“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 Even my post “Steppe ancestry” step by step from a year ago is already outdated.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

On the Ukraine Eneolithic outlier I6561 from Alexandria

sredni-stog-eneolithic-late

Over the past week or so, since the publication of new Corded Ware samples in Narasimhan, Patterson et al. (2019) and after finding out that the R1a-M417 star-like phylogeny may have started ca. 3000 BC, I have been ruminating the relevance of contradictory data about the Ukraine_Eneolithic_o sample from Alexandria, its potential wrong radiocarbon date, and its implications for the Indo-European question.

How many other similar ‘controversial’ samples are there which we haven’t even considered? And what mechanisms are in place to control that the case of Hajji_Firuz_CA I2327 is not repeated?

Ukraine Eneolithic outlier I6561

It was not the first time that I (or many others) have alternatively questioned its subclade or its date, but the contradictory data seem to keep piling up. We can still explain all these discrepancies by assuming that the radiocarbon date is correct – seeing how it is a direct and newly reported lab analysis – because it is an isolated individual from a poorly sampled region, so he may actually be the first one to show features proper of later Corded Ware-related samples.

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

The individual seems to be especially relevant for the Indo-European and Uralic homeland question. The last one to mention this sample in a publication was Anthony (2019), who considered it in common with two other Eneolithic samples from Dereivka to show how Anatolian farmer-related ancestry first appeared in the recently opened CHG mating network of the Pontic-Caspian steppes and forest-steppes during the Middle Eneolithic, after the expansion of Khvalynsk:

The currently oldest sample with Anatolian Farmer ancestry in the steppes in an individual at Aleksandriya, a Sredni Stog cemetery on the Donets in eastern Ukraine. Sredni Stog has often been discussed as a possible Yamnaya ancestor in Ukraine (Anthony 2007: 239- 254). The single published grave is dated about 4000 BC (4045–3974 calBC/ 5215±20 BP/ PSUAMS-2832) and shows 20% Anatolian Farmer ancestry and 80% Khvalynsk-type steppe ancestry (CHG&EHG). His Y-chromosome haplogroup was R1a-Z93, similar to the later Sintashta culture and to South Asian Indo-Aryans, and he is the earliest known sample to show the genetic adaptation to lactase persistence (I3910-T). Another pre-Yamnaya grave with Anatolian Farmer ancestry was analyzed from the Dnieper valley at Dereivka, dated 3600-3400 BC (grave 73, 3634–3377 calBC/ 4725±25 BP/ UCIAMS-186349). She also had 20% Anatolian Farmer ancestry, but she showed less CHG than Aleksandriya and more Dereivka-1 ancestry, not surprising for a Dnieper valley sample, but also showing that the old fifth-millennium-type EHG/WHG Dnieper ancestry survived into the fourth millennium BC in the Dnieper valley (Mathieson et al. 2018).

The main problem is that this sample has more than one inconsistent, anachronistic data compared to its reported precise radiocarbon date ca. 4045–3974 calBCE (5215±20BP, PSUAMS-2832). I summarized them on Twitter:

  • First known R1a-M417 sample, with subclade R1a-Y26 (Y2-), with formation date and TMRCA ca. 2750 BC (CI 95% ca. 3750–1950 BC), and proper of much later Steppe_MLBA bottlenecks. The closest available sample would be the Poltavka outlier of hg. R1a-Z94 (ca. 2700 BC), from a mixed cemetery that could belong to a later (likely Abashevo) layer; the closest related subclade is probably found in sample I12450 of Butkara_IA (ca. 800 BC).
  • NOTE. The formation date of upper clade R1a-Z93 is estimated ca. 3000 BC, with a CI 95% ca. 3550–2550 BC, suggesting that the actual TMRCA range for the subclade has most likely a lower maximum formation date than estimated with the available samples under Y3.

  • Ancestry and PCA cluster like Steppe_MLBA (see PCA below), different from neighbouring Sredni Stog samples of the roughly coetaneous Dereivka site (ca. 3600-3400 BC), and from a later Yamnaya sample from Dereivka (ca. 2800 BC), even more shifted toward WHG-related ancestry.
  • Allele for lactase persistence (I3910-T), found only much later among Bell Beakers, and still later in Sintashta and Steppe_MLBA samples. This suggests a strong selection in northern Europe and South Asia stemming from steppe-related (and not forest-steppe-related) peoples, postdating the age of massive Indo-European migrations.
  • Hajji Firuz Chalcolithic outlier

    My impression is that the Hajji_Firuz Chalcolithic outlier, initially dated ca. 5900-5500 BC, had much less reason to be questioned than this sample, since Pre-Yamnaya ancestry was (and apparently is still) believed by members of the Reich Lab to have come from south of the Caucasus, and to have arrived around that time or earlier to the North Caspian steppe, i.e. before the 5th millennium BC.

    The formation date of its initially reported haplogroup, R1b-Z2103, is ca. 4100 BC (CI 95% 4800-3500 BC), which seems also roughly compatible with that date and site – at least as compatible as R1a-Y3(xY2) is for ca. 4000 BC -, so it could have been interpreted as a migrant from the South Caspian region, potentially related to Proto-Anatolians, especially before the description of the Caucasus genetic barrier in Wang et al (2018). For some reason, though, the Hajji_Firuz sample was questioned, but this one didn’t even merited an interrogation mark.

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

    All in all, my guess is that genomic data of I6561 would have been a priori more compatible with a later period, during the expansion of East Corded Ware groups: at least Middle Dnieper culture, potentially Multi-Cordoned Ware culture, but most likely a Srubnaya-related one, given the most likely SNP mutation and TMRCA date, and the haplogroup variability found in the few samples available from that culture.

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

    Compatibility checks

    I tried to start a thread on the possibility that the radiocarbon date was wrong, and IF it were, how likely it would be that formal stats could actually show this, or how could we automatically prevent ancestry magic fiascos.

    In other words: if this guy were a Srubnaya-related individual actually dated e.g. ca. 1700 BC, and someone would try to ‘prove’ – based on the current open source tools alone – that he was the ancestor of expanding peoples of the 4th and 3rd millennium BC (i.e. Balkan outliers, Yamnaya, Corded Ware, you name it), could these results be formally challenged?

    I was hoping for some original brainstorming where people would propose crazy, essentially impossible to understand statistical models, say plotting dozens of well-studied mutations of different geographically related ancient samples with their reported dates, to visually highlight samples that don’t exactly fit with such a feature-based time series analysis; I mean, the kind of theoretical models I wouldn’t even be able to follow after the first two tweets or so. I didn’t receive an answer like that, but still:

    I have nothing to add to these answers, because I agree that all contradictory data are circumstancial.

    The current absolute lack of this kind of validity checks for ancestry models is disappointing, though, and leaves the so-called outliers in a dangerous limbo between “potentially very interesting samples” and “potentially wrongly dated samples”. Radiocarbon date is thus – together with compatibility of population source in terms of archaeological cultures and their potential relationship – a necessary variable to take into account in any statistical design: an error in one of these variables means a catastrophic error in the whole model.

    Formal stats

    For example, in these qpAdm models, I assumed Srubnaya, Ukraine_Eneolithic_outlier, and Bulgaria_MLBA samples were roughly coetaneous and potentially related to the Srubnaya-SabatinovkaNoua cultural horizon, hence stemming from a source close to:

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

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

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

    Apart from the lack of more models for comparison (I’m not going to dedicate more time to this), the results can’t be interpreted without a proper sampling and context, either, because (1) Poltavka_o may actually be from a much later group closely related to Srubnaya; (2) Bulgaria_MLBA is only one sample; and (3) there are only two samples from Potapovka; so the models here presented are basically useless, as many similar models that have been tested looking just for a formal “best fit”.

    So feel free to chime in and contribute with ideas as to how to detect in the future whether a sample is ancestral to or derived from others. I will post here informative answers from Twitter, too, if there are any. I don’t think a discussion about the potentially wrong date in this specific sample is very useful, because this seems impossible to prove or disprove at this point. Just what tools or data would you use to at least try and assess whether samples are compatible with its reported date or not – preferably in some kind of automated sieve that takes dozens or hundreds of samples into account.

    On the bright side, there is so much more than formal stats to arrive to relevant inferences about prehistoric populations, their movements and languages. That’s why I6561 didn’t matter for the conclusion by Anthony (2019) that it was the R1b-rich Eneolithic Don-Volga-Caucasus region the most likely Indo-Anatolian and Late Proto-Indo-European homeland, due to the creation of a wide Eneolithic mating network with extended exogamy practices, where Y-chromosome bottlenecks seem to be one of the main genomic data to take into account from the Neolithic to the Middle Bronze Age.

    And that is the same reason why it doesn’t matter that much for the Proto-Indo-European or Uralic question for me, either.

    Related

Proto-Tocharians: From Afanasievo to the Tarim Basin through the Tian Shan

tocharians-early-eneolithic

A reader commented recently that there is little information about Indo-Europeans from Central and East Asia in this blog. Regardless of the scarce archaeological data compared to European prehistory, I think it is premature to write anything detailed about population movements of Indo-Iranians in Asia, especially now that we are awaiting the updates of Narasimhan et al (2018).

Furthermore, there was little hope that Tocharians would be different than neighbouring Andronovo-like populations (see a recent post on my predicted varied admixture of Common Tocharians), so the history of both unrelated Late PIE languages would have had to be explained by the admixture of Afanasievo-related groups with peoples of Andronovo descent and their acculturation.

However, data reported recently by Ning, Wang et al. Current Biology (2019) confirmed that peoples of mainly Afanasievo ancestry – as opposed to those of Corded Ware-related ancestry expanding with the Srubna-Andronovo horizon – spread the Tocharian branch of Proto-Indo-European from the Altai into the Tian Shan area, surviving essentially unadmixed into the Early Iron Age.

This genetic continuity of Tocharians will no doubt help us disentangle a great part the ethnolinguistic history of speakers of the Tocharian branch of Proto-Indo-European, from Pre-Proto-Tocharians of Afanasievo to Common Tocharians of the Late Bronze Age/Iron Age eastern Tian Shan.

NOTE. Tocharian’s isolation from the rest of Late PIE dialects and its early and intense language contacts have always been the key to support an early migration and physical separation of the group, hence the traditional association with Afanasievo, a late Repin/early Yamna offshoot. Even with the current incomplete archaeological and genetic picture, there is no other option left for the expansion of Tocharian.

It is not possible to use the currently available ancestry data to map the evolution of Afanasievo ancestry, lacking a proper geographical and temporal transect of Central and East Asian groups. In spite of this, Ning, Wang, et al. (2019) is a huge leap forward, discarding some archaeological models, and leaving only a few potential routes by which Tocharians may have spread southward from the Altai.

NOTE. I have updated the maps of prehistoric cultures accordingly, with colours – as always – reflecting the language/ancestry evolution of the different groups, even though the archaeological data of some groups of Xinjiang remains scarce, so their ethnolinguistic attribution – and the colours picked for them – remain tentative.

xinjiang-andronovo-xiaohe-horizon-bronze-iron-age
A rough timeline of related archaeological sites from North Eurasia. Image modified from Yang (2019).

Tocharians

The recent book Ancient China and its Eurasian Neighbors. Artifacts, Identity and Death in the Frontier, 3000–700 BCE, by Linduff, Sun, Cao, and Liu, Cambridge University Press (2017) offers an interesting summary of the introduction of metalworking into western China.

Here are some relevant excerpts (emphasis mine):

Although [the Xinjiang] route is not uniformly agreed upon (Shelach-Lavi 2009: 134–46), this western transmission has been thought to have passed through eastern Kazakhstan, especially as it is manifest in Semireiche, with Yamnaya, Afanasievo (copper) and Andronovo (tin bronze) peoples (Mei 2000: Fig. 3). From Xinjiang this knowledge has been thought to have traveled through the Gansu Corridor via the Qijia peoples (Bagley 1999) and then into territories controlled by dynastic China. The dating of this process is still a problem, as the sites and their contents in Xinjiang are consistently later than those in Gansu, suggesting that the point of contact was in Gansu and that the knowledge then spread from there westward.

1. Eneolithic Altai

tocharians-chalcolithic-eneolithic
Afanasievo expansion ca. 3300-2600 BC. See full culture and ancient DNA maps.

The Afanasievo sites, as they are identified in Mongolia, for instance, make up an Eneolithic culture analogous to that of southern Siberia (3100/2500–2000 BCE) in the Upper Yenissei Valley that is characterized by copper tools and an economy reliant on horse, sheep and cattle breeding as well as hunting. (…) The Afanasievo is best known through study of its burials, which typically include groups of round barrows (kurgans), each up to 12 m in diameter with a stone kerb and covering a central pit grave containing multiple inhumations. In their Siberian context, burial pottery types and styles have suggested contacts with the slightly earlier Kelteminar culture of the Aral and Caspian Sea area.

The Afanasievo culture monuments, located in the northern Altai and in the Minusinsk Basin (the western Sayan), have been seen as analogous evidence for cross-Eurasian exchange. These complexes contain small collections of metal, and many of the items are made of brass, although golden, silver and iron ornaments were also identified. A mere one-fourth of these objects are tools and ornaments, while the rest consist of unshaped remains and semi-manufactured objects. Its metallurgical tradition has recently been dated by Chernykh to as early as 3100 to 2700 BCE (1992),making it more compatible chronologically with the early brass-using sites in Shaanxi mentioned above. Kovalev and Erdenebaatar have excavated barrows in Bayan-Ulgii, Mongolia, that have been carbon-dated to the first half of the third millennium BCE and associated by ceramic types and styles and burial patterns with the Afanasievo (Kovalev and Erdenebaatar 2009: 357–58). These mounded kurgans were covered with stone and housed rectangular, wooden-faced tombs that included Afanasievo-type bronze awls, plates and small “leaf-shaped” knife blades (Kovalev and Erdenebaatar 2009: Figs. 6 and 7).

They also excavated sites belonging to the more recently identified Chemurchek archaeological culture, located in the foothills of the Mongolian Altai (Kovalev 2014, 2015) (Fig. 2.6). These sites are carbon-dated to the same period as the Afanasievo burials or to c. 3100/2500–1800 BCE (six barrows in Khovd aimag and four in Bayan-Ulgo aimag). In the rectangular stone kerbed Chemurchek slab burials (Ulaaanhus sum, Bayan-ul’gi aimag and so forth), bronze items included awls; and at Khovd aimag, Bulgan sum, in addition to stone sculptures, three lead and one bronze ring were excavated (Kovalev and Erdenebaatar 2009: Figs. 2 and 3; Fig. 2.6). Although we will not know if they were produced locally until much further investigation is undertaken, these discoveries do document knowledge of various uses and types of metal objects in western and south central Mongolia. The types of metal items thus far recovered are simple tools (awls) and rings (ornamental?) not unlike those associated with Andronovo archaeological cultures as well.

This is a complex circumstance where archaeological evidence is not complete, but raises very important questions about transmission of metallurgical knowledge to and from areas in present-day China. In the 1970s some Afanasievo mounds were excavated in Central Mongolia by a Soviet–Mongolian expedition led by V. V. Volkov and E. A. Novgorodova (Novgorodova 1989: 81–85). Unfortunately, these mounds did not yield metal objects, only ceramics, but they show that the Afanasievo culture with the Eneolithic metallurgical tradition of manufacturing pure copper items had already moved east at least far as central Mongolia. In 2004, Kovalev and Erdenebaatar investigated a large Afanasievo mound, Kulala ula, in the extreme northwest of Mongolia, near the Russian border (Kovalev and Erdenebaatar 2009). There they found a copper knife and awl (Fig. 2.5). There are five C14 dates on wood, coal and human bones from this mound, which belong to the period 2890–2570 BCE. This shows that the Afanasievo culture were carriers of technology and produced artifacts in the first half of the third millennium BCE and that they also moved south along the foothills of the Mongolian Altai. Afanasievo culture in Altai and the Minusinsk basin is dated by C14 to 3600–2500 BCE (Svyatko et al. 2009; Polyakov 2010). In the north of Xinjiang in the Altai district, several typical egg-shaped vessels and two censers of Afanasievo types were found. Some of these have been obtained from the stone boxes (chambers of megalithic graves of the Chemurchek culture) (Kovalev 2011). Thus, the Afanasievo tradition of pure copper metallurgy must have spread to the northern foothills of the Tienshan Mountains no later than the mid-third millennium BCE. The links with Afanasievo and local cultures adjacent to and south of the mountains into present-day China can now be assumed.

tocharians-chalcolithic-late
Afanasievo – Chemurchek evolution ca. 2600-2200 BC. See full culture and ancient DNA maps.

2. Bronze Age Altai

Kovalev and Erdenebaatar (2014a) and later Tishkin, Grushin, Kovalev and Munkhbayar (2015) in Western Mongolia conducted large-scale excavations of megalithic barrows of the Chemurchek culture (dated about 2600–1800 BCE). This peculiar culture appeared in Dzungaria and the Mongolian Altai in the second quarter of the third millennium BCE and for some time existed together with the late Afanasievo culture, as evidenced by the findings of Afanasievo ceramics in Chemurchek graves, in the stone boxes. Unfortunately, in China we do not yet know of any metal object related,without doubt, to the Chemurchek culture. Kovalev, Erdenebaatar, Tishkin and Grushin found several leaden ear rings and one ring of tin bronze in three excavated Chemurchek stone boxes (Kovalev and Erdenebaatar 2014a; Tishkin et al. 2015). Such lead rings are typical for Elunino culture,which occupied the entire West Altai after 2400–2300 BCE (Tishkin et al. 2015). This culture had developed a tradition of bronze metallurgy with various dopants, primarily tin. Thus, the tradition of bronze metallurgy as early as this time could have penetrated the Mongolian Altai far to the south. In addition, in the Hadat ovoo Chemurchek stone box, Kovalev and Erdenebaatar discovered stone vessels refurbished with the help of copper “patches,” indicating the presence there of metallurgical production (Fig. 2.7) (Kovalev and Erdenebaatar 2014a). In one of the secondary

Chemurchek graves unearthed by Kovalev and Erdenebaatar in Bayan-Ulgi (2400–2220 BCE), a bronze awl was found (Kovalev and Erdenebaatar 2009). Kovalev and Erdenebaatar also discovered a new culture in the territory of Mongolia (Map 2.3), one that begins immediately after Chemurchek – Munkh-Khairkhan culture (Kovalev and Erdenebaatar 2009, 2014b). To date, about 17 mounds of this culture have been excavated in Khovd, Zavkhan, Khovsgol, Bulgan aimag of Mongolia. This culture dates from about 1800 to 1500 BCE, that is, contemporary with the Andronovo culture. Therefore, the Andronovo culture does not extend far into the territory of Mongolia. Three knives without dedicated handles or stems and five awls have been found in the Munkh-Khairkhan culture mounds (Fig. 2.8). All these products are made of tin bronze. (…) Additionally, eight Late Bronze Age burials (c. 1400–1100 BCE) were unearthed in the Bulgan sum of Khovd aimag and belong to another previously unknown culture called Baitag. And in the Gobi Altai, a new group of “Tevsh” sites dating to the Late Bronze Age were defined in Bayankhongor and South Gobi aimags (Miyamoto and Obata 2016: 42–50). From these Tevsh and Baitag sites, we see the expansion of burial goods to include beads of semiprecious stones (carnelian), bronze beads, buttons and rings and even the famous elaborate golden hair ornaments (Tevsh uul;Bogd sum;Uverkhanagia aimag) from the Baitag barrows (Kovalev and Erdenebaatar 2009: Fig. 5; Miyamoto and Obata 2016).

2.1. Chemurchek

About the Chemurchek culture, from A re-analysis of the Qiemu’erqieke (Shamirshak) cemeteries, Xinjiang, China, by Jia and Betts JIES (2010) 38(4):

The major characteristics of Qiemu’erqieke Phase I include:

  1. Burials with two orientations of approximately 20° or 345°.
  2. Rectangular enclosures built using large stone slabs. The size of the enclosure varies from a maximum of 28 x 30 m.*to a minimum of 10.5 x 4.4 m. (Figure 8, Table 2).
  3. *The stone enclosure located near Hayinar is the largest one at approximately 30 x 40 m. based on pacing of the site during a visit by the authors in 2008.

  4. Almost life-sized anthropomorphic stone stelae erected along one side of the stone enclosures (Lin Yun 2008).
  5. Single enclosures tend to contain one or more than one burial, all or some with stone cist coffins.
  6. The cist coffin is usually constructed using five large stone slabs, four for the sides and one on top, leaving bare earth at the base (Zhang Yuzhong 2007). Sometimes the insides of the slabs have simple painted designs (Zhang Yuzhong 2005).
  7. Primary and secondary burials occur in the same grave.
  8. Some decapitated bodies (up to 20) may be associated with the main burial in one cist.
  9. Bodies are commonly placed on the back or side with the legs drawn up.
  10. Grave goods include stone and bronze arrowheads, handmade gray or brown round-bottomed ovoid jars, and small numbers of flat-bottomed jars (Fig. 7).
  11. Clay lamps appear to occur together with roundbottomed jars.
  12. Complex incised decoration on ceramics is common but some vessels are undecorated.
  13. The stone vessels are distinctive for the high quality of manufacture.
  14. Stone moulds indicate relatively sophisticated metallurgical expertise.
  15. Artefacts made from pure copper occur.
  16. Sheep knucklebones (astragali) imply a tradition (as in historical and modern times) of keeping knucklebones for ritual or other purposes. They also indicate the herding of domestic sheep as part of the subsistence economy.
tocharians-bronze-age-early
Chemurchek culture ca. 2200-1750 BC. See full culture and ancient DNA maps.

Chemurchek dating

Available evidence suggests that the date range for Qiemu’erqieke Phase I should fall from the later third into the early second millennium BC. There are several reasons to suggest that the time span is around the early second millennium BC. Lin Yun (2008) (…) maintains that the bronze artefacts found in Phase I show a greater sophistication in the level of copper alloy technology than that of the pure copper artefacts common to the Afanasievo tradition. On this basis it might be suggested that the Afanasievo could be considered to be Chalcolithic with a time span across much of the third millennium BC ( Gorsdorf et al. 2004: 86, Fig. 1). Qiemu’erqieke Phase I, however, should more properly be considered as Bronze Age.

Lin Yun also used the bronze arrowhead from burial Ml 7 to narrow down the date of Qiemu’erqieke Phase I. Two arrowheads were found in this burial, one of them leaf shaped with a single barb on the back (Fig. 7:4). A similar arrowhead, together with its casting mould, has been found at the Huoshaogou site of Siba tradition (Li Shuicheng 2005, Sun Shuyun and Han Rufen 1997), in Gansu province, northwest China, dated around 2000-1800 BC (Li Shuicheng and Shui Tao 2000) . This supports a date in the early second millennium BC for the Qiemu’erqieke arrowhead. The painted, round-bottomed jar from the Tianshanbeilu cemetery Qia Weiming, Betts and Wu Xinhua 2008: Fig. 7, bottom left) has been considered as a hybrid between the Upper Yellow River Bronze Age cultures of Siba in northwest China and the steppe tradition of Qiemu’erqieke in west Siberia (Li Shuicheng 1999). If this assumption is correct, the date of Tianshanbeilu, around 2000 BC, can be used as a reference for Qiemu’erqieke Phase I (Jia Weiming, Betts and Wu Xinhua 2008, Lin Yun 2008, Li Shuicheng 1999). Stone arrowheads found in Qiemu’erqieke Phase I also imply that the date is likely to fall within the earlier part of the Bronze Age as no such stone arrowheads have yet been found elsewhere in sites of the Bronze Age in Xinlang dated after the beginning of the second millennium BC.*
*For example Chawuhu and Xiaohe cemeteries (Xinjiang Institute of Archaeology 1999, 2003).

pottery-afanasevo-chemurchek
Pottery of Afanasevo and East European traits from the Chemurchek complex. Image modified from Kovalev (2017).

(…) Pottery “oil burners” (goblet-like ceramic vessels, possibly lamps) have been found in three traditions: Afanasievo (Gryaznov and Krizhevskaya 1986:21), Okunevo and Qiemu’erqieke. It is believed that this oil-burner found in Siberia and the Altai is a heritage from the Yamnaya and Catacomb
cultures (Sulimirski 1970: 225, 425; Shishlina 2008:46) in the Caspian steppe further to the west, but does not seem to exist in known Andronovo cultures.
The oil-burner tends to disappear after around 2300 BC during the mid-Okunevo period. It is, however, possible that the tradition continues longer in the Qiemu’erqieke sites.

The construction of the stone enclosures also reveals a close connection between Qiemu’erqieke Phase I and the mid and late Okunevo tradition (Sokolova 2007). Slab built stone enclosures emerged in both the Okunevo and Afanasievo traditions (Gryaznov and Krizhevskaya 1986:15-23, Kovalev 2008, Sokolova 2007, Anthony 2007:310, Koryakova and Epimakhov 2007). In the early Afanasievo the enclosure is circular with no cist coffin (Anthony 2007:310, Gryaznov and Krizhevskaya 1986:20), but in the early stage of the Okunevo square stone enclosures with a single cist burial are dominant. Square or rectangular stone enclosures are a marked feature of Qiemu’erqieke Phase I, suggesting temporal relationships between Qiemu’erqieke Phase I and the Okunevo. In Okunevo chronological group II, possibly with influence from the Anfanasievo, circular stone enclosures appeared in combination with rectangular enclosures within individual cemeteries, referred to by Sokolova (2007: table 2) as hybrid examples. By Okunevo chronological group III, rectangular stone slab enclosures with multi-burials emerged again. This is the dominant form in Qiemu’erqieke Phase I. Okunevo burial traditions changed again to single cist burials in the late stage around chronological group V ( Sokol ova 2007). A specific mortuary rite of decapitated burials exists in both the Qiemu’erqieke and Okunevo traditions (Sokolova 2007, Chen Kwang-tzuu and Hiebert 1995), as does the occasional occurrence of painted designs on the interior of the slabs forming the cists ( e.g., Khavrin 1997: 70, fig. 4; 77: tab. IV.5). Based on these comparisons, the date of Qiemu’erqieke Phase I may well parallel that of the Okunevo from at least chronological group II around 2400 BC (Gorsdorf et al. 2004: fig. 1).

khuh-udzuur-barrow
Khuh Udzuuriin I-1 elite barrow (ca. 2470-2190 BC). Modified from Image modified from Kovalev (2014).

In addition to the pottery making tradition, the anthropomorphic stone stelae may also have earlier antecedents. In the Okunevo assemblage there are anthropomorphic stelae that are longer, thinner and more abstract than those of Qiemu’erqieke. There is no indication of such stelae in the Afanasievo tradition (Gryaznov and Krizhevskaya 1986:15-23). However, further to the west, anthropomorphic stone stelae are associated with the Kemi-Oba and Yamnya cultures around the third millennium BC (Telegin and Mallory 1994; Figure 13). Some major characteristics of these stelae such as the icons on the front face of the stelae (Telegin and Mallory 1994:8-9) also appear on stelae found in Qiemu’erqieke Phase I. Recalling the oil burners that may have been inherited from the Yamnya culture and which are found in the Afansievo, Okunevo and Qiemu’erqieke Phase I, it migh t be possible to speculate that Qiemu’erqieke Phase I has its origins even earlier than the first half of the third millennium BC. This idea has also been suggested by Kovalev ( 1999).

Despite the affinities with the Okunevo cultural tradition, Qiemu’erqieke Phase I appears to be a discrete regional variant. The ceramic assemblage shows traits unique to this cluster of sites, while the anthropomorphic stelae are also distinctive markers of this tradition.

khuh-udzuur-stela
Khuh Udzuur anthropomorphic stone stela, oriented toward the south – south-east. Image modified from Kovalev (2014).

3. Bronze Age Xinjiang

I recently reported on this blog the description of Xiaohe and Gumugou cemeteries from interesting Master’s thesis Shifting Memories: Burial Practices and Cultural Interaction in Bronze Age China: A study of the Xiaohe-Gumugou cemeteries in the Tarim Basin, by Yunyun Yang, Uppsala University, Department of Archaeology and Ancient History (2019).

It also offered a full summary of findings from prehistoric sites of Xinjiang related to the arrival of a cultural package from the Altai region, ultimately connected to Afanasievo. Relevant excerpts include the following (emphasis mine):

In Bronze Age Xinjiang, burials were diverse but also show some common features between different geographic sections. The main three mountains, including Kunlun Mountains, Tian Shan (mountains) and Altai Mountains, enclose the Tarim Basin, and the Dzungaria Basin, but leave the eastern part of the Tarim Basin and the south-eastern part of the Dzungaria Basin open (with easy access to the surroundings). The Hami Basin is located at the transitional area, connecting the two basins. Burials are mainly spread along the edge of the mountain ranges.

xinjiang-afanasievo-andronovo-bmac-tian-shan
An assumption of the spreading/expansion routes stone burial construct.

3.1. The Lop Nur region

In the Lop Nur region, the Xiaohe cemetery (2000-1450 BCE) and the Gumugou cemetery (1900-1800 BCE) had many common features shared, and so is the Keliyahe northern cemetery:

  • Cemeteries were located in sandy areas;
  • Rectangular/boat-shaped wooden coffins with monuments of wooden planks or poles;
  • Coffins had no bottoms;
  • The dead were placed lying straight on the back;
  • The dead were commonly buried in single graves.

The Gumugou cemetery contained six special sun-radiating-spokes burial pattern in addition to the normal burials, which were similar to the wooden coffin graves of the Xiaohe cemetery.

NOTE. For more on Xiaohe and Gumugou, see the recent post on Proto-Tocharians. See other papers on the Andronovo horizon for other Early to Middle Bronze Age cultural groups less clearly associated with the Xiaohe horizon, like Hazandu, Xintala, or the Chust culture.

From Shuicheng (2006):

An assemblage of early bronzes had been recovered from northwestern Xinjiang and the periphery of Dzungaria 准噶尔 Basin. It comprises a variety of utilitarian tools and weapons, and a small number of apparels. These artifacts bear the stamps of Andronovo Culture in form, artifact type and decorative pattern. The metallographic analysis on selected artifacts indicates that they comprise mainly of tin-bronzes that contain 2–10% of tin. Moreover, the chemical compositions of these artifacts are similar to that of the Andronovo Culture. Latter date (first half of the 1st millennium BC) artifacts of the assemblage include a small number of arsenic bronzes. In all, during the period between the mid-2nd and mid-1st millennium BC, copper and bronze artifacts coexisted in this region, albeit tin-bronze comprised the majority. The composition of alloy did not show significant change over time. Some colleagues pointed out that the Nulasai 奴拉赛 site at Nileke 尼勒克 County in the Yili 伊犁 River basin of Xinjiang was the pioneer in the use of “sulphuric ore–ice copper–copper”technology. It is also the only early smelting site in Euro-Asia that arsenic ore was added to deliberately produce an alloy

tocharians-bronze-age-middle
Prehistoric cultures of Xinjiang during the Middle Bronze Age. See full culture and ancient DNA maps.

3.2. The Hami Basin-the Balikun Grassland

From Yang (2019):

The Hami Basin-the Balikun Grassland area is located at the eastern part of Tian Shan. The area is divided in a northern basin and a southern basin by the east-west stretch of the Tian Shan. In the Hami Basin-the Balikun Grassland area, the main type of burials were earth-pit graves in the early Bronze Age, and burials of stone-pit with barrows became more common in the late Bronze Age. The Hami-Tianshan-Beilu cemetery is a representative of the earth-pit graves. The features of the Hami-Tianshan-Beilu cemetery (2000-1500 bce) here were:

  • Rectangular earth pit graves;
  • The dead were often in a hocker position lying on one side;
  • Commonly a single dead in one grave.
balikun-grassland
The Balikun grassland today (source).

The Hami-Wubu cemetery (earlier than 1000 bce) and the Yanbulake cemetery (1200-600 bce) are representatives of another common earth-pit graves. Common features here were:

  • Rectangular earth pits, with two storeys and/or roofed with wooden boards;
  • The dead was placed in a hocker position lying on one side;
  • Mostly a single dead in one grave.

Later there appeared more stone-pit graves in this area, and the features can be summarized as:

  • Round burial mounds, commonly constructed by stones or a mix of stones and earth;
  • Burial mounds with a sunken top or a normal (dome) top;
  • The diameter of the burial mounds varied between 3 and 25.4 m (but not necessarily limited in this scope);
  • Circular or rectangular stone kerbs;
  • Rectangular stone pits, constructed by earth, or stones, or a mix of earth and stones;
  • Rectangular stone pits contained wooden coffins (represented by the Yiwu Baiqi’er cemetery).
hami-basin-balikun-grassland-iron-age-burials
Some representatives of stone burials in the Hami Basin – the Balikun Grassland in the Iron Age (Adapted from: Xinjiang 2011, 29-41). Image modified from Yang (2019).

In the Hami Basin, the Bronze Age cemeteries show common burial features like earth pits and hocker position of the dead. With similar pottery styles in the Hami-Tianshan-Beilu cemetery to those in the Machang and Siba cultures (Xinjiang 2011: 17), it suggests possible cultural influence or people’s migrating from the Hexi Corridor in the east.

In the Balikun Grassland, burials in an earlier time contained mostly earth-pit graves but also a small number of stone-pit graves. The pebbles were imbedded in the floors and the walls of the graves in a rectangular shape, e.g. the Balikun-Nanwan cemetery (1600-1000 bce). In a later time, there appeared huge burial mounds with a sunken top, and with the diameters of the burial mounds varying from 3 to 25.4 m, e.g. the Balikun-Dongheigou cemetery and the Balikun-Heigouliang cemetery. The Yiwu-Bai’erqi and the Yiwu-Kuola cemeteries contained either round stone burial mounds or circular stone kerbs on the ground surface. Considering the three burial elements including burial mounds, stone pits and circular kerbs, the later period cemeteries in the Balikun Grassland were actually similar to cemeteries from the southern edge of the Altai Mountain area.

From Shuicheng (2006):

The Nanwan 南湾 cemetery site at Kuisu 奎苏 Town, Balikun 巴里坤 (1600–1100 BC) also yielded an assemblage of early bronzes. The style of its early phase artifacts is similar to that of the burials distributed in the North Tianshan Route. Some sorts of cultural connection should have existed between the two.

The dates of Yanbulake 焉不拉克 Culture (1300–700 BC) are comparatively late. Its metallurgy was a continuation of the western China tradition. Artifact types include a variety of utilitarian tools, weapons and apparels.

tocharians-bronze-age-late
Prehistoric cultures of Xinjiang during the Late Bronze Age. See full culture and ancient DNA maps.

3.3. The Turpan Basin-the middle part of Tian Shan

From Yang (2019):

Turpan Basin is located at the western part of the Hami Basin, and lies at the southern edge of the eastern Tian Shan. In the Turpan Basin-the middle part of Tian Shan area, the main representative of the Bronze Age cemeteries is the Yanghai Nr.1 cemetery. The features here were:

  • Elliptic earth pit graves, commonly covered by round logs on the top;
  • Some graves contained burial beds made of round logs or reeds;
  • The dead were mainly placed lying straight on the back;
  • Mostly a single dead in one grave.

In Iron Age, the stone burials became dominant, but the stone burials varied in different regions of the Turpan Basin-the middle part of Tian Shan area. Graves containing burial mounds, stone pit, and circular stone kerbs are represented by the Shanshan-Ertanggou cemetery, the Tuokexun-Alagou cemetery, the Urumqi-Chaiwobu cemetery and the Urumqi-Yizihu-Sayi cemetery, etc. The stone funeral construction features here are similar to those contemporary cemeteries in the Hami Basin-the Balikun Grassland area.

3.4. The southern edge of the western and middle part of Tian Shan

In the southern edge of the western and middle part of Tian Shan area, the main representatives of the late Bronze Age cemeteries are the Hejing-Chawuhu Nr.4 cemetery (around 1000-500 bce), the Hejing-Xiaoshankou cemetery, the Baicheng-cemetery, etc. The main burial features of the late Bronze Age and the early Iron Age cemeteries (see Fig.12) here were:

  • Burial mounds, constructed by stones or a mix of stones and earth;
  • Irregular circular or rectangular stone kerbs;
  • Stone pit graves in a bell-shape or a rectangular shape;
  • Stone pit graves constructed by imbedding pebbles or stone slabs in walls and floors;
  • The dead were often placed lying on their back with bent legs;
  • The dead were commonly reburied a second time with multiple burials.

From the late Bronze Age to the early Iron Age in this area, the burial traditions tended to be in a more varied way. In the stone burials with stone kerbs, there is a mixture of stone pit and earth pit graves. The burial features of the Iron Age cemeteries in this section were similar to those contemporary both in the Hami Basin-the Balikun Grassland area and in the Turpan Basin-the middle part of Tian Shan area.

From Shuicheng (2006):

The Chawuhu 察吾呼 Culture (1100–500 BC) distributes on the foothills between the middle section of the Tianshan Mountain Ranges and Tarim River. Its bronze assemblage comprises a variety of weapons, utilitarian tools and small apparels. They show no apparent temporal change in form and type through the four cultural phases. In addition, bronzes bear the Chawuhu characteristics were found in Hejing 和静, Baicheng 拜城 and Luntai 轮台 (Bügür). Yet, sites distributed along the Tarim River, such as Heshuo 和硕, Kuga 库车and Aksu 阿克苏, yielded remains of a bronze culture different from that of Chawuhu. Bronzes recovered include double-eared socketed axe, arrowheads, awls, knives, needles and bracelets. Their absolute dates have been estimated to be earlier than that of Chawuhu.

tocharians-iron-age-early
Prehistoric cultures of Xinjiang during the Early Iron Age. See full culture and ancient DNA maps

3.5. The Pamir Plateau

From Yang (2019):

A typical Bronze Age cemetery from the Pamir Plateau area is the Tashenku’ergan-Xiabandi cemetery (around 1000-500 bce). The burial features here were:

  • Mainly inhumations, but also a few cremations;
  • Burial mounds, constructed of stones;
  • Irregular circular or rectangular stone kerbs;
  • Mostly a single dead in one grave;
  • The dead was placed in a hocker position lying on one side.

The adoption of burial customs from the east supports the migration of Afanasievo-related peoples from the Tian Shan up to the Pamir Plateau, strongly influencing the findings of the Xiabandi cemetery, which has been dated from an early Bronze Age phase (ca. 1500-300 BC) to a late date up to ca. 600 BC.

While it is today unclear how far the Afanasievo admixture reached into the western Xinjiang, it seems that the Pamir Plateau remained culturally connected to neighbouring Andronovo-related cultures in pottery and metallurgical innovations, hence their language probably belonged – during most part of the Bronze and Iron Ages – to the Indo-Iranian branch, even though specific dialects might have changed with each new attested group.

In particular, it is possible that the early Andronovo groups related to the Xiaohe Horizon spoke Indo-Aryan or West Iranian dialects, while Saka-related groups replaced them – or an intermediate Tocharian-speaking group – with East Iranian dialects. A close interaction with West Iranian would justify the known ancient borrowings of Tocharian, although they could also be explained by contacts with Chust-related groups farther west. For more on this, see Ged Carling’s work on the different layers of Iranian loans.

Xinjiang BA/IA Summary

From Yang (2019):

In the early Bronze Age, there are distinct regional differences in the burial customs in and surrounding the Tarim Basin. At the southern edge of the Altai Mountains area, the burial customs included stone burial mounds, stone pit graves, circular or rectangular stone kerbs and stone human sculptures; the dead were placed lying straight on the back. In the Hami Basin-the Balikun Grassland area, the burial customs included earth pit graves; the dead were placed in a hocker position lying on one side. In the Turpan Basin-the middle part of Tian Shan area, the burial customs included earth pit graves; the dead were placed lying straight on the back. In the Lop Nur region, the burial customs included wooden coffins buried in sand; the dead were placed lying straight on the back.

But from the late Bronze Age to the early Iron Age, there was a common shift in burial customs from earth pit graves to stone burials in the Hami Basin-the Balikun Grassland area and in the Turpan Basin-the middle part of Tian Shan area. The main features of the stone burials include stone burial mounds, circular or rectangular stone kerbs, and the stone pit graves in the cemeteries. Similar stone burial customs commonly appeared at the southern edge of the western and middle part of Tian Shan area and the Pamir Plateau area in Iron Age. The burial features in most areas are in a mixture of both the earth pit graves and stone pit graves, especially in the Hami Basin-the Balikun Grassland area and the Turpan Basin-the middle part of Tian Shan area.

xinjiang-bronze-age-iron-age

From Shuicheng (2006):

Historians of metallurgy conducted metallographic analyses on a sample of 234 metal specimens recovered from 16 localities in eastern Xinjiang. They concluded that the metallurgic industry in eastern Xinjiang could be roughly partitioned into three developmental phases. The early phase is represented by the burials distributed in the North Tianshan Route. The majority of the metal assemblage was tin-bronzes; however, copper and arsenic-bronzes maintained considerable proportions. The middle phase is represented by the burials at Yanbulake. During this phase, tin-bronze still maintained the majority; the proportion of arsenic-bronze increased, and some of them were high arsenic-bronzes. The late phase is represented by the burials at Heigouliang 黑沟梁. The composition of lead increased in the bronze alloy in the expense of arsenic. In addition, this phase witnessed the appearance of high tin-bronze that composed up to 16% of tin and the appearance of brass, that is, an alloy of copper and zinc. The bronze alloy consistently contained significant amount of impurities regardless of temporal difference. Casting and forging technologies coexisted throughout the three phases. The early bronzes (2000–500 BC) of eastern Xinjiang, in general, contained arsenic; however, the composition of arsenic was usually under 8%, but a few artifacts contained more than 20% arsenic. In all, arsenic had long been used in the alloy-forming of the early bronzes in eastern Xinjiang. Consequently, arsenic-bronzes were widely found in the prehistoric archaeology of the region. The artifact types, chemical compositions and manufacture techniques of the bronze assemblage of the burials of the North Tianshan Route are similar to those of Siba Culture, indicating that eastern Xinjiang had played a significant role in the East-West interactions.

An assemblage of early bronzes had been recovered from northwestern Xinjiang and the periphery of Dzungaria 准噶尔 Basin. It comprises a variety of utilitarian tools and weapons, and a small number of apparels. These artifacts bear the stamps of Andronovo Culture in form, artifact type and decorative pattern. The metallographic analysis on selected artifacts indicates that they comprise mainly of tin-bronzes that contain 2–10% of tin. Moreover, the chemical compositions of these artifacts are similar to that of the Andronovo Culture. Latter date (first half of the 1st millennium BC) artifacts of the assemblage include a small number of arsenic-bronzes. In all, during the period between the mid-2nd and mid-1st millennium BC, copper and bronze artifacts coexisted in this region, albeit tin-bronze comprised the majority.

tocharians-iron-age-late
Prehistoric cultures of Xinjiang during the Late Iron Age. See full culture and ancient DNA maps.

Tocharians in population genomics

Prehistoric population movements between the Altai and the Tian Shan are difficult to pinpoint, not the least because of the division of these territories among three different countries and their archaeological teams, only recently (more) open to the international scholarship.

The available schematic archaeological picture, where migrations could only be roughly inferred, has been recently updated to a great extent by Ning, Wang et al. (2019), whose genetic analysis of the samples is as thorough as anyone could have asked for, with a level of detail which matches the complex genetic picture of the region by the Iron Age.

As a summary, here is what they described about the samples from Shirenzigou (ca 400-200 BC), corresponding to the Iron Age populations of the Hami Basin-the Balikun Grassland area, and closely related to the preceding Yanbulake Culture:

As shown in Figure S3, the Steppe_MLBA populations including Srubnaya, Andronovo, and Sintashta were shifted toward farming populations compared with Yamnaya groups and the Shirenzigou samples. This observation is consistent with ADMIXTURE analysis that Steppe_MLBA populations have an Anatolian and European farmer-related component that Yamnaya groups and the Shirenzigou individuals do not seem to have. The analysis consistently suggested Yamnaya-related Steppe populations were the better source in modeling the West Eurasian ancestry in Shirenzigou.

biplot-yamnaya-tocharians-shirenzigou
Biplot of f3-outgroup tests illustrating the Kostenki14 and Anatolia_N like ancestries in Shirenzigou individuals. Most Shirenzigou individuals were on a cline with Yamnaya and European hunter-gatherer groups, lacking the European farmer ancestry as compared to the Steppe_MLBA populations such as Andronovo, Srubnaya and Sintashta [S1-S5]. Horizontal and vertical bars represent ± 3 standard errors, corresponding to form of outgroup f3 tests on the x axis and y axis respectively.

We continued to use qpAdm to estimate the admixture proportions in the Shirenzigou samples by using different pairs of source populations, such as Yamnaya_Samara, Afanasievo, Srubnaya, Andronovo, BMAC culture (Bustan_BA and Sappali_ Tepe_BA) and Tianshan_Hun as the West Eurasian source and Han, Ulchi, Hezhen, Shamanka_EN as the East Eurasian source. In all cases, Yamnaya, Afanasievo, or Tianshan_Hun always provide the best model fit for the Shirenzigou individuals, while Srubnaya, Andronovo, Bustan_BA and Sappali_Tepe_BA only work in some cases.

p-values-shirenzigou-samples-han-chinese
Table S2. P values in modelling a two-way (P=rank 1) admixture in Shirenzigou samples using each of the four populations (Bustan_BA, Sappali_Tepe_BA, Andronovo.SG, Srubnaya) together with Han Chinese as two sources [S6], Related to Figure 2. We used the following set of outgroups populations: Dinka, Ust_Ishim, Kostenki14, Onge, Papuan, Australian, Iran_N, EHG, LBK_EN.

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

In the PCA, ADMIXTURE, outgroup f3 statistics [see Figure S4], as well as f4 statistics (Table S3), we observed the Shirenzigou individuals were closer to the present day Tungusic and Mongolic-speaking populations in northern Asia than to the populations in central and southern China, suggesting the northern populations might contribute more to the Shirenzigou individuals. Based on this, we then modeled Shirenzigou as a three-way admixture of Yamnaya_Samara, Ulchi (or Hezhen) and Han to infer the source from the East Eurasia side that contributed to Shirenzigou. We found the Ulchi or Hezhen and Han-related ancestry had a complicated and unevenly distribution in the Shirenzigou samples. The most Shirenzigou individuals derived the majority of their East Eurasian ancestry from Ulchi or Hezhen-related populations, while the following two individuals M820 and M15-2 have more Han related than Ulchi/ Hezhen-related ancestry

It is unclear whether the Chemurchek population will show a sizeable local contribution from neighbouring groups. The fact that Okunevo shows 20% Yamnaya-related ancestry strongly supports the nature of neighbouring stone-grave-building peoples of the Altai and the northern Tian Shan as mostly Afanasievo-like, and the apparent lack of contributions of Srubna/Andronovo-like ancestry in the early Hami-Balikun stone burial builders also speaks for radical population replacement events reaching the areas south of Tian Shan, at least initially.

While ancestry cannot settle linguistic questions, it seems that nomads of the Gansu and Qinghai grasslands retained an ancestry close to Andronovo, whereas nomads of the Hami Basin-Balikun grasslands and related populations of Xinjiang remained closely related to Afanasievo. This doesn’t preclude that the ancestors of the Yuezhi became acculturated under the influence of peoples from eastern Xinjiang, but all data combined suggest an isolation of both populations – relative to other groups and to each other – and it is therefore more likely that they spoke Indo-Iranian-related languages rather than a language of the Tocharian branch.

Haplogroups

In an interesting twist of events, despite the initially reported hg. R1b and Q, Tocharians from Shirenzigou actually show a haplogroup diversity comparable to that attested in other late Iron Age populations: a similar diversity is seen, for example, among Germanic, Baltic, and Balto-Finnic peoples of the Baltic region; among East Germanic or Scythians of the north Pontic region; or among Mediterranean peoples sampled to date. Iron Age peoples show thus a complex sociopolitical setting that overcame the previous patrilineal homogeneity of Bronze Age expansions.

tocharians-pca
PCA and ADMIXTURE for Shirenzigou Samples. Modified from the original to include in black squares samples related to Yamnaya. Modified from the paper to include labels of modern populations and a dotted lines with the cline formed by Shirenzigou, from (Yamnaya-like) Afanasievo to Central and East Asian-like populations. In red circles, samples with best fit for Andronovo-like ancestry. In green circles, samples with Han-related admixture.

M15-2 (with Han-related ancestry) is of the rare haplogroup Q1a-M120, while the samples with highest Steppe_MLBA-related ancestry are of hg. R1b-PH155, which points to their recent origin among Yuezhi, or to Hun-related populations showing an admixture related to the proto-historic nomads of the Gansu and Qinghai grasslands.

The expansion of Chemurchek-related peoples was probably associated more with hg. Q1a (dubious if it’s a Pre-ISOGG 2017 nomenclature, hence possibly Q1b), a haplogroup that might be found in Khvalynsk as a “significant minority” according to Anthony (2019), and it might also be attested in sampled individuals from Afanasievo in its late phase. This might be, therefore, a case similar to the early expansion of Indo-Europeans with R1b-V1636 lineages through the Volga – North Caucasus region, and of the later expansion with I2a-L699 lineages into the Balkans.

Haplogroup Q1a2-M25 is found in individual X3, whose Steppe ancestry is likely a combination of Afanasievo plus Andronovo-like ancestry heavily admixed with Hezhen/Ulchi-like populations, in line with the expected recent contacts with the neighbouring Xiongnu, Yuezhi, and other population movements affecting eastern Xinjiang.

Sample M4, which packs the most Afanasievo-like ancestry, is of hg. R1a-Z645, which – like sample M8R1 of hg. O – is most likely related to haplogroup resurgence events of local populations, which left the predominant Afanasievo-like admixture brought by builders of stone burials essentially intact, evidenced by the almost 100% of R1a found in the Xiaohe cemetery – and in most of the early Andronovo horizon – and among expanding Kangju and Wusun, as well as by the prevalence of hg. O among sampled East Asian populations.

A question that will only be answered with more samples is how and when the prevalent R1b-L23 and Q1b lineages among Afanasievo-related peoples began to be replaced to reach the high variability seen in Shirenzigou. Given the pastoralist nature of peoples around Tian Shan, the succeeding expansions of Proto-Tocharians, and the late isolation of different Common Tocharian groups, it is more than likely that this variability represents a late and local phenomenon within Xinjiang itself.

tocharians-antiquity
Peoples of Xinjiang during Antiquity. See full culture and ancient DNA maps.

Conclusion

Tocharians are one of the main pillars that confirm the Late Proto-Indo-European homeland of the R1b-rich populations of the Don-Volga region. There is already:

Just like the East Bell Beaker expansion from Yamnaya Hungary has confirmed that Corded Ware peoples did not partake in spreading Indo-European languages (spreading Uralic languages instead), data on the expansion of Tocharian speakers from Afanasievo to the Tian Shan was always there; population genomics is merely helping to connect the dots.

In summary, genetic research is supporting the expected linguistic expansions of the Neolithic and Bronze Age step by step, slowly but surely.

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

Yekaterinovsky Cape, a link between the Samara culture and early Khvalynsk

ekaterinovsky-cape

We already had conflicting information about the elite individual from the Yekaterinovsky Cape and the materials of his grave, which seemed quite old:

For the burial of 45 in the laboratory of the University of Pennsylvania, a 14C date was obtained: PSUAMS-2880 (Sample ID 16068)> 30 kDa gelatin Russia. 12, Ekaterinovka Grave 45 14C age (BP) 6325 ± 25 δ 13C (‰) –23.6 δ15 N (‰) 14.5. The results of dating suggest chronological proximity with typologically close materials from Yasinovatsky and Nikolsky burial grounds (Telegini et al. 2001: 126). The date obtained also precedes the existing dates for the Khvalynsk culture (Morgunova 2009: 14–15), which, given the dominance of Mariupol traits of the burial rite and inventory, confirms its validity. However, the date obtained for human bones does not exclude the possibility of a “reservoir effect” when the age can increase three or more centuries (Shishlin et al. 2006: 135–140).

Now the same date is being confirmed by the latest study published on the site, by Korolev, Kochkina, and Stachenkov (2019) and it seems it is really going to be old. Abstract (in part the official one, in part newly translated for clarity):

For the first time, pottery of the Early Eneolithic burial ground Ekaterinovsky Cape is published. Ceramics were predominantly located on the sacrificial sites in the form of compact clusters of fragments. As a rule, such clusters were located above the burials, sometimes over the burials, some were sprinkled with ocher. The authors have identified more than 70 vessels, some of which have been partially reconstructed. Ceramic was made with inclusion of the crushed shell into molding mass. The rims of vessels had the thickened «collar»; the bottoms had a rounded shape. The ornament was located on the rims and the upper part of the potteries. Fully decorated vessels are rare. The vessels are ornamented with prints of comb and rope stamps, with small pits. A particularity of ceramics ornamentation is presented by the imprints of soft stamps (leather?) or traces of leather form for the making of vessels. The ornamentation, made up of «walking comb» and incised lines, was used rarely as well as the belts of pits made decoration under «collar» of a rim. Some features of the ceramics decoration under study relate it with ceramics of the Khvalynsk culture. The ceramics of Ekaterinovsky Cape burial ground is attributed by the authors to the Samara culture. The ceramic complex under study has proximity to the ceramics from Syezzhe burial ground and the ceramics of the second phase of Samara culture. The chronological position is determined by the authors as a later period than the ceramics from the Syezzhe burial ground, and earlier than the chronological position of ceramics of the Ivanovka stage of the Samara culture and the Khvalynsk culture.

ekaterinovsky-cape-pottery
Ceramics from Ekaterinovsky Cape burial ground. 1–2, 4–5, 7–11 – ceramics from aggregations; 3, 6 – ceramics from the cultural layer.

More specifically:

Based on ceramic fragments from a large vessel from a cluster of sq.m. 14, the date received was: SPb-2251–5673 ± 120 BP. The second date was obtained in fragments from the aggregation [see picture above] from the cluster of sq.m. 45–46: SPb-2252–6372 ± 100 BP. The difference in dating indicates that the process of determining the chronology of the burial ground is far from complete, although we note that the earlier date almost coincided with the date obtained from the human bone from individual 45 (Korolev, Kochkina, Stashenkov, 2018, p. 300).

Therefore, the ceramics of the burial ground Ekaterinovsky Cape possess an originality that determines the chronological position of the burial ground between the earliest materials of the burial type in Syezzhe and the Khvalynsk culture. Techno-typological features of dishes make it possible to attribute it to the Samara culture at the stage preceding the appearance of Ivanovska-Khvalynsk ceramics.

It seems that this site showed cultural influences from the upstream region near the Kama-Vyatka interfluve, too, according to Korolev, Kochkina, Stashenkov, and Khokhlov (2018):

In 2017, excavation of burial ground Ekaterinovsky Cape were continued, located in the area of the confl uence of the Bezenchuk River in the Volga River. During the new excavations, 14 burials were studied. The skeleton of the buried were in a position elongated on the back, less often – crooked on the back with knees bent at the knees. In one burial (No. 90), a special position of the skeleton was recorded. In the burial number 90 in the anatomical order, parts of the male skeleton. This gave grounds for the reconstruction of his original position in a semi-sitting position with the support of elbows on the bottom of the pit. Noteworthy inventory: on the pelvic bones on the left lay a bone spoon, near the right humerus, the pommel of a cruciform club was found. A conclusion is made about the high social status of the buried. The results of the analysis of the burial allow us to outline the closest circle of analogies in the materials of Khvalynsky I and Murzikhinsky burial grounds.

Important sites mentioned in both papers and in this text:

To sum up, it seems that the relative dates we have used until now have to be corrected: older Khvalynsk I Khvalynsk II individuals, supposedly dated ca. 5200-4000 BC (most likely after 4700 BC), and younger Yekaterinovsky individuals, supposedly of the fourth quarter of the 5th millennium (ca. 4250-4000 BC), are possibly to be considered, in fact, roughly reversed, if not chronologically, at least culturally speaking.

Interestingly, this gives a new perspective to the presence of a rare fish- or reptile-headed pommel-scepter, which would be natural in a variable period of expansion of the horse and horse-related symbolism, a cultural trait rooted in the Samara culture attested in Syezzhe before the unification of the symbol of power under the ubiquitous Khvalynsk-Suvorovo horse-headed scepters and related materials.

ekaterinovsky-cape-pommel-mace
Ekaterinovsky Cape Burial Ground. Inventory of the burial no 90: 1, 2 – stone pommel of the mace; 3, 4 – bone article.

The Khvalynsk chieftain

If the reported lineages from Yekaterinovsky Cape are within the R1b-P297 tree, but without further clades, as Yleaf comparisons may suggest, there is not much change to what we have, and R1b-M269 could actually represent a part of the local population, but also incomers from the south (e.g. the north Caspian steppe hunter-gatherers like Kairshak), the east (with hunter-gatherer pottery), or the west near the Don River (in contact with Mariupol-related cultures, as the authors inferred initially from material culture).

Just like R1a-M417 became incorporated into the Sredni Stog groups after the Novodanilovka-Suvorovo expansion, probably as incoming hunter-gatherer pottery groups from the north admixing with peoples of “Steppe ancestry”, R1b-M269 lineages might have expanded explosively only during the Repin expansion, and maybe (like R1b-L51 later) they formed just a tiny part of the clans that dominated the steppe during the Khvalynsk-Novodanilovka community.

On the other hand, the potential finding of various R1b-M269/L23 samples in Yekaterinovsky Cape (including an elite individual) would suggest now, as it was supported in the original report by Mathieson et al. (2015), that these ancient R1b lineages found in the Volga – Ural region are in fact most likely all R1b-M269 without enough coverage to obtain proper SNP calls, which would simplify the picture of Neolithic expansions (yet again). From the supplementary materials:

10122 / SVP35 (grave 12). Male (confirmed genetically), age 20-30, positioned on his back with raised knees, with 293 copper artifacts, mostly beads, amounting to 80% of the copper objects in the combined cemeteries of Khvalynsk I and II. Probably a high-status individual, his Y-chromosome haplotype, R1b1, also characterized the high-status individuals buried under kurgans in later Yamnaya graves in this region, so he could be regarded as a founder of an elite group of patrilineally related families. His MtDNA haplotype H2a1 is unique in the Samara series.

khvalynsk-cemetery
Khvalynsk cemetery and grave gifts. Grave 90 contained copper beads and rings, a harpoon, flint blades, and a bird-bone tube. Both graves (90 and 91) were partly covered by Sacrificial Deposit 4 with the bones from a horse, a sheep, and a cow. Center: grave goods from the Khvalynsk cemetery-copper rings and bracelets, polished stone mace heads, polished stone bracelet, Cardium shell ornaments, boars tusk chest ornaments, flint blades, and bifiacial projectile points. Bottom: shell-tempered pottery from the Khvalynsk cemetery. After Agapov, Vasiliev, and Pestrikova 1990; and Ryndina 1998, Figure 31. Modified from Anthony (2007).

This remarkable Khvalynsk chieftain, whose rich assemblage may correspond to the period of domination of the culture all over the Pontic-Caspian steppes, has been consistently reported as of hg. R1b-L754 in all publications, including Wang et al. (2018/2019) tentative SNP calls in the supplementary materials (obtained with Yleaf, as the infamous Narasimhan et al. 2018 samples), but has been variously reported by amateurs as within the R1b-M73, R1b-V88, or (lately) R1b-V1636 trees, which makes it unlikely that quality of the sample is allowing for a proper SNP call.

The fact that Mathieson et al. (2015) considered it a member of the R1b-M269 clans appearing later in Yamna seems on point right now, especially if samples from Yekaterinovka are all within this tree. The relevance of R1b-L23 in the expansion of Repin and Yamna is reminiscent of the influence of successful clans among Yamna offshoots, such as Bell Beakers, and among Bell Beaker offshoots during the Bronze Age all over Europe.

Taking these younger expansions as example, it seems quite likely based on cultural links that (at least part of) the main clans of Khvalynsk were of R1b-M269 lineage, stemming from a R1b-dominated Samara culture, in line with the known succeeding expansions and the expected strictly patriarcal and patrilineal society of Proto-Indo-Europeans, which would have exacerbated the usual reduction in Y-chromosome haplogroup variability that happens during population expansions, and the aversion towards foreign groups while the culture lasted.

pontic-steppe-neolithic
Cultures of the Pontic-Caspian steppes and forest-steppes and surrounding areas during the Neolithic.

The finding of R1b-L23 in Yekaterinovka, associated with the Samara culture, before or during the Khvalynsk expansion, and close to the Khvalynsk site, would make this Khvalynsk chieftain most likely a member of the M269 tree (paradoxically, the only R1b-L754 branch amateurs have not yet reported for it). Similarly, the sample of a “Samara hunter-gatherer” of Lebyazhinka, of hg. R1b-P297, could also be under this tree, just like most R1b-M269 from Yamna are downstream from R1b-L23, and most reported R1b-M269 or R1b-L23 from Bell Beakers are under R1b-L151.

On the other hand, we know of the shortcomings of attributing a haplogroup expansion to the best known rulers, such as the famous lineages previously wrongly attributed to Niall of the Nine Hostages or Genghis Khan. The known presence of R1b-V1636 up to modern Greeks would be in line with an ancient steppe expansion that we know will show up during the Neolithic, although it could also be a sign of a more recent migration from the Caucasus. The presence of a sister clade of R1b-L23, R1b-PF7562, among modern Balkan populations, may also be attributed to a pre-Yamna steppe expansion.

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

On SNP calls

I reckon that even informal reports on SNP calls, like any other analyses, should be offered in full: not only with a personal or automatic estimation of the result, but with a detailed explanation of the good, dubious, and bad calls, alternatives to that SNP estimation, and a motivated reasoning of why one branch should be preferred over others. Downloading a sample and giving an instruction using a free software tool is never enough, as it became crystal clear recently for the hilariously biased and flawed qpAdm reports on Dutch Bell Beakers as the ‘missing link’ between Corded Ware and Bell Beakers…

Another example I can recall is the report of a R1a-Z93 subclade in the R1a-M417 sample ca. 4000 BC from Alexandria, which seems rather unlikely, seeing how this subclade must have split and expanded explosively with R1a-Z645 to the east with eastern Corded Ware groups, i.e. 1,000 years later, just like Z282 lineages expanded mainly to the north-east. But then again, as with the Khvalynsk chieftain, I have only seen indirect reports of that supposed SNP (including Y26+!), so we should just stick with its officially reported R1a-M417 lineage. This upstream haplogroup was, in fact, repeated with Yleaf’s tentative estimates in Wang et al. (2019) supplementary materials…

The combination of inexperienced, biased, or simply careless design, analyses, and reports, including SNP calls and qpAdm analyses (whether in forums or publications), however well-intentioned (or not) they might be, are hindering a proper analysis of data, adding to the difficulties we already have due to the scarcity of samples, their limited coverage, and the lack of proper context.

Some people like to repeat ad nauseam that archaeology and/or linguistics are ‘not science’ whenever they don’t fit their beliefs and myths based on haplogroup and/or ancestry. But it’s becoming harder and harder to rely on certain genetic data, too, and on their infinite changing interpretations, much more than it is to rely on linguistic and archaeological research, including data, assessments, and discussions that are open for anyone to review…if one is truly interested in them.

Happy new year 2019…and enjoy our new books!

song-sheep-horses-header

Sorry for the last weeks of silence, I have been rather busy lately. I am having more projects going on, and (because of that) I also wanted to finish a project I have been working on for many months already.

I have therefore decided to publish a provisional version of the text, in the hope that it will be useful in the following months, when I won’t be able to update it as often as I would like to:

EDIT (20 JAN 2019): For those of you who are more comfortable reading in your native language, I have placed some links to automatic translations by Google Translate. They might work especially well for the texts of A Game of Clans & A Clash of Chiefs.

Don’t forget to check out the maps included in the supplementary materials: I have added Y-DNA, mtDNA, and ADMIXTURE data using GIS software. The PCA graphics are also important to follow the main text.

NOTE. Right now the files are only in my server. I will try to upload them to Academia.edu and Research Gate when I have time, I have uploaded them to Academia.edu and ResearchGate, in case the websites are too slow.

I would have preferred to wait for a thorough revision of the section on archaeology and the linguistic sections on Uralic, but I doubt I will have time when the reviews come, so it was either now or maybe next December…

I say so in the introduction, but it is evident that certain aspects of the book are tentative to say the least: the farther back we go from Late Proto-Indo-European, the less clear are many aspects. Also, linguistically I am not convinced about Eurasiatic or Nostratic, although they do have a certain interest when we try to offer a comprehensive view of the past, including ethnolinguistic identities.

I cannot be an expert in everything, and these books cover a lot. I am bound to publish many corrections as new information appears and more reviews are sent. For example, just days ago (before SNP calls of Wang et al. 2018 were published) some paragraphs implied that AME might have expanded Nostratic from the Middle East. Now it does not seem so, and I changed them just before uploading the text. That’s how tentative certain routes are, and how much all of this may change. And that only if we accept a Nostratic phylum…

NOTE. Since the first book I wrote was the linguistic one, and I have spent the last months updating the archaeology + genetics part, now many of you will probably understand 1) why I am so convinced about certain language relationships and 2) how I used many posts to clarify certain ideas and receive comments. Many posts offer probably a good timeline of what I worked with, and when.

Acknowledgements

I did not add this section to the books, because they are still not ready for print, but I think this is due somewhere now. It is impossible to reference all who have directly or indirectly contributed to this, so this is a list of those I feel have played an important role.

I am indebted to the following people (which does not mean that they share my views, obviously):

First and foremost, to Fernando López-Menchero, for having the patience to review with detail many parts on Indo-European linguistics, knowing that I won’t accept many of his comments anyway. The additional information he offers is invaluable, but I didn’t want to turn this into a huge linguistic encyclopaedia with unending discussions of tiny details of each reconstructed word. I think it is already too big as it is.

I would not have thought about doing this if it were not for the interest of Wekwos (Xavier Delamarre) in publishing a full book about the Indo-European demic diffusion model (in the second half of 2017, I think). It was them who suggested that I extended the content, when all I had done until then was write an essay and draw some maps in my free time between depositing the PhD thesis and defending it.

Sadly, as much as I would like to publish a book with a professional publisher, I don’t think ancient DNA lends itself for the traditional format, so my requests (mainly to have free licenses and being able to review the text at will, as new genetic papers are published) were logically not acceptable. Also, the main aim of all volumes, especially the linguistic one, is the teaching of essentials of Late Proto-Indo-European and related languages, and this objective would be thwarted by selling each volume for $50-70 and only in printed format. I prefer a wider distribution.

At first I didn’t think much of this proposal, because I do not benefit from this kind of publications in my scientific field, but with time my interest in writing a whole, comprehensive book on the subject grew to the point where it was already an ongoing project, probably by the start of 2018.

I would not have been in contact with Wekwos if it were not for user Camulogène Rix at Anthrogenica, so thanks for that and for the interest in this work.

I would not have thought of writing this either if not for the spontaneous support (with an unexpected phone call!) of a professor of the Complutense University of Madrid, Ángel Gómez Moreno, who is interested in this subject – as is his wife, a professor of Classics more closely associated to Indo-European studies, and who helped me with a search for Indo-Europeanists.

EDIT (1 JAN 2019): I remembered that Karin Bojs sent me her book after reading the demic diffusion model. I may have also thought about writing a whole book back then, but mid-2017 is probably too early for the project.

Professor Kortlandt is still to review the text, but he contributed to both previous essays in some very interesting ways, so I hope he can help me improve the parts on Uralic, and maybe alternative accounts of expansion for Balto-Slavic, depending on the time depth that he would consider warranted according to the Temematic hypothesis.

The maps are evidently (for those who are interested in genetics) in part the result of the effort of the late Jean Manco: As you can see from the maps including Y-DNA and mtDNA samples, I have benefitted from her way of organising data and publishing it. Similarly, the work of Iain McDonald in assessing the potential migration routes of R1b and R1a in Europe with the help of detailed maps was behind my idea for the first maps, and consequently behind these, too.

I should thank all people responsible for the release of free datasets to work with, including the Reich and Jena labs, the Veeramah Lab, and also researchers from the Max Planck Institute or the Mainz Palaeogenetics group, who didn’t mind to share with me datasets to work with.

Readers of this blog with interesting comments have also been essential for the improvement of the texts. You can probably see some of your many contributions there. I may not answer many comments, because I am always busy (and sometimes I just don’t have anything interesting to say), but I try to read all of them.

EDIT (1 JAN 2019) I think I should mention at least Chetan, Egg, or Robert George; but then I would leave out old europe, Sgr Ganesh, or Tileman Ehlen; and if I include them I would leave out others…

Users of other sites, like Anthrogenica, whose particular points of view and deep knowledge of some very specific aspects are sometimes very useful. In particular, user Anglesqueville helped me to fix some issues with the merging of datasets to obtain the PCAs and ADMIXTURE, and prepared some individual samples to merge them.

Even without posting anything, Google Analytics keeps sending me messages about increasing user fidelity (returning users), and stats haven’t really changed (which probably means more people are reading old posts), so thank you for that.

I hope you enjoy the books.

Happy new year!

“Steppe ancestry” step by step: Khvalynsk, Sredni Stog, Repin, Yamna, Corded Ware

dzudzuana_pca-large

Wang et al. (2018) is obviously a game changer in many aspects. I have already written about the upcoming Yamna Hungary samples, about the new Steppe_Eneolithic and Caucasus Eneolithic keystones, and about the upcoming Greece Neolithic samples with steppe ancestry.

An interesting aspect of the paper, hidden among so many relevant details, is a clearer picture of how the so-called Yamnaya or steppe ancestry evolved from Samara hunter-gatherers to Yamna nomadic pastoralists, and how this ancestry appeared among Proto-Corded Ware populations.

anatolia-neolithic-steppe-eneolithic
Image modified from Wang et al. (2018). Marked are in orange: equivalent Steppe_Maykop ADMIXTURE; in red, approximate limit of Anatolia_Neolithic ancestry found in Yamna populations; in blue, Corded Ware-related groups. “Modelling results for the Steppe and Caucasus cluster. Admixture proportions based on (temporally and geographically) distal and proximal models, showing additional Anatolian farmer-related ancestry in Steppe groups as well as additional gene flow from the south in some of the Steppe groups as well as the Caucasus groups.”

Please note: arrows of “ancestry movement” in the following PCAs do not necessarily represent physical population movements, or even ethnolinguistic change. To avoid misinterpretations, I have depicted arrows with Y-DNA haplogroup migrations to represent the most likely true ethnolinguistic movements. Admixture graphics shown are from Wang et al. (2018), and also (the K12) from Mathieson et al. (2018).

1. Samara to Early Khvalynsk

The so-called steppe ancestry was born during the Khvalynsk expansion through the steppes, probably through exogamy of expanding elite clans (eventually all R1b-M269 lineages) originally of Samara_HG ancestry. The nearest group to the ANE-like ghost population with which Samara hunter-gatherers admixed is represented by the Steppe_Eneolithic / Steppe_Maykop cluster (from the Northern Caucasus Piedmont).

Steppe_Eneolithic samples, of R1b1 lineages, are probably expanded Khvalynsk peoples, showing thus a proximate ancestry of an Early Eneolithic ghost population of the Northern Caucasus. Steppe_Maykop samples represent a later replacement of this Steppe_Eneolithic population – and/or a similar population with further contribution of ANE-like ancestry – in the area some 1,000 years later.

PCA-caucasus-steppe-samara

This is what Steppe_Maykop looks like, different from Steppe_Eneolithic:

steppe-maykop-admixture

NOTE. This admixture shows how different Steppe_Maykop is from Steppe_Eneolithic, but in the different supervised ADMIXTURE graphics below Maykop_Eneolithic is roughly equivalent to Eneolithic_Steppe (see orange arrow in ADMIXTURE graphic above). This is useful for a simplified analysis, but actual differences between Khvalynsk, Sredni Stog, Afanasevo, Yamna and Corded Ware are probably underestimated in the analyses below, and will become clearer in the future when more ancestral hunter-gatherer populations are added to the analysis.

2. Early Khvalynsk expansion

We have direct data of Khvalynsk-Novodanilovka-like populations thanks to Khvalynsk and Steppe_Eneolithic samples (although I’ve used the latter above to represent the ghost Caucasus population with which Samara_HG admixed).

We also have indirect data. First, there is the PCA with outliers:

PCA-khvalynsk-steppe

Second, we have data from north Pontic Ukraine_Eneolithic samples (see next section).

Third, there is the continuity of late Repin / Afanasevo with Steppe_Eneolithic (see below).

3. Proto-Corded Ware expansion

It is unclear if R1a-M459 subclades were continuously in the steppe and resurged after the Khvalynsk expansion, or (the most likely option) they came from the forested region of the Upper Dnieper area, possibly from previous expansions there with hunter-gatherer pottery.

Supporting the latter is the millennia-long continuity of R1b-V88 and I2a2 subclades in the north Pontic Mesolithic, Neolithic, and Early Eneolithic Sredni Stog culture, until ca. 4500 BC (and even later, during the second half).

Only at the end of the Early Eneolithic with the disappearance of Novodanilovka (and beginning of the steppe ‘hiatus’ of Rassamakin) is R1a to be found in Ukraine again (after disappearing from the record some 2,000 years earlier), related to complex population movements in the north Pontic area.

NOTE. In the PCA, a tentative position of Novodanilovka closer to Anatolia_Neolithic / Dzudzuana ancestry is selected, based on the apparent cline formed by Ukraine_Eneolithic samples, and on the position and ancestry of Sredni Stog, Yamna, and Corded Ware later. A good alternative would be to place Novodanilovka still closer to the Balkan outliers (i.e. Suvorovo), and a source closer to EHG as the ancestry driven by the migration of R1a-M417.

PCA-sredni-stog-steppe

The first sample with steppe ancestry appears only after 4250 BC in the forest-steppe, centuries after the samples with steppe ancestry from the Northern Caucasus and the Balkans, which points to exogamy of expanding R1a-M417 lineages with the remnants of the Novodanilovka population.

steppe-ancestry-admixture-sredni-stog

4. Repin / Early Yamna expansion

We don’t have direct data on early Repin settlers. But we do have a very close representative: Afanasevo, a population we know comes directly from the Repin/late Khvalynsk expansion ca. 3500/3300 BC (just before the emergence of Early Yamna), and which shows fully Steppe_Eneolithic-like ancestry.

afanasevo-admixture

Compared to this eastern Repin expansion that gave Afanasevo, the late Repin expansion to the west ca. 3300 BC that gave rise to the Yamna culture was one of colonization, evidenced by the admixture with north Pontic (Sredni Stog-like) populations, no doubt through exogamy:

PCA-repin-yamna

This admixture is also found (in lesser proportion) in east Yamna groups, which supports the high mobility and exogamy practices among western and eastern Yamna clans, not only with locals:

yamnaya-admixture

5. Corded Ware

Corded Ware represents a quite homogeneous expansion of a late Sredni Stog population, compatible with the traditional location of Proto-Corded Ware peoples in the steppe-forest/forest zone of the Dnieper-Dniester region.

PCA-latvia-ln-steppe

We don’t have a comparison with Ukraine_Eneolithic or Corded Ware samples in Wang et al. (2018), but we do have proximate sources for Abashevo, when compared to the Poltavka population (with which it admixed in the Volga-Ural steppes): Sintashta, Potapovka, Srubna (with further Abashevo contribution), and Andronovo:

sintashta-poltavka-andronovo-admixture

The two CWC outliers from the Baltic show what I thought was an admixture with Yamna. However, given the previous mixture of Eneolithic_Steppe in north Pontic steppe-forest populations, this elevated “steppe ancestry” found in Baltic_LN (similar to west Yamna) seems rather an admixture of Baltic sub-Neolithic peoples with a north Pontic Eneolithic_Steppe-like population. Late Repin settlers also admixed with a similar population during its colonization of the north Pontic area, hence the Baltic_LN – west Yamna similarities.

NOTE. A direct admixture with west Yamna populations through exogamy by the ancestors of this Baltic population cannot be ruled out yet (without direct access to more samples), though, because of the contacts of Corded Ware with west Yamna settlers in the forest-steppe regions.

steppe-ancestry-admixture-latvia

A similar case is found in the Yamna outlier from Mednikarovo south of the Danube. It would be absurd to think that Yamna from the Balkans comes from Corded Ware (or vice versa), just because the former is closer in the PCA to the latter than other Yamna samples. The same error is also found e.g. in the Corded Ware → Bell Beaker theory, because of their proximity in the PCA and their shared “steppe ancestry”. All those theories have been proven already wrong.

NOTE. A similar fallacy is found in potential Sintashta→Mycenaean connections, where we should distinguish statistically that result from an East/West Yamna + Balkans_BA admixture. In fact, genetic links of Mycenaeans with west Yamna settlers prove this (there are some related analyses in Anthrogenica, but the site is down at this moment). To try to relate these two populations (separated more than 1,000 years before Sintashta) is like comparing ancient populations to modern ones, without the intermediate samples to trace the real anthropological trail of what is found…Pure numbers and wishful thinking.

Conclusion

Yamna and Corded Ware show a similar “steppe ancestry” due to convergence. I have said so many times (see e.g. here). This was clear long ago, just by looking at the Y-chromosome bottlenecks that differentiate them – and Tomenable noticed this difference in ADMIXTURE from the supplementary materials in Mathieson et al. (2017), well before Wang et al. (2018).

This different stock stems from (1) completely different ancestral populations + (2) different, long-lasting Y-chromosome bottlenecks. Their similarities come from the two neighbouring cultures admixing with similar populations.

If all this does not mean anything, and each lab was going to support some pre-selected archaeological theories from the 1960s or the 1980s, coupled with outdated linguistic models no matter what – Anthony’s model + Ringe’s glottochronological tree of the early 2000s in the Reich Lab; and worse, Kristiansen’s CWC-IE + Germano-Slavonic models of the 1940s in the Copenhagen group – , I have to repeat my question again:

What’s (so much published) ancient DNA useful for, exactly?

See also

Related