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

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 Even my post “Steppe ancestry” step by step from a year ago is already outdated.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

Corded Ware ancestry in North Eurasia and the Uralic expansion

uralic-clines-nganasan

Now that it has become evident that Late Repin (i.e. Yamnaya/Afanasevo) ancestry was associated with the migration of R1b-L23-rich Late Proto-Indo-Europeans from the steppe in the second half of the the 4th millennium BC, there’s still the question of how R1a-rich Uralic speakers of Corded Ware ancestry expanded , and how they spread their languages throughout North Eurasia.

Modern North Eurasians

I have been collecting information from the supplementary data of the latest papers on modern and ancient North Eurasian peoples, including Jeong et al. (2019), Saag et al. (2019), Sikora et al. (2018), or Flegontov et al. (2019), and I have tried to add up their information on ancestral components and their modern and historical distributions.

Fortunately, the current obsession with simplifying ancestry components into three or four general, atemporal groups, and the common use of the same ones across labs, make it very simple to merge data and map them.

Corded Ware ancestry

There is no doubt about the prevalent ancestry among Uralic-speaking peoples. A map isn’t needed to realize that, because ancient and modern data – like those recently summarized in Jeong et al. (2019) – prove it. But maps sure help visualize their intricate relationship better:

natural-modern-srubnaya-ancestry
Natural neighbor interpolation of Srubnaya ancestry among modern populations. See full map.
kriging-modern-srubnaya-ancestry
Kriging interpolation of Srubnaya ancestry among modern populations. See full map

Interestingly, the regions with higher Corded Ware-related ancestry are in great part coincident with (pre)historical Finno-Ugric-speaking territories:

uralic-languages-modern
Modern distribution of Uralic languages, with ancient territory (in the Common Era) labelled and delimited by a red line. For more information on the ancient territory see here.

Edit (29/7/2019): Here is the full Steppe_MLBA ancestry map, including Steppe_MLBA (vs. Indus Periphery vs. Onge) in modern South Asian populations from Narasimhan et al. (2018), apart from the ‘Srubnaya component’ in North Eurasian populations. ‘Dummy’ variables (with 0% ancestry) have been included to the south and east of the map to avoid weird interpolations of Steppe_MLBA into Africa and East Asia.

modern-steppe-mlba-ancestry2
Natural neighbor interpolation of Steppe MLBA-like ancestry among modern populations. See full map.

Anatolia Neolithic ancestry

Also interesting are the patterns of non-CWC-related ancestry, in particular the apparent wedge created by expanding East Slavs, which seems to reflect the intrusion of central(-eastern) European ancestry into Finno-Permic territory.

NOTE. Read more on Balto-Slavic hydrotoponymy, on the cradle of Russians as a Finno-Permic hotspot, and about Pre-Slavic languages in North-West Russia.

natural-modern-lbk-en-ancestry
Natural neighbor interpolation of LBK EN ancestry among modern populations. See full map.
kriging-modern-lbk-en-ancestry
Kriging interpolation of LBK EN ancestry among modern populations. See full map

WHG ancestry

The cline(s) between WHG, EHG, ANE, Nganasan, and Baikal HG are also simplified when some of them excluded, in this case EHG, represented thus in part by WHG, and in part by more eastern ancestries (see below).

modern-whg-ancestry
Natural neighbor interpolation of WHG ancestry among modern populations. See full map.
kriging-modern-whg-ancestry
Kriging interpolation of WHG ancestry among modern populations. See full map.

Arctic, Tundra or Forest-steppe?

Data on Nganasan-related vs. ANE vs. Baikal HG/Ulchi-related ancestry is difficult to map properly, because both ancestry components are usually reported as mutually exclusive, when they are in fact clearly related in an ancestral cline formed by different ancient North Eurasian populations from Siberia.

When it comes to ascertaining the origin of the multiple CWC-related clines among Uralic-speaking peoples, the question is thus how to properly distinguish the proportions of WHG-, EHG-, Nganasan-, ANE or BaikalHG-related ancestral components in North Eurasia, i.e. how did each dialectal group admix with regional groups which formed part of these clines east and west of the Urals.

The truth is, one ought to test specific ancient samples for each “Siberian” ancestry found in the different Uralic dialectal groups, but the simplistic “Siberian” label somehow gets a pass in many papers (see a recent example).

Below qpAdm results with best fits for Ulchi ancestry, Afontova Gora 3 ancestry, and Nganasan ancestry, but some populations show good fits for both and with similar proportions, so selecting one necessarily simplifies the distribution of both.

Ulchi ancestry

modern-ulchi-ancestry
Natural neighbor interpolation of Ulchi ancestry among modern populations. See full map.
kriging-modern-ulchi-ancestry
Kriging interpolation of Ulchi ancestry among modern populations. See full map.

ANE ancestry

natural-modern-ane-ancestry
Natural neighbor interpolation of ANE ancestry among modern populations. See full map.
kriging-modern-ane-ancestry
Kriging interpolation of ANE ancestry among modern populations. See full map.

Nganasan ancestry

modern-nganasan-ancestry
Natural neighbor interpolation of Nganasan ancestry among modern populations. See full map.
kriging-modern-nganasan-ancestry
Kriging interpolation of Nganasan ancestry among modern populations. See full map.

Iran Chalcolithic

A simplistic Iran Chalcolithic-related ancestry is also seen in the Altaic cline(s) which (like Corded Ware ancestry) expanded from Central Asia into Europe – apart from its historical distribution south of the Caucasus:

modern-iran-chal-ancestry
Natural neighbor interpolation of Iran Neolithic ancestry among modern populations. See full map.
kriging-modern-iran-neolithic-ancestry
Kriging interpolation of Iran Chalcolithic ancestry among modern populations. See full map.

Other models

The first question I imagine some would like to know is: what about other models? Do they show the same results? Here is the simplistic combination of ancestry components published in Damgaard et al. (2018) for the same or similar populations:

NOTE. As you can see, their selection of EHG vs. WHG vs. Nganasan vs. Natufian vs. Clovis of is of little use, but corroborate the results from other papers, and show some interesting patterns in combination with those above.

EHG

damgaard-modern-ehg-ancestry
Natural neighbor interpolation of EHG ancestry among modern populations, data from Damgaard et al. (2018). See full map.
damgaard-kriging-ehg-ancestry
Kriging interpolation of EHG ancestry among modern populations. See full map.

Natufian ancestry

damgaard-modern-natufian-ancestry
Natural neighbor interpolation of Natufian ancestry among modern populations, data from Damgaard et al. (2018). See full map.
damgaard-kriging-natufian-ancestry
Kriging interpolation of Natufian ancestry among modern populations. See full map.

WHG ancestry

damgaard-modern-whg-ancestry
Natural neighbor interpolation of WHG ancestry among modern populations, data from Damgaard et al. (2018). See full map.
damgaard-kriging-whg-ancestry
Kriging interpolation of WHG ancestry among modern populations. See full map.

Baikal HG ancestry

damgaard-modern-baikalhg-ancestry
Natural neighbor interpolation of Baikal hunter-gatherer ancestry among modern populations, data from Damgaard et al. (2018). See full map.
damgaard-kriging-baikal-hg-ancestry
Kriging interpolation of Baikal HG ancestry among modern populations. See full map.

Ancient North Eurasians

Once the modern situation is clear, relevant questions are, for example, whether EHG-, WHG-, ANE, Nganasan-, and/or Baikal HG-related meta-populations expanded or became integrated into Uralic-speaking territories.

When did these admixture/migration events happen?

How did the ancient distribution or expansion of Palaeo-Arctic, Baikalic, and/or Altaic peoples affect the current distribution of the so-called “Siberian” ancestry, and of hg. N1a, in each specific population?

NOTE. A little excursus is necessary, because the calculated repetition of a hypothetic opposition “N1a vs. R1a” doesn’t make this dichotomy real:

  1. There was not a single ethnolinguistic community represented by hg. R1a after the initial expansion of Eastern Corded Ware groups, or by hg. N1a-L392 after its initial expansion in Siberia:
  2. Different subclades became incorporated in different ways into Bronze Age and Iron Age communities, most of which without an ethnolinguistic change. For example, N1a subclades became incorporated into North Eurasian populations of different languages, reaching Uralic- and Indo-European-speaking territories of north-eastern Europe during the late Iron Age, at a time when their ancestral origin or language in Siberia was impossible to ascertain. Just like the mix found among Proto-Germanic peoples (R1b, R1a, and I1)* or among Slavic peoples (I2a, E1b, R1a)*, the mix of many Uralic groups showing specific percentages of R1a, N1a, or Q subclades* reflect more or less recent admixture or acculturation events with little impact on their languages.

*other typically northern and eastern European haplogroups are also represented in early Germanic (N1a, I2, E1b, J, G2), Slavic (I1, G2, J) and Finno-Permic (I1, R1b, J) peoples.

ananino-culture-new
Map of archaeological cultures in north-eastern Europe ca. 8th-3rd centuries BC. [The Mid-Volga Akozino group not depicted] Shaded area represents the Ananino cultural-historical society. Fading purple arrows represent likely stepped movements of subclades of haplogroup N for centuries (e.g. Siberian → Ananino → Akozino → Fennoscandia [N-VL29]; Circum-Arctic → forest-steppe [N1, N2]; etc.). Blue arrows represent eventual expansions of Uralic peoples to the north. Modified image from Vasilyev (2002).

The problem with mapping the ancestry of the available sampling of ancient populations is that we lack proper temporal and regional transects. The maps that follow include cultures roughly divided into either “Bronze Age” or “Iron Age” groups, although the difference between samples may span up to 2,000 years.

NOTE. Rough estimates for more external groups (viz. Sweden Battle Axe/Gotland_A for the NW, Srubna from the North Pontic area for the SW, Arctic/Nganasan for the NE, and Baikal EBA/”Ulchi-like” for the SE) have been included to offer a wider interpolated area using data already known.

Bronze Age

Similar to modern populations, the selection of best fit “Siberian” ancestry between Baikal HG vs. Nganasan, both potentially ± ANE (AG3), is an oversimplification that needs to be addressed in future papers.

Corded Ware ancestry

bronze-age-corded-ware-ancestry
Natural neighbor interpolation of Srubnaya ancestry among Bronze Age populations. See full map.

Nganasan-like ancestry

bronze-age-nganasan-like-ancestry
Natural neighbor interpolation of Nganasan-like ancestry among Bronze Age populations. See full map.

Baikal HG ancestry

bronze-age-baikal-hg-ancestry
Natural neighbor interpolation of Baikal Hunter-Gatherer ancestry among Bronze Age populations. See full map.

Afontova Gora 3 ancestry

bronze-age-afontova-gora-ancestry
Natural neighbor interpolation of Afontova Gora 3 ancestry among Bronze Age populations. See full map.

Iron Age

Corded Ware ancestry

Interestingly, the moderate expansion of Corded Ware-related ancestry from the south during the Iron Age may be related to the expansion of hg. N1a-VL29 into the chiefdom-based system of north-eastern Europe, including Ananyino/Akozino and later expanding Akozino warrior-traders around the Baltic Sea.

NOTE. The samples from Levänluhta are centuries older than those from Estonia (and Ingria), and those from Chalmny Varre are modern ones, so this region has to be read as a south-west to north-east distribution from the Iron Age to modern times.

iron-age-corded-ware-ancestry
Natural neighbor interpolation of Srubnaya ancestry among Iron Age populations. See full map.

Baikal HG-like ancestry

The fact that this Baltic N1a-VL29 branch belongs in a group together with typically Avar N1a-B197 supports the Altaic origin of the parent group, which is possibly related to the expansion of Baikalic ancestry and Iron Age nomads:

iron-age-baikal-ancestry
Natural neighbor interpolation of Baikal HG ancestry among Iron Age populations. See full map.

Nganasan-like ancestry

The dilution of Nganasan-like ancestry in an Arctic region featuring “Siberian” ancestry and hg. N1a-L392 at least since the Bronze Age supports the integration of hg. N1a-Z1934, sister clade of Ugric N1a-Z1936, into populations west and east of the Urals with the expansion of Uralic languages to the north into the Tundra region (see here).

The integration of N1a-Z1934 lineages into Finnic-speaking peoples after their migration to the north and east, and the displacement or acculturation of Saami from their ancestral homeland, coinciding with known genetic bottlenecks among Finns, is yet another proof of this evolution:

iron-age-nganasan-ancestry
Natural neighbor interpolation of Nganasan ancestry among Iron Age populations. See full map.

WHG ancestry

Similarly, WHG ancestry doesn’t seem to be related to important population movements throughout the Bronze Age, which excludes the multiple North Eurasian populations that will be found along the clines formed by WHG, EHG, ANE, Nganasan, Baikal HG ancestry as forming part of the Uralic ethnogenesis, although they may be relevant to follow later regional movements of specific populations.

iron-age-whg-ancestry
Natural neighbor interpolation of WHG ancestry among Iron Age populations. See full map.

Conclusion

It seems natural that people used to look at maps of haplogroup distribution from the 2000s, coupled with modern language distributions, and would try to interpret them in a certain way, reaching thus the wrong conclusions whose consequences are especially visible today when ancient DNA keeps contradicting them.

In hindsight, though, assuming that Balto-Slavs expanded with Corded Ware and hg. R1a, or that Uralians expanded with “Siberian” ancestry and hg. N1a, was as absurd as looking at maps of ancestry and haplogroup distribution of ancient and modern Native Americans, trying to divide them into “Germanic” or “Iberian”…

The evolution of each specific region and cultural group of North Eurasia is far from being clear. However, the general trend speaks clearly in favour of an ancient, Bronze Age distribution of North Eurasian ancestry and haplogroups that have decreased, diluted, or become incorporated into expanding Uralians of Corded Ware ancestry, occasionally spreading with inter-regional expansions of local groups.

Given the relatively recent push of Altaic and Indo-European languages into ancestral Uralic-speaking territories, only the ancient Corded Ware expansion remains compatible with the spread of Uralic languages into their historical distribution.

Related

A Song of Sheep and Horses, revised edition, now available as printed books

cover-song-sheep-and-horses

As I said 6 months ago, 2019 is a tough year to write a blog, because this was going to be a complex regional election year and therefore a time of political promises, hence tenure offers too. Now the preliminary offers have been made, elections have passed, but the timing has slightly shifted toward 2020. So I may have the time, but not really any benefit of dedicating too much effort to the blog, and a lot of potential benefit of dedicating any time to evaluable scientific work.

On the other hand, I saw some potential benefit for publishing texts with ISBNs, hence the updates to the text and the preparation of these printed copies of the books, just in case. While Spain’s accreditation agency has some hard rules for becoming a tenured professor, especially for medical associates (whose years of professional experience are almost worthless compared to published peer-reviewed papers), it is quite flexible in assessing one’s merits.

However, regional and/or autonomous entities are not, and need an official identifier and preferably printed versions to evaluate publications, such as an ISBN for books. I took thus some time about a month ago to update the texts and supplementary materials, to publish a printed copy of the books with Amazon. The first copies have arrived, and they look good.

series-song-sheep-horses-cover

Corrections and Additions

Titles
I have changed the names and order of the books, as I intended for the first publication – as some of you may have noticed when the linguistic book was referred to as the third volume in some parts. In the first concept I just wanted to emphasize that the linguistic work had priority over the rest. Now the whole series and the linguistic volume don’t share the same name, and I hope this added clarity is for the better, despite the linguistic volume being the third one.

Uralic dialects
I have changed the nomenclature for Uralic dialects, as I said recently. I haven’t really modified anything deeper than that, because – unlike adding new information from population genomics – this would require for me to do a thorough research of the most recent publications of Uralic comparative grammar, and I just can’t begin with that right now.

Anyway, the use of terms like Finno-Ugric or Finno-Samic is as correct now for the reconstructed forms as it was before the change in nomenclature.

west-east-uralic-schema

Mediterranean
The most interesting recent genetic data has come from Iberia and the Mediterranean. Lacking direct data from the Italian Peninsula (and thus from the emergence of the Etruscan and Rhaetian ethnolinguistic community), it is becoming clearer how some quite early waves of Indo-Europeans and non-Indo-Europeans expanded and shrank – at least in West Iberia, West Mediterranean, and France.

Finno-Ugric
Some of the main updates to the text have been made to the sections on Finno-Ugric populations, because some interesting new genetic data (especially Y-DNA) have been published in the past months. This is especially true for Baltic Finns and for Ugric populations.

ananino-culture-new

Balto-Slavic
Consequently, and somehow unsurprisingly, the Balto-Slavic section has been affected by this; e.g. by the identification of Early Slavs likely with central-eastern populations dominated by (at least some subclades of) hg. I2a-L621 and E1b-V13.

Maps
I have updated some cultural borders in the prehistoric maps, and the maps with Y-DNA and mtDNA. I have also added one new version of the Early Bronze age map, to better reflect the most likely location of Indo-European languages in the Early European Bronze Age.

As those in software programming will understand, major changes in the files that are used for maps and graphics come with an increasing risk of additional errors, so I would not be surprised if some major ones would be found (I already spotted three of them). Feel free to communicate these errors in any way you see fit.

bronze-age-early-indo-european
European Early Bronze Age: tentative langage map based on linguistics, archaeology, and genetics.

SNPs
I have selected more conservative SNPs in certain controversial cases.

I have also deleted most SNP-related footnotes and replaced them with the marking of each individual tentative SNP, leaving only those footnotes that give important specific information, because:

  • My way of referencing tentative SNP authors did not make it clear which samples were tentative, if there were more than one.
  • It was probably not necessary to see four names repeated 100 times over.
  • Often I don’t really know if the person I have listed as author of the SNP call is the true author – unless I saw the full SNP data posted directly – or just someone who reposted the results.
  • Sometimes there are more than one author of SNPs for a certain sample, but I might have added just one for all.
ancient-dna-all
More than 6000 ancient DNA samples compiled to date.

For a centralized file to host the names of those responsible for the unofficial/tentative SNPs used in the text – and to correct them if necessary -, readers will be eventually able to use Phylogeographer‘s tool for ancient Y-DNA, for which they use (partly) the same data I compiled, adding Y-Full‘s nomenclature and references. You can see another map tool in ArcGIS.

NOTE. As I say in the text, if the final working map tool does not deliver the names, I will publish another supplementary table to the text, listing all tentative SNPs with their respective author(s).

If you are interested in ancient Y-DNA and you want to help develop comprehensive and precise maps of ancient Y-DNA and mtDNA haplogroups, you can contact Hunter Provyn at Phylogeographer.com. You can also find more about phylogeography projects at Iain McDonald’s website.

Graphics
I have also added more samples to both the “Asian” and the “European” PCAs, and to the ADMIXTURE analyses, too.

I previously used certain samples prepared by amateurs from BAM files (like Botai, Okunevo, or Hittites), and the results were obviously less than satisfactory – hence my criticism of the lack of publication of prepared files by the most famous labs, especially the Copenhagen group.

Fortunately for all of us, most published datasets are free, so we don’t have to reinvent the wheel. I criticized genetic labs for not releasing all data, so now it is time for praise, at least for one of them: thank you to all responsible at the Reich Lab for this great merged dataset, which includes samples from other labs.

NOTE. I would like to make my tiny contribution here, for beginners interested in working with these files, so I will update – whenever I have time – the “How To” sections of this blog for PCAs, PCA3d, and ADMIXTURE.

-iron-age-europe-romans
Detail of the PCA of European Iron Age populations. See full versions.

ADMIXTURE
For unsupervised ADMIXTURE in the maps, a K=5 is selected based on the CV, giving a kind of visual WHG : NWAN : CHG/IN : EHG : ENA, but with Steppe ancestry “in between”. Higher K gave worse CV, which I guess depends on the many ancient and modern samples selected (and on the fact that many samples are repeated from different sources in my files, because I did not have time to filter them all individually).

I found some interesting component shared by Central European populations in K=7 to K=9 (from CEU Bell Beakers to Denmark LN to Hungarian EBA to Iberia BA, in a sort of “CEU BBC ancestry” potentially related to North-West Indo-Europeans), but still, I prefer to go for a theoretically more correct visualization instead of cherry-picking the ‘best-looking’ results.

Since I made fun of the search for “Siberian ancestry” in coloured components in Tambets et al. 2018, I have to be consistent and preferred to avoid doing the same here…

qpAdm
In the first publication (in January) and subsequent minor revisions until March, I trusted analyses and ancestry estimates reported by amateurs in 2018, which I used for the text adding my own interpretations. Most of them have been refuted in papers from 2019, as you probably know if you have followed this blog (see very recent examples here, here, or here), compelling me to delete or change them again, and again, and again. I don’t have experience from previous years, although the current pattern must have been evidently repeated many times over, or else we would be still talking about such previous analyses as being confirmed today…

I wanted to be one step ahead of peer-reviewed publications in the books, but I prefer now to go for something safe in the book series, rather than having one potentially interesting prediction – which may or may not be right – and ten huge mistakes that I would have helped to endlessly redistribute among my readers (online and now in print) based on some cherry-picked pairwise comparisons. This is especially true when predictions of “Steppe“- and/or “Siberian“-related ancestry have been published, which, for some reason, seem to go horribly wrong most of the time.

I am sure whole books can be written about why and how this happened (and how this is going to keep happening), based on psychology and sociology, but the reasons are irrelevant, and that would be a futile effort; like writing books about glottochronology and its intermittent popularity due to misunderstood scientist trends. The most efficient way to deal with this problem is to avoid such information altogether, because – as you can see in the current revised text – they wouldn’t really add anything essential to the content of these books, anyway.

Continue reading

Official site of the book series:
A Song of Sheep and Horses: eurafrasia nostratica, eurasia indouralica

Sintashta diet and economy based on domesticated animal products and wild resources

indo-iranian-sintashta-uralic-migrations

New paper (behind paywall) Bronze Age diet and economy: New stable isotope data from the Central Eurasian steppes (2100-1700 BC), by Hanks et al. J. Arch. Sci (2018) 97:14-25.

Interesting excerpts (emphasis mine):

Previous research at KA-5 was carried out by A. V. Epimakhov in 1994–1995 and 2002–2003 and resulted in the excavation of three Sintashta culture barrows (kurgans) that produced 35 burial pits and a reported 100 skeletons (Epimakhov, 2002, 2005; Epimakhov et al., 2005; Razhev and Epimakhov, 2004). Seven AMS radiocarbon dates on human remains from the cemetery yielded a date range of 2040–1730 cal. BC (2 sigma), which placed the cemetery within the Sintashta phase of the regional Bronze Age (Hanks et al., 2007). Twelve recently obtained AMS radiocarbon dates, taken from short-lived wood and charcoal species recovered from the Kamennyi Ambar settlement, have provided a date range of 2050–1760 cal. BC (2 sigma). Importantly, these dates confirm the close chronological relationship between the settlement and cemetery for the Middle Bronze Age phase and discount the possibility of a freshwater reservoir effect influencing the earlier dating of the human remains from the Kamennyi Ambar 5 cemetery (Epimakhov and Krause, 2013).

Sintashta cemeteries frequently yield fewer than six barrow complexes and the number of skeletons recovered represents a fraction of the total population that would have inhabited the settlements (Judd et al., 2018; Johnson and Hanks, 2012). Scholars have suggested that only members of higher status were afforded interment in these cemeteries and that principles of social organization structured placement of individuals within central or peripheral grave pits (Fig. 2) (Koryakova and Epimakhov, 2007: 75–81). In comparison with other Sintashta cemeteries that have been excavated, KA-5 provides one of the largest skeletal inventories currently available for study.

kamenniy-ambar
Upper – plan of Kamennyi Ambar settlement and cemetery; Lower – plan views of Kurgan 2 and Kurgan 4 from KA-5 Cemetery (kurgan plans redrawn from Epimakhov, 2005: 10, 79).

The KA-5 (MBA), Bestamak (MBA) and Lisakovsk (LBA) datasets exhibited a wide range of δ13C and δ15N values for both humans and herbivores (Figs. 5 and 6 & Table 8). This diversity in isotopic signals may be evident for a variety of reasons. For example, the range of values may be associated with a broad spectrum of C3 and C4 plant diversity in the ancient site biome or herbivore grazing patterns that included more diverse environmental niche areas in the microregion around the sampled sites. Herders also may have chosen to graze animals in niche areas due to recognized territorial boundaries between settlements and concomitant patterns of mobility. Importantly, data from Bolshekaragansky represents humans with lower δ15N values that are more closely associated with δ15N values of the sampled domestic herbivores (Fig. 6). When the archaeological evidence from associated settlement sites is considered, Bolshekaragansky, Bestamak, Lisakovsk and KA-5 have been assumed to represent populations that shared similar forms of pastoral subsistence economies with significant dietary reliance upon domesticated herbivore meat and milk. Human diets have δ13C values closely related to those of local herbivores in terms of the slope of the trendline and range of values (Fig. 6). Comparatively, the cemetery of Bolshekaragansky (associated with the Arkaim settlement) reflects individuals with trend lines closer to those of cattle and caprines and may indicate a stronger reliance on subsistence products from these species with less use of wild riverine and terrestrial resources. The site of Čiča is significantly different with elevated human δ15N isotopic values and depleted δ13C values indicative of a subsistence regime more closely associated with the consumption of freshwater resources, such as fish. The stable isotopic data in this instance is strongly supported by zooarchaeological evidence recovered from the Čiča settlement and also is indicative of significant diachronic changes from the LBA phases through the Iron Age (Fig. 6).

kamenniy-ambar-isotopic-chicha-lisakovsk-bestamark
Regional analysis and comparison of stable isotope results from humans (adults) and animals recovered from MBA and LBA cemeteries in the Southern Urals (Kamennyi Ambar 5 & Bolshekaragansky) northwestern Kazakhstan (Liskovsk & Bestamak) and southwestern Siberia (Čiča).

Conclusion

(…) The isotopic results from KA-5, and recent botanical and archaeological studies from the Kamennyi Ambar settlement, have not produced any evidence for the production or use of domesticated cereals. While this does not definitively answer the question as to whether Sintashta populations engaged in agriculture and/or utilized agricultural products, it does call into serious question the ubiquity of such practices across the region and correlates well with recent archaeological, bioarchaeological, and isotopic studies of human and animal remains from the Southwestern Urals region and Samara Basin (Anthony et al., 2016; Schulting and Richards, 2016). The results substantiate a broader spectrum subsistence diet that in addition to the use of domesticated animal products also incorporated wild flora, wild fauna and fish species. These findings further demonstrate the need to draw on multiple methods and datasets for the reconstruction of late prehistoric subsistence economies in the Eurasian steppes. When possible, this should include datasets from both settlements and associated cemeteries.

Variability in subsistence practices in the central steppes region has been highlighted by other scholars and appears to be strongly correlated with local environmental conditions and adaptations. More comprehensive isotopic studies of human, animal and fish remains are of fundamental importance to achieve more robust and empirically substantiated reconstructions of local biomes and to aid the refinement of regional and micro-regional economic subsistence models. This will allow for a fuller understanding of key diachronic shifts within dietary trends and highlight regional variation of such practices. Ultimately, this will more effectively index the diverse social and environmental variables that contributed to late prehistoric lifeways and the economic strategies employed by these early steppe communities.

Social organization of Sintashta-Petrovka

Interesting to remember now the recent article by Chechushkov et al. (2018) about the social stratificaton in Sintashta-Petrovka, and how it must have caused the long-lasting, peaceful admixture process that led to the known almost full replacement of R1b-L23 (mostly R1b-Z2103) by R1a-Z645 (mostly R1a-Z93) subclades in the North Caspian steppe, coinciding with the formation of the Proto-Indo-Iranian community and language (read my thoughts on this after Damgaard et al. 2018).

Here is another relevant excerpt from Chechushkov et al. (2018), translated from Russian:

settlement-kamenniy-ambar
The map of the settlement of Kamennyi Ambar with excavations, soil cores, and test pits. Legend: a — cuts of the sides of ravines; b — test pits of 2015—2017; c — test pits of 2004; d — soil-science samples with a cultural layer; e — soil-science samples without cultural layer; f — borders of archaeological sites (interpretation of the plan of magnetic anomalies); g — boundaries of excavated structures (1, 2, 4, 5, 7 — Sintashta-Petrovka culture; 3, 6 — Srubnaya-Alakul’ culture).

The analysis suggests that the Sintashta-Petrovka societies had a certain degree of social stratification, expressed both in selective funeral rituals and in the significant difference in lifestyle between the elite and the immediate producers of the product. The data obtained during the field study suggest that the elite lived within the fortifications, while a part of the population was outside their borders, on seasonal sites, and also in stationary non-fortified settlements. Probably, traces of winter settlements can be found near the walls, while the search for summer ones is a task of a separate study. From our point of view, the elite of the early complex societies of the Bronze Age of the Eurasian steppe originated as a response to environmental challenges that created risks for cattle farming. The need to adapt the team to the harsh and changing climatic conditions created a precedent in which the settled collectives of pastoralists – hunter-gatherers could afford the content and magnificent posthumous celebration of people and their families who were not engaged in the production or extraction of an immediate product. In turn, representatives of this social group directed their efforts to the adoption of socially significant decisions, the organization of collective labor in the construction of settlement-shelters and risked their lives, acting as military leaders and fighters.

Thus, in Bronze Age steppe societies, the formation, development and decline of social complexity are directly related to the intensity of pastoralism and the development of new territories, where collectives had to survive in part a new ecological niche. At the same time, some members of the collective took upon themselves the organization of the collective’s life, receiving in return a privileged status. As soon as the conditions of the environment and management changed, the need for such functions was virtually eliminated, as a result of which the privileged members of society dissolved into the general mass, having lost their lifetime status and the right to be allocated posthumously.

Also interesting for the MLBA haplogroup bottleneck in the region is the paper by Judd et al. (2017) about fast life history in Early Indo-Iranian territories.

On the arrival of haplogroup N1c1-L392

Regarding the special position of the Chicha-1 samples in the change of diet and economy during the Iron Age, it is by now well known that haplogroup N must have arrived quite late to North-East Europe, and possibly not linked with the expansion of Siberian ancestry – or linked only with some waves of Siberian ancestry in the region, but not all of them. See Lamnidis et al. (2018) for more on this.

Also, the high prevalence of haplogroup N among Fennic and Siberian (Samoyedic) peoples is not related: while the latter reflects probably the native (Palaeo-Siberian) population that acquired their Uralic branch during the MLBA expansions associated with Corded Ware groups, the former points to the expansion of Fennic peoples into Saamic territory (i.e. after the Fenno-Saamic split) as the most likely period of expansion of N1c1-L392 subclades (see known recent bottlenecks among Finns, and on Proto-Finnic dialectalization).

Probably related to these late incomers are the ancient DNA samples from the Sargat culture during the Iron Age, which show the arrival of N subclades in the region, replacing most – but not all – R1a lineages (see Pilipenko et al. (2017)). Regarding the site of Chicha-1, the following are relevant excerpts about the cultural situation that could have allowed for such stepped, diachronic admixture events in Northern Eurasia, from the paper Stages in the settlement history of Chicha-1: The Results of ceramic analysis, by Molodin et al. (2008):

The stratigraphic data allows us to make the following inference: originally, the settlement was inhabited by people bearing the Late Irmen culture. Later, the people of the Baraba trend of the Suzgun culture arrived at the site (Molodin, Chemyakina, 1984: 40–62). The Baraba-Suzgun pottery demonstrates features similar to what has been reported from the sites of the transitional Bronze to Iron Age culture in the pre-taiga and taiga zones in the Irtysh basin (Potemkina, Korochkova, Stefanov, 1995; Polevodov, 2003). The major morphological types are slightly and well-profiled pots with a short throat. (…)

chicha-irmen-tagar-baraba-forest-siberian
Map showing the location of Chicha-1.

During the following stage of development of the site, the Chicha population increased with people who practiced cultures others than those noted in earlier collections. The ceramic materials from layer 5 provide data on possible relationships. In addition to migrants from northwestern regions practicing the Suzgun culture, there were people bearing the Krasnoozerka culture. Available data also suggests that people from the northern taiga region with the Atlym culture visited the site.

However, people from the west and southwest represent the greatest migration to the region under study. In all likelihood they moved from the northern forest-steppe zone of modern Kazakhstan and practiced the Berlik culture. The spatial distribution analysis of the Chicha-1 site suggests that the Berlik population was rather large. The Berlik people formed a single settlement with the indigenous Late Irmen people and apparently waged certain common economic activities, but preserved their own ethnic and cultural specificity (Molodin, Parzinger, 2006: 49–55). Judging by the data on the chronological sequence of deposited artifacts, migration took place roughly synchronously, hence Chicha-1 became a real cultural and economic center.

(…) In sum, the noted distribution of ceramics over the culture-bearing horizons suggests that beginning with layer 5, traditions of ceramic manufacture described above were practiced, hence the relevant population inhabited the site. Apparently, there were two predominant traditions: the local Late Irmen cultural tradition and the Berlik tradition, which was brought by the immigrants. The Late Irmen people mostly populated the citadel, while the Berlik immigrants inhabited the areas to the east and the north of the citadel.

The stratigraphic data also suggest that the Early Sargat ceramics emerged at the site likely as a part of the Late Irmen tradition (…) Early Sargat ceramics is apparently linked with the Late Irmen tradition. Artifacts associated with the Sargat culture proper have been found in several areas of Chicha-1 (e.g., in excavation area 16). However, the Sargat people appeared at the site after it had been abandoned by its previous inhabitants, and had eventually become completely desolated. This happened no earlier than the 6th cent. BC, possibly in the 5th cent. BC (in fact, the radiocarbon dates for that horizon are close to the turn of the Christian era).

Related

On the Maykop – Upper Mesopotamia cultural province, distinct from the steppe

caucasus-europe

New paper (behind paywall) The Production of Thin‐Walled Jointless Gold Beads from the Maykop Culture Megalithic Tomb of the Early Bronze Age at Tsarskaya in the North Caucasus: Results of Analytical and Experimental Research, by Trifonov et al. Archaeometry (2018)

Interesting excerpts (emphasis mine):

In 1898, two megalithic tombs containing graves of a local social elite dated to the Early Bronze Age were discovered by N. I. Veselovsky near the village of Tsarskaya (modern Novosvobodnaya, Republic of Adygeya) (Fig. 1 (a)) (Baye 1900, 43–59; IAC 1901, 33–8; Sagona 2018, 281–97).

Radiocarbon dates place both tombs within the Novosvobodnaya phase of the Maykop culture, between c. 3200 and 2900 BC (Trifonov et al. 2017). Along with the human remains (one adult individual was interred in each dolmen), the tombs yielded rich funerary offerings, including artefacts made of gold, silver and semi-precious stones. (…) This paper presents results of a technical analysis of just one type of artefact, from kurgan 2 at Tsarskaya: thin-walled jointless beads made from gold.

caucasus-beads-mesopotamia-sumeria
(a) A map of the Caucasus and part of Western Asia, showing the locations of sites mentioned in the text: 1, Tsarskaya (modern Novosvobodnaya); 2, Maykop; 3, Staromyshastovskaya; 4, Andryukovskaya; 5, Psebaiskaya; 6, Inozemtsevo; 7, Kudakhurt; 8, Soyuq Bulaq; 9, Sé Girdan; 10, Tepe Gawra. (b) The string of thin-walled jointless gold beads, silver and carnelian beads from the dolmen in kurgan 2 at Tsarskaya, Western Caucasus (1898).

Ever since M. I. Rostovtzeff noted a stylistic similarity between Maykop art and Sumerian art (Rostovtzeff 1920) and M. V. Andreeva described this phenomenon within a broad cultural and chronological context (Andreeva 1977), new archaeological studies have only extended this picture of a vast cultural province that appeared between the Caucasus and the northern fringe of Western Asia (Trifonov 1987). The discovery of the Leyla-Tepe culture (Narimanov 1987) and Maykop-type kurgans in Azerbaijan (Lyonnet et al. 2008) and adjacent Iran (Muscarella 1969, 1971, 2003; Trifonov 2000) has confirmed the spatial and temporal unity of this phenomenon as a precondition for free circulation of cultural patterns and technical innovations across vast areas of the Caucasus and Western Asia. Jewellery made of gemstones and precious metals, primarily gold, was probably one such innovation.

Attempts to demarcate the historical region where the Maykop culture emerged and developed have emphasized the role of Upper Mesopotamia in the development of the Sumerian civilization and the definition of a northern centre of urbanization, independent from the centres of the south (Rothman 2002; Oats et al. 2007). The turn of the fourth millennium BC saw the development of various cultural traditions in south-east Anatolia, north-east Syria and north-west Iran; on the northern fringe, these traditions manifested themselves through the Maykop culture. Perhaps it is no coincidence that the first high-status burials containing gold and gemstone jewellery (including carnelian, turquoise and lapis lazuli) appear in these northern, rather than southern, centres in the first quarter of 4000 BC (e.g., Tepe Gawra, graves 109, 110) (Piasnall 2002). With regard to funeral rites and stylistic characteristics of jewellery pieces, these graves have many parallels with early Maykop burials (Munchaev 1975, 329; Trifonov 1987, 20).

It still remains unclear if the goldsmiths of Upper Mesopotamia mastered the technique of making thin-walled jointless beads. The gold beads from Tepe Gawra are described as spherical or ball-shaped, but their maximum diameter (5–8mm) always exceeds the length of the bore (3–4mm) (Tobler 1950, 89, 199, pl. LV, a). On the whole, these measurements are consistent with the proportions and sizes of some Maykop beads.(…)

It is quite possible that a distinctive technique of making thin-walled jointless beads from gold was a regional technological development of Maykop culture goldsmiths, within a wider tradition of Near East metalwork, as a type of production regulated by ritual beliefs (Gell 1992; Benzel 2013).

These deep-rooted Near East traditions of ritualization of the production and use of jewellery pieces made of gold, silver and gemstones in the Maykop culture, on the one hand, maintained familiar canons of ritual behaviour and, on the other, made perception of sophisticated symbolism of gemstones more difficult for neighbouring cultures with different living standards, levels of social development and value systems to understand. The jewellery traditions of the Maykop culture had no successors in the Caucasus or the adjacent steppes. In the third millennium BC, the goldsmiths of Europe and Asia had to reinvent the technique of making thin-walled jointless gold beads from scratch (Born et al. 2009).


Also interesting is Holocene environmental history and populating of mountainous Dagestan (Eastern Caucasus, Russia), by Ryabogina et al., Quaternary International (2018).

caucasus-dagestan-climate-population
The combination of Holocene environment changes and the settlement of the territory of Dagestan.

Related excerpts, about the climate of an adjacent region of the Caucasus before, during, and after the Maykop culture:

The 7th millennium BC featured a warm and arid climate, so that time corresponds to the steppe landscapes in the final stage of the Mesolithic. It is likely that the formation of a producing economy in the mountainous zone of Dagestan gradually emerged against this background. In the Neolithic period, the area remained almost treeless, as it was still warm and quite dry. However, archaeological data indicates that long-term settlements with well-developed farming spread in the mountainous zone around 6200-5500 BC.

The beginning of increasing humidity and the appearance of deciduous forests corresponds to the early Chalcolithic period of the Eastern Caucasus. It is the most poorly studied period in the history of this region. Covering a time span of 2000 years, this period was the least saturated by archaeological sites. At the start of this period, only the stands of herdsman in the mountain zone are known, dating to the second half of the 6th millennium BC (Gadgiev, 1991). It is still not clear whether the mountains were not settled in such a favorable climatic stage. The uncertainty may be due to the fact that people have chosen other ecological niches, or it could be we simply do not have data due to the insufficient archaeological survey of the territory. It is surprising that the turn to drier climate and the reduction of deciduous forests in the inner mountainous part of Dagestan, the large, long-term settlements like Ginchi emerge with pronounced specialization in agriculture (Fig. 7 panel (2)) (Gadgiev, 1991).

After the dry climate, simultaneously with cooling, the subsequent spread of pine forests coincides with the beginning of expansion of Kura-Araxes culture from the territory of Georgia through Chechnya to the mountainous Dagestan. Debates on the impact of past climate on Kura-Araxes societies in Transcaucasus have a long history (for the comprehensive review see, for example, Connor and Kvavadze, 2014 and references therein). In general, it is clear that after 3000 BC, forest cover in most areas of the Kura-Araxes region in the Transcaucasia reached its maximum extent in the Holocene (Connor and Kvavadze, 2014). However, at the same time lakes in Central Anatolia began to dry out and Caspian Sea levels fell (Roberts et al. 2011; Leroy et al. 2013), and arid conditions were identified in mountainous Dagestan in the 4th millennium. Clearly the regional moisture balance shifted in the Eastern Caucasus only in the late 4th to early 3rd millennium BC (this study). The only available radiocarbon dating of Dagestan confirms that the agricultural settlements of the Early Bronze Age appear not in the middle of the 4th millennium BC, but in the early 3rd millennium BC; that is not earlier than the stage of increasing moistening and the appearance of pine forests.

See also:

Recent Africa origin with hybridization, and back to Africa 70,000 years ago

mtdna-l-out-of-africa-expansion

Open access Carriers of mitochondrial DNA macrohaplogroup L3 basal lineages migrated back to Africa from Asia around 70,000 years ago, by Cabrera et al. BMC Evol Biol (2018) 18(98).

Abstract (emphasis mine):

Background

The main unequivocal conclusion after three decades of phylogeographic mtDNA studies is the African origin of all extant modern humans. In addition, a southern coastal route has been argued for to explain the Eurasian colonization of these African pioneers. Based on the age of macrohaplogroup L3, from which all maternal Eurasian and the majority of African lineages originated, the out-of-Africa event has been dated around 60-70 kya. On the opposite side, we have proposed a northern route through Central Asia across the Levant for that expansion and, consistent with the fossil record, we have dated it around 125 kya. To help bridge differences between the molecular and fossil record ages, in this article we assess the possibility that mtDNA macrohaplogroup L3 matured in Eurasia and returned to Africa as basal L3 lineages around 70 kya.

Results

The coalescence ages of all Eurasian (M,N) and African (L3 ) lineages, both around 71 kya, are not significantly different. The oldest M and N Eurasian clades are found in southeastern Asia instead near of Africa as expected by the southern route hypothesis. The split of the Y-chromosome composite DE haplogroup is very similar to the age of mtDNA L3. An Eurasian origin and back migration to Africa has been proposed for the African Y-chromosome haplogroup E. Inside Africa, frequency distributions of maternal L3 and paternal E lineages are positively correlated. This correlation is not fully explained by geographic or ethnic affinities. This correlation rather seems to be the result of a joint and global replacement of the old autochthonous male and female African lineages by the new Eurasian incomers.

Conclusions

These results are congruent with a model proposing an out-of-Africa migration into Asia, following a northern route, of early anatomically modern humans carrying pre-L3 mtDNA lineages around 125 kya, subsequent diversification of pre-L3 into the basal lineages of L3, a return to Africa of Eurasian fully modern humans around 70 kya carrying the basal L3 lineages and the subsequent diversification of Eurasian-remaining L3 lineages into the M and N lineages in the outside-of-Africa context, and a second Eurasian global expansion by 60 kya, most probably, out of southeast Asia. Climatic conditions and the presence of Neanderthals and other hominins might have played significant roles in these human movements. Moreover, recent studies based on ancient DNA and whole-genome sequencing are also compatible with this hypothesis.

homo-sapiens-neandertal-denisovan

You can also read the recent interesting open access review How did Homo sapiens evolve? by Julia Galway-Witham, Chris Stringer, Science (2018) 360:6395 1296-1298.

Related:

Demographic history and genetic adaptation in the Himalayan region

Open access Demographic history and genetic adaptation in the Himalayan region inferred from genome-wide SNP genotypes of 49 populations, by Arciero et al. Mol. Biol. Evol (2018), accepted manuscript (msy094).

Abstract (emphasis mine):

We genotyped 738 individuals belonging to 49 populations from Nepal, Bhutan, North India or Tibet at over 500,000 SNPs, and analysed the genotypes in the context of available worldwide population data in order to investigate the demographic history of the region and the genetic adaptations to the harsh environment. The Himalayan populations resembled other South and East Asians, but in addition displayed their own specific ancestral component and showed strong population structure and genetic drift. We also found evidence for multiple admixture events involving Himalayan populations and South/East Asians between 200 and 2,000 years ago. In comparisons with available ancient genomes, the Himalayans, like other East and South Asian populations, showed similar genetic affinity to Eurasian hunter-gatherers (a 24,000-year-old Upper Palaeolithic Siberian), and the related Bronze Age Yamnaya. The high-altitude Himalayan populations all shared a specific ancestral component, suggesting that genetic adaptation to life at high altitude originated only once in this region and subsequently spread. Combining four approaches to identifying specific positively-selected loci, we confirmed that the strongest signals of high-altitude adaptation were located near the Endothelial PAS domain-containing protein 1 (EPAS1) and Egl-9 Family Hypoxia Inducible Factor 1 (EGLN1) loci, and discovered eight additional robust signals of high-altitude adaptation, five of which have strong biological functional links to such adaptation. In conclusion, the demographic history of Himalayan populations is complex, with strong local differentiation, reflecting both genetic and cultural factors; these populations also display evidence of multiple genetic adaptations to high-altitude environments.

himalayan-map
Population samples analysed in this study. A. Map of South and East Asia, highlighting the four regions examined, and the colour assigned to each. B. Samples from the Tibetan Plateau. C.Samples from Nepal. D. Samples from Bhutan and India. The circle areas are proportional to the sample sizes. The three letter population codes in B-D are defined in supplementary table S1.

Relevant excerpts:

Genetic affinity to ancestral populations

We explored the genetic affinity between the Himalayan populations and five ancient genomes using f3-outgroup statistics. Himalayans show greater affinity to Eurasian hunter-gatherers (MA-1, a 24,000- year-old Upper Palaeolithic Siberian), and the related Bronze Age Yamnaya, than to European farmers (5,500-4,800 years ago; Fig. 5A) or to European hunter-gatherers (La Braña, 7,000 years ago; Fig. 5B), like other South and East Asian populations. We further explored the affinity of Himalayan populations by comparing them with the 45,000-year-old Upper Palaeolithic hunter-gatherer (Ust’-Ishim) and each of MA-1, La Braña, or Yamnaya. Himalayan individuals cluster together with other East Asian populations and show equal distance from Ust’-Ishim and the other ancient genomes, probably because Ust’-Ishim belongs to a much earlier period of time (supplementary fig. S15). We also explored genetic affinity between modern Himalayan populations and five ancient Himalayans (3,150 1,250 years old) from Nepal. The ancient individuals cluster together with modern Himalayan populations in a worldwide PCA (supplementary fig. S16), and the f3-outgroup statistics show modern high-altitude populations have the closest affinity with these ancient Himalayans, suggesting that these ancient individuals could represent a proxy for the first populations residing in the region (supplementary fig. S17 and supplementary table S4). Finally, we explored the genetic affinity of Himalayan samples with the archaic genomes of Denisovans and Neanderthals (Skoglund and Jakobsson 2011), and found that they show a similar sharing pattern with Denisovans and Neanderthals to the other South and East Asian populations. Individuals belonging to four Nepalese, one Cambodian, and three Chinese populations show the highest Denisovan sharing (after populations from Australia and Papua New Guinea) but these values are not significantly greater than other South and East Asian populations (supplementary figs. S18 and S19).

himalayan-pca
Genetic structure of the Himalayan region populations from analyses using unlinked SNPs. A. PCA of the Himalayan and HGDP-CEPH populations. Each dot represents a sample, coded by region as indicated. The Himalayan region samples lie between the HGDP-CEPH East Asian and South Asian samples on the right-hand side of the plot. B. PCA of the Himalayan populations alone. Each dot represents a sample, coded by country or region as indicated. Most samples lie on an arc between Bhutanese and Nepalese samples; Toto (India) are seen as extreme outlier in the bottom left corner, while Dhimal (Nepal) and Bodo (India) also form outliers.

NOTE. The variance explained in the PCA graphics seems to be too high. This happened recently also with the Damgaard et al. (2018) papers (see here the comment by Iosif Lazaridis).

Similarities and differences between high-altitude Himalayan

The most striking example is provided by the Toto from North India, an isolated tribal group with the lowest genetic diversity of the Himalayan populations examined here, indicated by the smallest long-term Ne (supplementary fig. S5), and a reported census size of 321 in 1951 (Mitra 1951), although their numbers have subsequently increased. Despite this extreme substructure, shared common ancestry among the high-altitude populations (Fig. 2C and Fig. 3) can be detected, and the Nepalese in general are distinguished from the Bhutanese and Tibetans (Fig. 2C) and they also cluster separately (Fig. 3). In a worldwide context, they share an ancestral component with South Asians (supplementary fig. S2). On the other hand, the Tibetans do not show detectable population substructure, probably due to a much more recent split in comparison with the other populations (Fig. 2C and supplementary fig. S6). The genetic similarity between the high-altitude populations, including Tibetans, Sherpa and Bhutanese, is also supported by their clustering together on the phylogenetic tree, the PCA generated from the co-ancestry matrix generated by fineSTRUCTURE (supplementary fig. S10 and S11), the lack of statistical significance for most of the D-statistics tests (Yoruba, Han; high-altitude Himalayan 1, high-altitude Himalayan 2), and the absence of correlation between the increased genetic affinity to lowland East Asians and the spatial location of the Himalayan populations (supplementary figs. S12 and S13). Together, these results suggest the presence of a single ancestral population carrying advantageous variants for high-altitude adaptation that separated from lowland East Asians, and then spread and diverged into different populations across the Himalayan region. (…)

Recent admixture events

himalayan-admixture
Genetic structure of the Himalayan region populations from analyses using unlinked SNPs. C. ADMIXTURE (K values of 2 to 6, as indicated) analysis of the Himalayan samples. Note that most increases in the value of K result in single population being distinguished. Population codes in C are defined in supplementary table S1.

Himalayan populations show signatures of recent admixture events, mainly with South and East Asian populations as well as within the Himalayan region itself. Newar and Lhasa show the oldest signature of admixture, dated to between 2,000 and 1,000 years ago. Majhi and Dhimal display signatures of admixture within the last 1,000 years. Chetri and Bodo show the most recent admixture events, between 500 and 200 years ago (Fig. 4, supplementary tables S3). The comparison between the genetic tree and the linguistic association of each Himalayan population highlights the agreement between genetic and linguistic sub-divisions, in particular in the Bhutanese and Tibetan populations. Nepalese populations show more variability, with genetic sub-clusters of populations belonging to different linguistic affiliations (Fig. 3B). Modern high-altitude Himalayans show genetic affinity with ancient genomes from the same region (supplementary fig. S17), providing additional support for the idea of an ancient high-altitude population that spread across the Himalayan region and subsequently diverged into several of the present-day populations. Furthermore, Himalayan populations show a similar pattern of allele sharing with Denisovans as other South-East Asian populations (supplementary fig. S18 and S19). Overall, geographical isolation, genetic drift, admixture with neighbouring populations and linguistic subdivision played important roles in shaping the genetic variability we see in the Himalayan region today.

Related:

Ancient genomes document multiple waves of migration in south-east Asian prehistory

southeast-asia-reich

Open access preprint at bioRxiv Ancient genomes document multiple waves of migration in Southeast Asian prehistory, by Lipson, Cheronet, Mallick, et al. (2018).

Abstract (emphasis mine):

Southeast Asia is home to rich human genetic and linguistic diversity, but the details of past population movements in the region are not well known. Here, we report genome-wide ancient DNA data from thirteen Southeast Asian individuals spanning from the Neolithic period through the Iron Age (4100-1700 years ago). Early agriculturalists from Man Bac in Vietnam possessed a mixture of East Asian (southern Chinese farmer) and deeply diverged eastern Eurasian (hunter-gatherer) ancestry characteristic of Austroasiatic speakers, with similar ancestry as far south as Indonesia providing evidence for an expansive initial spread of Austroasiatic languages. In a striking parallel with Europe, later sites from across the region show closer connections to present-day majority groups, reflecting a second major influx of migrants by the time of the Bronze Age.

south-east-asian-admixture-graph
Schematics of admixture graph results. (A) Wider phylogenetic context. (B) Details of the Austroasiatic clade. Branch lengths are not to scale, and the order of the two events on the Nicobarese lineage in (B) is not well determined (Supplementary Text).

Featured image, from the article: “Overview of samples. (A) Locations and dates of ancient individuals. Overlapping positions are shifted slightly for visibility. (B) PCA with East and Southeast Asians. We projected the ancient samples onto axes computed using the present-day populations (with the exception of Mlabri, who were projected instead due to their large population-speci c drift). Present-day colors indicate language family affiliation: green, Austroasiatic; blue, Austronesian; orange, Hmong-Mien; black, Sino-Tibetan; magenta, Tai-Kadai.”

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