Common pitfalls in human genomics and bioinformatics: ADMIXTURE, PCA, and the ‘Yamnaya’ ancestral component

invasion-from-the-steppe-yamnaya

Good timing for the publication of two interesting papers, that a lot of people should read very carefully:

ADMIXTURE

Open access A tutorial on how not to over-interpret STRUCTURE and ADMIXTURE bar plots, by Daniel J. Lawson, Lucy van Dorp & Daniel Falush, Nature Communications (2018).

Interesting excerpts (emphasis mine):

Experienced researchers, particularly those interested in population structure and historical inference, typically present STRUCTURE results alongside other methods that make different modelling assumptions. These include TreeMix, ADMIXTUREGRAPH, fineSTRUCTURE, GLOBETROTTER, f3 and D statistics, amongst many others. These models can be used both to probe whether assumptions of the model are likely to hold and to validate specific features of the results. Each also comes with its own pitfalls and difficulties of interpretation. It is not obvious that any single approach represents a direct replacement as a data summary tool. Here we build more directly on the results of STRUCTURE/ADMIXTURE by developing a new approach, badMIXTURE, to examine which features of the data are poorly fit by the model. Rather than intending to replace more specific or sophisticated analyses, we hope to encourage their use by making the limitations of the initial analysis clearer.

The default interpretation protocol

Most researchers are cautious but literal in their interpretation of STRUCTURE and ADMIXTURE results, as caricatured in Fig. 1, as it is difficult to interpret the results at all without making several of these assumptions. Here we use simulated and real data to illustrate how following this protocol can lead to inference of false histories, and how badMIXTURE can be used to examine model fit and avoid common pitfalls.

admixture-protocol
A protocol for interpreting admixture estimates, based on the assumption that the model underlying the inference is correct. If these assumptions are not validated, there is substantial danger of over-interpretation. The “Core protocol” describes the assumptions that are made by the admixture model itself (Protocol 1, 3, 4), and inference for estimating K (Protocol 2). The “Algorithm input” protocol describes choices that can further bias results, while the “Interpretation” protocol describes assumptions that can be made in interpreting the output that are not directly supported by model inference

Discussion

STRUCTURE and ADMIXTURE are popular because they give the user a broad-brush view of variation in genetic data, while allowing the possibility of zooming down on details about specific individuals or labelled groups. Unfortunately it is rarely the case that sampled data follows a simple history comprising a differentiation phase followed by a mixture phase, as assumed in an ADMIXTURE model and highlighted by case study 1. Naïve inferences based on this model (the Protocol of Fig. 1) can be misleading if sampling strategy or the inferred value of the number of populations K is inappropriate, or if recent bottlenecks or unobserved ancient structure appear in the data. It is therefore useful when interpreting the results obtained from real data to think of STRUCTURE and ADMIXTURE as algorithms that parsimoniously explain variation between individuals rather than as parametric models of divergence and admixture.

For example, if admixture events or genetic drift affect all members of the sample equally, then there is no variation between individuals for the model to explain. Non-African humans have a few percent Neanderthal ancestry, but this is invisible to STRUCTURE or ADMIXTURE since it does not result in differences in ancestry profiles between individuals. The same reasoning helps to explain why for most data sets—even in species such as humans where mixing is commonplace—each of the K populations is inferred by STRUCTURE/ADMIXTURE to have non-admixed representatives in the sample. If every individual in a group is in fact admixed, then (with some exceptions) the model simply shifts the allele frequencies of the inferred ancestral population to reflect the fraction of admixture that is shared by all individuals.

Several methods have been developed to estimate K, but for real data, the assumption that there is a true value is always incorrect; the question rather being whether the model is a good enough approximation to be practically useful. First, there may be close relatives in the sample which violates model assumptions. Second, there might be “isolation by distance”, meaning that there are no discrete populations at all. Third, population structure may be hierarchical, with subtle subdivisions nested within diverged groups. This kind of structure can be hard for the algorithms to detect and can lead to underestimation of K. Fourth, population structure may be fluid between historical epochs, with multiple events and structures leaving signals in the data. Many users examine the results of multiple K simultaneously but this makes interpretation more complex, especially because it makes it easier for users to find support for preconceptions about the data somewhere in the results.

In practice, the best that can be expected is that the algorithms choose the smallest number of ancestral populations that can explain the most salient variation in the data. Unless the demographic history of the sample is particularly simple, the value of K inferred according to any statistically sensible criterion is likely to be smaller than the number of distinct drift events that have practically impacted the sample. The algorithm uses variation in admixture proportions between individuals to approximately mimic the effect of more than K distinct drift events without estimating ancestral populations corresponding to each one. In other words, an admixture model is almost always “wrong” (Assumption 2 of the Core protocol, Fig. 1) and should not be interpreted without examining whether this lack of fit matters for a given question.

admixture-pitfalls
Three scenarios that give indistinguishable ADMIXTURE results. a Simplified schematic of each simulation scenario. b Inferred ADMIXTURE plots at K= 11. c CHROMOPAINTER inferred painting palettes.

Because STRUCTURE/ADMIXTURE accounts for the most salient variation, results are greatly affected by sample size in common with other methods. Specifically, groups that contain fewer samples or have undergone little population-specific drift of their own are likely to be fit as mixes of multiple drifted groups, rather than assigned to their own ancestral population. Indeed, if an ancient sample is put into a data set of modern individuals, the ancient sample is typically represented as an admixture of the modern populations (e.g., ref. 28,29), which can happen even if the individual sample is older than the split date of the modern populations and thus cannot be admixed.

This paper was already available as a preprint in bioRxiv (first published in 2016) and it is incredible that it needed to wait all this time to be published. I found it weird how reviewers focused on the “tone” of the paper. I think it is great to see files from the peer review process published, but we need to know who these reviewers were, to understand their whiny remarks… A lot of geneticists out there need to develop a thick skin, or else we are going to see more and more delays based on a perceived incorrect tone towards the field, which seems a rather subjective reason to force researchers to correct a paper.

PCA of SNP data

Open access Effective principal components analysis of SNP data, by Gauch, Qian, Piepho, Zhou, & Chen, bioRxiv (2018).

Interesting excerpts:

A potential hindrance to our advice to upgrade from PCA graphs to PCA biplots is that the SNPs are often so numerous that they would obscure the Items if both were graphed together. One way to reduce clutter, which is used in several figures in this article, is to present a biplot in two side-by-side panels, one for Items and one for SNPs. Another stratagem is to focus on a manageable subset of SNPs of particular interest and show only them in a biplot in order to avoid obscuring the Items. A later section on causal exploration by current methods mentions several procedures for identifying particularly relevant SNPs.

One of several data transformations is ordinarily applied to SNP data prior to PCA computations, such as centering by SNPs. These transformations make a huge difference in the appearance of PCA graphs or biplots. A SNPs-by-Items data matrix constitutes a two-way factorial design, so analysis of variance (ANOVA) recognizes three sources of variation: SNP main effects, Item main effects, and SNP-by-Item (S×I) interaction effects. Double-Centered PCA (DC-PCA) removes both main effects in order to focus on the remaining S×I interaction effects. The resulting PCs are called interaction principal components (IPCs), and are denoted by IPC1, IPC2, and so on. By way of preview, a later section on PCA variants argues that DC-PCA is best for SNP data. Surprisingly, our literature survey did not encounter even a single analysis identified as DC-PCA.

The axes in PCA graphs or biplots are often scaled to obtain a convenient shape, but actually the axes should have the same scale for many reasons emphasized recently by Malik and Piepho [3]. However, our literature survey found a correct ratio of 1 in only 10% of the articles, a slightly faulty ratio of the larger scale over the shorter scale within 1.1 in 12%, and a substantially faulty ratio above 2 in 16% with the worst cases being ratios of 31 and 44. Especially when the scale along one PCA axis is stretched by a factor of 2 or more relative to the other axis, the relationships among various points or clusters of points are distorted and easily misinterpreted. Also, 7% of the articles failed to show the scale on one or both PCA axes, which leaves readers with an impressionistic graph that cannot be reproduced without effort. The contemporary literature on PCA of SNP data mostly violates the prohibition against stretching axes.

pca-how-to
DC-PCA biplot for oat data. The gradient in the CA-arranged matrix in Fig 13 is shown here for both lines and SNPs by the color scheme red, pink, black, light green, dark green.

The percentage of variation captured by each PC is often included in the axis labels of PCA graphs or biplots. In general this information is worth including, but there are two qualifications. First, these percentages need to be interpreted relative to the size of the data matrix because large datasets can capture a small percentage and yet still be effective. For example, for a large dataset with over 107,000 SNPs for over 6,000 persons, the first two components capture only 0.3693% and 0.117% of the variation, and yet the PCA graph shows clear structure (Fig 1A in [4]). Contrariwise, a PCA graph could capture a large percentage of the total variation, even 50% or more, but that would not guarantee that it will show evident structure in the data. Second, the interpretation of these percentages depends on exactly how the PCA analysis was conducted, as explained in a later section on PCA variants. Readers cannot meaningfully interpret the percentages of variation captured by PCA axes when authors fail to communicate which variant of PCA was used.

Conclusion

Five simple recommendations for effective PCA analysis of SNP data emerge from this investigation.

  1. Use the SNP coding 1 for the rare or minor allele and 0 for the common or major allele.
  2. Use DC-PCA; for any other PCA variant, examine its augmented ANOVA table.
  3. Report which SNP coding and PCA variant were selected, as required by contemporary standards in science for transparency and reproducibility, so that readers can interpret PCA results properly and reproduce PCA analyses reliably.
  4. Produce PCA biplots of both Items and SNPs, rather than merely PCA graphs of only Items, in order to display the joint structure of Items and SNPs and thereby to facilitate causal explanations. Be aware of the arch distortion when interpreting PCA graphs or biplots.
  5. Produce PCA biplots and graphs that have the same scale on every axis.

I read the referenced paper Biplots: Do Not Stretch Them!, by Malik and Piepho (2018), and even though it is not directly applicable to the most commonly available PCA graphs out there, it is a good reminder of the distorting effects of stretching. So for example quite recently in Krause-Kyora et al. (2018), where you can see Corded Ware and BBC samples from Central Europe clustering with samples from Yamna:

NOTE. This is related to a vertical distorsion (i.e. horizontal stretching), but possibly also to the addition of some distant outlier sample/s.

pca-cwc-yamna-bbc
Principal Component Analysis (PCA) of the human Karsdorf and Sorsum samples together with previously published ancient populations projected on 27 modern day West Eurasian populations (not shown) based on a set of 1.23 million SNPs (Mathieson et al., 2015). https://doi.org/10.7554/eLife.36666.006

The so-called ‘Yamnaya’ ancestry

Every time I read papers like these, I remember commenters who kept swearing that genetics was the ultimate science that would solve anthropological problems, where unscientific archaeology and linguistics could not. Well, it seems that, like radiocarbon analysis, these promising developing methods need still a lot of refinement to achieve something meaningful, and that they mean nothing without traditional linguistics and archaeology… But we already knew that.

Also, if this is happening in most peer-reviewed publications, made by professional geneticists, in journals of high impact factor, you can only wonder how many more errors and misinterpretations can be found in the obscure market of so many amateur geneticists out there. Because amateur geneticist is a commonly used misnomer for people who are not geneticists (since they don’t have the most basic education in genetics), and some of them are not even ‘amateurs’ (because they are selling the outputs of bioinformatic tools)… It’s like calling healers ‘amateur doctors’.

NOTE. While everyone involved in population genetics is interested in knowing the truth, and we all have our confirmation (and other kinds of) biases, for those who get paid to tell people what they want to hear, and who have sold lots of wrong interpretations already, the incentives of ‘being right’ – and thus getting involved in crooked and paranoid behaviour regarding different interpretations – are as strong as the money they can win or loose by promoting themselves and selling more ‘product’.

As a reminder of how badly these wrong interpretations of genetic results – and the influence of the so-called ‘amateurs’ – can reflect on research groups, yet another turn of the screw by the Copenhagen group, in the oral presentations at Languages and migrations in pre-historic Europe (7-12 Aug 2018), organized by the Copenhagen University. The common theme seems to be that Bell Beaker and thus R1b-L23 subclades do represent a direct expansion from Yamna now, as opposed to being derived from Corded Ware migrants, as they supported before.

NOTE. Yes, the “Yamna → Corded Ware → Únětice / Bell Beaker” migration model is still commonplace in the Copenhagen workgroup. Yes, in 2018. Guus Kroonen had already admitted they were wrong, and it was already changed in the graphic representation accompanying a recent interview to Willerslev. However, since there is still no official retraction by anyone, it seems that each member has to reject the previous model in their own way, and at their own pace. I don’t think we can expect anyone at this point to accept responsibility for their wrong statements.

So their lead archaeologist, Kristian Kristiansen, in The Indo-Europeanization of Europé (sic):

kristiansen-migrations
Kristiansen’s (2018) map of Indo-European migrations

I love the newly invented arrows of migration from Yamna to the north to distinguish among dialects attributed by them to CWC groups, and the intensive use of materials from Heyd’s publications in the presentation, which means they understand he was right – except for the fact that they are used to support a completely different theory, radically opposed to those defended in Heyd’s model

Now added to the Copenhagen’s unending proposals of language expansions, some pearls from the oral presentation:

  • Corded Ware north of the Carpathians of R1a lineages developed Germanic;
  • R1b borugh [?] Italo-Celtic;
  • the increase in steppe ancestry on north European Bell Beakers mean that they “were a continuation of the Yamnaya/Corded Ware expansion”;
  • Corded Ware groups [] stopped their expansion and took over the Bell Beaker package before migrating to England” [yep, it literally says that];
  • Italo-Celtic expanded to the UK and Iberia with Bell Beakers [I guess that included Lusitanian in Iberia, but not Messapian in Italy; or the opposite; or nothing like that, who knows];
  • 2nd millennium BC Bronze Age Atlantic trade systems expanded Proto-Celtic [yep, trade systems expanded the language]
  • 1st millennium BC expanded Gaulish with La Tène, including a “Gaulish version of Celtic to Ireland/UK” [hmmm, dat British Gaulish indeed].

You know, because, why the hell not? A logical, stable, consequential, no-nonsense approach to Indo-European migrations, as always.

Also, compare still more invented arrows of migrations, from Mikkel Nørtoft’s Introducing the Homeland Timeline Map, going against Kristiansen’s multiple arrows, and even against the own recent fantasy map series in showing Bell Beakers stem from Yamna instead of CWC (or not, you never truly know what arrows actually mean):

corded-ware-migrations
Nørtoft’s (2018) maps of Indo-European migrations.

I really, really loved that perennial arrow of migration from Volosovo, ca. 4000-800 BC (3000+ years, no less!), representing Uralic?, like that, without specifics – which is like saying, “somebody from the eastern forest zone, somehow, at some time, expanded something that was not Indo-European to Finland, and we couldn’t care less, except for the fact that they were certainly not R1a“.

This and Kristiansen’s arrows are the most comical invented migration routes of 2018; and that is saying something, given the dozens of similar maps that people publish in forums and blogs each week.

NOTE. You can read a more reasonable account of how haplogroup R1b-L51 and how R1-Z645 subclades expanded, and which dialects most likely expanded with them.

We don’t know where these scholars of the Danish workgroup stand at this moment, or if they ever had (or intended to have) a common position – beyond their persistent ideas of Yamnaya™ ancestral component = Indo-European and R1a must be Indo-European – , because each new publication changes some essential aspects without expressly stating so, and makes thus everything still messier.

It’s hard to accept that this is a series of presentations made by professional linguists, archaeologists, and geneticists, as stated by the official website, and still harder to imagine that they collaborate within the same professional workgroup, which includes experienced geneticists and academics.

I propose the following video to close future presentations introducing innovative ideas like those above, to help the audience find the appropriate mood:

Related

The Yampil Barrow complex and the Yamna connection with forest-steppe cultures

yamna-diet-pca

Researchers involved in the investigation of the Yampil Barrow Complex are taking the opportunity of their latest genetic paper to publish and upload more papers in Academia.edu.

NOTE. These are from the free volume 22 of Baltic-Pontic Studies, Podolia “Barrow Culture” Communities: 4th/3rd-2nd Mill. BC. The Yampil Barrow Complex: Interdisciplinary Studies, whose website gives a warning depending on your browser (because of the lack of secure connection). Here is a link to the whole PDF.

Here are some of them, with interesting excerpts (emphasis mine):

1. Kurgan rites in the Eneolithic and Early Bronze age Podolia in light of materials from the funerary ceremonial centre at Yampil, by Piotr Włodarczak (2017).

The particular interest in this group stemmed from its specific location within the “Yamnaya cultural-historical entity”: its exposure to Central European Corded ware culture (further as CWC) on the one hand, and discernible contact with communities representing the Globular Amphorae culture (GAC), expanding to the south-east, on the other [e.g. Szmyt 1999; 2000]. The location on the fringes of the north-western variant of the Yamnaya culture (YC) [acc. to Merpert 1974; cf Rassamakin 2013a; 2013b; Rassamakin, Nikolova 2008] opened up an interesting perspective for tracing the transfer of Central European cultural patterns to the North Pontic area, and for determining the specificity of the cultural model of steppe communities, which due to their geographic location seemed somehow predestined for westward expansion.

yampil-barrow-complex
locations of Eneolithic and Early bronze age kurgan cemeteries in Podolia 1-7 – yampil cluster (1 – dobrianka, 2 – Klembivka, 3 – Pidlisivka, 4 – Porohy, 5 – Pysarivka, 6 – Prydnistryanske, 7 – Severynivka), 8-11 – Kamienka cluster (8 – hrustovaia, 9 – Kuzmin, 10 – Ocniţa, 11 – Podoima), 12 – mocra, 13 – Tymkove

Podolia kurgans originate from various stages of the Eneolithic and Early bronze ages, and this chronological diversity is reflected in differences in construction of mounds and central graves for which kurgans were originally built (being burials of the “kurgans’ founders”). These oldest burials link with various Eneolithic and YC communities, and the taxonomic attribution of some of the phenomena discussed here poses difficulties. This stems from the nature of the finds, which are sometimes only slightly distinctive and often retrieved from contexts difficult to interpret (e.g. from kurgans damaged to a significant degree). Another reason for the high discordance and ambiguity of opinions lies in the nature of the problem itself, since taxonomic definitions can be no more than proxies for cultural processes which are both fluid and multi-directional. This is particularly evident for phenomena associated with the Eneolithic and the very beginnings of the Bronze Age in steppe and forest-steppe areas [e.g. Rassamakin 2013; Manzura 2016], while later stages (the classic and late YC) are marked by much more regularity in terms of funeral rituals. Funerary behaviours displayed by Eneolithic steppe groups were the outcome of intercultural relationships and often combined elements borrowed from different milieus [e.g. Rassamakin 2008: 215, 216]. One consequence of this is the multitude of approaches to the description of Eneolithic phenomena proposed in the literature, with the controversies the situation creates. This is also true for the Podolia kurgans discussed here, where chronology is relatively easy to interpret while taxonomical attributions are much more difficult. A good example in this context is a recently published complex at Prydnistryanske, which has been linked either with the late Trypilia group of Gordinești [Klochko et al 2015d] or with the Eneolithic steppe formation known as Zhivotilovka-Volchansk [Manzura 2016], or recently with the Bursuceni group [Demcenko 2016].

A distinct feature of Podolia kurgans having YC burials is the multi-phase nature of their mounds, a feature recorded throughout the North Pontic area. It is particularly evident in the cases of sequences of burials (typically two burials) placed in the central parts of kurgans and connected with separate stages of the mound’s construction. In this context, the temporal and cultural relationship between the older and younger burial becomes a very interesting issue. Younger burials typically revealed traits characteristic of the YC complex, while older ones were often different and distinguished by a different shape of the grave pit and sometimes a different arrangement and orientation of the body as well. In the most evident cases, older pits held a body in the extended position, reminiscent of the Postmariupol/ Kvityana tradition (…). In such cases, the older grave often stands out with a funerary tradition diverging from model YC behaviours, in terms of orientation, body position, and constructional features.

yamna-corded-ware-podolia-yampil
Location of Yampil and Kamienka ceremonial centres, and barrows of the Yamnaya culture, Corded Ware culture, and Late Eneolithic groups of the Podolia Plateau and adjacent areas. Legend. 1 – barrows and barrow groups of the Yamnaya culture; 2 – barrows and barrow groups of the Corded Ware culture; 3 – Eneolithic barrows; 4 – barrows of undetermined cultural attribution, dated to the 3rd millennium BC [after Włodarczak 2014b, revised]

Kvitjana and Trypillia

The Pre-Yamnaya (Eneolithic) phase came to be distinguished in kurgan cemeteries from the Podolie region after the discovery of burials in extended position (i.e. of the Kvityana/Postmariupol type) at Ocniţa (Fig 10: 2, 3) [kurgans 6 and 7; Manzura et al 1992] and Tymkove (Fig 10: 1) [Subbotin et al 2000, 84, ris 3: 4]. In all these three cases the burials marked the oldest phase of mound construction, and later YC burials were dug into the central part of the kurgan, which entailed the remodelling and considerable enlargement of the mound. Both the chronological and taxonomic positions of extended burials in the North Pontic area are subjects of debate [e.g. Manzura 2010; Rassamakin 2013; Ivanova 2015, 280-282] (…)

The chronological position of graves with burials in extended position can be narrowed down thanks to stratigraphic observations made in kurgans at Bursuceni, between the Dniester and Prut rivers [Yarovoy 1978]. Graves from this site were younger than the burials representing the Zhivotilovka-Volchansk tradition and older than those linked with the early phase of YC based on a relatively compact series of radiocarbon dates obtained for graves of the Zhivotilovka-Volchansk group, the chronology of burials in extended position can be determined as the very close of the 4th – beginning of the 3rd millennia BC (most likely around 3100-2800 BC).

Early and late Yamna

A model ceremonial-funerary complex created by a YC community is a group of kurgans in Pysarivka village [harat et al 2014: 104-165]. Nine mounds have been explored there, of which eight (1, 3-9) yielded central burials of YC sharing a number of similar features (Fig 13). The deceased were placed in regular, rectangular pits having vertical walls Vykids (mounds of soil extracted while digging grave pits) formed regular narrow walls surrounding each grave, and seem to have been integral elements of sepulchral architecture. Chambers were covered with 5-7 timbers/planks arranged parallel to the grave’s longer axis. Another characteristic element was that of wooden stakes driven symmetrically into the bottom along grave chamber edges, recorded in four cases. The deceased were laid on their backs, in a contracted position with the knees up. The head was as a rule turned to W, with possible deflections towards NW or SW Skeletons bore traces of painting with ochre.

kurgan-yampil-yamna
Prydnistryanske, Yampil region reconstruction of stages of grave IV/4 construction by M. Podsiadło

The role of south-eastern connections at the early stage of YC development can also be seen in grave IV/4 at Prydnistryanske. This is indicated by a combined (wood and stone) roof construction involving stela-like slabs, and by the skull of the deceased characteristically painted with red pigment. The absolute date obtained for grave IV/4 (ca 3100-3000 bC) suggests its early provenance [Goslar et al 2015]. The grave was most likely connected with the oldest stage of enlargement of the Eneolithic barrow [Klochko et al 2015].

The middle phase of YC is quite clearly evident in Podolia kurgans, it is marked by burials dug into the existing mounds. These are either single burials inserted into different parts of the mounds, or groups of graves forming arches around a central part. Graves with steps leading to the burial chamber are typical of that stage, and they were wider than those in the centres of kurgans. Chambers were typically roofed with planks or timbers placed perpendicularly to the grave’s longer axis burials on one side and burials on the back but leaning to either side become more numerous, and upper limbs were most often placed in A, G, H, or I arrangements ceramic vessels become more common in graves, including forms indicative of contacts with GAC and CWC milieus.


2. The previously announced paper on a specific burial showing postmortem marks: Ritual position and “tattooing” techniques in the funeral practices of the “Barrow cultures” of the Pontic-Caspian steppe/forest-steppe area Porohy 3A, Yampil region, Vinnytsia Oblast: Specialist analysis research perspectives, by Żurkiewicz et al. (2018):

Based on the anatomical properties of the structure of a human body, the histological structure of the skin and location of the dye used for tattooing, having conducted an analysis of postmortem changes occurring within the skin after death, and having taken into consideration the continuous and regular nature of the pattern on the ulnae of the individual from grave no. 10, an interdisciplinary team of researchers has concluded that there is no possibility of a transfer of tattoo dye from the skin onto the surface of an individual’s bone.

The analysis of two ulnae documented in this article indicates that the patterns were made using tree tar, postmortem and directly onto the skeletonised human remains. The placement of the individual’s ulnae in grave no. 10 (Fig. 10), and the location of patterns on the upper skin surface, that is, on surfaces accessible without changing the arrangement of the body, may suggest that the patterns were created on the skeletonised remains without the need to change their placement in the pit (= in situ).

The present conclusions ought to see the beginning of a wider research programme focused on the analysis of the techniques used to create decorations on bones in “kurgan cultures” communities in the context of the Pontic-Caspian Region.

ulna-marks
Porohy, Yampil Region, barrow 3A, feature 10. Macro- and microscopic examination results: 1 – right ulna with visible decorations and close-up of the decoration; 2 – left ulna with visible decorations and close-up of the decoration. Photo by D. Lorkiewicz-Muszyńska

3. Builders and users of ritual centres, Yampil barrow complex: studies of diett based on stable carbon nitrogen isotope composition, by Goslar et al. (2017).

Foxtail millet caryopses are used to make primarily flour, groats and pancakes [lityńska-zając, wasylikowa 2005: 109]. Grains and flour are easily digestible and as such, they are recommended to infants and the elderly. Grains are also fed to fowl and poultry in Asia, foxtail millet is used to make beer and wine, while in China it is also used for medicinal purposes [Hanelt 2001 (Ed )]. Various dishes and beverages made from broomcorn and foxtail millet caryopses in Eurasia are listed by Sakamoto [1987a]. Detailed ethnobotanical studies of the cultivation, crop processing and food preparation in the Iberian Peninsula were presented by Moreno-Larrazabal et al.[2015] .

The geographical area under discussion can be related to historical and ethnographic data indicating the use of grits and groats in the diet. They had been known in the menus of European societies since the ‘pre-agrarian’ times. The isotope finding of millet domination in the diet of middle Dniester Yampil Barrow Complex, complemented by bioarchaeological data from the upper steppe Dniester area (from the similarly ‘early-barrow’ Usatovo group/culture with strongly marked ‘eastern’ civilization influences), makes it reasonable to consider the possibility that already in the prologue of late Eneolithic-Early bronze barrow culture (3300- 2800 BC) development there was a clear dividing line of millet groats use – or millet presence – that is, so-called yagla groats (yagla, yagly = millet in Old Slavic languages).

correlation-diet-dereivka-isotopic
Composition of stable carbon and nitrogen isotopes in bone collagen from the Yampil Barrow Complex against the ranges of isotopic composition expected for various diet components [after Gerling 2015: Fig 6 16] The meaning of colours and symbols concerning the Yampil Barrow Complex is the same as in Fig 3 For the sake of comparison, the isotopic composition in human >bones from two sites on the dnieper (ca 5200-5000 bC) is given, in which the share of freshwater fish in the diet was confirmed by the measurements of the reservoir effect [lillie et al. 2009]

Related

On the origin of haplogroup R1b-L51 in late Repin / early Yamna settlers

steppe-eneolithic-migrations

A recent comment on the hypothetical Central European origin of PIE helped me remember that, when news appeared that R1b-L51 had been found in Khvalynsk ca. 4250-4000 BC, I began to think about alternative scenarios for the expansion of this haplogroup, with one of them including Central Europe.

Because, if YFull‘s (and Iain McDonald‘s) estimation of the split of R1b-L23 in L51 and Z2103 (ca. 4100 BC, TMRCA ca. 3700 BC) was wrong, by as much as the R1a-Z645 estimates proved wrong, and both subclades were older than expected, then maybe R1b-L51 was not part of the Yamna expansion, but rather part of an earlier expansion with Suvorovo-Novodanilovka into central Europe.

That is, R1b-L51 and R1b-Z2103 would have expanded wih Khvalynsk-Novodanilovka migrants, and they would have either disappeared among local populations, or settled and expanded with successful lineages in certain regions. I think this may give rise to two potential models.

A hidden group in the European east-central steppes?

Here is what Heyd (2011), for example, has to say about the effect of the Khvalynsk-Novodanilovka expansion in the 4th millennium BC, with the first Kurgan wave that shuttered the social, economic, and cultural foundations of south-eastern Europe (before the expansion of west Yamna migrants in the region):

indo-european-anatolian-uralic-migrations
Proto-Anatolian migrations with Khvalynsk-Novodanilovka expansion, including ADMIXTURE data from Wang et al. (2018).

As the Boleraz and Baden tumuli cases in Serbia and Hungary demonstrate, there are earlier, 4th millennium cal. B.C. round tumuli in the Carpathian basin. There are also earlier north-Pontic steppe populations who infiltrated similar environments west of the Black Sea prior to the rise of the Yamnaya culture. This situation can be traced back to the 2nd half of the 5th millennium cal. B.C. to a group of distinct burials, zoomorphic maceheads, long flint blades, triangular flint points, etc., summarized under the term Suvurovo-Novodanilovka (Govedarica 2004; Rassamakin 2004; Anthony 2007; Heyd forthcoming 2011). They also erected round personalized tumuli, though smaller in size and height, above inhumations of single individuals. Suvorovo and Casimcea are the key examples in the lower Danube region of Romania. In northeast Bulgaria, the primary grave of Polska Kosovo (ochre-stained supine extended body position: information communicated by S. Alexandrov) can also be seen as such, as should the Targovishte-“Gonova mogila” primary grave 1 in the Thracian plain with a burial arranged in a supine position with flexed legs, southeast-northwest orientated, and strewed with ochre (Kanchev 1991 , p. 56- 57; Ivanova Gaydarska 2007). In addition to the many copper and shell beads, the 17.4cm long obsidian blade is exceptional, which links this grave to the Csongrád-“Kettoshalom” grave in the south Hungarian plain (Ecsedy 1979). It also yielded an obsidian blade ( 13.2cm long) and copper, shell and limestone beads.

suvorovo-novodanilovka-expansion-europe
The Southeast European distribution of graves of the Suvorovo-Novodanilovka group and such unequipped ones mentioned in the text which can be attributed by burial custom and stratigraphic position in the barrow, plus zoomorphic and abstract animal head sceptres as well as specific maceheads with knobs as from Decea Maresului (mid-5th millennium until around 4000 BC). Heyd (2016).

However, no traces of a tumulus have been recorded above the Kettoshalom tomb. Conventionally, it is dated to the Bodrogkeresztur-period in east Hungary, shortly after 4000 cal. B.C., which would correspond very well with the suggested Cernavodă I (or its less known cultural equivalent in the Thracian plain) attribution for the “Gonova mogila” grave, a cultural background to which the Csongrád grave should have also belonged. Bodrogkeresztur and Cernavodă I periods are not the only examples of 4th millennium cal. B.C. tumuli and burials displaying this steppe connection. Indeed we can find this early steppe impact throughout the 4th millennium cal. B.C. These include adscriptions to the Horodiștea II (Corlateni-Dealul Stadole, grave I: Burtanescu l 998, p. 37; Holbocai, grave 34: Coma 1998, p. 16); to Gordinești-Cernavodă 11 (Liești-Movila Arbănașu, grave 22: Brudiu 2000); to Gorodsk-Usatovo (Corlăteni Dealul Cetăţii, grave I: Comșa 1998, p. 17- 18, in Romania; Durankulak, grave 982: Vajsov 2002, in Bulgaria); and to Cernavodă III(Golyama Detelina, tum. 4: Leshtakov, Borisov 1995), and early (end of 4th millennium cal. B.C.) Ezero in Ovchartsi, primary grave (Kalchev 1994, p. 134-138) and Golyama Detelina, tum. 2 (Kanchev 1991) in Bulgaria. Also the Boleráz and Baden tumuli of Banjevac-Tolisavac and Mokrin in the south Carpathian basin account for this, since one should perhaps take into account primary grave 12 of the Sárrédtudavari-Orhalom tumulus in the Hungarian Alfold: a left-sided crouched juvenile ( 15- 17 y) individual in an oval, NW-SE orientated grave pit 14C dated to 3350-3100 cal. B.C. at 2 sigma (Dani, Ncpper 2006). Neither the burial custom (no ochre strewing or depositing a lump of ochre has been recorded), nor date account for its ascription to the Yamnaya!

All of these tumuli and burials demonstrate, though, that there is already a constant but perhaps low-level 4th millennium cal. B.C. steppe interaction, linking the regions of the north of the Black Sea with those of the west, and reaching deep into the Carpathian basin. This has to be acknowledged. even if these populations remain small, bounded to their steppe habitat with an economy adapted to this special environment, and are not always visible in the record. Indirect hints may help in seeing them, such as the frequent occurrence of horse bones, regarded as deriving from domesticated horses, in Hungarian Baden settlements (Bokonyi 1978; Benecke 1998), and in those of the south German Cham Culture (Matuschik 1999, p. 80-82) and the east German Bernburg Culture (Becker 1999; Benecke 1999). These occur, however, always in low numbers, perhaps not enough to maintain and regenerate a herd. Does this point us towards otherwise archaeologically hidden horsebreeders in the Carpathian basin, before the Yamnaya? In any case, I hope to make one case clear: these are by no means Yamnaya burials in the strict definition! Attribution to the Yamnaya in its strict definition applies.

pit-graves-central-europe
Distribution of Pit-Grave burials west of the Black Sea likely dating to the 2nd half of the 4th millennium BC (triangles: side-crouched burials; filled circles: supine extended burials; open circles: suspected). In Alin Frînculeasa, Bianca Preda, Volker Heyd, Pit-Graves, Yamnaya and Kurgans along the Lower Danube.

Also, about the expansion of Yamna settlers along the steppes:

However, it should have been made clear by the distribution map of the Western Yamnaya that they were confining themselves solely to their own, well-known, steppe habitat and therefore not occupying, or pushing away and expelling, the locally settled farming societies. Also, living solely in the steppes requires another lifestyle, and quite different economic and social bases, most likely very different to the established farming societies. Although surely regarded as incoming strangers, they may therefore not have been seen as direct competitors. This argument can be further enforced when remembering that the lowlands and the steppes in the southeast of Europe had already been populated throughout the 4th millennium cal. B.C., as demonstrated above, by societies with a similar north-Pontic steppe origin and tradition, albeit in lower numbers. It is only for these groups that the Yamnaya may have become a threat, but their common origin and perhaps a similar economic/ social background with comparable lifestyles would surely have assisted to allow rapid assimilation. More important, though, is that farming societies in this region may therefore have been accustomed to dealing and interacting with different people and ethnic strangers for a long time. (…)

When assessing farming and steppe societies’ interaction from a general point of view, attitudes can diverge in three main directions:

  1. the violent one; with raids, fights, struggles, warfare, suppression and finally the superiority and exploitation of the one over the other;
  2. the peaceful one; with a continuous exchange of gifts, goods, work, information and genes in a balanced reciprocal system, leading eventually to the merging of the two societies and creation of a new identity;
  3. the neutral one; with the two societies ignoring each other for a long time.

What we see from trying to understand the record of the Yamnaya, based on their tumuli and burials, and the local and neighbouring contemporary societies, based on their settlements, hoards, and graves, is likely a mixture of all three scenarios, with the balance perhaps more towards exchange in a highly dynamic system with alterations over time. However, violence and raids cannot be ruled out; they would be difficult to see in the archaeological record; or only indirectly, such as the building of hill forts, particularly the defence-like chain of Vucedol hillforts along the south shore of the Danube on the Serbian/Croatian border zone (Tasic 1995a), and the retreat of people into them (Falkenstein 1998, p. 261-262), with other interpretations also possible. And finally, we are dealing here with very different local and neighbouring societies, as well as with more distant contemporary ones, looking, in reality, rather like a chequer board of societies and archaeological cultures (see Parzinger 1993 for the overview). These display different regional backgrounds and traditions leading to different social and settlement organizations, different economic bases and material cultures in the wide areas between Prut and Maritza rivers, and Black Sea and Tisza river. They surely found their individual way of responding to the incoming and settling Yamnaya people.

yamna-tumuli-west-carpathians
Yamnaya tumuli signalling the expansion of West Yamna from ca. 3100 BC (especially after ca. 2950 BC). Heyd (2011).

The best data we have about this potential non-Yamna origin of R1b-L51 – and thus in favour of its admixture in the Carpathian basin – lies in:

  1. The majority of R1a-Z2103 subclades found to date among Yamna samples.
  2. The presence of R1b-Z2103 in the Catacomb culture – in the Northern Caucasus and in Ukraine.
  3. The limited presence of (ancient and modern) R1b-L51 in eastern Europe and India, whose isolated finds are commonly (and simplistically) attributed to ‘late migrations’.
  4. The presence of R1b-L51 (xZ2103) in cultures related to the ‘Yamna package’, but supposedly not to Yamna settlers. So for example I7043, of haplogroup R1b-L151(xU106,xP312), ca. 2500-2200 BC from Szigetszentmiklós-Üdülősor, probably from the Bell Beaker (Csepel group), but maybe from the early Nagýrev culture.
  5. The expansion of its subclades apparently only from a single region, around the Carpathian basin, in contrast to R1b-Z2103.
  6. The already ‘diluted’ steppe admixture found in the earliest samples with respect to Yamna, which points to the appearance after the Yamna admixture with the local population.
  7. Ukrainian archaeologists (in contrast to their Russian colleagues) point to the relevance of North Pontic cultures like Kvitjana and Lower Mikhailovka in the development of Early Yamna in the west, and some eastern European researchers also believe in this similarity.
  8. If R1b-Z2103 and R1b-L51 had expanded with Suvorovo-Novodanilovka migrants to the west, and had admixed later as Hungary_LCA-LBA-like peoples with Yamna migrants during the long-term contacts with other ‘kurganized cultures’ ca. 2900-2500 BC in the Great Hungarian Plains, it could explain some peculiar linguistic traits of North-West Indo-European, and also why R1b-Z2103 appears in cultures associated with this earlier ‘steppe influence’ (i.e. not directly related to Yamna) such as Vučedol (with a R1b-Z2103 sample, see below). That could also explain the presence of R1b-L151(xP312, xU106) in similar Balkan cultures, possibly not directly related to Yamna.
PCA-r1b-l51
Image modified from Wang et al. (2018). PCA of ancient and modern samples. Red circle in dashed line around Varna, Greece Neolithic, and (approximate position of) Smyadovo outliers, part of Khvalynsk-Novodanilovka settlers.

A hidden group among north or west Pontic Eneolithic steppe cultures?

The expansion of Khvalynsk as Novodanilovka into the North Pontic area happened through the south across the steppe, near the coast, with the forest-steppe region working as a clear natural border for this culture of likely horse-riding chieftains, whose economy was probably based on some rudimentary form of mobile pastoralism.

Although archaeologists are divided as to the origin of each individual Middle Eneolithic group near the Black Sea after the end of the Khvalynsk-Novodanilovka period, it seems more or less clear that steppe cultures like Cernavodă, Lower Mikhailovka, or Kvitjana are closer (or “more archaic”) in their steppe features, which connects them to Volga–Ural and Northern Caucasus cultures, like Northern Caucasus, Repin or Khvalynsk.

On the other hand, forest-steppe cultures like Dereivka (including Alexandria) show innovative traits and contacts with para- or sub-Neolithic cultures to the north, like Comb-Pit Ware groups, apart from corded decoration influenced by Trypillian groups to the west, especially in their later (‘Proto-Corded Ware‘) stage after ca. 3500 BC.

If Ukrainian researchers like Rassamakin are right, Early Yamna expanded not only from Repin settlers, but also from local steppe cultures adopting Repin traits to develop an Early Yamna culture, similar to how eastern (Volga–Ural groups) seem to have synchronously adopted Early Yamna without massive affluence of Repin settlements.

Furthermore, local traits develop in southern groups, like anthropomorphic stelae (shared with Kemi-Oba, direct heir of Lower Mikhailovka), and rich burials featuring wagons. These traits are seen in west Yamna settlers.

north-pontic-kvityana-dereivka-repin
Modified from Rassamakin (1999), adding red color to Repin expansion. The system of the latest Eneolithic Pointic cultures and the sites of the Zhivotilovo-Volchanskoe type: 1) Volchanskoe; 2) Zhivotilovka; 3) Vishnevatoe; 4) Koisug.

Problems of this model include:

  1. On the North Pontic area – in contrast to the Volga–Ural region – , there was a clear “colonization” wave of Repin settlers, also supported by Ukrainian researchers, based on the number of new settlements and burials, and on the progressive retreat of Dereivka, Kvitjana, as well as (more recent) Maykop- and Trypillia-related groups from the North Pontic area ca. 3350/3300 BC. It seems unlikely that these expansionist, semi-nomadic, cattle-breeding, patrilineally-related steppe clans that were driving all native populations out of their territories suddenly decided, at some point during their spread into the North Pontic area ca. 3300-3100 BC, to join forces with some foreign male lineages from the area, and then continue their expansion to the west…
  2. Similar to the fate of R1b-P297 subclades in the Baltic after the expansion of Corded Ware migrants, previous haplogropus of the North Pontic region – such as R1a, R1b-V88, and I2 subclades basically disappeared from the ancient DNA record after the expansion of Khvalynsk-Novodanilovka, and then after the expansion of Yamna, as is clear from Yamna, Afanasevo, and Bell Beaker samples obtained to date. This, in combination with what we know about Y-chromosome bottlenecks in post-Neolithic expansions, leaves little space to think that a big enough territorial group with a majority of “native” haplogroups could survive later expansions (be it R1b-L51 or R1a-Z645).
  3. Supporting an expansion of the same male (and partly female) population, the Yamna admixture from east to west is quite homogeneous, with the only difference found in (non-significant) EEF-like proportion which becomes elevated in distant areas [apart from significant ‘southern’ contribution to certain outlier samples]. Based on the also homogeneous Y-DNA picture, the heterogeneity must come, in general, from the female exogamy practiced by expanding groups.
  4. There is a short period, spanning some centuries (approximately 3300-2700 BC), in which the North Pontic area – especially the forest-steppe territories to the west of the Dnieper, i.e. the Upper Dniester, Boh, and Prut-Siret areas – are a chaos of incoming and emigrating, expanding and shrinking groups of different cultures, such as late Trypillian groups, Maykop-related traits, TRB, GAC, (Proto-)Corded Ware, and Early Yamna settlements. No natural geographic frontier can be delimited between these groups, which probably interacted in different ways. Nevertheless, based on their cultural traits, admixture, and especially on their Y-DNA, it seems that they never incorporated foreign male lineages, beyond those they probably had during their initial expansion trends.
  5. The further expansionist waves of Early Yamna seen ca. 3100 BC, from the Danube Delta to the west, give an overall image of continuously expanding patrilineal clans of R1b-M269 subclades since the Khvalynsk-Novodanilovka migration, in different periodic steps, mostly from eastern Pontic-Caspian nuclei, usually overriding all encountered cultures and (especially male) populations, rather than showing long-term collaboration and interaction. Such interaction is seen only in exceptional cases, e.g. the long-term admixture between Abashevo and Poltavka, as seen in Proto-Indo-Iranian peoples and their language.
PCA-Ukraine-r1b-l51
Image modified from Wang et al. (2018). PCA of ancient and modern samples. Arrows depicting Khvalynsk -> Yamna drift (blue), and hypothetic approximate Ukraine Eneolithic -> Yamna drift accompanying R1b-L51 (red).

Consequences

We are living right now an exemplary ego-, (ethno-)nationalism-, and/or supremacy-deflating moment, for some individuals of eastern and northern European descent who believed that R1a or ‘steppe ancestry proportions’ meant something special. The same can be said about those who had interiorized some social or ethnolinguistic meaning for the origin of R1b in western Europe, N1c in north-eastern Europe, as well as Greeks, Iranians, Armenians, or Mediterranean peoples in general of ‘Near Eastern’ ancestry or haplogroups, or peoples of Near Eastern origin and/or language.

These people had linked their haplogroups or ancestry with some fantasy continuity of ‘their’ ancestral populations to ‘their’ territories or languages (or both), and all are being proven wrong.

Apart from teaching such people a lesson about what simplistic views are useful for – whether it is based on ABO or RH group, white skin, blond hair, blue eyes, lactase persistence, or on the own ancestry or Y-DNA haplogroup -, it teaches the rest of us what can happen in the near future among western Europeans. Because, until recently, most western Europeans were comfortably settled thinking that our ancestors were some remnant population from an older, Palaeolithic or Mesolithic population, who acquired Indo-European languages by way of cultural diffusion in different periods, including only minor migrations.

Judging by what we can see now among some individuals of Northern and Eastern European descent, the only thing that can worsen the air of superiority among western Europeans is when they realize (within a few years, when all these stupid battles to control the narrative fade) that not only are they the cultural ‘heirs’ of the Graeco-Roman tradition that began with the Roman Empire, but that most of them are the direct patrilineal descendants of Khvalynsk, Yamna, Bell Beaker, and European Bronze Age peoples, and thus direct descendants of Middle PIE, Late PIE, and NWIE speakers.

steppe-chalcolithic-migrations
Steppe-related migrations ca. 3100-2600 BC with tentative linguistic identification.

The finding of R1b-L51 and R1b-Z2103 among expanding Suvorovo-Novodanilovka chieftains, with pockets of R1b-L51 remaining in steppe-like societies of the Balkans and the Carpathian Basin, would have beautifully complemented what we know about the East Yamna admixture with R1a-Z93 subclades (Uralic speakers) ca. 2600-2100 BC to form Proto-Indo-Iranian, and about the regional admixtures seen in the Balkans, e.g. in Proto-Greeks, with the prevalent J subclades of the region.

It would have meant an end to any modern culture or nation identifying themselves with the ‘true’ Late PIE and Yamna heirs, because these would be exclusively associated with the expansion of R1b-Z2103 subclades with late Repin, and later as the full-fledged Late PIE with Yamna settlers to south-east and central Europe, and to the southern Urals. The language would have had then obviously undergone different language changes in all these territories through long-lasting admixture with other populations. In that sense, it would have ended with the ideas of supremacy in western Europe before they even begin.

The most likely future

However limited the evidence, it seems that R1b-L51 expanded with Yamna, though, based on the estimates for the haplogroups involved, and on marginal hints at the variability of L23 subclades within Yamna and neighbouring populations. If R1b-L51 expanded with West Repin / Early Yamna settlers, this is why they have not yet been found among Yamna samples:

steppe-eneolithic-migrations
Simplified map of Repin expansions from ca. 3500/3400 BC.
  • The subclade division of Yamna settlers needs not be 50:50 for L51:Z2103, either in time or in space. I think this is the simplistic view underlying many thoughts on this matter. Many different expanding patrilineal clans of L23 subclades may have been more or less successful in different areas, and non-Z2103 may have been on the minority, or more isolated relative to Z2103-clans among expanding peoples on the steppe, especially on the east. In fact, we usually talk in terms of “Z2103 vs. L51” as if
    1. these two were the only L23 subclades; and
    2. both had split and succeeded (expanding) synchronously;

    that is, as if there had not been multiple subclades of both haplogroups, and as if there had not been different expansion waves for hundreds of years stemming from different evolving nuclei, involving each time only limited (successful) clans. Many different subclades of haplogroups L23 (xZ2103, xL51), Z2103, and L51 must have been unsuccessful during the ca. 1,500 years of late Khvalynsk and late Repin-Early Yamna expansions in which they must have participated (for approximately 60-75 generations, based on a mean 20-25 years).

  • If we want to imagine a pocket of ‘hidden’ L51 for some region of the North Pontic or Carpathian region, the same can be imagined – and much more likely – for any unsampled territory of expanding late Repin/Early Yamna settlers from the Lower Don – Lower Volga region (probably already a mixed society of L51 and Z2103 subclades since their beginning, as the early Repin culture, ca. 3800 BC), with L51 clans being probably successful to the west.
  • The Repin culture expanded only in small, mobile settlements from the Lower Don – Lower Volga to the north, east, and south, starting ca. 3500/3400 BC, in the waves that eventually gave a rather early distant offshoot in the Altai region, i.e. Afanasevo. Starting ca. 3300 BC in the archaeological record, the majority of R1b-Z2103 subclades found to date in Afanasevo also supports either
    • a mixed Repin society, with Z2103-clans predominating among eastern settlers; or
    • a Repin society marked by haplogroup L51, and thus a cultural diffusion of late Repin/Early Yamna traits among neighbouring (Khvalynsk, Samara, etc.) groups of essentially the same (early Khvalynsk-Novodanilovka) genetic stock in the Volga–Ural region.

    Both options could justify a majority of Z2103 in the Lower Volga–Ural region, with the latter being supported by the scattered archaeological remains of late Repin in the region before the synchronous emergence of Early Yamna findings in the whole Pontic-Caspian steppe.

  • Most Z2103 from Yamna samples to date are from around 3100 BC (in average) onward, and from the right bank of the Lower Don to the east, particularly from the Lower Volga–Ural area (especially the Samara region), which – based on the center of expansion of late Repin settlers – may be depicting an artificially high Z2103-distribution of the whole Yamna community.
repin-expansion-khvalynsk-cultures
Repin expansion into the Volga–Ural region from ca. 3500/3400 BC. Map made by me based on maps and data from Morgunova (2014, 2016). Lopatino is marked with number 64.
  • Yamna sample I0443, R1b-L23 (Y410+, L51-), ca. 3300-2700 BCE from Lopatino II, points to an intermediate subclade between L23 and L51, near one of the supposed late Repin sites (based on kurgan burials with late Repin cultural traits) in the Samara region.
  • Other Balkan cultures potentially unrelated to the Yamna expansion also show Z2103 (and not only L51) subclades, like I3499 (ca. 2884-2666 calBC), of the Vučedol culture, from Beli Manastir-Popova zemlja, which points to the infiltration of Yamna peoples in other cultures. In any case, the appearance of R1b-L23 subclades in the region happens only after the Yamna expansion ca. 3100 BC, probably through intrusions into different neighbouring regions, if these Balkan cultures are not directly derived from Yamna settlements (which is probably the case of the Csepel Bell Beaker or early Nagýrev sample, see above).
  • The diversity of haplogroups found in or around the Carpathian Basin in Late Chalcolithic / Early Bronze Age samples, including L151(xP312, xU106), P312, U106, Z2103, makes it the most likely sink of Yamna settlers, who spread thus with expanding family clans of different R1b-L23 subclades.
  • Even though some Yamna vanguard groups are known to have expanded up to Saxony-Anhalt before ca. 2700 BC, haplogroup Z2103 seems to be restricted to more eastern regions, which suggests that R1b-L51 was already successful among expanding West Yamna clans in Hungary, which gave rise only later to expanding East Bell Beakers (overwhelmingly of L151 subclades). The source of R1b-L51 and L151 expansion over Z2103 must lie therefore in the West Yamna period, and not in the Bell Beaker expansion.
indo-european-uralic-migrations-yamna-gac
Yamna migrants ca. 3300-2600. Most likely site of admixture with GAC circled in red.
  • The R1b-Z2103 found in Poltavka, Catacomb, and to the south point to a late migration displacing the western R1b-L51, only after the late Repin expansion. This is also seen in the steppe ancestry and R1b-Z2103 south of the Caucasus, in Hajji Firuz, which points to this route as a potential source of the supposed “Earliest Proto-Indo-Iranian” (the mariannu term) of the Near East. A similar replacement event happened some centuries later with expanding R1a-Z93 subclades from the east wiping out haplogroup R1b-Z2103 from the Pontic-Caspian steppe.
  • Many ancient samples from Khvalynsk, Northern Caucasus, Yamna, or later ones are reported simply as R1b-M269 or L23, without a clear subclade, so the simplistic ‘Yamna–Z2103’ picture is not real: if one takes into account that Z2103 might have been successful quite early in the eastern region, it is more likely to obtain a successful Y-SNP call of a Z2103 subclade in the Volga–Ural region than a xZ2103 one.
  • There are some modern samples of R1b-L51 in eastern Europe and Asia, whose common simplistic attribution to “late expansions” is usually not substantiated; and also ancient R1b-L51 samples might be confirmed soon for Asia.
  • ‘Western’ features described by archaeologists for West Yamna settlers, associated with Kemi Oba and southern Yamna groups in the North Pontic area – like rich burials with anthropomorphic stelae and wagons – are actually absent in burials from settlers beyond Bulgaria, which does not support their affiliation with these local steppe groups of the Black Sea. Also, a mix with local traditions is seen accross all Early Yamna groups of the Pontic-Caspian steppe, and still genetics and common cultural traits point to their homogeneization under the same patrilineal clans expanding continuously for centuries. The maintenance of local traditions (as evidenced by East Bell Beakers in Iberia related to Iberian Proto-Beakers) is often not a useful argument in genetics, especially when the female population is not replaced.
yamna-settlers-hungary
Yamna settlers in the Great Pannonian Plain, showing only kurgans of Hungary ca. 2950-2500 BC. Yamna Hungary was one of the biggest West Yamna provinces. From Hórvath et al. (2013).

Conclusion

This is what we know, using linguistics, archaeology, and genetics:

  • Middle Proto-Indo-European expanded with Khvalynsk-Novodanilovka after ca. 4800 BC, with the first Suvorovo settlements dated ca. 4600 BC.
  • Archaic Late Proto-Indo-European expanded with late Repin (or Volga–Ural settlers related to Khvalynsk, influenced by the Repin expansion) into Afanasevo ca. 3500/3400 BC.
  • Late Proto-Indo-European expanded with Early Yamna settlers to the west into central Europe and the Balkans ca. 3100 BC; and also to the east (as Pre-Proto-Indo-Iranian) into the southern Urals ca. 2600 BC.
  • North-West Indo-European expanded with Yamna Hungary -> East Bell Beakers, from ca. 2500 BC.
  • Proto-Indo-Iranian expanded with Sintashta, Potapovka, and later Andronovo and Srubna from ca. 2100 BC.

It seems that the subclades from Khvalynsk ca. 4250-4000 BC were wrongly reported – like those of Narasimhan et al. (2018). However, even if they are real and YFull estimates have to be revised, and even if the split had happened before the expansion of Suvorovo-Novodanilovka, the most likely origin of R1b-L51 among Bell Beakers will still be the expansion of late Repin / Early Yamna settlers, and that is what ancient DNA samples will most likely show, whatever the social or political consequences.

The only relevance of the finding of R1b-L51 in one place or another – especially if it is found to be a remnant of a Middle PIE expansion coupled with centuries of admixture and interaction in the Carpathian Basin – is the potential influence of an archaic PIE (or non-IE) layer on the development of North-West Indo-European in Yamna Hungary -> East Bell Beaker. That is, more or less like the Uralic influence related to the appearance of R1a-Z93 among Proto-Indo-Iranians, of R1a-Z284 among Pre-Germanic peoples, and of R1a-Z282 among Balto-Slavic peoples.

I think there is little that ancient DNA samples from West Yamna could add to what we know in general terms of archaeology or linguistics at this point regarding Late PIE migrations, beyond many interesting details. I am sure that those who have not attributed some random 6,000-year-old paternal ancestor any magical (ethnic or nationalist) meaning are just having fun, enjoying more and more the precise data we have now on European prehistoric populations.

As for those who believe in magical consequences of genetic studies, I don’t think there is anything for them to this quest beyond the artificially created grand-daddy issues. And, funnily enough, those who played (and play) the ‘neutrality’ card to feel superior in front of others – the “I only care about the truth”-type of lie, while secretly longing for grandpa’s ethnolinguistic continuity – are suffering the hardest fall.

Related

Mitogenomes show likely origin of elevated steppe ancestry in neighbouring Corded Ware groups

west-yamna-corded-ware

Open Access Mitochondrial genomes reveal an east to west cline of steppe ancestry in Corded Ware populations, by Juras et al., Scientific Reports (2018) 8:11603.

Interesting excerpts (emphasis mine, references have been deleted for clarity):

Ancient DNA was extracted from the Corded Ware culture individuals excavated in southeastern Poland (N = 12) and Moravia (N = 3). Late Eneolithic (N = 5) and Bronze Age human remains (N = 25) originated from western Ukraine and came from the Yampil barrow cemetery complex located in the north–western region of the Black Sea. Bronze Age individuals were associated with different archaeological cultures, including Yamnaya (N = 14), Catacomb (N = 2), Babyno (N = 4) and Noua (N = 5).

The PCA results described 50.62% of the variability and were combined with the k-means clustering (with the k value of 5 as the best representation of the data, at the average silhouette of 0.2608). Based on these results individuals associated with the western and eastern Yamnaya horizon (YAE and YAW in Fig. 2) were grouped within a cluster consisting of populations from central Eurasia and Europe (blue cluster) including people associated with eastern Corded Ware culture (CWPlM) and Baltic Corded Ware culture (CWBal). This cluster did not contain any populations linked with early Neolithic farmers (red), or hunter-gatherers (green and yellow). On the other hand, k-means clustering linked the western Corded Ware culture-associated population (CWW) with Near East and Neolithic farmer ancestry groups from western and central Europe.

pca-cwc-yamna
Modified image, from the paper. PCA based on mitochondrial DNA haplogroup frequencies with k-means clustering. The two principal components explained 50.62% of the total variance. Loading vectors, representing mitochondrial haplogroup contributions, are highlighted as grey arrows. Populations are grouped into four clusters according to k-means. Population abbreviations are as follows: BABA – Bronze Age Balkans; CAT – Catacomb Culture; CWPlM – Corded Ware Culture from Poland and Moravia; CWBal – Baltic Corded Ware Culture; IAK – Iron Age Kazakchstan; IASI – Iron Age Syberia – Aldy Bel Culture; SCA – Scytho-Siberian Pazyryk (Altai); SCR – Rostov-Scythians, Samara; SCU – Scythians from Moldova and Ukraine; TAG – Tagar Culture; GAC – Globular Amphora Culture; YAW – western Yamnaya horizon population from Ukraine and Bulgaria; YAE – eastern Yamnaya horizon population; BAC – Baalberge Culture; BANE – Bronze Age Near East; BEC – Bernburg Culture; CHAHu – Chalcolithic Hungary; CWW – Corded Ware Culture west; CHABA – Chalcolitic Balkans; EBAG – Early Bronze Age Germany; FBC – Funnel Beaker Culture; IAG – Iron Age Germany; MNG – Middle Neolithic Germany; LBK – Linear Pottery Culture; LDN – Late Danubian Neolithic; MIC – Minoans; NEBA – Neolithic Balkans; PPNE – Pre-Pottery Near East; SCG – Schöningen group; SMC – Salzmünde Culture; AND – Andronovo Culture; BASI – Bronze Age Siberia; PWC – Pitted Ware Culture; HGE – eastern hunter-gatherers; NEUk- Neolithic Ukraine; HGS – southern hunter-gatherers; HGBal – Baltic hunter-gatheres; HGC – central huther-gatherers.

Pairwise mtDNA-based FST values, visualized on MDS using the raw non-linearized FST (stress value = 0.099) (Fig. 4), also supported the PCA results and indicated that western and eastern Yamnaya horizon groups (YAW and YAE) were closer to people associated with the eastern Corded Ware culture (CWPlM) (FST = 0.00; FST = 0.01, respectively; both p > 0.05) and Baltic Corded Ware culture (CWBal) (FST = 0.00; FST = 0.00, respectively; both p > 0.05), than to populations associated with the western Corded Ware culture (CWW) (FST = 0.047 and FST = 0.059, respectively; both statistically significant p < 0.05). Western and eastern Yamnaya horizon groups also showed close genetic affinity to the Iron Age western Scythians (SCU) (FST = 0.0022 and FST = 0.006, respectively, both p > 0.05). The most distant populations to the Yamnaya horizon groups were western hunter-gatherers (HGW) (FST = 0.23 and FST = 0.15, p < 0.001). The FST-based MDS reflected the general European population history in the post-LGM period as the three highest FST scores were detected between western hunter-gatherers (HGW) and people associated with Linear Pottery culture (LBK) (FST = 0.33, p < 0.001), between eastern hunter-gatherers (HGE) and Baltic hunter-gatherers (HGBal) (FST = 0.35, p < 0.05), and between western (HGW) and eastern hunter-gatherers (HGE) (FST = 0.36, p < 0.05). The Yamnaya horizon groups (YAE and YAW) were placed centrally between northern hunter-gatherers (HGN) and Neolithic farmers (LDN), in direct proximity to the Bronze and Iron Age populations from Eastern Europe (SCU, BARu, SRU) and close to individuals associated with eastern and Baltic Corded Ware culture.

yamna-corded-ware-pca
Modified image, from the paper. In circles, relevant European groups for the question of ‘steppe ancestry’. MDS plot based on FST values calculated from mitochondrial genomes. Population abbreviations: BBC – Bell Beaker Culture; BAHu – Bronze Age Hungary; BARu – Bronze Age Russia; CWPlM – Corded Ware Culture from Poland and Moravia; CWW – western Corded Ware Culture; CWBal – Baltic Corded Ware Culture; EBAG – Early Bronze Age Germany; GAC – Globular Amphora Culture; HGE – eastern hunter-gatherers; HGN – northern hunter-gatherers; HGW – western hunter-gatherers; HGBal – Baltic hunter-gatherers; LBK – Linear Pottery Culture; LDN – Late Danubian Neolithic; MNE – Middle Neolithic; NENE – Near Eastern Neolithic; SCU – Scythians from Moldova and Ukraine; SRU – Rostov-Scythians, Samara.

Among the analyzed samples, we identified two Catacomb culture-associated individuals (poz220 and poz221) belonging to hg X4. They are the first ancient individuals assigned to this particular lineage. Haplogroup X4 is rare among present day populations and has been found only in one individual each from Central Europe, Balkans, Anatolia and Armenia.

Moreover, we have reported mtDNA haplotypes that might be associated with the migration from the steppe and point to genetic continuity in the north Pontic region from Bronze Age until the Iron Age. These haplotypes were assigned to hgs U5, U4, U2 and W3. MtDNA hgs U5a and U4, identified in this study among Yamnaya, Late Eneolithic and Corded Ware culture-associated individuals, have previously been found in high frequencies among northern and eastern hunter-gatherers. Moreover, they appeared in the north Pontic region in populations associated with Mesolithic (hg U5a), Eneolithic (Post-Stog) (hg U4), Yamnaya (hgs U5, U5a), Catacomb (hgs U5 and U5a) and Iron Age Scythians (hg U5a), suggesting genetic continuity of these particular mtDNA lineages in the Pontic region from, at least, the Bronze Age. Hgs U5a and U4-carrying populations were also present in the eastern steppe, along with individuals from the Yamnaya culture from Samara region, the Srubnaya and the Andronovo from Russia. Interestingly, hg U4c1 found in the Yamnaya individual (poz224) has so-far been found only in two Bell Beaker- associated individuals and one Late Bronze Age individual from Armenia, which might suggest a steppe origin for hg U4c1. A steppe origin can possibly also be assigned to hg U4a2f, found in one individual (poz282) but not reported in any other ancient populations to date, and to U5a1- the ancestral lineage of U5a1b, reported for individual poz232, which was identified not only in Corded Ware culture-associated population from central and eastern Europe, but also in representatives of Catacomb culture from the north Pontic region, Yamnaya from Bulgaria and Russia, Srubnaya and Andronovo-associated groups. Hg U2e, reported for Late Eneolithic individual (poz090), was also identified in western Corded Ware culture-associated individual and in succeeding Sintashta, Potapovka and Andronovo groups, suggesting possible genetic continuity of U2e1 in the western part of the north Pontic region.

Hgs W3a1 and W3a1a, found in two Yamnaya individuals from this study (poz208 and poz222), were also identified in Yamnaya-associated individuals from the Russia Samara region and later in Únětice and Bell Beaker groups from Germany, supporting the idea of an eastern European steppe origin of these haplotypes and their contribution to the Yamnaya migration toward the central Europe. The W3a1 lineage was not identified in Neolithic times and, thus, we assume that it appeared in the steppe region for the first time during the Bronze Age. Notably, hgs W1 and W5, which predate the Bronze Age in Europe, were found only in individuals associated with the early Neolithic farmers from Starčevo in Hungary (hg W5), early Neolithic farmers from Anatolia (hg W1-T119C), and from the Schöningen group (hg W1c) and Globular Amphora culture from Poland (hg W5).

west-yamna-west-corded-ware

Some comments

The most recent radiocarbon dates show that Early Yamna expanded to the west with Repin settlers of the Lower Don ca. 3350/3300 BC. At the end of the 4th millennium, then, these settlers dominated over groups whose population had in turn also elevated ‘steppe ancestry’ (at least from ca. 4000 BC, as shown by Ukraine Eneolithic samples from the forest-zone), and probably replaced the male population completely, as evidenced by other Yamna and Poltavka, and later Bell Beaker, Catacomb, and Sintashta samples.

The ‘second wave’ of expansion of Yamna settlers to the west, into east-central European steppes, began probably ca. 3100/3000 BC, and – based on material culture – stemmed mainly from the North Pontic area. The Yampil Barrow Complex on the Dnieper (which I recently wrote about) seems to be part of one of the groups of western Yamna migrants: those who migrated westward from the left bank of the Dniester to the west into the Prut-Siret region, and north along the Prut.

This region is the key for population movements that gave rise to the Corded Ware culture (see another recent post on Corded Ware origins). It is quite likely that we will see a dance of late Trypillia / Usatovo, GAC, (Proto-)Corded Ware, and Yamna samples in this area. Judging by the clear-cut Y-DNA bottlenecks we are seeing in Neolithic populations, especially among steppe pastoralists, the difference between groups in recovered ancient samples will not only be clear from their culture, but also from their male lineages.

Based on the number of burials studied from the different settlement regions for West Yamna migrants, the Prut-Siret group was one of the smallest new Yamna ‘provinces’ in south-eastern Europe, and was probably overrun early, although – since kurgan findings continued into the Catacomb culture in the Yampil complex – the Dnieper region was well-enough connected to the core North Pontic area to be kept into its retreating territory by 2500 BC, as was the Danube delta, in contrast with other east-central European areas.

steppe-chalcolithic-migrations
Steppe-related migrations ca. 3100-2600 BC with tentative linguistic identification.

Taking into account that the earliest Corded Ware burials are from ca. 2900 BC (in the Single Grave culture), and that the earliest A-horizon pottery expanded from Lesser Poland (a syncretic pottery based on the previous GAC-type) a century later, it is likely that what this paper shows for Corded Ware in eastern Europe and the Baltic is what I have suggested many times (see here, or here) as the most likely reason for elevated steppe ancestry (and close PCA cluster) of the Baltic LN ‘outliers’: the exogamy of Corded Ware groups with females from Yamna or a North Pontic steppe culture with similar ancestry.

If Proto-Corded Ware populations of the North Pontic region did not have an identical “steppe ancestry” to these eastern CW groups already during the Eneolithic (which is the other possibility), I might be right in their more recent exogamy, and this could be seen in this study by the close cluster of east Corded Ware (especially Baltic) mtDNA to GAC and Yamna West groups, and distant from previous hunter-gatherer populations of the area, which suggests that expanding males from the Volhynia/Podolia region practiced exogamy mainly with southern groups.

I think this is probably related to demographic pressure imposed on other populations by the explosive expansion of pastoralists with their new subsistence economy (part of the “Secondary Products Revolution”), which the hunter-gatherer and farmer population of Europe could not keep up with (as seen later in the admixture of expanding East Bell Beakers), although studies on European prehistoric demography are scarce and too general to tell us anything relevant for this precise period and region.

Related

Yamna female shows decoration of bones after body decomposition

Interesting press release from the Institute of Archaeology at Adam Mickiewicz University in Poznań:

In an open access report last year, Anthropological Description of Skeletal Material from the Dniester Barrow-cemetery Complex, Yampil Region, Vinnitsa Oblast (Ukraine), the team lead by Liudmyla Litvinova – of the Ukrainian Academy of Science – published their findings from the skeletons in different burial mounds along the border with Moldavia, ranging from Eneolithic to Iron Age burials.

yampil-barrows-ukraine
Map of Yampil barrows, showing administrative borders: 1 – Klembivka barrow 1; 2 – Porohy, barrow 3A; 3 – Pidlisivka, barrow 1; 4 – Prydnistryanske, barrows 1-4; 5 – barrows; 6 – excavated barrows; 7 – Ukrainian-Moldovan frontier; 8 – Yampil Region border

In one Yamnaya burial rested a young woman aged 25-30. It was so described in the original paper:

Barrow 3A, feature 10. A very poorly-preserved skeleton with a badly damaged skull. The preserved bones include small fragments of the cranial vault and mandible and larger ones of the upper and lower limbs, pelvis fragments and vertebrae. The skeleton belonged to a female aged 25-30 years (adultus). Due to the poor state of preservation of long bones, it was not possible to reconstruct her stature. Palaeopathological lesions: LEH on both lower canines (age of the individual at the time of both defects: 4.5-5.0 years); caries on the upper left third molar.

reconstruction-yamna-female
Burial and reconstruction. Foto by Michał Podsiadło.

This is what the team has discovered since then:

While drawing and photographing the burial, our attention was drawn to regular patterns, such as parallel lines visible on both elbow bones. At first, we approached the discovery with caution – maybe the traces were left by animals, we wondered

– Says Danuta Żurkiewicz from the Institute of Archaeology, Adam Mickiewicz University in Poznań, who prepared an article on the decorations.

It is surprising that the procedure of decorating the bones had to be done after death and the process of body decomposition. This is clearly indicated by the location of the decoration on the bone surface and the way dye was applied.

yamna-female-marks-forearm
Detail of the forearm, from Żurkiewicz. Modified by me, I added rectangles around the marks on the distal end and middle third of the cubitus. You can see the marks on the cubitus with more detail in the original article.

Some time after the woman’s death the grave was reopened, bone decoration was performed and the bones were re-arranged in anatomical order.

According to Żurkiewicz, this discovery is unique – so far, no comparable custom among other prehistoric communities in Europe has been recorded.

Until now, the few similar discoveries have been interpreted as remnants of tattoos, but none of them have been analysed using so many modern methods, which is why they can not be confirmed with full confidence

Żurkiewicz believes that:

However, women were rarely buried in them. The deceased, whose bones were covered with patterns, had to be an important member of the community.

These findings will be detailed in volume 22 of Baltic-Pontic Studies, which will be available online on the De Gruyter Open platform in August.

My opinion – without knowing anything about the case, site, or archaeology of kurgans in general, just from my knowledge in Orthopaedic Surgery – is that it would be quite easy to make those marks on the cubitus post-mortem, because the cubitus has a very easy surgical access (just under the skin, mostly). On the other hand, opening the grave after decomposition to take the bone, make those marks, and put it back, seems too much work to achieve the same result…

If the marks had been on another anatomical site (say, the anterior aspect of the sacrum, or the inner aspect of the cranium, etc.) maybe the butchery needed to mark the bones would not be worth it (especially for a relative of the deceased), but in this case I hope they have a good reason to support why it must have been made after decomposition.

EDIT (4 AUG 2018): The published paper on this specific burial and the marks: Ritual position and “tattooing” techniques in the funeral practices of the “Barrow cultures” of the Pontic-Caspian steppe/forest-steppe area Porohy 3A, Yampil region, Vinnytsia Oblast: Specialist analysis research perspectives, by Żurkiewicz et al. (2018).

See also on the same region Eneolithic, Yamnaya and Noua culture cemeteries from the first half of the 3rd and the middle of the 2nd millennium BC, Porogy, site 3A, Yampil region, Vinnitsa oblast: Archaeometric and Chronometric Description, Ritual and Tazonomic-Topogenetic identification, by Viktor Klochko et al. (2015), B-P S, vol. 20, P. 78-141.

Related

When Bell Beakers mixed with Eneolithic Europeans: Pömmelte and the Europe-wide concept of sanctuary

pommelte-enclosure

Recent open access paper The ring sanctuary of Pömmelte, Germany: a monumental, multi-layered metaphor of the late third millennium BC, by Spatzier and Bertemes, Antiquity (2018) 92(363):655-673.

Interesting excerpts (emphasis mine):

In recent decades, evidence has accumulated for comparable enclosures of later dates, including the Early Bronze Age Únětice Culture between 2200 and 1600 BC, and thus into the chronological and cultural context of the Nebra sky disc. Based on the analysis of one of these enclosure sites, recently excavated at Pömmelte on the flood plain of the Elbe River near Magdeburg, Saxony-Anhalt, and dating to the late third millennium BC

The main occupation began at 2321–2211 cal BC, with the stratigraphically earliest features containing exclusively Bell Beaker finds. Bell Beaker ceramics continue after 2204–2154 cal BC (boundary occupation I/II), although they were probably undecorated, but are now complemented by Únětice Culture (and other Early Bronze Age) types. At this time, with features common to both cultures predominate. Only contexts dating to the late main occupation phase (late phase II) and thereafter contained exclusively Únětice Culture finds. Evidently, the bearers of the Bell Beaker Culture were the original builders of the enclosure. During a second phase of use, Final Neolithic and Early Bronze Age cultures coexisted and intermingled. The material remains, however, should not be taken as evidence for successive groups of differing archaeological cultures, but as witnesses to a cultural transition from the Bell Beaker Culture to the Únětice Culture (Spatzier 2015). The main occupation ended 2086–2021 cal BC with the deconstruction of the enclosure; Bell Beaker finds are now absent. Finally, a few features (among them one shaft) and radiocarbon dates attest the sporadic re-use of the site in a phase of abandonment/re-use that ended 1636– 1488 cal BC.

pommelte-enclosure-occupation-stratigraphy
Cultural sequence and chronological model of the Pömmelte enclosure’s occupation (dates in 1σ-precision) (designed by André Spatzier).

How the above-ground structures possibly influenced perception may reveal another layer of meaning that highlights social functions related to ritual. While zone I was disconnected from the surroundings by a ‘semi-translucent’ post-built border, zones II/III were separated from the outside world by a wooden wall (i.e. the palisade), and zone III probably separated individuals from the crowd gathered in zone II. Accessing the interior or centre therefore meant passing through transitional zones, to first be secluded and then segregated. Exiting the structure meant re-integration and re-connection. The experience possibly induced when entering and leaving the monument reflects the three stages of ‘rites of passage’ described by van Gennep (1909): separation, liminality and incorporation. The enclosure’s outer zone(s) represents the pre- and post-liminal phase; the central area, the liminal phase. Seclusion and liminality in the interior promoted a sense of togetherness, which can be linked to Turner’s “communitas” (1969: 132–33). We might therefore see monuments such as the Pömmelte enclosure as important communal structures for social regulation and the formation of identity.

ring-sanctuary-of-pommelte
Layers of meaning of the Pömmelte enclosure as deduced from the archaeological record (design by André Spatzier).

(…) The long-term stability of these connotations must be emphasised. As with the tradition of making depositions, these meanings were valid from the start of the occupation — c. 2300 BC — until at least the early period following the deconstruction event, c. 2050 BC. While the spatial organisation and the solar alignment of the main entrances were maintained throughout the main occupation, stone axes and ‘formal’ graves indicate the continuation of the spatial concepts described above until the twentieth to nineteenth centuries BC.

These layers of meaning mirror parallel concepts of space including, although not necessarily restricted to, the formation of group identities (see Hansen & Meyer 2013: 5). They can perhaps be better understood as a ‘cosmological geography’ manifested in the symbolism of superimposed levels of conceptual ideas related to space and to certain cardinal points (Figure 8). This idea is closely related to Eliade’s (1959: 29–36) understanding of “organized — hence comicized — territory”, that is territory consecrated to provide orientation within the homogeneity of the chaotic ‘outside world’, and the equivalence of spatial consecration and cosmogony. Put differently, the Pömmelte enclosure can be interpreted as a man-made metaphor and an icon of the cosmos, reflecting the Weltanschauung (a comprehensive conception of the world) of the people who built and used it. By bringing together Eliade and Rappaport’s ideas of meaningfulness in relation to religious experience (Rappaport 1999: 391–95), it may be argued that Pömmelte was a place intended to induce oneness with the cosmos. In combining multiple layers that symbolically represent different aspects of life (first-ordermeaning), the enclosure became an icon metaphorically representing the world (second-order-meaning). As this icon was the place to reaffirm life symbolism ritually, through their actions, people perhaps experienced a sense of rootedness in, or unity with, the cosmos (highest-order-meaning). Although we can only speculate about the perceptions of ancient people, such a theory aiming to describe general principles of religious experience can provide insight.

Conclusions

The circular enclosure of Pömmelte is the first Central European monumental complex of primarily sacred importance that has been excavated and studied in detail. It reveals aspects of society and belief during the transition from the Final Neolithic to the Early Bronze Age, in the second half of the third millennium BC. Furthermore, it offers details of ritual behaviour and the way that people organised their landscape. A sacred interior was separated from the profane environment, and served as a venue for rites that secured the continuity of the social, spiritual and cosmic order. Ancestor worship formed another integral part of this: a mound-covered burial hut and a square-shaped ditch sanctuary (located, respectively, within and near the enclosure’s south-eastern sector; cf. Figure 2)—dating to 2880–2580 cal BC and attributed to the Corded Ware Culture (Spatzier 2017a: 235–44)—suggest that this site was deliberately chosen. With construction of the ring sanctuary, this place gained an immense expansion in meaning—comparable to Stonehenge. Through architectural transformation, both of these sites developed into sanctuaries with increasingly complex religious functions, including in relation to the cult of the dead. The cosmological and social functions, and the powerful symbolism of the Nebra sky disc and hoard (Meller 2010: 59–70), are reflected in Pömmelte’s monumental architecture.

All of these features—along with Pömmelte’s dating, function and complex ring structure—are well documented for British henge monuments (Harding 2003; Gibson 2005). The continuous use of circular enclosures in Central Europe from around 3000– 1500 BC remains to be confirmed, but strong evidence indicates usage spanning from the fifth to the first millennia BC (Spatzier 2017a: 273–96). From 2500 BC onwards, examples in Central Europe, Iberia and Bulgaria (Bertemes 2002; Escudero Carrillo et al. 2017) suggest a Europe-wide concept of sanctuary. This indicates that in extensive communication networks at the beginning of bronze metallurgy (Bertemes 2016), intellectual and religious contents circulated alongside raw materials. The henge monuments of the British Isles are generally considered to represent a uniquely British phenomenon, unrelated to Continental Europe; this position should now be reconsidered. The uniqueness of Stonehenge lies, strictly speaking, with its monumental megalithic architecture.

pommelte-enclosure-space
Model of the spatial organisation of the Pömmelte enclosure (designed by André Spatzier).

The Classical Bell Beaker heritage

No serious scholar can argue at this point against the male-biased East Bell Beaker migrations that expanded the European languages related to Late Proto-Indo-European-speaking Yamna (see David Reich’s comments), and thus most likely North-West Indo-European – the ancestor of Italo-Celtic, Germanic, and Balto-Slavic, apart from Pre-Celtic IE in the British Isles, Lusitano-Galician in Iberia, or Messapic in Italy (see here a full account).

With language, these migrants (several ten thousands) brought their particular Weltanschauung to all of Western, Central, and Northern Europe. Their admixture precisely in Hungary shows that they had close interactions with non-Indo-European peoples (genetically related to the Globular Amphorae culture), something that we knew from the dozens of non-Indo-European words reconstructed exclusively for North-West Indo-European, apart from the few reconstructed non-Indo-European words that NWIE shares with Palaeo-Balkan languages, which point to earlier loans from their ancestors, Yamna settlers migrating along the lower Danube.

It is not difficult to imagine that the initial East Bell Beaker group shared a newly developed common cosmological point of view that clashed with other neighbouring Yamna-related worldviews (e.g. in Balkan EBA cultures) after the cultural ties with Yamna were broken. Interesting in this respect is for example their developed (in mythology as in the new North-West Indo-European concept) *Perkwūnos, the weather god – probably remade (in language as in concept) from a Yamna minor god also behind Old Indian parjányas, the rain god – as one of the main gods from the new Pantheon, distinct from *Dyēus patēr, the almighty father sky god. In support of this, the word *meldh-n- ‘lightning’, behind the name of the mythological hammer of the weather god (cf. Old Norse Mjǫllnir or Latvian Milna), was also a newly coined North-West Indo-European term, although the myth of the hero slaying the dragon with the magical object is older.

perkunos-perkunas
The Hand of Perkūnas by Mikalojus Konstantinas Čiurlionis, from Wikipedia

Circular enclosures are known in Europe since the Neolithic. Also, the site selected for the Pömmelte enclosure had been used to bury Corded Ware individuals some centuries before its construction, and Corded Ware symbolism (stone axe vs. quern) is seen in the use given by Bell Beakers and later Únětice at this place. All this and other regional similarities between Bell Beakers and different local cultures (see here an example of Iberian Bell Beakers) points to syncretism of the different Bell Beaker groups with preceding cultures in the occupied regions. After all, their genealogical ancestors included also those of their maternal side, and not all encountered males disappeared, as is clearly seen in the resurge of previous paternal lineages in Central-East Europe and in Scandinavia. The admixture of Bell Beakers with previous groups (especially those of similar steppe-related ancestry from Corded Ware) needs more complex analyses to clarify potential early dialectal expansions (read what Iosif Lazaridis has to say).

The popular “big and early” expansions

These syncretic trends gave rise to distinct regional cultures, and eventually different local groups rose to power in the new cultural regions and ousted the old structures. Social norms, hierarchy, and pantheons were remade. Events like this must have been repeated again and again in Bronze and Iron Age Europe, and in many cases it was marked by a difference in the prevailing archaeological culture attested, and probably accompanied by certain population replacements that will be seen with more samples and studies of fine-scale population structure.

Some of these cultural changes, marked by evident haplogroup or admixture replacement, are defined as a ‘resurge’ of ancestry linked to previous populations, although that is obviously not equivalent to a resurge of a previous cultural group, because they usually represent just a successful local group of the same supraregional culture with a distinct admixture and/or haplogroup (see e.g. resurge of R1a-Z645 in Central-East European Bronze Age). Social, religious, or ethnic concepts may have changed in each of these episodes, along with the new prestige dialect.

NOTE. A recent open access paper on two newly studied Middle Bronze Age inhumations from Stonehenge give an interesting idea of potential differences in social identities, in ancestry and geographic origin (which characterize ethnicity) may have been marked by differences in burial ceremonies: Lives before and after Stonehenge: An osteobiographical study of four prehistoric burials recently excavated from the Stonehenge World Heritage Site, by Mays et al. Journal of Archaeological Science: Reports (2018) 20:692-710.

This must have happened then many times during the hundreds (or thousands in some cases) of years until the first attestation of a precise ancient language and culture (read e.g. about one of the latest branches to be attested, Balto-Slavic). Ancient language contacts, like substrates or toponymy, can only rarely be detected after so many changes, so their absence (or the lack of proper studies on them) is usually not relevant – and certainly not an argument – in scholarly discussions. Their presence, on the other hand, is a proof of such contacts.

chalcolithic_late_Europe_Bell_Beaker
Diachronic map of Late Copper Age migrations including Classical Bell Beaker (east group) expansion from central Europe ca. 2600-2250 BC

We have dozens of papers supporting Uralic dialectal substrate influence on Pre-Germanic, Proto-Balto-Slavic, and Pre- and Proto-Indo-Iranian (and even Proto-Celtic), as well as superstrate influence of Palaeo-Germanic (i.e. from Pre- to Proto-Germanic) and Proto-Balto-Slavic into Proto-Finno-Saamic, much stronger than the Indo-Iranian adstrate influence on Finno-Ugric (see the relative importance of each influence) which locates all these languages and their evolution to the north and west of the steppe (with Proto-Permic already separated, in North-East Europe, as is Proto-Ugric further east near the Urals), probably around the Baltic and Scandinavia after the expansion of Bell Beakers. These connections have been known in linguistics for decades.

Apart from some early 20th century scholars, only a minority of Indo-Europeanists support nowadays an Indo-European (i.e. centum) substrate for Balto-Slavic, to keep alive an Indo-Slavonic group based on a hypothetical 19th century Satem group; so e.g. Holzer with his Temematic, and Kortlandt supporting him, also with some supposed Indo-European substrate with heavy non-Indo-European influence for Germanic and Balto-Slavic, that now (thanks mainly to the views of the Copenhagen group) have been linked to the Corded Ware culture, as it has become clear even to them that Bell Beakers expanded North-West Indo-European.

NOTE. The Temematic etymologies have been (all of them) fully dismissed e.g. in Matasović (2013). I have already explained why an Indo-Slavonic group from Sredni Stog is not tenable, and genetics (showing Late PIE only from Yamna expansions) is proving that, too.

For their part, only a minority among Uralicists, such as Kuz’mina, Parpola or Häkkinen, believe in an ‘eastern’ origin of Uralic languages, around the Southern Urals. Genomic finds – like their peers – are clearly not supporting their views. But even if we accept this hypothesis, there is little space beyond Abashevo and related East Corded Ware cultures after the recent papers on Corded Ware and Fennoscandian samples. And yet here we are:

The Copenhagen “Homeland” interactive map

copenhagen-group-map
Brought to you by the Copenhagen fantasy map series, Indo-Europeans after (no, really, after) the expansion of Yamna settlers in Hungary ca. 2700 BC: Yamna settlers have magically disappeared. Yamna-related Balkan EBA cultures and the hundreds of Yamna kurgans around the Lower Danube and in Hungary up to Saxony-Anhalt do not exist. Dat huge mythical Middle Dnieper territory lasting (unchanged) for a thousand years, in sooo close contact with Yamna territory (so beautifully ‘linked’ together that they must have been BFFs and admixed!). Uralic Mesolithic hunter-gatherers resisting IE invasions in Volosovo for 1,500 years like Asterix’ Gaulish village against the Romans. Tiny pockets of Bell Beakers will eventually emerge from (surprise!) Corded Ware territories beautifully scattered over Central and Northern Europe (unlike those eastern CWC mega-regions). And, of course, you can almost see Kroonen & Iversen’s Kurgan Pre-Germanic mixing already with their agricultural substrate TRB precisely in full-IE Denmark (quite appropriate for the Danish school). And sheep symbols representing wool finds, for no reason. A great map to mock for years to come, with each new genetic paper.

The new propaganda tool GIS timeline map of the Copenhagen group:

  • consciously ignores Yamna settlers along the Danube, in the Balkans, and in Hungary, and initial East Bell Beakers, i.e. the obvious origin and expansion of North-West Indo-Europeans, but in contrast magnifies (and expands in time) regions for Sredni Stog / Corded Ware cultures (which suggests that this is yet another absurd attempt to revive the theories of the Danish school…);
  • substitutes arrows for Kron-like colors (where danger red = Indo-European) with the same end result of many other late 20th century whole-Europe Kurgan maps, linking Sredni Stog and Corded Ware with Yamna, but obviating the precise origin of Corded Ware peoples (is it Sredni Stog, or is it that immutable Middle Dnieper group? is it West Yamna, or Yamna Hungary? is it wool, or is it wheels?);
  • relegates Uralic speakers to a tiny corner, a ‘Volosovo’ cultural region, thus near Khvalynsk/Yamna (but not too much), that miraculously survives surrounded by all-early-splitting, all-Northern Eneolithic Indo-Europeans, thus considering Uralic languages irrelevant not only to locate the PIE Urheimat, but also to locate their own homeland; also, cultures identified in color with Uralic speakers expand until the Iron Age with enough care not to even touch in the map one of the known R1a samples published to date (because, for some people, apparently R1a must be Indo-European); and of course N1c or Siberian ancestry are irrelevant, too;
  • and adds findings of wheels and wool probably in support of some new ideas based on yet another correlation = causation argument (that I cannot then properly criticize without access to its reasoning beyond cute SmartArt-like symbols) similar to their model – already becoming a classic example of wrong use of statistical methods – based on the infamously named Yamnaya ancestral component, which is obviously still used here, too.

The end result is thus similar to any other simplistic 1990s Gimbutas (or rather the recently radicalized IE Sredni Stog -> Corded Ware -> BBC version by the Danish workgroup) + 2000s R1a-map + 2010s Yamnaya ancestry; but, hard to believe, it is published in mid-2018. A lot of hours of senseless effort, because after its publication it becomes ipso facto outdated.

For comparison of Yamna and Bell Beaker expansions, here is a recent simplistic, static (and yet more accurate) pair of maps, from the Reich Lab:

corded-ware-bell-beaker
Cultural maps from Eneolithic and Chalcolithic cultures in Wang et al. (2018).

If the Copenhagen group keeps on pushing Gimbutas’ long ago outdated IE Sredni Stog -> Corded Ware theory as modified by Kristiansen, with their recently invented Corded Ware -> Bell Beaker model in genetics, at some point they are bound to clash with the Reich-Jena team, which seems to have less attachment to the classic Kurgan model and the wrong interpretations of the 2015 papers, and that would be something to behold. Because, as Cersei would say: “When you play the game of thrones, you win or you die. There is no middle ground.” And when you play the game of credibility, after so many, so wrong publications, well…

NOTE. I have been working on a similar GIS tool for quite some time, using my own maps and compiled genetic data, which I currently only use for my 2018 revision of the Indo-European demic diffusion model. Maybe within some weeks or months I will be able to publish the maps properly, after the revised papers. It’s a pitty that so much work on GIS and analysis with genetic data and cultural regions has to be duplicated, but I intend to keep some decent neutrality in my revised cultural maps, and this seems impossible at this point with some workgroups who have put all their eggs in one broken basket…

Related

About Scepters, Horses, and War: on Khvalynsk migrants in the Caucasus and the Danube

steppe-horse-sceptre-khvalynsk

dergachev-scepters-khavlynsk-horsesAbout two months ago I stumbled upon a gem in archaeological studies related to Proto-Indo-Europeans, the book О скипетрах, о лошадях, о войне: этюды в защиту миграционной концепции М.Гимбутас (On sceptres, on horses, on war: Studies in defence of M. Gimbutas’ migration concepts), 2007, by V. A. Dergachev, from the Institute of Cultural Heritage of the Moldavian Republic.

Dergachev’s work dedicates 488 pages to a very specific Final Neolithic-Eneolithic period in the Pontic-Caspian steppe, and the most relevant parts of the book concern the nature and expansion of horses and horse domestication, horse-head scepters, and other horse-related symbology – arguably the most relevant cultural signs associated with Proto-Indo-European speakers in this period.

I haven’t had enough time to read the whole book, but I have read with interest certain important chapters.

About Scepters

Typological classification

The genetic and chronological relationship of horse-head pommel-scepters is classified with incredible detail, to the extent that one could divide subregions among those cultures using them.

khvalynsk-horse-head-scepters
Scheme of regional distribution – chronological – typological development of the carved horse-head stone scepters.

Simplified conclusions of this section include (emphasis mine):

  1. The [horse-head pommel-]scepters arose originally in the depth of the Khvalynsk culture. Following the now well-known finds, they are definitely related to those of the Middle Volga group.
  2. horse-head-pommel-scepters-distribution
    General scheme of genetic and chronological development of carved scepters by visual assessment of morphological details.
  3. In their next modifications, these scepters continued to evolve and develop into the area of the Khvalynsk culture in its latest stages, and possibly later.
  4. Simultaneously, with the same modifications, these scepters “are introduced” into common usage in the Novodanilovka culture, which in its spread by one wing was in contact and interspersed immediately with the area of Khvalynsk remains; and on the other hand, far in the south – in the Pre-Kuban and Ciscaucasian regions – within the range of the Domaikopska culture; and in the west – in the Carpathian – Post-Kuban – with the areas of early agricultural cultures Cucuteni A – Trypillia B1, Gumelnița-Karanovo VI.
  5. The simultaneous presence in the areas of the Ciscaucasian, Carpatho-Danubian, and especially Novodinilovka cultures, whose carriers continue the Khvalynian traditions of making stone scepters, and the scepters themselves (in their non-functional implication in the local cultural environment), all definitely allow us to view these findings as imported Novodanilovka objects.
distribution-horse-scepters
Schematic depiction of the spread of horse-head scepters in the Middle Eneolithic. See a full version with notes here.

Cultural relevance of scepters

The text goes on to make an international comparison of scepters and their relevance as a cultural phenomenon, with its strong symbolic functions as divine object, its use in times of peace, in times of war, and in a system of ritual power.

horse-scepters-steppe
Restoration of V. A. Dergachev: a) model for restoration – Paleolithic and Neolithic wands; b) the expected appearance of the Eneolithic scepter on the handle with a coupling (according to Dergachev 2007).
Especially interesting is the section dedicated to Agamemnon’s scepter in the Iliad, one of the oldest Indo-European epics. Here is an excerpt from Illiad II.100-110 (see here the Greek version) with the scepter’s human and divine genealogy:

Then among them lord Agamemnon uprose, bearing in his hands the sceptre which Hephaestus had wrought with toil. Hephaestus gave it to king Zeus, son of Cronos, and Zeus gave it to the messenger Argeïphontes; and Hermes, the lord, gave it to Pelops, driver of horses, and Pelops in turn gave it to Atreus, shepherd of the host; and Atreus at his death left it to Thyestes, rich in flocks, and Thyestes again left it to Agamemnon to bear, that so he might be lord of many isles and of all Argos.

About the horse

His studies on horse remains show an interesting, detailed quantitative and statistical approach to the importance and (cultural and chronological) origin of horses (and likely horse domestication) in each culture.

Although the part on horse remains is probably a bit outdated today, after many recent studies of Eneolithic steppe sites (see here one example), it still shows the relative distribution of horse bone remains among different steppe cultures, which is probably similar to what could be reported today:

distribution-horses-steppe-eneolithic
Territorial distribution of horse remains in the Middle Eneolithic period. Absolute and relative numbers.

Even more interesting is the relationship of the distribution of horse remains with archaeological complexes and horse-related symbols. Some excerpts from the conclusions of this section:

  1. Accounting and analysis of archeo-zoological and archaeological data proper for a horse for a vast area from the Tisza and the Middle Danube to the Caucasus and the Urals (which includes the main cultures of the western agricultural, Caucasian, and Eastern European cultural zones) clearly points to the eastern cultural zone as a zone of the originally the most important social significance of a horse as the only possible zone of the earliest domestication, horseback riding and all-round use of a horse. In relation to the eastern, the western land – the ancient Carpatho-Danubian or the Caucasian cultural zones – are secondary and subordinate to the first on the phenomenon under consideration.
  2. horse-symbols
    Horse-shaped hanger-amulets made of bone.
  3. The first quantitative leap in the manifestation of the remnants of a horse, marking itself and the first qualitative changes in the social status of this animal, is due mainly to the Middle Volga culture of the developed Neolithic of the Middle Volga region (in part, the Southwest Urals), which, accordingly, determine the cultural context, time and geographic region – or, the initial, single and main epicenter of the process of taming and domestication of a horse.
  4. On the one hand, the subsequent substantial increase in the number of horse remnants, and, on the other, the wide inclusion of the horse in cults, rituals, funerary rituals (horse pendants, ornamented metacarpus, horse bones, sacrificial altars) in the Samara culture of the Early Eneolithic of the same region definitely indicates the continuing increase in the social significance of this species of animal, which was most likely expressed in the final design of a specialized horse breeding culture and, accordingly, in a wide range of applications using a horse for riding. At the same time, we can observe the beginning of the transfer of the already domesticated horse from the original historical and geographic epicenter to other cultures of the eastern cultural zone and, in part, the cultures closest to the periphery of this zone, into the western agricultural zone (Bolgrad-Aldeni P, Pre-CuCuteni-Trypillya A) .
  5. expansion-horse-steppe
    Schematic depiction of cultures and regional-chronological distribution of percentage of horse remains. (Depicted are arrows from Middle Volga and Samara culture to the rest)
  6. Middle Eneolithic – early stages. One of the leading places in the remnants of the horse is in the Middle Volga region, the Khvalynsk culture. Genetically related to the Samara, the Khvalynsk I culture preserves the traditions of the ritual, cultural meaning, the treatment of the image of a horse in funerals (altars, horse bones, funerary rituals). But, At the same time, it is in this precise culture that the image of the horse, included in the social symbolism (horse-head pommel-scepter), for the first time it acquires a special, maximum social significance. That is why the appearance and subsequent widespread distribution of the social symbols in Novodanilovka-type objects can definitely be considered as another qualitative leap in the social significance of a horse – its use for military purposes for close and distant expeditions. And such an interpretation is fully confirmed from the analysis of Novodanilovka-type objects, which is the subject of discussion.
  7. Judging by the osteological data and the typological evolution of the horse-head scepters, the Khvalynian culture and remains of the Novodanilovka type are already associated with the relatively widespread and intensive findings of domesticated horses in various areas of the eastern cultural zone (semi-desert regions of the Lower Volga and the Caspian region – Khvalynsk culture, forest-steppe and steppe from the Volga to the Dnieper – Sredni Stog, Repin cultures), and the western – agricultural (Gumelnitsa, Cucuteni A-Tripolye Bl), and the Caucasus (Pre-Maykop) zones, where, however, the horse played a very modest role.
  8. samara-khvalynsk-horses
    Schematic depiction of cultures and regional-chronological distribution of zooarchaeological and ritual data on horses. (Shadowed are from top to bottom the Middle Volga, Samara, Khvalynsk, and Novodanilovka; in bold, other percentages of unrelated cultures: e.g. to the left of Khvalynsk and Novodanilovka, Sredni Stog with 29.65% overall horse bone remains, but 0% of horse symbolism)
  9. From the functional point of view, according to the sum of the data, there is no reason to doubt that in the eastern zone the horse is already present in the Late Neolithic period. Since its domestication and the emergence of a specialized horse breeding, it has been also widely used for meat, milk and dairy products (including the traditional hippace tradition of the later Scythians), and since the beginning of the early Eneolithic for transport and for riding purposes. Another thing is the horse as a means of war, a means of distant travel and expansion. The beginning of the use of a horse for these purposes, in the opinion of the author, is determined by the appearance of social symbolism in the form of horse-head scepters, and is most fully reflected in the memories of the Khvalynsk culture and, in particular, the Novodanilovka type. Concerning western or Caucasian cultural zones related to Khvalynsk, the horse is thought to have been linked to the eastern region, used mainly for riding, as a means of transport and for communication, which, however, does not exclude its use for meat.

These are the main conclusions-interpretations, suggesting the analysis and archaeological and other sources containing information about the horse. And as for our pommel-scepters, then, as can be seen from these sources, the main thing is that the culture of the Middle Volga region, according to all the data, definitely accumulates in itself the longest traditions associated with the gradual increase of social significance of the horse. And if so, this circumstance motivates the possibility or necessity of appearing in the environment of the bearers of this culture of unique signs-symbols that carry within themselves or reflect the image of this animal as an extremely significant social reality. The revealed and characterized quality, as a matter of fact, fill or open by themselves the hypothetical elements we have previously identified, the meanings of that particularity, folded in the social sign-symbol, in our case – the horse-head-shaped scepter.

horse-symbolism-rituals-steppe
Archaeological sites with objects (signs-symbols) related to horses. Horse-head scepters included in other maps are excluded from this one (notice the conspicuous absence of such objects in Sredni Stog and neighbouring North Pontic regions).

The relevance of Dergachev’s work

As you certainly know by now if you are a usual reader of this blog, there were two other seminal publications that same year correcting and expanding Gimbutas’ model:

Each one of these works taken independently (especially the books) may give a different version of Proto-Indo-European migrations; Anthony and Dergachev are heirs of Gimbutas’ simplistic kurgan-based model, and of other previous, now rejected ideas, and they reflect them whenever they don’t deal with first-hand investigation (and even sometimes when interpreting their own data). Taken together – and especially in combination with recent genetic studies – , though, they describe a clearer, solider model of how Proto-Indo-Europeans developed and expanded.

distribution-scepters-steppe
Distribution of horse-head scepters, according to Dergachev, Sorokin (1986).

Anthony’s publication overshadowed the importance of Dergachev’s work for the English-speaking world – and by extension for the rest of us. However, V. A. Dergachev’s updated study of his previous work on steppe cultures shows the right, thorough, and diligent way of describing the expansion of early Khvalynsk-Novodanilovka chieftains with the horse and horse symbolism into the Caucasus and the Lower Danube (like the seminal work of Harrison & Heyd 2007 described the expansion of Yamna settlers with East Bell Beakers, culturally opposed to Corded Ware and to the Proto-Beakers). On the other hand, Anthony’s broad-brush, superficial description of thousands of years of potential Indo-European-speaking peoples gave a migration picture that – although generally right (like radiocarbon-based Iberian origin of the Bell Beaker culture was right) – was bound to be wrong in some essential details, as we are seeing in archaeology and genetics.

NOTE. As I have said before, Anthony’s interpretations of Sredni Stog culture representing a sort of ‘peasants’ under the rule of Novodanilovka chiefs was based on old theories of Telegin, who changed his mind – as did the rest of the Russian school well before the publication of Dergachev’s book, considering both as distinct cultural phenomena. Anthony selected the old interpretation, not to follow a Gimbutas / Kristiansen model of Sredni Stog being Indo-European and expanding with GAC into Corded Ware (because, for him, Corded Ware peoples were originally non-Indo-European speakers): he seems to have done it to prove that Proto-Anatolian traveled indeed through the North Pontic area, i.e. to avoid the regional ‘gap’ in the maps, if you like. Then with the expansion of Repin over the area, Sredni Stog peoples would have been absorbed. With genetic investigation, as we know, and with this kind of detailed archaeological studies, the traditional preference for “large and early” IE territories – proper of the mid-20th century – are no longer necessary.

sredni-stog-suvorovo-novodanilovka-cernavoda
Anthony (2007): “Steppe and Danubian sites at the time of the Suvorovo-Novodanilovka intrusion, about 4200-3900 BC.”

Steppe Eneolithic

We already had in 2016 a Samara hunter-gatherer sample dated ca. 5600 BC, representative of EHG ancestry, of haplogroup R1b1a. We also had three early Khvalynsk samples from Samara Eneolithic dated ca. 4600 BC, with a drift towards (what we believe now is) a population from the Caucasus, showing haplogroups Q1a, R1a1(xM198), and R1b1a, the last one described in its paper as from a high-status burial, similar to high-status individuals buried under kurgans in later Yamna graves (of R1b-L23 lineages), and therefore likely a founder of an elite group of patrilineally-related families, while the R1a1 sample showed scarce decoration, and does not belong to the M417 lineage expanded later in Sredni Stog or Corded Ware.

In 2017 we knew of the Ukraine_Eneolithic sample I6561, from Alexandria, of a precise subclade (L657) of haplogroup R1a-Z93, dated ca. 4000 BC, and likely from the Sredni Stog (or maybe Kvitjana) culture. This sample alone makes it quite likely that the expansion of R1a-Z645 subclades happened earlier than expected, and that it was associated with movements along forest-steppe cultures, most likely along the Upper Dniester or Dnieper-Dniester corridor up to the Forest Zone.

We have now confirmation that Khvalynsk samples from the Yekaterinovka Cape settlement ca. 4250-4000 BC were reported by a genetic lab (to the archaeological team responsible) as being of R1b-L23 subclades, although the precise clades (reported as P312 and U106) are possibly not accurate.

NOTE. Curiously enough, and quite revealing for the close relationship of scepters to the ritual source of power for Khvalynsk chieftains (political and/or religious leaders), the scepter found in the elite burial 45 of the Ekaterinovka cape (a riverine settlement) shows a unique zoomorphic carving, possibly resembling a toothed fish or reptile, rather than the most common horse-related motifs of the time.

ekaterinovka-cape-scepter
Zoomorphic carved stone scepter of the Ekaterinovka Cape burial 45: photos (left) and schematic depiction (right).

With Wang et al. (2018), a real game-changer in the Khvalynsk – Sredni Stog (and also in the Yamna/Bell Beaker – Corded Ware) opposition, we also know that two Steppe Eneolithic samples from the Northern Caucasus Piedmont, dated ca. 4300-4100 BC, show haplogroup R1b1. Although its direct connection to the expansion of early Khvalynsk with horse-related symbolism is not clear from the archaeological information shared (none), this is what the paper has to say about them:

The two distinct clusters are already visible in the oldest individuals of our temporal transect, dated to the Eneolithic period (~6300-6100 yBP/4300-4100 calBCE). Three individuals from the sites of Progress 2 and Vonjuchka 1 in the North Caucasus piedmont steppe (‘Eneolithic steppe’), which harbor Eastern and Caucasian hunter-gatherer related ancestry (EHG and CHG, respectively), are genetically very similar to Eneolithic individuals from Khalynsk II and the Samara region19, 27. This extends the cline of dilution of EHG ancestry via CHG/Iranian-like ancestry to sites immediately north of the Caucasus foothills.

In contrast, the oldest individuals from the northern mountain flank itself, which are three first degree-related individuals from the Unakozovskaya cave associated with the Darkveti-Meshoko Eneolithic culture (analysis label ‘Eneolithic Caucasus’) show mixed ancestry mostly derived from sources related to the Anatolian Neolithic (orange) and CHG/Iran Neolithic (green) in the ADMIXTURE plot (Fig. 2C). While similar ancestry profiles have been reported for Anatolian and Armenian Chalcolithic and Bronze Age individuals20, 23, this result suggests the presence of the mixed Anatolian/Iranian/CHG related ancestry north of the Great Caucasus Range as early as ~6500 years ago.

On the specific burials, we have e.g. the recent open access paper New cases of trepanations from the 5th to 3rd millennia BC in Southern Russia in the context of previous research: Possible evidence for a ritually motivated tradition of cranial surgery?, by Gresky et al. J Am Phys Anthropol (2016):

During the late 5th millennium BC, cultural groups of the Eneolithic occupied the northern circumpontic area and the areas between the North Caucasus and the Lower Volga. For the first time, individual inhumations were placed below low burial mounds (Rassamakin, 2011). During the 4th millennium BC, the area split into two cultural spheres. In the northern steppe area communities continued with the burial practice of crouched inhumations below low mounds, with this culturally transforming into the early Pit Grave culture. In contrast, in the Caucasian foothill zone and the neighbouring steppe, the Majkop-Novosvobodnaya culture emerged (Kohl and Trifonov, 2014). Similarly, during the 3rd millennium BC, two cultural spheres influenced the area: The North Caucasian Culture dominated the Caucasian foothills for the next five centuries, while in the steppe area between the Lower Don and the Caucasus, regional groups of the Catacomb Culture existed side-by-side.

Burials of the Eneolithic epoch (late 5th millennium BC)

The oldest group of individuals with trepanations are found in the North Caucasian variant of the late circumpontic Eneolithic and date to the last third of the 5th millennium BC (Korenevsky, 2012). Burials of this epoch are inhumations in shallow pits, chiefly without burial goods, but covered with large quantities of red ochre. Of special interest is a collective burial of seven individuals from VP 1/12, who were interred together in a secondary burial ritual. The sites of Tuzluki, Mukhin, Voinuchka, Progress, and Sengileevskii all belong to this period.

PCA-caucasus-khvalynsk-sredni-stog
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. An EHG and a Caucasus ‘clouds’ have been drawn, leaving Pontic-Caspian steppe and derived groups between them.See the original file here.

Without the datasets to test different models, you can only imagine what is happening with the processed, secondary data we have. The position of Eneolithic Steppe cluster in the PCA (probably Khvalynsk-related peoples already influenced by the absorbed, previous Caucasus population), as well as other potential Caucasus groups intermediate between Steppe Maykop and Caucasus Maykop (as suggested by other ancient and modern Caucasus samples), may indicate that Yamna is between Khvalynsk and such intermediate Caucasus populations (as the source of the additional CHG-related ancestry) and – as the paper itself states – that it also received additional EEF contribution, probably from the western cultures absorbed during these Khvalynsk-Novodanilovka migrations (or later during Khvalynsk/Repin migrations).

Also interpreted in light of these early Khvalynsk-Novodanilovka migrations of horse riding chieftains (and their close contacts with the Caucasus), you can clearly see where the similar CHG-like contribution to Ukraine Eneolithic and other North Pontic forest-steppe cultures (which later contributed to Proto-Corded Ware peoples) must have come from. The simplistically reported proportions of EHG:CHG:EEF ancestry might be similar in many of these groups, but the precise origin and evolution of such ancestral components is certainly not the same: statistical methods will eventually show this, when (and if) we have many more samples, but for the moment Y-DNA is the most obvious indicator of such differences.

There was no steppe people speaking a steppe language AKA immutable Proto-Indo-European: the glottochronological models spanning thousands of years are not valid for the steppe, just as they are not valid for an Anatolian homeland, nor for a Caucasus homeland. The actual cultural-historical early Sredni Stog – Khvalynsk community, formed earlier than ca. 5000 BC, is a thousand years older than the expansion of Khvalynsk with the horse, and some two thousand years older than the expansion of Khvalynsk-Repin/Early Yamna migrants (see here for the latest genetic research).

What lies between the formation of that early Eneolithic cultural-historical community, and what we see in archaeology and genetics in Middle and Late Eneolithic steppe cultures, is the radical differentiation of western (Ukraine Eneolithic, mainly forest-steppe) and eastern (Samara and Khvalynsk/Repin, mainly steppe) cultures and peoples, i.e. precisely the period of differentiation of an eastern, Proto-Indo-Hittite-speaking early Khvalynsk community (that expanded with the horse and horse-related symbols) from a western, probably Early Proto-Uralic speaking community of the North Pontic forest-steppe cultural area.

NOTE. I am not against a Neolithic ‘steppe’ language. But this steppe language was spoken before and/or during the first Neolithisation wave, and should be associated with Indo-Uralic. If there was no Indo-Uralic language, then some communities would have developed Early Proto-Indo-European and Early Proto-Uralic side by side, in close contact to allow for dozens of loanwords or wanderwords to be dated to this period (where, simplistically, PIH *H corresponds to EPU *k, with some exceptions).

steppe-forest-change
Map of a) steppe – forest-steppe border during the Eneolithic in the Pontic-Caspian region and b) the border today, showing a more limited steppe zone in the North Pontic area (reason for the specific ways of expansion of horse-related cultures and horse-related nomadic pastoralism during the Eneolithic).

The convergence that we see in PCA and Admixture of Yamna and the earliest Baltic LN / Corded Ware ‘outlier’ samples (if not directly related exogamy of some Baltic LN/CWC groups with Yamna migrants, e.g. those along the Prut), must be traced back to the period of genetic drift that began precisely with these Khvalynsk-Novodanilovka expansions, also closely associated with populations of the Caucasus, thus bringing North Pontic forest-steppe cultures (probably behind Proto-Corded Ware peoples) nearer to Khvalynsk, and both by extension to Yamna.

We have seen this problem arise in Bell Beaker samples expanding all over Europe, turning from a fully Yamnaya-like population to something else entirely in different regions, from more EEF-like to more CWC-like, sharing one common trait: Y-DNA. We are seeing the same happen with Balkan groups and Mycenaeans, with Old Hittites, and with steppe MLBA from Andronovo peoples expanding over Central and South Asia, and we know that patrilineal clans and thus Y-chromosome bottlenecks were common after Neolithisation, especially with nomadic pastoralist steppe clans (and probably also with many previous population expansions).

Steppe Eneolithic peoples were thus no different to other previous and posterior expanding groups, and ancestry is going to be similar for people living in neighbouring regions, so Y-DNA will remain the essential tool to distinguish different peoples (see here a summary of Proto-Indo-Europeans expanding R1b-L23).

We are nevertheless still seeing “R1b zombies” (a quite appropriate name I read on Anthrogenica) still arguing for a Western European origin of R1b-L23 based on EEF-like ancestry and few steppe-related contribution found in Iberian Bell Beakers (read what David Reich has to say on this question); and “OIT zombies” still arguing for IVC representing Proto-Indo-European, based on Iran_N ancestry and the minimal steppe ancestry-related impact on certain ancient Asian cultures, now partly helped by “Caucasus homeland zombies” with the new PIE=CHG model; apart from many other pet theory zombies rising occasionally from their graves here and there. Let’s hope that this virus of the undead theories does not spread too strongly to the R1a-Indo-European association, when the official data on Khvalynsk, West Yamna, and Yamna Hungary come out and show that they were dominated by R1b-L23 lineages.

Because we need to explore in detail the continuation of Khvalynsk-related (potential Proto-Anatolian) cultures in the Lower Danube and the Balkans, e.g. from Cernavoda I to Cernavoda III, then maybe to Ezero, and then to Troy; as well as the specific areas of Late Indo-European expansions associated with Early Yamna settlers turning into Bell Beakers, Balkan EBA, and Steppe MLBA-associated cultures. There is a lot of work to do on proper definition of Bronze Age cultures and their potential dialects, as well as convergence and divergence trends, and not only of Indo-European, but also of Uralic-speaking communities derived from Corded Ware cultures.

If we let the narratives of the 2000s in Genetics (in combination with the 1960s in Archaeology) dominate the conversation, then a lot of time will be absurdly lost until reality imposes itself. And it will.

EDIT (2 JUL 2018): Some sentences corrected, and some information added to the original post.

Related

Climatic conditions in the Cis-Ural Steppe region and the Repin culture

cis-ural-region

New paper (behind paywall) Climate and Vegetation Changes over the Past 7000 Years in the Cis-Ural Steppe, by Khokhlova, Morgunova, Khokhlov, and Gol’eva, Eurasian Soil Sc. (2018) 51: 506.

Abstract (emphasis mine):

A multilayered archaeological site Turganik Settlement in the valley of the Tok River in the Cis- Ural steppe (Orenburg oblast) was examined with the use of paleopedological and microbiomorph methods. Ancient people inhabited this area in the Latest Neolithic (Eneolithic) (5th millennium BC) and Early Bronze (4th millennium BC) ages. It was found that cultural layers dating back to the Atlantic period of the Holocene had been formed under conditions of a predominance of grassy–forb vegetation with a small portion of tree species and dry climate; the ancient settlement was not affected by floods and was suitable for permanent living. It is probable that soils of the chestnut type with salinization and solonetzic features were developed in that time. The final stages of the accumulation of cultural layers were marked by strong shortterm floods, whose sediments partly masked the features of the previous long arid epoch. The highest degree of aridity was at the end of the Atlantic period. In the Subboreal and Subatlantic periods, soils of the meadowchernozemic type were formed; the spore–pollen spectra of these periods are characterized by a higher portion of tree species and by the presence of phytoliths of meadow grasses. The climatic conditions were generally colder and more humid, though some short-term aridization stages could take place. Some of these stages are recorded in the thickness of the studied sediments.

Interesting excerpts:

Paleosols buried under archaeological monuments of different periods represent a valuable archieve of information about the paleoenvironment. Most of the works in the field of archaeological pedology deal with earthen burial sites and kurgans [2, 5, 7, 9, 11]. Paleosols buried under the kurgans present us the paleoenvironmental records of a relatively short time before they were buried under the kurgan bodies. The study of kurgans created in different times makes it possible to characterize paleosol sequences storing information on longer periods of time in the second half of the Holocene. However, groups of kurgans that were consecutively created during the entire time span of kurgan construction, beginning from about 6000 yrs BC to the Early Medieval epoch, are few in number [8, 18, 22]. Even for such groups of kurgans, there are considerable time intervals that cannot be characterized because kurgans were not constructed during them. Hence, it is impossible to study the soils buried during these intervals. To reconstruct paleoenvironmental conditions for them, certain interpolation is required [29].

At the same time, there are archaeological sites — ancient settlements — the material of which gradually accumulated during very long time, e.g., beginning from the Middle Holocene to the present. Though such objects may also contain “missing layers” for certain periods, when the processes of denudation, erosion, or deflation predominated over sediment accumulation, they represent an almost continuous record on information about the paleoenvironmental conditions from the beginning of their functioning [25]. The most valuable among such sites are those that retain information on those periods of the Holocene that cannot be characterized on the basis of available data on the paleosols buried under the kurgans. In particular, this is the Atlantic period (7500–5000 yrs ago), because the construction of kurgans began only in the second half of this period (within the Volga–Ural interfluve [14]), and such ancient kurgans are rarely found. We studied such an archaeological site in the valley of the Tok River in the Cis-Ural steppe zone in Orenburg oblast. This site is known as the ancient Turganik settlement.

We studied different layers of the Turganik settlement with the use of a set of methods in order reconstruct the paleoenvironmental conditions (climate and vegetation) for the entire period of the accumulation of these sediments.

Thus, the Atlantic period of the Holocene in the Cis-Uralian steppe was characterized by dry climatic conditions with the driest stage during the Early Bronze Age (the Early Yamnaya culture of the middle of the fourth millennium BC). The Subboreal and Subatlantic periods were generally colder and wetter, though they also included short-term aridization phases, some of which were recorded in the sediment thickness.

This site is at the core of the interaction of Samara, Khvalynsk, and Repin cultures during the Eneolithic.

You can read more about it and the nature of Repin described by Morgunova (in favour of Gimbutas’ model), as combining traditions from Eneolithic steppe cultures from Khvalynsk to Sredni Stog, e.g. in Pottery from the Volga area in the Samara and South Urals region from Eneolithic to Early Bronze Age (2015).

repin-khvalynsk
Eneolithic settlements (1–5, 7, 10–16, 20, 22–43, 48, 50), burial grounds (6, 8–9, 17–19, 21, 47, 49) and kurgans (44–46) of the steppe Ural-Volga region: 1 Ivanovka; 2 Turganik; 3 Kuzminki; 4 Mullino; 5 Davlekanovo; 6 Sjezheye (burial ground); 7 Vilovatoe; 8 Ivanovka; 9 Krivoluchye; 10–13 LebjazhinkaI-III-IV-V; 14 Gundorovka; 15–16 Bol. Rakovka I-II; 17–18 Khvalunsk I-II; 19 Lipoviy Ovrag; 20 Alekseevka; 21 Khlopkovskiy; 22 Kuznetsovo I; 23 Ozinki II; 24 Altata; 25 Monakhov I; 26 Oroshaemoe; 27 Rezvoe; 28 Varpholomeevka; 29 Vetelki; 30 Pshenichnoe; 31 Kumuska; 32 Inyasovo; 33 Shapkino VI; 34 Russkoe Truevo I; 35 Tsaritsa I-II; 36 Kamenka I; 37 Kurpezhe-Molla; 38 Istay; 39 Isekiy; 40 Koshalak; 41 Kara-Khuduk; 42 Kair-Shak VI; 43 Kombakte; 44 Berezhnovka I-II; 45 Rovnoe; 46 Politotdelskoe; 47 burial near s. Pushkino; 48 Elshanka; 49 Novoorsk; 50 Khutor Repin.

The migration model of Anthony (2007, 2015), who collaborated with this group, is a more precise description of how peoples from the east of the Don River (mainly Khvalynsk/Repin cultures) migrated to develop a greater Yamna community, with Repin-type material culture expanding east of the Urals (into Afanasevo) and west of the Don River (into previous Sredni Stog/Kvitjana territory) – which I followed for the Indo-European demic diffusion model (we have recent samples of other potential Khvalynsk/Repin-related migrations).

NOTE. I usually refer to this Khvalynsk/Repin migration in genomics as of ‘Khvalynsk migrants’, for simplicity purposes, given that the few samples we have are from Khvalynsk, and that cultural regions east of the Don are difficult to differentiate precisely. However, it remains to be seen if – as I proposed – there are genetic differences between Repin and Khvalynsk groups, especially regarding R1b-L23 subclades – I proposed mainly Z2103 for Khvalynsk, L51 for Repin, a difference which has not been confirmed for the moment in Afanasevo, probably of Pre-Tocharian dialect, an archaic Northern dialect of Late PIE.

Anthony’s model of Khvalynsk/Repin as Yamna forefathers is probably, as we are seeing in Yamna samples, the right interpretation of peoples behind pots, compared to Gimbutas’ general idea of expanding kurgans of the 1970s.

On the other hand, the alternative Russian school version of Yamna developing from a heterogeneous community of Khvalynsk-Sredni Stog-Lower Danube cultures is probably by now to be fully dismissed, in archaeology (as Morgunova says) as in genetics.

Related:

Steppe and Caucasus Eneolithic: the new keystones of the EHG-CHG-ANE ancestry in steppe groups

indo-uralic-ehg-chg-ane-ancestry

Some interesting excerpts from Wang et al. (2018):

An interesting observation is that steppe zone individuals directly north of the Caucasus (Eneolithic Samara and Eneolithic steppe) had initially not received any gene flow from Anatolian farmers. Instead, the ancestry profile in Eneolithic steppe individuals shows an even mixture of EHG and CHG ancestry, which argues for an effective cultural and genetic border between the contemporaneous Eneolithic populations in the North Caucasus, notably Steppe and Caucasus. Due to the temporal limitations of our dataset, we currently cannot determine whether this ancestry is stemming from an existing natural genetic gradient running from EHG far to the north to CHG/Iran in the south or whether this is the result of farmers with Iranian farmer/ CHG-related ancestry reaching the steppe zone independent of and prior to a stream of Anatolian farmer-like ancestry, where they mixed with local hunter-gatherers that carried only EHG ancestry.

PCA-caucasus-khvalynsk-sredni-stog
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. An Eastern European (blue) and a Caucasus (brown) ‘clouds’ have been drawn in dotted circles, leaving Pontic-Caspian steppe and derived groups between them.See the original file here.

Concerning the influences from the south, our oldest dates from the immediate Maykop predecessors Darkveti-Meshoko (Eneolithic Caucasus) indicate that the Caucasus genetic profile was present north of the range ~6500 BP, 4500 calBCE. This is in accordance with the Neolithization of the Caucasus, which had started in the flood plains of the great rivers in the South Caucasus in the 6th millennium BCE from where it spread to the West and Northwest Caucasus during the 5th millennium BCE9, 49. It remains unclear whether the local CHG ancestry profile (represented by Late Upper Palaeolithic/Mesolithic individuals from Kotias Klde and Satsurblia in today’s Georgia) was also present in the North Caucasus region before the Neolithic. However, if we take the Caucasus hunter-gatherer individuals from Georgia as a local baseline and the oldest Eneolithic Caucasus individuals from our transect as a proxy for the local Late Neolithic ancestry, we notice a substantial increase in Anatolian farmer-related ancestry. This in all likelihood is linked to the process of Neolithization, which also brought this type of ancestry to Europe. As a consequence, it is possible that Neolithic groups could have reached the northern flanks of the Caucasus earlier50 (Supplementary Information 1) and in contact with local hunter gatherers facilitated the exploration of the steppe environment for pastoralist economies. Hence, additional sampling from older individuals is needed to fill this temporal and spatial gap.

The newest paper of the Reich/Jena group has brought samples (probably) much nearer to the actual CHG and ANE contribution seen in Eneolithic steppe peoples than the previously available Kotias Klde, Satsurblia, Afontova Gora 3, or Mal’ta.

It is impossible to say without direct access to the samples, but it is very likely that we will soon be able to break down different gross contributions from groups similar to these Steppe/Caucasus Neolithic ancestral groups into the diverse Eneolithic cultures of the Pontic-Caspian steppe, and thus trace more precisely each of these cultures to their genetic (and thus ethnolinguistic) heirs.

qpgraph-eneolithic-steppe
Admixture Graph modelling of the population history of the Caucasus region. We started with a skeleton tree without admixture including Mbuti, Loschbour and MA1. We grafted onto this EHG, CHG, Globular_Amphora, Eneolithic_steppe, Maykop, and Yamnaya_Caucasus, adding them consecutively to all possible edges in the tree and retaining only graph solutions that provided no differences of |Z|>3 between fitted and estimated statistics. The worst match is |Z|=2.824 for this graph. We note that the maximum discrepancy is f4(MA1, Maykop; EHG, Eneolithic_steppe) = -3.369 if we do not add the 4% EHG ancestry to Maykop. Drifts along edges are multiplied by 1000 and dashed lines represent admixture.”

Some more representative samples from Eneolithic steppe, steppe-forest and forest zone cultures of Eastern Europe will probably help with the fine-scale structure of different Chalcolithic groups, especially the homeland of early Corded Ware groups.

These new samples seem another good reason (like the Botai and R1b-M73) to rethink the role of (what I assumed were) different westward Mesolithic Eurasian waves of expansion influencing the formation of an Indo-Uralic and Indo-European community in Eastern Europe, and return to the simpler idea of local contributions from North Caucasus and steppe peoples absorbed by expanding EHG-like groups.

Related:

Post-Neolithic Y-chromosome bottleneck explained by cultural hitchhiking and competition between patrilineal clans

Open access study Cultural hitchhiking and competition between patrilineal kin groups explain the post-Neolithic Y-chromosome bottleneck, by Zeng, Aw, and Feldman, Nature Communications (2018).

Abstract (emphasis mine):

In human populations, changes in genetic variation are driven not only by genetic processes, but can also arise from cultural or social changes. An abrupt population bottleneck specific to human males has been inferred across several Old World (Africa, Europe, Asia) populations 5000–7000 BP. Here, bringing together anthropological theory, recent population genomic studies and mathematical models, we propose a sociocultural hypothesis, involving the formation of patrilineal kin groups and intergroup competition among these groups. Our analysis shows that this sociocultural hypothesis can explain the inference of a population bottleneck. We also show that our hypothesis is consistent with current findings from the archaeogenetics of Old World Eurasia, and is important for conceptions of cultural and social evolution in prehistory.

Relevant excerpts:

y-dna-bottleneck
Tree of Y-chromosome genotypes from samples found among cultures with hunter-gatherer subsistence, and agropastoralist subsistence. The blue background represents hunter-gatherer subsistence while the green background represents agropastoralist subsistence. Letters in red circles match individuals from sites with their archaeological context. Note that R1b-P321 is synonymous with R1b-S116. Adapted from Figs. 3, 4, 5 and 6 of Kivisild67, with addition of information from Olalde et al.64. The vertical axis represents time; the position of branch points represent the ages of branch-defining mutations, with nomenclature and age from yfull (https://www.yfull.com/tree/)

Our hypothesis explains the bottleneck as a consequence of intergroup competition between patrilineal kin groups, which caused cultural hitchhiking between Y-chromosomes and cultural groups and reduction in Y-chromosomal diversity. Competition between demes can dramatically reduce genetic diversity within a population1, especially if the population is structured such that variation is greater between demes than within demes. Culturally transmitted kinship ideals and norms can cause homophilous sorting and limit interdemic gene flow, creating homogeneous demes that differ strongly from one another. Patrilineal corporate kin groups, with coresiding male group members descending from a common male ancestor, would produce such an effect on Y-chromosomes only, as patrilineal corporate kin groups generally coexist with female exogamy40, which would homogenize the mitochondrial gene pools of different groups41,42.

With intergroup competition between patrilineal corporate kin groups, two mechanisms would operate to reduce Y-chromosomal diversity. First, patrilineal corporate kin groups produce high levels of Y-chromosomal homogeneity within each social group due to common descent, as well as high levels of between-group variation. Second, the presence of such groups results in violent intergroup competition preferentially taking place between members of male descent groups, instead of between unrelated individuals. Casualties from intergroup competition then tend to cluster among related males, and group extinction is effectively the extinction of lineages.

There is evidence that other analogous situations involving gene-culture hitchhiking in culturally-defined social groups may have affected genetic diversity. Central Asian pastoralists, who are organized into patriclans, have high levels of intergroup competition and demonstrate ethnolinguistic and population-genetic turnover down into the historical period59. They also have a markedly lower diversity in Y-chromosomal lineages than nearby agriculturalists42,60. In fact, Central Asians are the only population whose male effective population size has not recovered from the post-Neolithic bottleneck; it remains disproportionately reduced, compared to female estimates using mtDNA4. Central Asians are also the only population to have star-shaped expansions of Y-chromosomes within the historical period, which may be due to competitive processes that led to the disproportionate political success of certain patrilineal clans60.

The simulation offers an interesting graphic. I had been thinking for some time about developing an interactive image with waves of expansion showing how only few haplogroups expand and thus their variability is reduced in successive migration waves, because a lot of people seemed not to be willing to accept this:

y-dna-bottleneck-simulation
Schematic of the steps in the simulation, according to the order described in the algorithm. a (i) Patrilineal (PT) starting conditions, where cultural groups strictly determine haplogroup type. a (ii) The non-patrilineal (NPT) condition where they are perfectly uncorrelated. b The killing step, with a more (PT) and less (NPT) patrilineal starting condition. The number of deaths in each group is inversely related to group size. The blue cultural group goes extinct in both cases. This causes the haplogroup represented by the diamonds to go extinct in PT, but no haplogroup extinction occurs in NPT. c The mutation step, where a small number of individuals in the largest haplogroup change their haplogroup. d The regeneration step, where (i) is a replica of (b) PT (iii), and (d) (ii) shows how the original number of individuals before the killing step is restored by proportionally increasing the number of individuals in all cells. e Group fission step. Where an empty row occurs, the largest cultural group splits, and half the individuals form a new cultural group in the empty row. The step in which we remove cultural groups that are too small—between (c, d) (see Methods)—is not shown

You only have to imagine this process happening in many successive waves of expansion (external as well as internal to each culture) since the first Neolithic expansions in the steppe in the late-6th millennium BC, even before the formation of the Khvalynsk-Sredni Stog cultural-historical community, to understand what happened in the next thousands of years with evolving patrilineal clans and their distinct cultures.

The whole paper is an interesting read. It’s great to see sociology and genetics finally catch up and interact to develop more complex anthropological hypotheses.

The fact that this paper appears in mid-2018 and geneticists are beginning to discuss this only now when their statistical methods fail to explain the obvious (see David Reich’s recent interview) seems anachronistic, though, because all this was quite clear already in 2015 – at least for those who were looking for mainstream Yamna – Bell Beaker connections, instead of inventing new migration pathways to justify the results of certain statistical analyses

Anyway, better late than never.

Also, they use YFull estimates, which vindicates my use of them in the Indo-European demic diffusion model (2017). On the other hand, their use of these estimates right now in 2018 for R1a-M417 and R1b-M269 – when we know of a R1a-Z93 case much older than YFull’s estimated 5,000 YBP for this subclade, and possibly for R1b-L23, too, is the biggest pitfall in their temporal assessment, although the bottlenecks seen in Chalcolithic expansions seem to have indeed began during the Mesolithic-Neolithic transition in the steppe.

So, say goodbye (if you haven’t already) to dat fantasy ‘steppe people’ of mixed R1a/R1b descent cooperating with the same mixed steppe language, all represented by the Yamnaya™ ancestral component, and say hello to distinct, competing ethnolinguistic steppe groups during the Neolithic.

Related: