“Steppe ancestry” step by step (2019): Mesolithic to Early Bronze Age Eurasia

Featuredyamnaya-gac-maykop-corded-ware-bell-beaker

The recent update on the Indo-Anatolian homeland in the Middle Volga region and its evolution as the Indo-Tocharian homeland in the Don–Volga area as described in Anthony (2019) has, at last, a strong scientific foundation, as it relies on previous linguistic and archaeological theories, now coupled with ancient phylogeography and genomic ancestry.

There are still some inconsistencies in the interpretation of the so-called “Steppe ancestry”, though, despite the one and a half years that have passed since we first had access to the closest Pontic–Caspian steppe source populations. Even my post “Steppe ancestry” step by step from a year ago is already outdated.

Admixture

The population selection process for models shown below included (1) plausibility of potential influences in the particular geographic and archaeological context; (2) looking for their clusters or particular samples in the PCA; and (3) testing with qpAdm for potential source populations that might have been involved in their development.

The results and graphics posted are therefore intended to simplistically show potential admixture events between populations potentially close to the actual sources of the target samples, whenever such mating networks could be supported by archaeology.

NOTE. This is an informal post and I am not a geneticist, so I am turning this flexibility to my advantage. If any reader is – for some strange reason – looking for a strict hypothesis testing, for the use of a full set of formal stats (as used e.g. in Ning et al. 2019 for Proto-Tocharians), and correctly redacted and peer-reviewed text, this is not the right place to find them.

spatial-pedigree-geographic-admixture
An example pedigree (a) of a focal individual sampled in the modern day, placed in its geographic context to make the spatial pedigree (b). Dashed lines denote matings, and solid lines denote parentage, with red hues for the maternal ancestors and blue hues for the paternal ancestors. In the spatial pedigree, each plane represents a sampled region in a discrete (nonoverlapping) generation, and each dot shows the birth location of an individual. The pedigree of the focal individual is highlighted back through time and across space. Image modified from Bradburd and Ralph (2019).

Despite the natural impulse to draw straight mixture trajectories (see e.g. Wang et al. 2019), simply adding or subtracting samples used for a PCA shows how the plot is affected by different variables (see e.g. what happens by including more South Asian samples to the PCA below), hence the need to draw curved arrows – not necessarily representing a sizable drift; at least not in recent prehistoric admixture events for which we have a reasonable chronological transect.

reich-arrows-admixture-neolithic-bronze-age
Representation of mixture events between European prehistoric peoples in the PCA. Image modified from David Reich‘s Who We Are and How We Got Here (2018).

Ethnolinguistic identification is a risky business that brings back memories of an evil use of cultural history and its consequences (at least in Western Europe, where this tradition was discontinued after WWII), but it seems necessary for those of us who want to find some confirmation of proposed dialectal schemes and language contacts.

Eneolithic Steppe vs. Steppe Maykop

First things first: I tested Bronze Age Eurasian peoples for the only two true steppe populations sampled to date, as potential sources of their “Steppe ancestry” – conventionally described as an EHG:CHG admixture, similar to that found in the first sampled Yamnaya individuals. I used the rightpops of Wang et al. (2018), but with a catch: since authors used WHG as a leftpop and Villabruna as a rightpop, and I find that a little inconsequential*, I preferred the strategy in Ning et al. (2019), contrasting as outgroup Eneolithic_Steppe (ca. 4300 BC) vs. Steppe_Maykop (ca. 3500 BC) when testing for WHG as a source population.

*WHG usually includes samples from a ‘western’ cluster (Loschbour and La Braña) and an ‘eastern’ cluster (Villabruna and Koros), see Lipson et al. (2017). Therefore, it doesn’t make much sense to include the same (or a very similar) population as a source AND an outgroup.

NOTE. For all other qpAdm analyses below, where WHG was not used as leftpop, I have used Villabruna as rightpop following Wang et al. (2019).

greater-caucasus-steppe-ancestry
Map of samples and sites mentioned in Wang et al. (2019), modified from the original to include labels of Eneolithic_Steppe and Steppe_Maykop samples. See PCA and ADMIXTURE grahpic for the identification of specific samples.

Results are not much different from what has been reported. In general, Yamnaya and related groups such as Bell Beakers and Steppe-related Chalcolithic/Bronze Age populations show good fits for Eneolithic_Steppe as their closest source for Steppe ancestry, and bad fits for Steppe_Maykop, whereas Corded Ware groups show the opposite, supporting their known differences.

This trend seems to be tempered in some groups, though, most likely due the influence of Samara_LN-like admixture in Circum-Baltic Late Neolithic and Eastern Corded Ware groups, and the influence of Anatolia_N/EEF-like admixture in Balkan and late European CWC or BBC groups. In fact, the more EEF-related ancestry in a populatoin, the less reliable these generic models (and even specific ones) seem to become when distinguishing the Steppe-related source.

NOTE. For more on this, see the discussion on Circum-Baltic Corded Ware peoples, and the discussion on Mycenaeans and their potential source populations.

These are just broad strokes of what might have happened around the Pontic–Caspian steppes before and during the Early Bronze Age expansions. The most relevant quest right now for Indo-European studies is to ascertain the chain of admixture events that led to the development and expansion of Indo-Uralic and its offshoots, Indo-European and Uralic.

mesolithic-eastern-europe-post-swiderian
Eastern European Mesolithic with the expansion of Post-Swiderian cultures. See full map.

A history of Steppe ancestry

This post is divided in (more or less accurate) chronological developments as follows:

  1. Hunter-gatherer pottery and the steppes
  2. Khvalynsk and Sredni Stog
  3. Post-Stog and Proto-Corded Ware
  4. Yamnaya and Afanasievo

1. Hunter-gatherer pottery and the steppes

I laid out in the ASOSAH book series the general idea – based on attempts to reconstruct the linguistic ancestor of Indo-Uralic – that Eurasiatic speakers might have expanded with the North-Eastern Techno-Complex that spread through north-eastern Europe during the warm period represented by the transition of the Palaeolithic to the Mesolithic.

If one were to trust the traditional migrationist view, a post-Swiderian population expanded from central-eastern Europe (potentially related originally to Epi-Gravettian peoples, represented by WHG ancestry) into north-eastern Europe, and then further east into the Trans-Urals, to then reappear in eastern Europe as a back-migration represented by the spread of hunter-gatherer pottery.

The marked shift from WHG-like towards EHG-related ancestry from Baltic Mesolithic (ca. 30%) to Combed Ware cultures (ca. 65%-100%) supports this continuous westward expansion, that is possibly best represented in the currently available sampling by the ‘south-eastern’ shift (CHG:ANE-related) of the hunter-gatherer from Lebyazhinka IV (5600 BC) relative to the older one from Sidelkino (9300 BC), both from the Samara region in the Middle Volga:

Mesolithic-Neolithic transition ca. 7000-6000 BC, with hunter-gatherer pottery groups spreading westwards. See full map.

From Anthony (2019):

Along the banks of the lower Volga many excavated hunting-fishing camp sites are dated 6200-4500 BC. They could be the source of CHG ancestry in the steppes. At about 6200 BC, when these camps were first established at Kair-Shak III and Varfolomievka, they hunted primarily saiga antelope around Dzhangar, south of the lower Volga, and almost exclusively onagers in the drier desert-steppes at Kair-Shak, north of the lower Volga. Farther north at the lower/middle Volga ecotone, at sites such as Varfolomievka and Oroshaemoe hunter-fishers who made pottery similar to that at Kair-Shak hunted onagers and saiga antelope in the desert-steppe, horses in the steppe, and aurochs in the riverine forests. Finally, in the Volga steppes north of Saratov and near Samara, hunter-fishers who made a different kind of pottery (Samara type) and hunted wild horses and red deer definitely were EHG. A Samara hunter-gatherer of this era buried at Lebyazhinka IV, dated 5600-5500 BC, was one of the first named examples of the EHG genetic type (Haak et al. 2015). This individual, like others from the same region, had no or very little CHG ancestry. The CHG mating network had not yet reached Samara by 5500 BC.

Given the lack of a proper geographical and chronological transect of ancient DNA from eastern European groups, and the discontinuous appearance of both R1b-M73 and R1b-M269 lineages on both sides of the Urals within the WHG:ANE cline, where EHG appears to have formed, it is impossible at this point to assert anything with enough degree of certainty. For simplicity purposes, though, I risked to equate the expansion of R1b-M73 in West Siberia as potentially associated with Micro-Altaic, and the expansion of hg. R1b-M269 with the spread of Indo-Uralic on both sides of the Urals.

NOTE. For incrementally speculative associations of languages with prehistoric cultures and their potential link to ancestry ± haplogroup expansions, you can check sections on Early Indo-Europeans and Uralians, Indo-Uralians, Altaic peoples, Eurasians, or Nostratians. I explained why I made these simplistic choices here.

While this identification of the Indo-Uralic expansion with hg. R1b is more or less straightforward for the Cis-Urals, given the available ancient DNA samples, it will be very difficult (if at all possible) to trace the migration of these originally R1b-M269-rich populations into Trans-Uralian groups that could eventually be linked to Yukaghir speakers. The sheer number of potential admixture events and bottlenecks in Siberian forest, taiga, and tundra regions since the Mesolithic until Yukaghirs were first attested is guaranteed to give more than one headache in upcoming years…

neolithic-steppes-samara-mariupol
Spread of hunter-gatherer pottery in eastern Europe ca. 6000-5000 BC. See full map.

The slight increase in WHG-related ancestry in Ukraine Neolithic groups relative to Mesolithic ones questions the arrival of this eastern influence in the north Pontic area, or at least its relevance in genomic terms, although the cluster formed is similar to the previous one and to Combed Ware groups – despite the Central European and Baltic influences in the north Pontic region – with some samples showing 0% change relative to Mesolithic groups.

ukraine-samara-mesolithic-neolithic-evolution
Structure and change in hunter-gatherer-related populations, from Mathieson et al. (2018). Inferred ancestry proportions for populations modelled as a mixture of WHG, EHG and CHG. Dashed lines show populations from the same geographic region. Percentages indicate proportion of WHG + EHG ancestry. Standard errors range from 1.5 to 8.3%.

NOTE. For more on Indo-Uralic and its reconstruction from a linguistic point of view, check out its dedicated section on ASOSAH, or the recently published (behind paywall) The Precursors of Proto-Indo-European, edited by Kloekhorst and Pronk, Brill (2019). Authors of specific chapters have posted their contributions to Academia.edu, where they can be downloaded for free.

2. Khvalynsk and Sredni Stog

The cluster formed by the three available samples of the Khvalynsk culture (early 5th millennium BC) might be described, as expected from its position in the PCA, as a mixture of EHG-like populations of the Middle Volga with CHG-like ancestry close to that represented by samples from Progress-2 and Vonyuchka, in the North Caucasus Piedmont (ca. 4300 BC):

This variable CHG-like admixture shown in the wide cluster formed by the available Khvalynsk-related samples support the interpretation of a recently created CHG mating network in Anthony (2019):

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. 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.

steppe-ancestry-pca-neolithic-khvalynsk
Detail of the PCA of Eurasian samples, including Neolithic clusters with the hypothesized gene flows related to (1) the formation and (2) expansion of Khvalynsk and the (3) emergence of late Sredni Stog. See full image.

The richest copper assemblage found in all Khvalynsk burials belongs to an individual of hg. R1b-V1636 and intermediate Samara_HG:Eneolithic_Steppe ancestry, while full Eneolithic_Steppe-like admixture in the Middle Volga is represented by the commoner of Khvalynsk II, of hg. Q1. The finding of hg. R1b-V1636 in the North Caucasus Piedmont – and R1b-P297 in the Samara region (probably including Yekaterinovka) begs the question of the origin of hg. R1b-V1636 in the Khvalynsk community. Based on its absence in ancient samples from the forest zone, it is tempting to assign it to steppe hunter-gatherers down the Lower Volga and possibly to the east of it, who infiltrated the Samara region precisely during these population movements described by Anthony (2019).

Suvorovo-related samples from the Balkans, including the Varna and Smyadovo outliers of Steppe ancestry, are closely related to the Khvalynsk expansion:

Similarly, the ancestry of late Sredni Stog samples from Dereivka seem to be directly related to the expansion of Mariupol-like individuals over populations of Suvorovo-Novodanilovka-like admixture, as suggested by the resurgence of typical Ukraine Neolithic haplogroups, the shift in the PCA, and the models of Eneolithic_Steppe vs. Steppe_Maykop above:

#EDIT (11 Nov 2019): In fact, the position of the unpublished Greece_Neolithic outlier that appeared in the Wang et al. (2018) preprint (see full PCA and ADMIXTURE) show that the expanding Suvorovo chiefs from the Balkans formed a tight cluster close to the two published outliers with Steppe ancestry from Bulgaria.

The Ukraine_Neolithic outlier, possibly a Novodanilovka-related sample suggests, based on its position in the PCA close to the late Trypillian outlier of Steppe-related ancestry, that Ukraine_Eneolithic samples from Dereivka are a mixture of Ukraine_Neolithic and a Novodanilovka-like community similar to Suvorovo.

The Trypillian_Eneolithic-like admixture found among Proto-Corded Ware peoples (see below) would then feature potentially a small Steppe_Eneolithic-like component already present in the north Pontic area, too.

pca-suvorovo-novodanilovka-khvalynsk-trypillia-greece-ukraine-neolithic-outlier
Image modified from Wang et al. (2018). Samples projected in PCA of 84 modern-day West Eurasian populations (open symbols). Previously known clusters have been marked and referenced. Marked and labelled are the Balkan samples referenced in this text An EHG and a Caucasus ‘clouds’ have been drawn, leaving Pontic-Caspian steppe and derived groups between them. See the original file here.

Furthermore, whereas Anthony (2019) mentions a long-lasting predominance of hg. R1b in elite graves of the Eneolithic Volga basin, not a single sample of hg. R1a is mentioned supporting the community formed by the Alexandria individual, supposedly belonging to late Sredni Stog groups, but with a Corded Ware-like genetic profile (suggesting yet again that it is possibly a wrongly dated sample).

NOTE. A lack of first-hand information rather than an absence of R1a-M417 samples in the north Pontic forest-steppes would not be surprising, since Anthony is involved in the archaeology of the Middle Volga, but not in that of the north Pontic area.

eneolithic-pontic-caspian-steppe-khvalynsk-novodanilovka-suvorovo
Khvalynsk expansion through the Pontic–Caspian steppes in the early 5th millennium BC. See full map.

3. Post-Stog and Proto-Corded Ware

The origin of the Pre-Corded Ware ancestry is still a mystery, because of the heterogeneity of the sampled groups to date, and because the only ancestral sample that had a compatible genetic profile – I6561 from Alexandria – shows some details that make its radiocarbon date rather unlikely.

The most likely explanation for the closest source population of Corded Ware groups, found in the three core samples of Steppe_Maykop and in Trypillian Eneolithic samples from the first half of the 4th millennium BC, is still that a population of north Pontic forest-steppe hunter-gatherers hijacked this kind of ancestry, that was foreign to the north Pontic region before the Late Eneolithic period, later expanding east and west through the Podolian–Volhynian upland, due to the complex population movements of the Late Eneolithic.

NOTE. The idea of Trypillia influencing the formation of the Steppe_MLBA ancestry proper of Uralic peoples has been around for quite some time already, since the publication of Narasimhan et al. (2018) (see here or here).

steppe-ancestry-pca-corded-ware-bronze-age
Detail of the PCA of Eurasian samples, including Corded Ware groups and related clusters, as well as outliers, with hypothesized gene flows related to the (1) formation and (2) initial expansion of Pre-Corded Ware ancestry, as well as (3) later regional admixture events. See full image.

The specifics of how the Proto-Corded Ware community emerged remain unclear at this point, despite the simplistic description by Rassamakin (1999) of the Late Eneolithic north Pontic population movements as a two-stage migration of 1) late Trypillian groups (Usatovo) west → east, and (2) Late Maykop–Novosvobodnaya east → west. So, for example, Manzura (2016) on the Zhivotilovka “cultural-historical horizon” (emphasis mine):

Indeed, the very complex combination of different cultural traits in the burial sites of the Zhivotilovka type is able to generate certain problems in the search for the origins of this phenomenon. The only really consistent attribute is the burial rite in contracted position on the left or right side. Yu. Rassamakin is correct in asserting that this position of the deceased can be considered as new in the North Pontic region (Rassamakin 1999, 97). However, this opinion can be accepted only partially for the territory between Dniester and Lower Don. This position is well known in the Usatovo culture in the Northwest Pontic region, although skeletons on the right side are evidenced there only in double burials, whereas single burials contain the deceased only in a contracted position on the left side. On the other hand, the southern and western orientation of the deceased, which is one of the main burial traits of the Zhivotilovka type, is not characteristic of the Usatovo culture. Nevertheless, it is possible to suppose that at least part of the Usatovo population could have played a part in the formation of the cultural type under consideration here. One aspect of this cultural tradition, for instance, could be represented by skeletons on the left side and oriented in north-eastern and eastern directions.

Especially close ties can be traced between the Zhivotilovka and Maykop-Novosvobodnaya traditions, as exemplified by similar burial customs and various grave goods. It is beyond any doubt that the Maykop-Novosvobodnaya population was actively involved in the spread of the main Zhivotilovka cultural traits. The influence of North Caucasian traditions can be well observed, at least as far as the Dnieper Basin, but farther west influence is not manifested pronouncedly. The role of cultural units situated between the Dniester and Don rivers in the process of emergence of the Zhivotilovka type looks somewhat vague. Now, it can be quite confidently asserted that at the end of the 4th millennium BC this territory was settled by migrants from the North Caucasus and Carpathian-Dniester region. This event in theory had to stimulate cultural transformations in the Azov-Black Sea steppes and, thus, bearers of local cultural traditions perhaps could have participated in forming the culture under consideration. In any event, the Zhivotilovka type can be regarded as a complex phenomenon that emerged within the regime of intensive cultural dialogue and that it absorbed totally diff erent cultural traditions. The spread of the Zhivotilovka graves across the Pontic steppes from the Carpathians to the Lower Don or even to the Kuban Basin clearly signalizes a rapid dissolution of former cultural borders and the beginning of active movements of people, things and ideas over vast territories.

zhivotilovka-horizon-north-pontic-area

What were the factors or reasons that could have provoked this event? In the beginning of the second half of the 4th millennium BC two advanced cultural centers emerged in the south of Eastern Europe. These were the Maykop-Novosvobodnaya and Usatovo cultures, which in spite of their separation by great distances were structurally very alike. This is expressed in similar monumental burial architecture, complex burial rites, even the composition of grave goods, developed bronze metallurgy, high standards of material culture, etc. Both cultures in a completely formed state exemplify prosperous societies with a high level of economic and social organization, which can correspond to the type of ranked or early complex societies. Normally, the social elite in such polities tends to rigidly control basic domains social, economic and spiritual life using different mechanisms, even open compulsion (Earle 1987, 294-297). To some extent similar social entities can be found at this moment in the forest-steppe zone of the Carpathian-Dniester region, as reflected by the well organized settlement of Brânzeni III and the Vykhatitsy cemetery (Маркевич 1981; Дергачев 1978). In spite of their complex character, such societies represent rather friable structures, which could rapidly disintegrate due to unfavourable inner or external factors.

The societies in question emerged and existed during a time of favourable natural climatic conditions, which is considered to be a transitional period from the Atlantic to the Subboreal period, lasting approximately from 3600 to 3300 cal BC, or a climatic optimum for the steppe zone (Иванова и др. 2011, 108; Спиридонова, Алешинская 1999, 30-31). These conditions to a large degree could guarantee a stable exploitation of basic resources and support existing social hierarchies. However, after 3300 cal BC significant climatic changes occurred, accompanied by an increasing aridization and fall in temperature. This event is usually termed the “Piora oscillation” or “Rapid Climatic Event”, and is regarded as having been of global character (Magny, Haas 2004). These rapid changes could have seriously disturbed existing economic and social relations and finally provoked a similar rapid disintegration of complex social structures. In this case the sites of the Zhivotilovka type could represent mere fragments of former prosperous societies, which under conditions of the absence of centralized social control and stable cultural borders tried to recombine social and economic ties. However, the population possessed the necessary social experience and important technological resources, such as developed stock-breeding based on the breeding of small cattle and wheeled transport, so they were ready for opening new territories in their search for a better life.

maykop-trypillia-intrusion-steppes
Disintegration, migration, and imports of the Azov–Black Sea region. First migration event (solid arrows): Gordineşti–Maikop expansion (groups: I – Bursuchensk; II – Zhyvotylivka; III – Vovchans’k; IV – Crimean; V – Lower Don; VI – pre-Kuban). Second migration event (hollow arrows): Repin expansion. After Rassamakin (1999), Demchenko (2016).

For more on chronology and the potentially larger, longer-lasting Zhivotilovka–Volchansk–Gordineşti cultural horizon and its expansion through the Podolian–Volhynian upland, read e.g. on the Yampil Complex in the latest volume 22 of Baltic-Pontic Studies (2017):

In the forest-steppe zone of the North-West Pontic area, important data concerning the chronological position of the Zhivotilovka-Volchansk group have been produced by the exploration of the Bursuceni kurgan, which is still awaiting full publication [Yarovoy 1978; cf. also Demcenko 2016; Manzura 2016]. Burials linked with the mentioned group were stratigraphically the eldest in the kurgan, and pre-dated a burial in the extended position and [Yamnaya culture] graves. Two of these burials (features 20 and 21) produced radiocarbon dates falling around 3350-3100 BC [Petrenko, Kovaliukh 2003: 108, Tab. 7]. Similar absolute age determinations were obtained for Podolia kurgans at Prydnistryanske [Goslar et al. 2015]. These dates, falling within the Late Eneolithic, mark the currently oldest horizon of kurgan burials in the forest-steppe zone of the North-West Pontic area. The Podolia graves linked with other, older traditions of the steppe Eneolithic seem to represent a slightly later horizon dated to the transition between the Late Eneolithic and Early Bronze Age.

The presence on the left bank of the Dniester River of kurgans associated with the Eneolithic tradition, which at the same time reveals connections with the Gordineşti-Kasperovce-Horodiştea complex, raises questions about the western range of the new trend in funerary rituals, and its potential connection with the expansion of the late Trypilia culture to the West Podolia and West Volhynia Regions. The data potentially suggesting the attribution of kurgans from the upper Dniester basin to this period is patchy and difficult to verify [e.g. Liczkowce – see Sulimirski 1968: 173]. In this context, the discovery of vessels in the Gordineşti style in a kurgan at Zawisznia near Sokal is inspiring [Antoniewicz 1925].

zhivotilovka-volchansk-burial-podolia
Burials representing funerary traditions of Zhivotilovka-Volchansk group in Podolie kurgans: 1 – Porohy, grave 3A/7, 2 – Kuzmin, grave 2/2 [after Klochko et al. 2015b, Bubulich, Khakhey 2001]

Another interesting aspect of potential source populations, in combination with those above for Eneolithic_Steppe vs. Steppe_Maykop, are groups with worse fits for Steppe_Maykop_core, which include Potapovka and Srubnaya, as reported by Wang et al. (2018), but also Sintastha_MLBA (although not Andronovo). This is compatible with the long-term admixture of Abashevo chiefs dominating over a majority of Poltavka-like herders in the Don-Volga-Ural steppes during the formation of the Sintashta-Potapovka-Filatovka community, also visible in the typical Yamnaya lineages and Yamnaya-like ancestry still appearing in the region centuries after the change in power structures had occurred.

NOTE. If you feel tempted to test for mixtures of Khvalynsk_EN, Eneolithic_Steppe, Yamnaya, etc. as a source population for Corded Ware, go for it, but it’s almost certain to give similar ‘good’ fits – whatever the model – in some Corded Ware groups and not in others. It is still unclear, as far as I know, how to formally distinguish a mixture of Corded Ware-related from a Yamnaya-related source in the same model, and the results obtained with a combination of Steppe_Maykop-related + Eneolithic_Steppe-related sources will probably artificially select either one or the other source, as it probably happened in Ning et al. (2019) with Proto-Tocharian samples (see qpAdm values) that most likely had a contribution of both, based on their known intense interactions in the Tarim Basin.

eneolithic-pontic-caspian-steppes-east-europe
Expansion of north Pontic cultures and related groups during the Late Eneolithic. See full map.

4. Yamnaya and Afanasievo

I don’t think it makes much sense to test for GAC (or Iberia_CA, for that matter) as Wang et al. (2019) did, given the implausibility of them taking part in the formation of late Repin during the mid-4th millennium BC around the Don-Volga interfluve (represented by its offshoots Yamnaya and Afanasievo), whether these or other EEF-related populations show ‘better’ fits or not. Therefore, I only tested for more or less straightforward potential source populations:

steppe-ancestry-pca-yamnaya-hungary-bulgaria-vucedol
Detail of the PCA of Eurasian samples, including Yamnaya groups and related clusters, as well as outliers, with hypothesized gene flows related to its (1) formation and (2) expansion. Also included is the inferred position of the admixed sample Yamnaya_Hungary_EBA1. See full image.

Quite unexpectedly – for me, at least – it appears that Afanasievo and Yamnaya invariably prefer Khvalynsk_EN as the closest source rather than a combination including Eneolithic_Steppe directly. In other words, late Repin shows largely genetic continuity with the Steppe ancestry already shown by the three sampled individuals from the Khvalynsk II cemetery, in line with the known strong bottlenecks of Khvalynsk-related groups under R1b lineages, visible also later in Afanasievo and Yamnaya and derived Indo-European-speaking groups under R1b-L23 subclades.

NOTE. This explains better the reported bad fits of models using directly Eneolithic_Steppe instead of Khvalynsk_EN for Afanasievo and Yamnaya Kalmykia, as is readily evident from the results above, instead of a rejection of an additional contribution to an Eneolithic_Steppe-like population, as I interpreted it, based on Anthony (2019).

repin-zhivotilovka-north-pontic-steppe
Map of major sites of the Zhivotilovka-Volchansk group (A) and Repin culture (B), by Rassamakin (see 1994 and 2013). (A) 1 – Primorskoye; 2 – Vasilevka; 3 – Aleksandrovka; 4 – Boguslav; 5 – Pavlograd; 6 – Zhivotilovka; 7 – Podgorodnoye; 8 – Novomoskovsk; 9- Sokolovo; 10 – Dneprelstan; 11- Razumovka; 12 – Pologi; 13 – Vinogradnoye; 14 – Novo-Filipovka; 15 – Volchansk; 16 – Yuryevka; 17 – Davydovka; 18 – Novovorontsovka; 19 – Ust-Kamenka; 20 – Staroselye; 21- Velikaya Aleksandrovka; 22- Kovalevka; 23 – Tiraspol; 24 – Cura-Bykuluy; 25 – Roshkany; 26 – Tarakliya; 27 – Kazakliya; 28 – Bolgrad; 29 – Sarateny; 30 – Bursucheny; 31 – Novye Duruitory; 232 – Kosteshty. (B) 1 – Podgorovka; 2 – Aleksandria; 3 – Volonterovka; 4 – Zamozhnoye; 5 – Kremenevka; 6 – Ogorodnoye; 7 – Boguslav; 8 – Aleksandrovka; 9 – Verkhnaya Mayevka; 10 – Duma Skela; 11 – Zamozhnoye; 12 – Mikhailovka II.

This might suggest that the Steppe ancestry visible in samples from Progress-2 and Vonyuchka, sharing the same cluster with the Khvalynsk II cemetery commoner of hg. Q1, most likely represents North Caspian or Black Sea–Caspian steppe hunter-gatherer ancestry that increased as Khvalynsk settlers expanded to the south-west towards the Greater Caucasus, probably through female exogamy. That would mean that Steppe_Maykop potentially represents the ‘original’ ancestry of steppe hunter-gatherers of the North Caucasus steppes, which is also weakly supported by the available similar admixture of the Lola culture. The chronology, geographical location and admixture of both clusters seemed to indicate the opposite.

eneolithic-steppe-maykop-ehg-chg-ag2
Modelling results for the Steppe and Caucasus cluster. Additional ‘eastern’ AG-Siberian gene flow in Steppe Maykop relative to Eneolithic Steppe. From Wang et al. (2019).

Due to the limitations of the currently available sampling and statistical tools, and barring the dubious Alexandria outlier, it is unclear how much of the late Trypillian-related admixture of late Repin (as reflected in Yamnaya and Afanasievo) corresponds to late Trypillian, Post-Stog, or Proto-Corded Ware groups from the north Pontic area. A mutual exchange suggestive of a common mating network (also supported by the mixed results obtained when including Khvalynsk_EN as source for early Corded Ware groups) seem to be the strongest proof to date of the Late Proto-Indo-European – Uralic contacts reflected in the period when post-laryngeal vocabulary was borrowed (with some samples predating the merged laryngeal loss), before the period of intense borrowing from Pre- and Proto-Indo-Iranian.

Between-group differences of Yamnaya samples are caused – like those between Corded Ware groups – by the admixture of a rapidly expanding society through exogamy with regional populations, evidenced by the inconstant affinities of western or southern outliers for previous local populations of the west Pontic or Caucasus area. This explanation for the gradual increase in local admixture is also supported by the strong, long-term patrilineal system and female exogamy practiced among expanding Proto-Indo-Europeans.

chalcolithic-early-bronze-yamnaya-corded-ware-vucedol
Groups of the Yamnaya culture and its western expansion after ca. 3100 BC, and Corded Ware after ca. 2900 BC See full map.

Bell Beakers and Mycenaeans

This Eneolithic_Steppe ancestry is also found among Bell Beaker groups (see above). More specifically, all Bell Beaker groups prefer a source closest to a combination of Yamnaya from the Don and Baden LCA individuals from Hungary, rather than with Corded Ware and GAC, despite the quite likely admixture of western Yamnaya settlers with (1) south-eastern European (west Pontic, Balkan) Chalcolithic populations during their expansion through the Lower Danube and with (2) late Corded Ware groups (already admixed with GAC-like populations) during their expansion as East Bell Beakers:

Similarly, Mycenaeans show good fits for a source close to the Yamnaya outlier from Bulgaria:

steppe-ancestry-pca-bell-beakers-mycenaeans
Detail of the PCA of Eurasian samples, including Bell Beaker and Balkan EBA groups and related clusters, as well as outliers, including ancestral Yamnaya samples from Hungary (position inferred) and Bulgaria. Also marked are Minoans, Mycenaeans and Armenian BA samples. See full image.

You can read more on Yamnaya-related admixture of Bell Beakers and Mycenaeans, and on Afanasievo-related admixture of Iron Age Proto-Tocharians.

Conclusion

The use of the concept of “Yamnaya ancestry”, then “Steppe ancestry” (and now even “Yamnaya Steppe ancestry“?) has already permeated the ongoing research of all labs working with human population genomics. Somehow, the conventional use of Yamnaya_Samara samples opposed to a combination of other ancient samples – alternatively selected among WHG, EHG, CHG/Iran_N, Anatolia_N, or ANE – has spread and is now unquestionably accepted as one of the “three quite distinct” ancestral groups that admixed to form the ancestry of modern Europeans, which is a rather odd, simplistic and anachronistic description of prehistory…

It has now become evident that authors involved with the Proto-Indo-European homeland question – and the tightly intertwined one of the Proto-Uralic homeland – are going to dedicate a great part of the discussion of many future papers to correct or outright reject the conclusions of previous publications, instead of simply going forward with new data.

The most striking argument to mistrust the current use of “Steppe ancestry” (as an alternative name for Yamnaya_Samara, and not as ancestry proper of steppe hunter-gatherers) is not the apparent difference in direct Eneolithic sources of Steppe ancestry for Corded Ware and Yamnaya-related peoples – closer to the available samples classified as Steppe_Maykop and Eneolithic_Steppe, respectively – or their different evolution under marked Y-DNA bottlenecks.

It is not even the lack of information about the distant origin of these Pontic–Caspian steppe hunter-gatherers of the 5th and 4th millennium BC, with their shared ancestral component potentially separated during the warmer Palaeolithic-Mesolithic transition, when the steppes were settled, without necessarily sharing any meaningful recent history before the formation of the Proto-Indo-Uralic community.

NOTE. I have raised this question multiple times since 2017 (see e.g. here or here).

The most striking paradox about simplistically misinterpreting “Steppe ancestry” as representative of Indo-European expansions is that those sub-Neolithic Pontic–Caspian steppe hunter-gatherers that had this ancestry in the 6th millennium BC were probably non-Indo-European-speaking communities, most likely related to the North(West) Caucasian language family, based on the substrate of Indo-Anatolian that sets it apart from Uralic within the Indo-Uralic trunk, and on later contacts of Indo-Tocharian with North-West Caucasian and Kartvelian, the former probably represented by Maykop and its contact with the Repin and early Yamnaya cultures.

NOTE. For more on this, see Allan Bomhard’s recent paper on the Caucasian substrate hypothesis and its ongoing supplement Additional Proto-Indo-European/Northwest Caucasian Lexical Parallels.

steppe-ancestry-racimo
“Spatiotemporal kriging of YAM steppe ancestry during the Holocene, using 5000 spatial grid points. The colors represent the predicted ancestry proportion at each point in the grid.” Image with evolution from ca. 2800 BC until the present day, modified from Racimo et al. (2019). The Copenhagen group considers the expansion of this component as representative of expanding Indo-Europeans…

This kind of error happens because we all – hence also authors, peer reviewers, and especially journal editors – love far-fetched conclusions and sensational titles, forgetting what a paper actually shows and – always more importantly in scientific reports – what it doesn’t show. This is particularly true when more than one field is involved and when extraordinary claims involve aspects foreign to the journal’s (and usually the own authors’) main interests. One would have thought that the glottochronological fiasco published in Science in 2012 (open access in PMC) should have taught an important lesson to everyone involved. It didn’t, because apparently no one has felt the responsibility or the shame to retract that paper yet, even in the age of population genomics.

If anything, the excesses of mathematical linguistics – using computational methods to try and reconstruct phylogenetic trees – have perpetuated a form of misunderstood Scientism which blindly relies on a simple promise made by authors in the Materials and Method section (rarely if ever kept beyond it) to use statistics rather than resorting to the harder, well-informed, comprehensive reasoning that is needed in the comparative method. After all, why should anyone invest hundreds of hours (or simply show an interest in) learning about historical linguistics, about ancient Indo-European or Uralic languages, carefully argumenting and discussing each and every detail of the reconstruction, when one can simply rely on the own guts to decide what is Science and what isn’t? When one can trust a promise that formulas have been used?

The conservative, null hypothesis when studying prehistoric Eurasian samples related to evolving cultures was universally understood as no migration, or “pots not people” (as most western archaeologists chose to believe until recently), whereas the alternative one should have been that there were in fact migration events, some of them potentially related to the expansion of Eurasian languages ancestral to the historically attested ones. Beyond this migrationist view there were obviously dozens of thorough theories concerning potential linguistic expansions associated with specific prehistoric cultures, and a myriad of less developed alternatives, all of which deserved to be evaluated after the null hypothesis had been rejected.

Despite the shortcomings of the 2015 papers and their lack of testing or discussion of different language expansion models, the spread of the so-called “Yamnaya ancestry” – an admixture especially prevalent (after the demise of the Yamnaya) among the most likely ancient Uralic-speaking groups as well as among modern Uralic speakers and recently acculturated groups from Eastern Europe – has been nevertheless invariably concluded by each lab to support the theories of their leading archaeologist, often combined with pre-aDNA theories of geneticists based on modern haplogroup distributions. This is as evident a case of confirmation bias, circular reasoning, and jumping to conclusions as it gets.

Why many researchers of other labs have chosen to follow such conclusions instead of challenging or simply ignoring them is difficult to understand.

Related

Bell Beakers and Mycenaeans from Yamnaya; Corded Ware from the forest steppe

eba-yamnaya-ancestry-hungary

I have recently written about the spread of Pre-Yamnaya or Yamnaya ancestry and Corded Ware-related ancestry throughout Eurasia, using exclusively analyses published by professional geneticists, and filling in the gaps and contradictory data with the most reasonable interpretations. I did so consciously, to avoid any suspicion that I was interspersing my own data or cherry picking results.

Now I’m finished recapitulating the known public data, and the only way forward is the assessment of these populations using the available datasets and free tools.

Understanding the complexities of qpAdm is fairly difficult without a proper genetic and statistical background, which I won’t pretend to have, so its tweaking to get strictly correct results would require an unending game of trial and error. I have sadly little time for this, even taking my tendency to procrastination into account… so I have used a simple model akin to those published before – in particular, the outgroup selection by Ning, Wang et al. (2019), who seem to be part of the only group interested in distinguishing Yamnaya-related from Corded Ware-related ancestry, probably the most relevant question discussed today in population genomics regarding the Proto-Indo-European and Proto-Uralic homelands.

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.

I have used for all analyses below a merged dataset including the curated one of the Reich Lab, the latest on Central and South Asia by Narasimhan, Patterson et al. (2019), on Iberia by Olalde et al. (2019), and on the East Baltic by Saag et al. (2019), as well as datasets including samples from Wang et al. (2019) and Lamnidis et al. (2018). I used (and intend to use) the same merged dataset in all cases, despite its huge size, to avoid adding one more uncontrolled variable to the analyses, so that all results obtained can be compared.

I try to prepare in advance a bunch of relevant files with left pops and right pops for each model:

  1. It seems a priori more reasonable to use geographically and chronologically closer proxy populations (say, Trypillia or GAC for Steppe-related peoples) than hypothetic combinations of ancestral ones (viz. Anatolian farmer, WHG, and EHG).
  2. This also means using subgroups closer to the most likely source population, such as (Don-Volga interfluve) Yamnaya_Kalmykia rather than (Middle Volga) Yamnaya_Samara for the western expansion of late Repin/early Yamnaya, or the early Germany_Corded_Ware.SG or Czech_Corded Ware for the group closest to the Proto-Corded Ware population (see below), likely neighbouring the Upper Vistula region.
  3. I usually test two source populations for different targets, which seems like a much more efficient way of using computer resources, whenever I know what I want to test, since I need my PC back for its normal use; whenever I don’t know exactly what to test, I use three-way admixture models and look for subsets to try and improve the results.

I have probably left out some more complex models by individualizing the most relevant groups, but for the time being this would have to do. Also, no other formal stats have been used in any case, which is an evident shortcoming, ruling out an interpretation drawn directly and only from the results below.

Full qpAdm results for each batch of samples are presented in a Google Spreadsheet, with each tab (bottom of the page) showing a different combination of sources, usually in order of formally ‘best’ (first to the left) to ‘worst’ (last to the right) fits, although the order is difficult to select in highly heterogeneous target groups, as will be readily visible.

maykop-trypillia-intrusion-steppes
Disintegration, migration, and imports of the Azov–Black Sea region. First migration event (solid arrows): Gordineşti–Maikop expansion (groups: I – Bursuchensk; II – Zhyvotylivka; III – Vovchans’k; IV – Crimean; V – Lower Don; VI – pre-Kuban). Second migration event (hollow arrows): Repin expansion. After Rassamakin (1999), Demchenko (2016).

Corded Ware origins

The latest publications on the Yampil barrow complex have not improved much our understanding of the complexity of Corded Ware origins from an archaeological point of view, involving multiple cultural (hence likely population) influences. This bit is from Ivanova et al., Baltic-Pontic Studies (2015) 20:1, and most hypotheses of the paper remain unanswered (except maybe for the relevance of the Złota group):

In the light of the above outline therefore one should argue that the ‘architecture of barrows’ associated in the ‘Yampil landscape’ of the Middle Dniester Area with the Eneolithic (specifically, mainly with the TC), precedes the development of a similar phenomenon that can be observed from 2900/2800 BC in the Upper Dniester Area and drainage basin of the Upper Vistula, associated with the CWC [Goslar et al. 2015; Włodarczak 2006; 2007; 2008; Jarosz, Włodarczak 2007]. The most consuming research question therefore is whether ritual customs making use of Eneolithic (Tripolye) ‘barrow architecture’ could have penetrated northwards along the Dniester route, where GAC communities functioned. One could also ask what role the rituals played among the autochthons [Kośko 2000; Włodarczak 2008; 2014: 335; Ivanova, Toshchev 2015b].

This issue has already been discussed with a resulting tentative systemic taxonomy in the studies of Włodarczak, arguing for the Złota culture (ZC) in the Vistula region as an illustration of one of the (Małopolska) reception centres of civilization inspirations from the oldest Pontic ‘barrow culture’ circle associated with the Eneolithic and Early Bronze Age [Włodarczak 2008]. Notably, it is in the ZC that one can notice a set of cultural traits (catacomb grave construction, burial details, forms and decoration of vessels) analogous to those shared by the north-western Black Sea Coast groups of the forest-steppe Eneolithic (chiefly Zhyvotilovka-Volchansk) and the Late Tripolye circle (chiefly Usatovo-Gordinești-Horodiștea-Kasperovtsy).

gac-trypillia-usatovo-corded-ware
Globular Amphorae culture „exodus” to the Danube Delta: a – Globular Amphorae culture; b – GAC (1), Gorodsk (2), Vykhvatintsy (3) and Usatovo (4) groups of Trypillia culture; c – Coţofeni culture; d – northern border of the late phase of Baden culture;red arrows – direction of Globular Amphora culture expansion; blue arrow – direction of „reflux” of Globular Amphora culture (apud Włodarczak, 2008, with changes).

Taking into account that I6561 might be wrongly dated, we cannot include the Corded Ware-like sample of the end-5th millennium BC in the analysis of Corded Ware origins. That uncertainty in the chronology of the appearance of “Steppe ancestry” in Proto-Corded Ware peoples complicates the selection of any potential source population from the CHG cline.

Nevertheless, the lack of hg. R1a-M417 and sizeable Pre-Yamnaya-related ancestry in the sampled Pontic forest-steppe Eneolithic populations (represented exclusively by two samples from Dereivka ca. 3600-3400 BC) would leave open the interesting possibility that a similar ancestry got to the forest-steppe region between modern Poland and Ukraine during the known complex population movements of the Late Eneolithic.

It is known that Corded Ware-derived groups and Steppe Maykop show bad fits for Pre-Yamnaya/Yamnaya ancestry, and also that Steppe Maykop is a potential source of “Steppe-related ancestry” within the Eneolithic CHG mating network of the Pontic-Caspian steppes and forest-steppes. Testing Corded Ware for recent Trypillia and Maykop influences, proper of Late Trypillia and Late Maykop groups in the North Pontic area (such as Zhyvotylivka–Vovchans’k and Gordineşti) side by side with potential Pre-Yamnaya and Yamnaya sources makes thus sense:

Now, the main obvious difference between Khvalynsk-Yamnaya and Corded Ware is the long-lasting, pervasive Y-chromosome bottlenecks under R1b lineages in the former, compared to the haplogroup variability and late bottleneck under R1a-M417 in the latter, which speaks in favour – on top of everything else – of a different community of sub-Neolithic hunter-gatherers including hg. R1a-M417 hijacking the expansion of Steppe_Maykop-related ancestry around the Volhynian-Podolian Upland.

Akin to how Yamnaya patrilineal descendants hijacked regional EEF (±CWC) ancestry components mainly through exogamy, dragging them into the different expanding Bell Beaker groups (see below), but kept their Indo-European languages, these hunter-gatherers that admixed with peoples of “Steppe ancestry” were the most likely vector of expansion of Uralic languages in Eastern Europe.

corded-ware-from-trypillia-maykop
PCA of ancient Eurasian samples. Marked likely Proto-Corded Ware samples and potential origin of its PCA cluster based on qpAdm results. See full PCA and more related files.

Baltic Corded Ware

One of the most interesting aspects of the results above is the surprising heterogeneity of the different regional groups, which is also reflected in the Y-DNA variability of early Corded Ware samples.

Seeing how Baltic CWC groups, especially the early Latvia_LN sample, show particularly bad fits with the models above, it seems necessary to test how this population might have come to be. My first impression in 2017 was that they could represent early Corded Ware groups admixed with Yamnaya settlers through their interactions along the Dnieper-Dniester corridor.

However, I recently predicted that the most likely admixture leading to their ancestry and PCA cluster would involve a Corded Ware-like group and a group related to sub-Neolithic cultures of eastern Europe, whose best proxy to date are EHG-like Khvalynsk samples (i.e. excluding the outlier with Pre-Yamnaya ancestry, I0434):

corded-ware-pca-sub-neolithic-europe
Detail of the PCA of the Corded Ware expansion. See full PCA and more related files.

Late Corded Ware + Yamnaya vanguard

Relevant are also the mixtures of Corded Ware from Esperstedt, and particularly those of the sample I0104, which I have repeated many times in this blog I suspected to be influenced by vanguard Yamnaya settlers:

The infeasible models of CWC + Yamnaya_Kalmykia ± Hungary_Baden (see below for Bell Beakers) and the potential cluster formed with other samples from the Baltic suggest that it could represent a more complex set of mixtures with sub-Neolithic populations. On the other hand, its location in Germany, late date (ca. 2500 BC or later), and position in the PCA, together with the good fits obtained for Germany_Beaker as a source, suggest that the increase in Steppe-related ancestry + EEF makes it impossible for the model (as I set it) to directly include Yamnaya_Kalmykia, despite this excess Steppe-related ancestry actually coming from Yamnaya vanguard groups.

I think it is very likely that the future publication of EEF-admixed Yamnaya_Hungary samples (or maybe even Yamnaya vanguard samples) will improve the fits of this model.

These results confirm at least the need to distrust the common interpretation of mixtures including late Corded Ware samples from Esperstedt (giving rise to the “up to 75% Yamnaya ancestry of CWC” in the 2015 papers) as representative of the Corded Ware culture as a whole, and to keep always in mind that an admixture of European BA groups including Corded Ware Esperstedt as a source also includes East BBC-like ancestry, unless proven otherwise.

yamnaya-vanguard-corded-ware-chalcolithic-early
Yamnaya vanguard groups in Corded Ware territory before the expansion of Bell Beakers (ca. 2500 BC). See full map.

Bell Beaker expansion

A hotly (re)debated topic in the past 6 months or so, and for all the wrong reasons, is the origin of the Bell Beaker folk. Archaeology, linguistics, and different Y-chromosome bottlenecks clearly indicate that Bell Beakers were at the origin of the North-West Indo-European expansion in Europe, while the survival of Corded Ware-related groups in north-eastern Europe is clearly related to the expansion of Uralic languages.

NOTE. For the interesting case of Proto-Indo-Iranians expanding with Corded Ware-like ancestry, see more on the formation of Sintashta-Potapovka-Filatovka from East Uralic-speaking Abashevo and Pre-Proto-Indo-Iranian-speaking Poltavka herders. See also more on R1a in Indo-Iranians and on the social complexity of Sintashta.

Nevertheless, every single discarded theory out there seems to keep coming back to life from time to time, and a new wave of interest in “Bell Beaker from the Single Grave culture” somehow got revived in the process, too, because this obsession – unlike the “Bell Beakers from Iberia Chalcolithic” – is apparently acceptable in certain circles, for some reason.

We know that Iberian Beakers, British Beakers, or Sicilian EBA – representing the most likely closest source population of speakers of Proto-Galaico-Lusitanian, Pre-Celtic Indo-European, and Proto-Elymian, respectively – have already been successfully tested for a direct origin among Western European Beakers in Olalde et al. (2018), Olalde et al. (2019), and Fernandes et al. (2019).

This success in ascertaining a closer Beaker source is probably due to the physical isolation of the specific groups (related to Germany_Beaker, Netherlands_Beaker, and NE_Mediterranean_Beaker samples, respectively) after their migration into regions dominated by peoples without Steppe-related ancestry. Furthermore, Celtic-speaking populations expanding with Urnfield south of the Pyrenees also show a good fit with a source close to France_Beaker.

So I decided to test sampled Bell Beaker populations, to see if it could shed light to the most likely source population of individual Beaker groups and the direction of migration within Central Europe, i.e. roughly eastwards or westwards. As it was to be expected for closely related populations (see the relevant discussion here), an attempt to offer a simplistic analysis of direction based on formal stats does not make any sense, because most of the alternative hypotheses cannot be rejected:

Not only because of the similar values obtained, but because it is absurd to take p-values as a measure of anything, especially when most of these conflicting groups with slightly ‘better’ or ‘worse’ p-values represent multiple different mixtures of the type (Yamnaya + EEF) + (Corded Ware + EEF ± Yamnaya), impossible to distinguish without selecting proper, direct ancestral populations…

A further example of how explosive the Bell Beaker expansion was into different territories, and of their extensive local admixture, is shown by the unsuccessful attempt by Olalde et al. (2018) to obtain an origin of the EEF source for all Beaker groups (excluding Iberian Beakers):

bell-beaker-local-population-iberia
Investigating the genetic makeup of Beaker-complex-associated individuals. Testing different populations as a source for the Neolithic ancestry component in Beaker-complex-associated individuals. The table shows P values (* indicates values > 0.05) for the fit of the model: ‘Steppe_EBA + Neolithic/Copper Age’ source population.
burials-yamnaya-hungary
Map of attested Yamnaya pit-grave burials in the Hungarian plains; superimposed in shades of blue are common areas covered by floods before the extensive controls imposed in the 19th century; in orange, cumulative thickness of sand, unfavourable loamy sand layer. Marked are settlements/findings of Boleráz (ca. 3500 BC on), Baden (until ca. 2800 BC), Kostolac (precise dates unknown), and Yamna kurgans (from ca. 3100/3000 BC on).

Now, there is a simpler way to understand what kind of Steppe-related ancestry is proper of Bell Beakers. I tested two simple models for some Beaker groups: Yamnaya + Hungary Baden vs. Corded Ware + GAC Poland. After all, the Bell Beaker folk should prefer a source more closely related to either Yamnaya Hungary or Central European Corded Ware:

Interestingly, models including Yamnaya + Baden show good fits for the most important groups related to North-West Indo-Europeans, including Bell Beakers from Germany, the Netherlands, Italy, and Poland, representing the most likely closest source populations of speakers of Pre-Proto-Celtic, Pre-Proto-Germanic, Proto-Italo-Venetic, and Pre-Proto-Balto-Slavic, respectively.

The admixed Yamnaya samples from Hungary that will hopefully be published soon by the Jena Lab will most likely further improve these fits, especially in combination with intermediate Chalcolithic populations of the Middle and Upper Danube and its tributaries, to a point where there will be an absolute chronological and geographical genomic trail from the fully Yamnaya-like Yamnaya settlers from Hungary to all North-West Indo-European-speaking groups of the Early Bronze Age.

The only difference between groups will be the gradual admixture events of their source Beaker group with local populations on their expansion paths, including peoples of mainly EEF, CWC+EEF, or CWC+EEF+Yamnaya related ancestry. There is ample evidence beyond ancestry models to support this, in particular continued Y-DNA bottlenecks under typical Yamnaya paternal lineages, mainly represented by R1b-L51 subclades.

east-bell-beaker-group-expansion
Distribution of the Bell Beaker East Group, with its regional provinces, as of c. 2400 cal BC (after Heyd et al. 2004, modified). See full maps.

European Early Bronze Age

European EBA groups that might show conflicting results due to multiple admixture events with Corded Ware-related populations are the Únětice culture and the Nordic Late Neolithic.

The results for Únětice groups seem to be in line with what is expected of a Central European EBA population derived from Bell Beakers admixed with surrounding poulations of East Bell Beaker and/or late (Epi-)Corded Ware descent.

Potential models of mixture for Nordic Late Neolithic samples – despite the bad fits due to the lack of direct ancestral CWC and BBC groups from Denmark – seem to be impossible to justify as derived exclusively from Single Grave or (even less) from Battle Axe peoples, supporting immigration waves of Bell Beakers from the south and further admixture events with local groups through maritime domination.

PCA of ancient European samples. Marked are Bronze Age clusters. See full PCAs.

Balkans Bronze Age

The potential origin of the typical Corded Ware Steppe-related ancestry in the social upheaval and population movements of the Dnieper-Dniester forest-steppe corridor during the 4th millennium BC raises the question: how much do Balkan Bronze Age groups owe their ancestry to a population different than the spread of Pre-Yamnaya-like Suvorovo-Novodanilovka chieftains? Furthermore, which Bronze Age groups seem to be more likely derived exclusively from Pre-Yamnaya groups, and which are more likely to be derived from a mixture of Yamnaya and Pre-Yamnaya? Do the formal stats obtained correspond to the expected results for each group?

Since the expansion of hg. I2a-L699 (TMRCA ca. 5500 BC) need not be associated with Yamnaya, some of these values – together with the assessment of each individual archaeological culture – may question their origin in a Yamnaya-related expansion rather than in a Khvalynsk-related one.

NOTE. These are the last ones I was able to test yesterday, and I have not thought these models through, so feel free to propose other source and target groups. In particular, complex movements through the North Pontic area during the Late Eneolithic would suggest that there might have been different Steppe-ancestry-related vs. EEF-related interactions in the north-west and west Pontic area before and during the expansion of Yamnaya.

Mycenaeans

One of the key Indo-European populations that should be derived from Yamnaya to confirm the Steppe hypothesis, together with North-West Indo-Europeans, are Proto-Greeks, who will in turn improve our understanding of the preceding Palaeo-Balkan community. Unfortunately, we only have Mycenaean samples from the Aegean, with slight contributions of Steppe-related ancestry.

Still, analyses with potential source populations for this Steppe ancestry show that the Yamnaya outlier from Bulgaria is a good fit:

The comparison of all results makes it quite evident the why of the good fits from (Srubnaya-related) Bulgaria_MLBA I2163 or of Sintashta_MLBA relative to the only a priori reasonable Yamnaya and Catacomb sources: it is not about some hypothetical shared ancestor in Graeco-Aryan-speaking East Yamnaya– or even Catacomb-Poltavka-related groups, because all available Yamnaya-related peoples are almost indistinguishable from each other (at least with the sampling available today). These results reflect a sizeable contribution of similar EEF-related populations from around the Carpathians in both Steppe-related groups: Corded Ware and Yamnaya settlers from the Balkans.

mycenaeans-minyan-ware-greece-minoan
Cultural groups in and around the Balkans during the Early Bronze Age. See full maps.

qpAdm magic

In hobby ancestry magic, as in magic in general, it is not about getting dubious results out of thin air: misdirection is the key. A magician needs to draw the audience attention to ‘remarkable’ ancestry percentages coupled with ‘great’ (?) p-values that purportedly “prove” what the audience expects to see, distracting everyone from the true interesting aspects, like statistical design, the data used (and its shortcomings), other opposing models, a comparison of values, a proper interpretation…you name it.

I reckon – based on the examples above – that the following problems lie at the core of bad uses of qpAdm:

  1. In the formal aspect, the poor understanding of what p-values and other formal stats obtained actually mean, and – more importantly – what they don’t mean. The simplistic trend to accept results of a few analyses at face value is necessarily wrong, in so far as there is often no proper reasoning of what is being assessed and how, and there is never a previous opinion about what could be expected if the alternative hypotheses were true.
  2. In the interpretation aspect, the poor judgement of accompanying any results with simplistic, superficial, irrelevant, and often plainly wrong archaeological or linguistic data selected a posteriori; the inclusion of some racial or sociopolitical overtones in the mixture to set a propitious mood in the target audience; and a sort of ritualistic theatrics with the main theme of ‘winning’, that is best completed with ad hominems.

If you get rid of all this, the most reasonable interpretation of the output of a model proposed and tested should be similar to Nick Patterson’s words in his explanation of qpWave and qpAdm use:

Here we see that, at least in this analysis there are reasonable models with CordedWareNeolithic is a mix of either WHG or LBKNeolithic and YamnayaEBA. (…) The point of this note is not to give a serious phylogenetic analysis but the results here certainly support a major Steppe contribution to the Corded Ware population, which is entirely concordant with the archaeology [?].

Very far, as you can see, from the childish “Eureka! I proved the source!”-kind of thinking common among hobbyists.

The Mycenaean case is an illustrative example: if the Yamnaya outlier from Bulgaria were not available, and if one were not careful when designing and assessing those mixture models, the interpretation would range from erroneous (viz. a Graeco-Aryan substrate, as I initially thought) to impossible (say, inventing migration waves of Sintashta or Srubnaya peoples into Crete). The models presented above show that a contribution of Yamnaya to Mycenaeans couldn’t be rejected, and this alone should have been enough to accept Yamnaya as the most likely source population of “Steppe ancestry” in Proto-Greeks, pending intermediate samples from the Balkans. In other words, one could actually find that ‘the best’ p-values for source populations of Mycenaeans is a combination of modern Poles + Turks, despite the impracticality of such a model…

I haven’t been able to reproduce results which supposedly showed that Corded Ware is more likely to be derived from (Pre-)Yamnaya than other source population, or that Corded Ware is better suited as the ancestral population of Bell Beakers. The analyses above show values in line with what has been published in recent scientific papers, and what should be expected based on linguistics and archaeology. So I’ll go out on a limb here and say that it’s only through a careful selection of outgroups and samples tested, and of as few compared models as possible, that you could eventually get this kind of results and interpretation, if at all.

Whether that kind of special care for outgroups and samples is about (a) an acceptable fine-tuning of the analyses, (b) a simplistic selection dragged from the first papers published and applied indiscriminately to all models, or (c) cherry picking analyses until results fit the expected outcome, is a question that will become mostly irrelevant when future publications continue to support an origin of the expansion of ancient Indo-European languages in Khvalynsk- and Yamnaya-related migrations.

Feel free to suggest (reasonable) modifications to correct some of these models in the comments. Also, be sure to check out other values such as proportions, SD or SNPs of the different results that I might have not taken into account when assessing ‘good’ or ‘bad’ fits.

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

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

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

The genetic and cultural barrier of the Pontic-Caspian steppe – forest-steppe ecotone

steppe-forest-steppe-biomes

We know that the Caucasus Mountains formed a persistent prehistoric barrier to cultural and population movements. Nevertheless, an even more persistent frontier to population movements in Europe, especially since the Neolithic, is the Pontic-Caspian steppe – forest-steppe ecotone.

Like the Caucasus, this barrier could certainly be crossed, and peoples and cultures could permeate in both directions, but there have been no massive migrations through it. The main connection between both regions (steppe vs. forest-steppe/forest zone) was probably through its eastern part, through the Samara region in the Middle Volga.

The chances of population expansions crossing this natural barrier anywhere else seem quite limited, with a much less porous crossing region in the west, through the Dnieper-Dniester corridor.

A Persistent ecological and cultural frontier

It is very difficult to think about any culture that transgressed this persistent ecological and cultural frontier: many prehistoric and historical steppe pastoralists did appear eventually in the neighbouring forest-steppe areas during their expansions (e.g. Yamna, Scythians, or Turks), as did forest groups who permeated to the south (e.g. Comb Ware, GAC, or Abashevo), but their respective hold in foreign biomes was mostly temporary, because their cultures had to adapt to the new ecological environment. Most if not all groups originally from a different ecological niche eventually disappeared, subjected to renewed demographic pressure from neighbouring steppe or forest populations…

The Samara region in the Middle Volga may be pointed out as the true prehistoric link between forests and steppes (see David Anthony’s remarks), something reflected in its nature as a prehistoric sink in genetics. This strong forest – forest-steppe – steppe connection was seen in the Eurasian technocomplex, during the expansion of hunter-gatherer pottery, in the expansion of Abashevo peoples to the steppes (in one of the most striking cases of population admixture in the area), with Scythians (visible in the intense contacts with Ananyino), and with Turks (Volga Turks).

steppe-forest-steppe-europe
Simplified map of the distribution of steppes and forest-steppes (Pontic and Pannonian) and xeric grasslands in Eastern Central Europe (with adjoining East European ranges) with their regionalisation as used in the review (Northern—Pannonic—Pontic). Modified from Kajtoch et al. (2016).

Before the emergence of pastoralism, the cultural contacts of the Pontic region (i.e. forest-steppes) with the Baltic were intense. In fact, the connection of the north Pontic area with the Baltic through the Dnieper-Dniester corridor and the Podolian-Volhynian region is essential to understand the spread of peoples of post-Maglemosian and post-Swiderian cultures (to the south), hunter-gatherer pottery (to the north), TRB (to the south), Late Trypillian groups (north), GAC (south), or Comb Ware (south) (see here for Eneolithic movements), and finally steppe ancestry and R1a-Z645 with Corded Ware (north). After the complex interaction of TRB, Trypillia, GAC, and CWC during the expansion of late Repin, this traditional long-range connection is lost and only emerges sporadically, such as with the expansion of East Germanic tribes.

A barrier to steppe migrations into northern Europe

One may think that this barrier was more permeable, then, in the past. However, the frontier is between steppe and forest-steppe ecological niches, and this barrier evolved during prehistory due to climate changes. The problem is, before the drought that began ca. 4000 BC and increased until the Yamna expansion, the steppe territory in the north Pontic region was much smaller, merely a strip of coastal land, compared to its greater size ca. 3300 BC and later.

This – apart from the cultural and technological changes associated with nomadic pastoralism – justifies the traditional connection of the north Pontic forest-steppes to the north, broken precisely after the expansion of Khvalynsk, as the north Pontic area became gradually a steppe region. The strips of north Pontic and Azov steppes and Crimea seem to have had stronger connections to the Northern Caucasus and Northern Caspian steppes than with the neighbouring forest-steppe areas during the Upper Palaeolithic, Mesolithic, and Neolithic.

NOTE. We still don’t know the genetic nature of Mikhailovka or Ezero, steppe-related groups possibly derived from Novodanilovka and Suvorovo close to the Black Sea (which possibly include groups from the Pannonian plains), and how they compare to neighbouring typically forest-steppe cultures of the so-called late Sredni Stog groups, like Dereivka or partly Kvityana.

steppe-forest-steppe-migration-routes
Typical migration routes through European steppes and forest-steppes. Red line represents the persistent cultural and genetic barrier, with the latest evolution in steppe region represented by the shift from dashed line to the north. Arrows show the most common population movements. Modified from Kajtoch et al. (2016).

Despite the Pontic-Caspian steppes and forest-steppes neighbouring each other for ca. 2,000 km, peoples from forested and steppe areas had an obvious advantage in their own regions, most likely due to the specialization of their subsistence economy. While this is visible already in Palaeolithic and Mesolithic hunter-gatherers, the arrival of the Neolithic package in the Pontic-Caspian region incremented the difference between groups, by spreading specialized animal domestication. The appearance of nomadic pastoralism adapted to the steppe, eventually including the use of horses and carts, made the cultural barrier based on the economic know-how even stronger.

Even though groups could still adapt and permeate a different territory (from steppe to forest-steppe/forest and vice-versa), this required an important cultural change, to the extent that it is eventually complicated to distinguish these groups from neighbouring ones (like north-west Pontic Mesolithic or Neolithic groups and their interaction with the steppes, Trypillia-Usatovo, Scythians-Thracians, etc.). In fact, this steppe – forest-steppe barrier is also seen to the east of the Urals, with the distinct expansion of Andronovo and Seima-Turbino/Andronovo-like horizons, which seem to represent completely different ethnolinguistic groups.

As a result of this cultural and genetic barrier, like that formed by the Northern Caucasus:

1) No steppe pastoralist culture (which after the emergence of Khvalynsk means almost invariably horse-riding, chariot-using nomadic herders who could easily pasture their cows in the huge grasslands without direct access to water) has ever been successful in spreading to the north or north-west into northern Europe, until the Mongols. No forest culture has ever been successful in expanding to the steppes, either (except for the infiltration of Abashevo into Sintashta-Potapovka).

2) Corded Ware was not an exception: like hunter-gatherer pottery before it (and like previous population movements of TRB, late Trypillia, GAC, Comb Ware or Lublin-Volhynia settlers) their movements between the north Pontic area and central Europe happened through forest-steppe ecological niches due to their adaptation to them. There is no reason to support a direct connection of CWC with true steppe cultures.

3) The so-called “Steppe ancestry” permeated the steppe – forest-steppe ecotone for hundreds of years during the 5th and early 4th millennium BC, due to the complex interaction of different groups, and probably to the aridization trend that expanded steppe (and probably forest-steppe) to the north. Language, culture, and paternal lineages did not cross that frontier, though.

EDIT (4 FEB 2019): Wang et al. is out in Nature Communications. They deleted the Yamna Hungary samples and related analyses, but it’s interesting to see where exactly they think the trajectory of admixture of Yamna with European MN cultures fits best. This path could also be inferred long ago from the steppe connections shown by the Yamna Hungary -> Bell Beaker evolution and by early Balkan samples:

wang-yamna-connection
Prehistoric individuals projected onto a PCA of 84 modern-day West Eurasian populations (open symbols). Dashed arrows indicate trajectories of admixture: EHG—CHG (petrol), Yamnaya—Central European MN (pink), Steppe—Caucasus (green), and Iran Neolithic—Anatolian Neolithic (brown). Modified from the original, a red circle has been added to the Yamna-Central European MN admixture.

Related

ASoSaH Reread (II): Y-DNA haplogroups among Uralians (apart from R1a-M417)

corded-ware-yamna-ancestry

This is mainly a reread of from Book Two: A Game of Clans of the series A Song of Sheep and Horses: chapters iii.5. Early Indo-Europeans and Uralians, iv.3. Early Uralians, v.6. Late Uralians and vi.3. Disintegrating Uralians.

“Sredni Stog”

While the true source of R1a-M417 – the main haplogroup eventually associated with Corded Ware, and thus Uralic speakers – is still not known with precision, due to the lack of R1a-M198 in ancient samples, we already know that the Pontic-Caspian steppes were probably not it.

We have many samples from the north Pontic area since the Mesolithic compared to the Volga-Ural territory, and there is a clear prevalence of I2a-M223 lineages in the forest-steppe area, mixed with R1b-V88 (possibly a back-migration from south-eastern Europe).

R1a-M459 (xR1a-M198) lineages appear from the Mesolithic to the Chalcolithic scattered from the Baltic to the Caucasus, from the Dniester to Samara, in a situation similar to haplogroups Q1a-M25 and R1b-L754, which supports the idea that R1a, Q1a, and R1b expanded with ANE ancestry, possibly in different waves since the Epipalaeolithic, and formed the known ANE:EHG:WHG cline.

y-dna-khvalynsk
Y-DNA samples from Khvalynsk and neighbouring cultures. See full version.

The first confirmed R1a-M417 sample comes from Alexandria, roughly coinciding with the so-called steppe hiatus. Its emergence in the area of the previous “early Sredni Stog” groups (see the mess of the traditional interpretation of the north Pontic groups as “Sredni Stog”) and its later expansion with Corded Ware supports Kristiansen’s interpretation that Corded Ware emerged from the Dnieper-Dniester corridor, although samples from the area up to ca. 4000 BC, including the few Middle Eneolithic samples available, show continuity of hg. I2a-M223 and typical Ukraine Neolithic ancestry.

NOTE. The further subclade R1a-Z93 (Y26) reported for the sample from Alexandria seems too early, given the confidence interval for its formation (ca. 3500-2500 BC); even R1a-Z645 could be too early. Like the attribution of the R1b-L754 from Khvalynsk to R1b-V1636 (after being previously classifed as of Pre-V88 and M73 subclade), it seems reasonable to take these SNP calls with a pinch of salt: especially because Yleaf (designed to look for the furthest subclade possible) does not confirm for them any subclade beyond R1a-M417 and R1b-L754, respectively.

The sudden appearance of “steppe ancestry” in the region, with the high variability shown by Ukraine_Eneolithic samples, suggests that this is due to recent admixture of incoming foreign peoples (of Ukraine Neolithic / Comb Ware ancestry) with Novodanilovka settlers.

The most likely origin of this population, taking into account the most common population movements in the area since the Neolithic, is the infiltration of (mainly) hunter-gatherers from the forest areas. That would confirm the traditional interpretation of the origin of Uralic speakers in the forest zone, although the nature of Pontic-Caspian settlers as hunter-gatherers rather than herders make this identification today fully unnecessary (see here).

EDIT (3 FEB 2019): As for the most common guesstimates for Proto-Uralic, roughly coinciding with the expansion of this late Sredni Stog community (ca. 4000 BC), you can read the recent post by J. Pystynen in Freelance Reconstruction, Probing the roots of Samoyedic.

eneolithic-ukraine-corded-ware
Late Sredni Stog admixture shows variability proper of recent admixture of forest-steppe peoples with steppe-like population. See full version here.

NOTE. Although my initial simplistic interpretation (of early 2017) of Comb Ware peoples – traditionally identified as Uralic speakers – potentially showing steppe ancestry was probably wrong, it seems that peoples from the forest zone – related to Comb Ware or neighbouring groups like Lublyn-Volhynia – reached forest-steppe areas to the south and eventually expanded steppe ancestry into east-central Europe through the Volhynian Upland to the Polish Upland, during the late Trypillian disintegration (see a full account of the complex interactions of the Final Eneolithic).

The most interesting aspect of ascertaining the origin of R1a-M417, given its prevalence among Uralic speakers, is to precisely locate the origin of contacts between Late Proto-Indo-European and Proto-Uralic. Traditionally considered as the consequence of contacts between Middle and Upper Volga regions, the most recent archaeological research and data from ancient DNA samples has made it clear that it is Corded Ware the most likely vector of expansion of Uralic languages, hence these contacts of Indo-Europeans of the Volga-Ural region with Uralians have to be looked for in neighbours of the north Pontic area.

sredni-stog-repin-contacts
Sredni Stog – Repin contacts representing Uralic – Late Indo-European contacts were probably concentrated around the Don River.

My bet – rather obvious today – is that the Don River area is the source of the earliest borrowings of Late Uralic from Late Indo-European (i.e. post-Indo-Anatolian). The borrowing of the Late PIE word for ‘horse’ is particularly interesting in this regard. Later contacts (after the loss of the initial laryngeal) may be attributed to the traditionally depicted Corded Ware – Yamna contact zone in the Dnieper-Dniester area.

NOTE. While the finding of R1a-M417 populations neighbouring R1b-L23 in the Don-Volga interfluve would be great to confirm these contacts, I don’t know if the current pace of more and more published samples will continue. The information we have right now, in my opinion, suffices to support close contacts of neighbouring Indo-Europeans and Uralians in the Pontic-Caspian area during the Late Eneolithic.

Classical Corded Ware

After some complex movements of TRB, late Trypillia and GAC peoples, Corded Ware apparently emerged in central-east Europe, under the influence of different cultures and from a population that probably (at least partially) stemmed from the north Pontic forest-steppe area.

Single Grave and central Corded Ware groups – showing some of the earliest available dates (emerging likely ca. 3000/2900 BC) – are as varied in their haplogroups as it is expected from a sink (which does not in the least resemble the Volga-Ural population):

Interesting is the presence of R1b-L754 in Obłaczkowo, potentially of R1b-V88 subclade, as previously found in two Central European individuals from Blätterhole MN (ca. 3650 and 3200 BC), and in the Iron Gates and north Pontic areas.

Haplogroups I2a and G have also been reported in early samples, all potentially related to the supposed Corded Ware central-east European homeland, likely in southern Poland, a region naturally connected to the north Pontic forest-steppe area and to the expansion of Neolithic groups.

corded-ware-haplogroups
Y-DNA samples from early Corded Ware groups and neighbouring cultures. See full version.

The true bottlenecks under haplogroup R1a-Z645 seem to have happened only during the migration of Corded Ware to the east: to the north into the Battle Axe culture, mainly under R1a-Z282, and to the south into Middle Dnieper – Fatyanovo-Balanovo – Abashevo, probably eventually under R1a-Z93.

This separation is in line with their reported TMRCA, and supports the split of Finno-Permic from an eastern Uralic group (Ugric and Samoyedic), although still in contact through the Russian forest zone to allow for the spread of Indo-Iranian loans.

This bottleneck also supports in archaeology the expansion of a sort of unifying “Corded Ware A-horizon” spreading with people (disputed by Furholt), the disintegrating Uralians, and thus a source of further loanwords shared by all surviving Uralic languages.

Confirming this ‘concentrated’ Uralic expansion to the east is the presence of R1a-M417 (xR1a-Z645) lineages among early and late Single Grave groups in the west – which essentially disappeared after the Bell Beaker expansion – , as well as the presence of these subclades in modern Central and Western Europeans. Central European groups became thus integrated in post-Bell Beaker European EBA cultures, and their Uralic dialect likely disappeared without a trace.

NOTE. The fate of R1b-L51 lineages – linked to North-West Indo-Europeans undergoing a bottleneck in the Yamna Hungary -> Bell Beaker migration to the west – is thus similar to haplogroup R1a-Z645 – linked to the expansion of Late Uralians to the east – , hence proving the traditional interpretation of the language expansions as male-driven migrations. These are two of the most interesting genetic data we have to date to confirm previous language expansions and dialectal classifications.

It will be also interesting to see if known GAC and Corded Ware I2a-Y6098 subclades formed eventually part of the ancient Uralic groups in the east, apart from lineages which will no doubt appear among asbestos ware groups and probably hunter-gatherers from north-eastern Europe (see the recent study by Tambets et al. 2018).

Corded Ware ancestry marked the expansion of Uralians

Sadly, some brilliant minds decided in 2015 that the so-called “Yamnaya ancestry” (now more appropriately called “steppe ancestry”) should be associated to ‘Indo-Europeans’. This is causing the development of various new pet theories on the go, as more and more data contradicts this interpretation.

There is a clear long-lasting cultural, populational, and natural barrier between Yamna and Corded Ware: they are derived from different ancestral populations, which show clearly different ancestry and ancestry evolution (although they did converge to some extent), as well as different Y-DNA bottlenecks; they show different cultures, including those of preceding and succeeding groups, and evolved in different ecological niches. The only true steppe pastoralists who managed to dominate over grasslands extending from the Upper Danube to the Altai were Yamna peoples and their cultural successors.

corded-ware-yamna-pca
Corded Ware admixture proper of expanding late Sredni Stog-like populations from the forest-steppe. See full version here.

NOTE. You can also read two recent posts by FrankN in the blog aDNA era, with detailed information on the Pontic-Caspian cultures and the formation of “steppe ancestry” during the Palaeolithic, Mesolithic and Neolithic: How did CHG get into Steppe_EMBA? Part 1: LGM to Early Holocene and How did CHG get into Steppe_EMBA? Part 2: The Pottery Neolithic. Unlike your typical amateur blogger on genetics using few statistical comparisons coupled with ‘archaeolinguoracial mumbo jumbo’ to reach unscientific conclusions, these are obviously carefully redacted texts which deserve to be read.

I will not enter into the discussion of “steppe ancestry” and the mythical “Siberian ancestry” for this post, though. I will just repost the opinion of Volker Heyd – an archaeologist specialized in Yamna Hungary and Bell Beakers who is working with actual geneticists – on the early conclusions based on “steppe ancestry”:

[A]rchaeologist Volker Heyd at the University of Bristol, UK, disagreed, not with the conclusion that people moved west from the steppe, but with how their genetic signatures were conflated with complex cultural expressions. Corded Ware and Yamnaya burials are more different than they are similar, and there is evidence of cultural exchange, at least, between the Russian steppe and regions west that predate Yamnaya culture, he says. None of these facts negates the conclusions of the genetics papers, but they underscore the insufficiency of the articles in addressing the questions that archaeologists are interested in, he argued. “While I have no doubt they are basically right, it is the complexity of the past that is not reflected,” Heyd wrote, before issuing a call to arms. “Instead of letting geneticists determine the agenda and set the message, we should teach them about complexity in past human actions.

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