-gatherer and 70% Neolithic farmer ancestry, but lack steppe ancestry. To formally test different admixture models and estimate mixture proportions, we then used qpAdm (7) and find that the Polish Globular Amphora/Złota group individuals can be modeled as a mix of western European hunter-gatherer (17%) and Anatolian Neolithic farmer (83%) ancestry (SI Appendix, Table S2), mirroring the results of previous studies.

zlota-steppe-ancestry-cwc
Table S2. qpADM results. The ancestry of most Globular Amphora/Złota group individuals
can be modelled as a two-way mixture of Mesolithic western hunter-gatherers (WHG), and early Anatolian Neolithic farmers (Barcın). The five individuals from Książnice (Złota group) show evidence for additional gene flow, most likely from an eastern source.

The lack of a direct genetic connection of Corded Ware peoples with the Złota group despite their common “steppe-like traits” – shared with Yamna – reveals, once more, how the few “Yamna-like” traits of Corded Ware do not support a direct connection with Indo-Europeans, and are the result of the expansion of the so-called steppe package all over Europe, and particularly among cultures closely related to the Khvalynsk expansion, and later under the influence of expanding Yamna peoples.

The results from Książnice may support that early Corded Ware peoples were in close contact with GAC peoples in Lesser Poland during the complex period of GAC-Trypillia-CWC interactions, and especially close to the Złota group at the beginning of the 3rd millennium BC. Nevertheless, patrilineal clans of Złota apparently correspond to Globular Amphorae populations, with the only male sample available yet being within haplogroup I2a-L801, prevalent in GAC.

NOTE. The ADMIXTURE of Złota samples in common with GAC samples (and in contrast with the shared Sredni Stog – Corded Ware “steppe ancestry”) makes the possibility of R1a-M417 popping up in the Złota group from now on highly unlikely. If it happened, that would complicate further the available picture of unusually diverse patrilineal clans found among Uralic speakers expanding with early Corded Ware groups, in contrast with the strict patrilineal and patrilocal culture of Indo-Europeans as found in Repin, Yamna and Bell Beakers.

Once again the traditional links between groups hypothesized by archaeologists – like Gimbutas and Kristiansen in this case – are wrong, as is the still fashionable trend in descriptive archaeology, of supporting 1) wide cultural relationships in spite of clear-cut inter-cultural differences (and intra-cultural uniformity kept over long distances by genetically-related groups), 2) peaceful interactions among groups based on few common traits, and 3) regional population continuities despite cultural change. These generalized ideas made some propose a steppe language shared between Pontic-Caspian groups, most of which have been proven to be radically different in culture and genetics.

gimbutas-kurgan-indo-european
The background shading indicates the tree migratory waves proposed by Marija Gimbutas, and personally checked by her in 1995. Image from Tassi et al. (2017).

Furthermore, paternal lines show once again marked bottlenecks in expanding Neolithic cultures, supporting their relevance to follow the ethnolinguistic identity of different cultural groups. The steppe- or EHG-related ancestry (if it is in fact from early Corded Ware peoples) in Książnice was thus probably, as in the case of Trypillia, in the form of exogamy with females of neighbouring groups:

The presence of unrelated females and related males in the grave is interesting because it suggests that the community at Koszyce was organized along patrilineal lines of descent, adding to the mounting evidence that this was the dominant form of social organization among Late Neolithic communities in Central Europe. Usually, patrilineal forms of social organization go hand in hand with female exogamy (i.e., the practice of women marrying outside their social group). Indeed, several studies (11, 12) have shown that patrilocal residence patterns and female exogamy prevailed in several parts of Central Europe during the Late Neolithic. (…) the high diversity of mtDNA lineages, combined with the presence of only a single Y chromosome lineage, is certainly consistent with a patrilocal residence system.

funnelbeaker-trypillia-corded-ware
Map of territorial ranges of Funnel Beaker Culture (and its settlement concentrations in Lesser Poland), local Tripolyan groups and Corded Ware Culture settlements (■) at the turn of the 4th/3rd millennia BC.

Since ancient and modern Uralians show predominantly Corded Ware ancestry, and Proto-Uralic must have been in close contact with Proto-Indo-European for a very long time – given the different layers of influence that can be distinguished between them -, it follows as logical consequence that the North Pontic forest-steppes (immediately to the west of the PIE homeland in the Don-Volga-Ural steppes) is the most likely candidate for the expansion of Proto-Uralic, accompanying the spread of Sredni Stog ancestry and a bottleneck under R1a-M417 lineages.

The early TMRCAs in the 4th millennium BC for R1a-M417 and R1a-Z645 support this interpretation, like the R1a-M417 sample found in Sredni Stog. On the other hand, the resurgence of typical GAC-like ancestry in late Corded Ware groups, with GAC lineages showing late TMRCAs in the 3rd millennium BC, proves the disintegration of Corded Ware all over Europe (except in Textile Ceramics- and Abashevo-related groups) as the culture lost its cohesion and different local patrilineal clans used the opportunity to seize power – similar to how eventually I2a-L621 infiltrated eastern (Finno-Ugrian) groups.

Related

Yamna the likely source of modern horse domesticates; the closest lineage, from East Bell Beakers

Open access Tracking Five Millennia of Horse Management with Extensive Ancient Genome Time Series, by Fages et al. Cell (2019).

Interesting excerpts (emphasis mine):

The earliest archaeological evidence of horse milking, harnessing, and corralling is found in the ∼5,500-year-old Botai culture of Central Asian steppes (Gaunitz et al., 2018, Outram et al., 2009; see Kosintsev and Kuznetsov, 2013 for discussion). Botai-like horses are, however, not the direct ancestors of modern domesticates but of Przewalski’s horses (Gaunitz et al., 2018). The genetic origin of modern domesticates thus remains contentious, with suggested candidates in the Pontic-Caspian steppes (Anthony, 2007), Anatolia (Arbuckle, 2012, Benecke, 2006), and Iberia (Uerpmann, 1990, Warmuth et al., 2011). Irrespective of the origins of domestication, the horse genome is known to have been reshaped significantly within the last ∼2,300 years (Librado et al., 2017, Wallner et al., 2017, Wutke et al., 2018). However, when and in which context(s) such changes occurred remains largely unknown.

To clarify the origins of domestic horses and reveal their subsequent transformation by past equestrian civilizations, we generated DNA data from 278 equine subfossils with ages mostly spanning the last six millennia (n = 265, 95%) (Figures 1A and 1B; Table S1; STAR Methods). Endogenous DNA content was compatible with economical sequencing of 87 new horse genomes to an average depth-of-coverage of 1.0- to 9.3-fold (median = 3.3-fold; Table S2). This more than doubles the number of ancient horse genomes hitherto characterized. With a total of 129 ancient genomes, 30 modern genomes, and new genome-scale data from 132 ancient individuals (0.01- to 0.9-fold, median = 0.08-fold), our dataset represents the largest genome-scale time series published for a non-human organism (Tables S2, S3, and S4; STAR Methods).

genetic-affinities-horse-domesticates-pca
Genetic Affinities.
(A)
Principal Component Analysis (PCA) of 159 ancient and modern horse genomes showing at least 1-fold average depth-of-coverage. The overall genetic structure is shown for the first three principal components, which summarize 11.6%, 10.4% and 8.2% of the total genetic variation, respectively. The two specimens MerzlyYar_Rus45_23789 and Dunaujvaros_Duk2_4077 discussed in the main text are highlighted. See also Figure S7 and Table S5 for further information.
(B) Visualization of the genetic affinities among individuals, as revealed by the struct-f4 algorithm and 878,475 f4 permutations. The f4 calculation was conditioned on nucleotide transversions present in all groups, with samples were grouped as in TreeMix analyses (Figure 3). In contrast to PCA, f4 permutations measure genetic drift along internal branches. They are thus more likely to reveal ancient population substructure.

Discovering Two Divergent and Extinct Lineages of Horses

Domestic and Przewalski’s horses are the only two extant horse lineages (Der Sarkissian et al., 2015). Another lineage was genetically identified from three bones dated to ∼43,000–5,000 years ago (Librado et al., 2015, Schubert et al., 2014a). It showed morphological affinities to an extinct horse species described as Equus lenensis (Boeskorov et al., 2018). We now find that this extinct lineage also extended to Southern Siberia, following the principal component analysis (PCA), phylogenetic, and f3-outgroup clustering of an ∼24,000-year-old specimen from the Tuva Republic within this group (Figures 3, 5A and S7A). This new specimen (MerzlyYar_Rus45_23789) carries an extremely divergent mtDNA only found in the New Siberian Islands some ∼33,200 years ago (Orlando et al., 2013) (Figure 6A; STAR Methods) and absent from the three bones previously sequenced. This suggests that a divergent ghost lineage of horses contributed to the genetic ancestry of MerzlyYar_Rus45_23789. However, both the timing and location of the genetic contact between E. lenensis and this ghost lineage remain unknown.

modern-horse-domesticates-przewalski-hungary
Population modeling of the demographic changes and admixture events in extant and extinct horse lineages. The two models presented show best fitting to the observed multi-dimensional SFS in momi2. The width of each branch scales with effective size variation, while colored dashed lines indicate admixture proportions and their directionality. The robustness of each model was inferred from 100 bootstrap pseudo-replicates. Time is shown in a linear scale up to 120,000 years ago and in a logarithmic scale above.

Modeling Demography and Admixture of Extinct and Extant Horse Lineages

Phylogenetic reconstructions without gene flow indicated that IBE differentiated prior to the divergence between DOM2 and Przewalski’s horses (Figure 3; STAR Methods). However, allowing for one migration edge in TreeMix suggested closer affinities with one single Hungarian DOM2 specimen from the 3rd mill. BCE (Dunaujvaros_Duk2_4077), with extensive genetic contribution (38.6%) from the branch ancestral to all horses (Figure S7B).This, and the extremely divergent IBE Y chromosome (Figure 6B), suggest that a divergent but yet unidentified ghost population could have contributed to the IBE genetic makeup.

Rejecting Iberian Contribution to Modern Domesticates

The genome sequences of four ∼4,800- to 3,900-year-old IBE specimens characterized here allowed us to clarify ongoing debates about the possible contribution of Iberia to horse domestication (Benecke, 2006, Uerpmann, 1990, Warmuth et al., 2011). Calculating the so-called fG ratio (Martin et al., 2015) provided a minimal boundary for the IBE contribution to DOM2 members (Cahill et al., 2013) (Figure 7A). The maximum of such estimate was found in the Hungarian Dunaujvaros_Duk2_4077 specimen (∼11.7%–12.2%), consistent with its TreeMix clustering with IBE when allowing for one migration edge (Figure S7B). This specimen was previously suggested to share ancestry with a yet-unidentified population (Gaunitz et al., 2018). Calculation of f4-statistics indicates that this population is not related to E. lenensis but to IBE (Figure 7B; STAR Methods). Therefore, IBE or horses closely related to IBE, contributed ancestry to animals found at an Early Bronze Age trade center in Hungary from the late 3rd mill. BCE. This could indicate that there was long-distance exchange of horses during the Bell Beaker phenomenon (Olalde et al., 2018). The fG minimal boundary for the IBE contribution into an Iron Age Spanish horse (ElsVilars_UE4618_2672) was still important (~9.6%–10.1%), suggesting that an IBE genetic influence persisted in Iberia until at least the 7th century BCE in a domestic context. However, fG estimates were more limited for almost all ancient and modern horses investigated (median = ~4.9%–5.4%; Figure 7A).

horse-lineages-domesticates-przewalski-dom2-botai
TreeMix Phylogenetic Relationships. The tree topology was inferred using a total of ∼16.8 million transversion sites and disregarding migration. The name of each sample provides the archaeological site as a prefix, and the age of the specimen as a suffix (years ago). Name suffixes (E) and (A) denote European and Asian ancient horses, respectively. See Table S5 for dataset information. Image modified to include the likely ancestor of domesticates in a red circle, represented by Yamna, the most likely direct ancestor of the Dunaujvarus specimen.

Iron Age horses

Y chromosome nucleotide diversity (π) decreased steadily in both continents during the last ∼2,000 years but dropped to present-day levels only after 850–1,350 CE (Figures 2B and S2E; STAR Methods). This is consistent with the dominance of an ∼1,000- to 700-year-old oriental haplogroup in most modern studs (Felkel et al., 2018, Wallner et al., 2017). Our data also indicate that the growing influence of specific stallion lines post-Renaissance (Wallner et al., 2017) was responsible for as much as a 3.8- to 10.0-fold drop in Y chromosome diversity.

We then calculated Y chromosome π estimates within past cultures represented by a minimum of three males to clarify the historical contexts that most impacted Y chromosome diversity. This confirmed the temporal trajectory observed above as Byzantine horses (287–861 CE) and horses from the Great Mongolian Empire (1,206–1,368 CE) showed limited yet larger-than-modern diversity. Bronze Age Deer Stone horses from Mongolia, medieval Aukštaičiai horses from Lithuania (C9th–C10th [ninth through the tenth centuries of the Common Era]), and Iron Age Pazyryk Scythian horses showed similar diversity levels (0.000256–0.000267) (Figure 2A). However, diversity was larger in La Tène, Roman, and Gallo-Roman horses, where Y-to-autosomal π ratios were close to 0.25. This contrasts to modern horses, where marked selection of specific patrilines drives Y-to-autosomal π ratios substantially below 0.25 (0.0193–0.0396) (Figure 2A). The close-to-0.25 Y-to-autosomal π ratios found in La Tène, Roman, and Gallo-Roman horses suggest breeding strategies involving an even reproductive success among stallions or equally biased reproductive success in both sexes (Wilson Sayres et al., 2014).

Lineage is used in this paper, as in many others in genetics, as defined by a specific ancestry. I keep that nomenclature below. It should not be confused with the “lineages” or “lines” referring to Y-chromosome (or mtDNA) haplogroups.

Supporting the “archaic” nature of the Hungarian BBC horses expanding from the Pontic-Caspian steppes are:

  • Among Y-chromosome lines, the common group formed by Botai-Borly4 (closely related to DOM2), Scythian horses from Aldy Bel (Arzhani), Iron Age horses from Estonia (Ridala), horses from the Xiongnu culture (Uushgiin Uvur), and Roman horses from Autricum (Chartres).
  • Among mtDNA lines, the common group formed by Botai samples, LebyazhinkaIV NB35, and different Eurasian domesticates, including many ancient Western European ones, which reveals a likely expansion of certain subclades east and west with the Repin culture.
  • (…) DOM2 contributed 22% to the ancestor of Przewalski’s horses ca. 9.47 kya, suggesting the Holocene optimum, rather than the Eneolithic Botai culture (∼5.5 kya), as a period of population contact. This pre-Botai introgression could explain the Y chromosome topology, where Botai horses were reported to carry two different segregating haplogroups: one occupied a basal position in the phylogeny while the other was closely related to DOM2. Multiple admixture pulses, however, are known to have occurred along the divergence of DOM2 and the Botai-Borly4 lineage, including 2.3% post-Borly4 contribution to DOM2, and a more recent 6.8% DOM2 intogression into Przewalski’s horses (Gaunitz et al., 2018). Model C2 parameters accommodate all these as a single admixture pulse, likely averaging the contributions of all these multiple events.

    horse-domesticate-y-dna-mtdna
    Tip labels are respectively composed of individual sample names, their reference number as well as their age (years ago, from 2017). Red, orange, light green, green, dark green and blue refer to modern horses, ancient DOM2, Botai horses, Borly4 horses, Przewalski’s horses and E. lenensis, respectively. Black refers to wild horses not yet identified to belong to any particular cluster in absence of sufficient genome-scale data. Clades composed of only Przewalski’s horses or ancient DOM2 horses were collapsed to increase readability.

    (A) Best maximum likelihood tree retracing the phylogenetic relationships between 270 mitochondrial genomes.

    B) Best Y chromosome maximum likelihood tree (GTRGAMMA substitution model) excluding outgroup. Node supports are indicated as fractions of 100 bootstrap pseudoreplicates. Bootstrap supports inferior to 90% are not shown. The root was placed on the tree midpoint. See also Table S5 for dataset information.

    Image modified from the paper, including a red square in archaic groups that contain the Hungarian sample, and a red circle around the most likely common ancestral stallion and mare from the Pontic-Caspian steppes.

    The paper cannot offer a detailed picture of ancient horse domestication, but it is yet another step in showing how Repin/Yamna is the most likely source of expansion of horse domesticates in Eurasia. Even more interestingly, Yamna settlers in Hungary probably expanded an ancient lineage of that horse at the same time as they spread with the Classical Bell Beaker culture. Remarkable parallels are thus found between:

    The expansion of an ancient line of horse domesticates related to Yamna Hungary/East Bell Beakers seems to be confirmed by the pre-Iberian sample from Vilars I, Els Vilars4618 2672 (ca. 700-550 BC), likely of Iberian Beaker descent, showing a lineage older than the Indo-Iranian ones, which later replaced most European lines.

    NOTE. For known contacts between Yamna and Proto-Beakers just before the expansion of East Bell Beakers, see a recent post on Vanguard Yamna groups.

    The findings of the paper confirm the expansion of the horse firstly (and mainly) through the steppe biome, mimicking the expansion of Proto-Indo-Europeans first, and then replaced gradually (or not so gradually) by lines brought to Europe during westward expansions of Bronze Age, Iron Age, and later specialized horse-riding steppe cultures. The expansion also correlates well with the known spread of animal traction and pastoralism before 2000 BC:

    animal-traction-europe
    Top image: Map with evidence of animal traction before ca. 2000 BC. Bottom image: frequency of finds of evidence for animal traction (orange), cylinder seals (purple) and potter’s wheels (green) in the 4th and 3rd millennium BC (query from the Digital Atlas of Innovations). The data points to an early peak in the expansion of this innovation at the turn of the 4th–3rd millennium BC, while direct evidence supports a radical increase from around the mid–3th millennium BC until the early 2nd millennium, coinciding with the expansion of East Bell Beakers and related European Early Bronze Age cultures. Data and image modified from Klimscha (2017).

    EDIT (3 MAY 2019): A recent reminder of these parallel developments by David Reich in Insights into language expansions from ancient DNA:

    • Yamna expansion to the west “with horses and wagons”, with a more homogeneous ancestry in modern Europeans due to later migrations from the east (and north):
    • “Descendants” of Yamna (once the culture was already “dead”), expanding to the east mainly with Corded Ware ancestry:

    Another recent open access paper on horse domestication is The horse Y chromosome as an informative marker for tracing sire lines, by Felkel et al. Scientific Reports (2019).

    Related

Uralic speakers formed clines of Corded Ware ancestry with WHG:ANE populations

steppe-forest-tundra-biomes-uralic

The preprint by Jeong et al. (2018) has been published: The genetic history of admixture across inner Eurasia Nature Ecol. Evol. (2019).

Interesting excerpts, referring mainly to Uralic peoples (emphasis mine):

A model-based clustering analysis using ADMIXTURE shows a similar pattern (Fig. 2b and Supplementary Fig. 3). Overall, the proportions of ancestry components associated with Eastern or Western Eurasians are well correlated with longitude in inner Eurasians (Fig. 3). Notable outliers include known historical migrants such as Kalmyks, Nogais and Dungans. The Uralic- and Yeniseian-speaking populations, as well as Russians from multiple locations, derive most of their Eastern Eurasian ancestry from a component most enriched in Nganasans, while Turkic/Mongolic speakers have this component together with another component most enriched in populations from the Russian Far East, such as Ulchi and Nivkh (Supplementary Fig. 3). Turkic/Mongolic speakers comprising the bottom-most cline have a distinct Western Eurasian ancestry profile: they have a high proportion of a component most enriched in Mesolithic Caucasus hunter-gatherers and Neolithic Iranians and frequently harbour another component enriched in present-day South Asians (Supplementary Fig. 4). Based on the PCA and ADMIXTURE results, we heuristically assigned inner Eurasians to three clines: the ‘forest-tundra’ cline includes Russians and all Uralic and Yeniseian speakers; the ‘steppe-forest’ cline includes Turkic- and Mongolic-speaking populations from the Volga and Altai–Sayan regions and Southern Siberia; and the ‘southern steppe’ cline includes the rest of the populations.

eurasian-clines-uralic-altaic
The first two PCs summarizing the genetic structure within 2,077 Eurasian individuals. The two PCs generally mirror geography. PC1 separates western and eastern Eurasian populations, with many inner Eurasians in the middle. PC2 separates eastern Eurasians along the northsouth cline and also separates Europeans from West Asians. Ancient individuals (color-filled shapes), including two Botai individuals, are projected onto PCs calculated from present-day individuals.

For the forest-tundra populations, the Nganasan + Srubnaya model is adequate only for the two Volga region populations, Udmurts and Besermyans (Fig. 5 and Supplementary Table 8).

For the other populations west of the Urals, six from the northeastern corner of Europe are modelled with additional Mesolithic Western European hunter-gatherer (WHG) contribution (8.2–11.4%; Supplementary Table 8), while the rest need both WHG and early Neolithic European farmers (LBK_EN; Supplementary Table 2). Nganasan-related ancestry substantially contributes to their gene pools and cannot be removed from the model without a significant decrease in the model fit (4.1–29.0% contribution; χ2 P ≤ 1.68 × 10−5; Supplementary Table 8).

west-urals-finno-ugrians-qpadm
Supplementary Table 8. QpAdm-based admixture modeling of the forest-tundra cline populations. For the 13 populations west of the Urals, we present a four-way admixture model, Nganasan+Srubnaya+WHG+LBK_EN, or its minimal adequate subset. Modified from the article, to include colors for cultures, and underlined best models for Corded Ware ancestry among Uralians.

NOTE. It doesn’t seem like Hungarians can be easily modelled with Nganasan ancestry, though…

For the 4 populations east of the Urals (Enets, Selkups, Kets and Mansi), for which the above models are not adequate, Nganasan + Srubnaya + AG3 provides a good fit (χ2 P ≥ 0.018; Fig. 5 and Supplementary Table 8). Using early Bronze Age populations from the Baikal Lake region (‘Baikal_EBA’; Supplementary Table 2) as a reference instead of Nganasan, the two-way model of Baikal_EBA + Srubnaya provides a reasonable fit (χ2 P ≥ 0.016; Supplementary Table 8) and the three-way model of Baikal_EBA + Srubnaya + AG3 is adequate but with negative AG3 contribution for Enets and Mansi (χ2 P ≥ 0.460; Supplementary Table 8).

east-urals-ugric-samoyedic-qpadm
Supplementary Table 8. QpAdm-based admixture modeling of the forest-tundra cline populations. For the four populations east of the Urals, we present three admixture models: Baikal_EBA+Srubnaya, Baikal_EBA+Srubnaya+AG3 and Nganasan+Srubnaya+AG3. For each model, we present qpAdm p-value, admixture coefficient estimates and associated 5 cM jackknife standard errors (estimate ± SE). Modified from the article, to include colors for cultures, and underlined best models for Corded Ware ancestry among Uralians.

Bronze/Iron Age populations from Southern Siberia also show a similar ancestry composition with high ANE affinity (Supplementary Table 9). The additional ANE contribution beyond the Nganasan + Srubnaya model suggests a legacy from ANE-ancestry-rich clines before the Late Bronze Age.

bronze-age-iron-age-karasuk-mezhovska-tagar-qpadm
Supplementary Table 9. QpAdm-based admixture modeling of Bronze and Iron Age populations of southern Siberia. For ancieint individuals associated with Karasuk and Tagar cultures, Nganasan+Srubnaya model is insufficient. For all five groups, adding AG3 as the third ancestry or substituting Nganasan with Baikal_EBA with higher ANE affinity provides an adequate model. For each model, we present qpAdm p-value, admixture coefficient estimates and associated 5 cM jackknife standard errors (estimate ± SE). Models with p-value ≥ 0.05 are highlighted in bold face. Modified from the article, to include colors for cultures, and underlined best models for Corded Ware ancestry among Uralians.

Lara M. Cassidy comments the results of the study in A steppe in the right direction (you can read it here):

Even among the earliest available inner Eurasian genomes, east–west connectivity is evident. These, too, form a longitudinal cline, characterized by the easterly increase of a distinct ancestry, labelled Ancient North Eurasian (ANE), lowest in western European hunter-gatherers (WHG) and highest in Palaeolithic Siberians from the Baikal region. Flow-through from this ANE cline is seen in steppe populations until at least the Bronze Age, including the world’s earliest known horse herders — the Botai. However, this is eroded over time by migration from west and east, following agricultural adoption on the continental peripheries (Fig. 1b,c).

Strikingly, Jeong et al. model the modern upper steppe cline as a simple two-way mixture between western Late Bronze Age herders and Northeast Asians (Fig. 1c), with no detectable residue from the older ANE cline. They propose modern steppe peoples were established mainly through migrations post-dating the Bronze Age, a sequence for which has been recently outlined using ancient genomes. In contrast, they confirm a substantial ANE legacy in modern Siberians of the northernmost cline, a pattern mirrored in excesses of WHG ancestry west of the Urals (Fig. 1b). This marks the inhospitable biome as a reservoir for older lineages, an indication that longstanding barriers to latitudinal movement may indeed be at work, reducing the penetrance of gene flows further south along the steppe.

eurasian-clines-uralic-turkic-mongol-altaic
The genomic formation of inner Eurasians. b–d, Depiction of the three main clines of ancestry identified among Inner Eurasians. Sources of admixture for each cline are represented using proxy ancient populations, both sampled and hypothesised, based on the study’s modelling results. The major eastern and western ancestries used to model each cline are shown in bold; the peripheral admixtures that gave rise to these are also shown. Additional contributions to subsections of each cline are marked with dashed lines. b, The northernmost cline, illustrating the legacy of WHG and ANE-related populations. c,d, The upper (c) and lower (d) steppe clines are shown, both of which have substantial eastern contributions related to modern Tungusic speakers. The authors propose these populations are themselves the result of an admixture between groups related to the Nganasan, whose ancestors potentially occupied a wider range, and hunter-gatherers (HGs) from the Amur River Basin. While the upper steppe cline in c can be described as a mixture between this eastern ancestry and western steppe herders, the current model for the southern steppe cline as shown in d is not adequate and is likely confounded by interactions with diverse bordering ancestries. Credit: Ecoregions 2017, Resolve https://ecoregions2017.appspot.com/

Given the findings as reported in the paper, I think it should be much easier to describe different subclines in the “northernmost cline” than in the much more recent “Turkic/Mongolic cline”, which is nevertheless subdivided in this paper in two clines. As an example, there are at least two obvious clines with “Nganasan-related meta-populations” among Uralians, which converge in a common Steppe MLBA (i.e. Corded Ware) ancestry – one with Palaeo-Laplandic peoples, and another one with different Palaeo-Siberian populations:

siberian-clines-uralic-altaic
PCA of ancient and modern Eurasian samples. Ancient Palaeo-Laplandic, Palaeosiberian, and Altai clines drawn, with modern populations labelled. See a version with higher resolution.

The inclusion of certain Eurasian groups (or lack thereof) in the PCA doesn’t help to distinguish these subclines visually, and I guess the tiny “Naganasan-related” ancestral components found in some western populations (e.g. the famous ~5% among Estonians) probably don’t lend themselves easily to further subdivisions. Notice, nevertheless, the different components of the Eastern Eurasian source populations among Finno-Ugrians:

uralic-admixture-qpadm
Characterization of the Western and Eastern Eurasian source ancestries in inner Eurasian populations. [Modified from the paper, includes only Uralic populations]. a, Admixture f3 values are compared for different Eastern Eurasian (Mixe, Nganasan and Ulchi; green) and Western Eurasian references (Srubnaya and Chalcolithic Iranians (Iran_ChL); red). For each target group, darker shades mark more negative f3 values. b, Weights of donor populations in two sources characterizing the main admixture signal (date 1 and PC1) in the GLOBETROTTER analysis. We merged 167 donor populations into 12 groups (top right). Target populations were split into five groups (from top to bottom): Aleuts; the forest-tundra cline populations; the steppe-forest cline populations; the southern steppe cline populations; and ‘others’.

Also remarkable is the lack of comparison of Uralic populations with other neighbouring ones, since the described Uralic-like ancestry of Russians was already known, and is most likely due to the recent acculturation of Uralic-speaking peoples in the cradle of Russians, right before their eastward expansions.

west-eurasian-east-eurasian-ancestry
Supplementary Fig. 4. ADMIXTURE results qualitatively support PCA-based grouping of inner Eurasians into three clines. (A) Most southern steppe cline populations derive a higher proportion of their total Western Eurasian ancestry from a source related to Caucasus, Iran and South Asian populations. (B) Turkic- and Mongolic-speaking populations tend to derive their Eastern Eurasian ancestry more from the Devil’s Gate related one than from Nganasan-related one, while the opposite is true for Uralic- and Yeiseian-speakers. To estimate overall western Eurasian ancestry proportion, we sum up four components in our ADMIXTURE results (K=14), which are the dominant components in Neolithic Anatolians (“Anatolia_N”), Mesolithic western European hunter-gatherers (“WHG”), early Holocene Caucasus hunter-gatherers (“CHG”) and Mala from southern India, respectively. The “West / South Asian ancestry” is a fraction of it, calculated by summing up the last two components. To estimate overall Eastern Eurasian ancestry proportion, we sum up six components, most prevalent in Surui, Chipewyan, Itelmen, Nganasan, Atayal and early Neolithic Russian Far East individuals (“Devil’s Gate”). Eurasians into three clines. (A) Most southern steppe cline populations derive a higher proportion of their total Western Eurasian ancestry from a source related to Caucasus, Iran and South Asian populations. (B) Turkic- and Mongolic-speaking populations tend to derive their Eastern Eurasian ancestry more from the Devil’s Gate related one than from Nganasan-related one, while the opposite is true for Uralic- and Yeiseian-speakers. To estimate overall western Eurasian ancestry proportion, we sum up four components in our ADMIXTURE results (K=14), which are the dominant components in Neolithic Anatolians (“Anatolia_N”), Mesolithic western European hunter-gatherers (“WHG”), early Holocene Caucasus hunter-gatherers (“CHG”) and Mala from southern India, respectively. The “West / South Asian ancestry” is a fraction of it, calculated by summing up the last two components. To estimate overall Eastern Eurasian ancestry proportion, we sum up six components, most prevalent in Surui, Chipewyan, Itelmen, Nganasan, Atayal and early Neolithic Russian Far East individuals (“Devil’s Gate”).

A comparison of Estonians and Finns with Balts, Scandinavians, and Eastern Europeans would have been more informative for the division of the different so-called “Nganasan-like meta-populations”, and to ascertain which one of these ancestral peoples along the ancient WHG:ANE cline could actually be connected (if at all) to the Cis-Urals.

Because, after all, based on linguistics and archaeology, geneticists are not supposed to be looking for populations from the North Asian Arctic region, for “Siberian ancestry”, or for haplogroup N1c – despite previous works by their peers – , but for the Bronze Age Volga-Kama region…

Related

How the genocidal Yamnaya men loved to switch cultures

yamnaya-expansion-bell-beaker

After some really interesting fantasy full of arrows, it seems Kristiansen & friends are coming back to their most original idea from 2015, now in New Scientist’s recent clickbait Story of most murderous people of all time revealed in ancient DNA (2019):

Teams led by David Reich at Harvard Medical School and Eske Willerslev at the University of Copenhagen in Denmark announced, independently, that occupants of Corded Ware graves in Germany could trace about three-quarters of their genetic ancestry to the Yamnaya. It seemed that Corded Ware people weren’t simply copying the Yamnaya; to a large degree they actually were Yamnayan in origin.

If you think you have seen that movie, it’s because you have. They are at it again, Corded Ware from Yamna, and more “steppe ancestry” = “more Indo-European. It seems we haven’t learnt anything about “Steppe ancestry” since 2015. But there’s more:

Genocidal peoples who “switch cultures”

Burial practices shifted dramatically, a warrior class appeared, and there seems to have been a sharp upsurge in lethal violence. “I’ve become increasingly convinced there must have been a kind of genocide,” says Kristian Kristiansen at the University of Gothenburg, Sweden.

The collaboration revealed that the origin and initial spread of Bell Beaker culture had little to do – at least genetically – with the expansion of the Yamnaya or Corded Ware people into central Europe. “It started in It is in that region that the earliest Bell Beaker objects – including arrowheads, copper daggers and distinctive Bell-shaped pots – have been found, in archaeological sites carbon-dated to 4700 years ago. Then, Bell Beaker culture began to spread east, although the people more or less stayed put. By about 4600 years ago, it reached the most westerly Corded Ware people around where the Netherlands now lies. For reasons still unclear, the Corded Ware people fully embraced it. “They simply take on part of the Bell Beaker package and become Beaker people,” says Kristiansen.

The fact that the genetic analysis showed the Britons then all-but disappeared within a couple of generations might be significant. It suggests the capacity for violence that emerged when the Yamnaya lived on the Eurasia steppe remained even as these people moved into Europe, switched identity from Yamnaya to Corded Ware, and then switched again from Corded Ware to Bell Beaker.

Notice what Kristiansen did there? Yamnaya men “switched identities” into Corded Ware, then “switched identities” into Bell Beakers…So, the most aggresive peoples who have ever existed, exterminating all other Europeans, were actually not so violent when embracing wholly different cultures whose main connection is that they built kurgans (yes, Gimbutas lives on).

NOTE. By the way, just so we are clear, only Indo-Europeans are “genocidal”. Not like Neolithic farmers, or Palaeolithic or Mesolithic populations, or more recent Bronze Age or Iron Age peoples, who also replaced Y-DNA from many regions…

yamnaya-corded-ware-bell-beaker

In fact, there is much stronger evidence that these Yamnaya Beakers were ruthless. By about 4500 years ago, they had pushed westwards into the Iberian Peninsula, where the Bell Beaker culture originated a few centuries earlier. Within a few generations, about 40 per cent of the DNA of people in the region could be traced back to the incoming Yamnaya Beakers, according to research by a large team including Reich that was published this month. More strikingly, the ancient DNA analysis reveals that essentially all the men have Y chromosomes characteristic of the Yamnaya, suggesting only Yamnaya men had children.

“The collision of these two populations was not a friendly one, not an equal one, but one where the males from outside were displacing local males and did so almost completely,” Reich told New Scientist Live in September. This supports Kristiansen’s view of the Yamnaya and their descendants as an almost unimaginably violent people. Indeed, he is about to publish a paper in which he argues that they were responsible for the genocide of Neolithic Europe’s men. “It’s the only way to explain that no male Neolithic lines survived,” he says.

So these unimaginably violent Yamnaya men had children exclusively with their Y chromosomes…but not Dutch Single Grave peoples. These great great steppe-like northerners switched culture, cephalic index…and Y-chromosome from R1a (and others) to R1b-L151 to expand Italo-Celtic From The West™.

It’s hilarious how (exactly like their latest funny episode of PIE from south of the Caucasus) this new visionary idea copied by Copenhagen from amateur friends (or was it the other way around?) had been already rejected before this article came out, in Olalde et al. (2019), and that “Corded Ware=Indo-European” fans have become a parody of themselves.

What’s not to love about 2019 with all this back-and-forth hopping between old and new pet theories?

NOTE. I would complain (again) that the obsessive idea of the Danes is that Denmark CWC is (surprise!) the Pre-Germanic community, so it has nothing to do with “steppe ancestry = Indo-European” (or even with “Corded Ware = Indo-European”, for that matter), but then again you have Koch still arguing for Celtic from the West, Kortlandt still arguing for Balto-Slavic from the east, and – no doubt worst of all – “R1a=IE / R1b=Vasconic / N1c=Uralic” ethnonationalists arguing for whatever is necessary right now, in spite of genetic research.

So prepare for the next episode in the nativist and haplogroup fetishist comedy, now with western and eastern Europeans hand in hand: Samara -> Khvalynsk -> Yamnaya -> Bell Beaker spoke Vasconic-Tyrsenian, because R1b. Wait for it…

Vanguard Yamnaya groups

On a serious note, interesting comment by Heyd in the article:

A striking example of this distinction is a discovery made near the town of Valencina de la Concepción in southern Spain. Archaeologists working there found a Yamnaya-like kurgan, below which was the body of a man buried with a dagger and Yamnaya-like sandals, and decorated with red pigment just as Yamnaya dead were. But the burial is 4875 years old and genetic information suggests Yamnaya-related people didn’t reach that far west until perhaps 4500 years ago. “Genetically, I’m pretty sure this burial has nothing to do with the Yamnaya or the Corded Ware,” says Heyd. “But culturally – identity-wise – there is an aspect that can be clearly linked with them.” It would appear that the ideology, lifestyle and death rituals of the Yamnaya could sometimes run far ahead of the migrants.

NOTE. I have been trying to find which kurgan is this, reviewing this text on the archaeological site, but didn’t find anything beyond occasional ochre and votive sandals, which are usual. Does some reader know which one is it?

yamna-expansion-bell-beakers
Yamna expansion and succeeding East Bell Beaker expansion, without color on Bell Beaker territories. Notice vanguard Yamna groups in blue where East Bell Beakers later emerge. See original image with Bell Beaker territories.

Notice how, if you add all those vanguard Yamna findings of Central and Western Europe, including this one from southern Spain, you begin to get a good idea of the territories occupied by East Bell Beakers expanding later. More or less like vanguard Abashevo and Sintashta finds in the Zeravshan valley heralded the steppe-related Srubna-Andronovo expansions in Turan…

It doesn’t seem like Proto-Beaker and Yamna just “crossed paths” at some precise time around the Lower Danube, and Yamna men “switched cultures”. It seems that many Yamna vanguard groups, probably still in long-distance contact with Yamna settlers from the Carpathian Basin, were already settled in different European regions in the first half of the 3rd millennium BC, before the explosive expansion of East Bell Beakers ca. 2500 BC. As Heyd says, there are potentially many Yamna settlements along the Middle and Lower Danube and tributaries not yet found, connecting the Carpathian Basin to Western and Northern Europe.

These vanguard groups would have more easily transformed their weakened eastern Yamna connections with the fashionable Proto-Beaker package expanding from the west (and surrounding all of these loosely connected settlements), just like the Yamna materials from Seville probably represent a close cultural contact of Chalcolithic Iberia with a Yamna settlement (the closest known site with Yamna traits is near Alsace, where high Yamna ancestry is probably going to be found in a Bell Beaker R1b-L151 individual).

This does not mean that there wasn’t a secondary full-scale migration from the Carpathian Basin and nearby settlements, just like Corded Ware shows a secondary (A-horizon?) migration to the east with R1a-Z645. It just means that there was a complex picture of contacts between Yamna and European Chalcolithic groups before the expansion of Bell Beakers. Doesn’t seem genocidal enough for a popular movie, tho.

Related