Resurge of local populations in the final Corded Ware culture period from Poland

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Open access A genomic Neolithic time transect of hunter-farmer admixture in central Poland, by Fernandes et al. Scientific Reports (2018).

Interesting excerpts (emphasis mine, stylistic changes):

Most mtDNA lineages found are characteristic of the early Neolithic farmers in south-eastern and central Europe of the Starčevo-Kőrös-Criş and LBK cultures. Haplogroups N1a, T2, J, K, and V, which are found in the Neolithic BKG, TRB, GAC and Early Bronze Age samples, are part of the mitochondrial ‘Neolithic package’ (which also includes haplogroups HV, V, and W) that was introduced to Europe with farmers migrating from Anatolia at the onset of the Neolithic17,31.

A noteworthy proportion of Mesolithic haplogroup U5 is also found among the individuals of the current study. The proportion of haplogroup U5 already present in the earliest of the analysed Neolithic groups from the examined area differs from the expected pattern of diversity of mtDNA lineages based on a previous archaeological view and on the aDNA findings from the neighbouring regions which were settled by post-Linear farmers similar to BKG at that time. A large proportion of Mesolithic haplogroups in late-Danubian farmers in Kuyavia was also shown in previous studies concerning BKG samples based on mtDNA only, although these frequencies were derived on the basis of very small sample sizes.

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A significant genetic influence of HG populations persisted in this region at least until the Eneolithic/Early Bronze Age period, when steppe migrants arrived to central Europe. The presence of two outliers from the middle and late phases of the BKG in Kuyavia associated with typical Neolithic burial contexts provides evidence that hunter-farmer contacts were not restricted to the final period of this culture and were marked by various episodes of interaction between two societies with distinct cultural and subsistence differences.

The identification of both mitochondrial and Y-chromosome haplogroup lineages of Mesolithic provenance (U5 and I, respectively) in the BKG support the theory that both male and female hunter-gatherers became part of these Neolithic agricultural societies, as has been reported for similar cases from the Carpathian Basin, and the Balkans. The identification of an individual with WHG affinity, dated to ca. 4300 BCE, in a Middle Neolithic context within a BKG settlement, provides direct evidence for the regional existence of HG enclaves that persisted and coexisted at least for over 1000 years, from the arrival of the LBK farmers ca. 5400 BCE until ca. 4300 BCE, in proximity with Neolithic settlements, but without admixing with their inhabitants.

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Principal component analysis with modern populations greyed out on the background (top), ADMIXTURE results with K = 10 with samples from this study amplified (bottom).

The analysis of two Late Neolithic cultures, the GAC and CWC, shows that steppe ancestry was present only among the CWC individuals analysed, and that the single GAC individual had more WHG ancestry than previous local Neolithic individuals. (…) The CWC’s affinity to WHG, however, contrasts with results from published CWC individuals that identified steppe ancestry related to Yamnaya as the major contributor to the CWC genomes, while here we report also substantial contributions from WHG that could relate to the late persistence of pockets of WHG populations, as supported by the admixture results of N42 and the finding of the 4300-year-old N22 HG individual. These results agree with archaeological theories that suggest that the CWC interaction with incoming steppe cultures was complex and that it varied by region.

Some comments

About the analyzed CWC samples, it is remarkable that, even though they are somehow related to each other, they do not form a tight cluster. Also, their Y-DNA (I2a), and this:

When compared to previously published CWC data, our CWC group (not individuals) is genetically significantly closer to WHG than to steppe individuals (Z = −4.898), a result which is in contrast with those for CWC from Germany (Z = 2.336), Estonia (Z = 0.555), and Latvia (Z = 1.553).

ancestry-proportions-poland
Ancestry proportions based on qpAdm. Visual representation of the main results presented in Supplementary Table S5. Populations from this study marked with an asterisk. Values and populations in brackets show the nested model results marked in green in Supplementary Table S5.

Włodarczak (2017) talks about the CWC period in Poland after ca. 2600 BC as a time of emergence of an allochthnous population, marked by the rare graves of this area, showing infiltrations initially mainly from Lesser Poland, and later (after 2500 BC) from the western Baltic zone.

Since forest sub-Neolithic populations would have probably given more EHG to the typical CWC population, these samples support the resurge of ‘local’ pockets of GAC- or TRB-like groups with more WHG (and also Levant_Neolithic) ancestry.

The known presence of I2a2a1b lineages in GAC groups in Poland also supports this interpretation, and the subsistence of such pockets of pre-steppe-like populations is also seen with the same or similar lineages appearing in comparable ‘resurge’ events in Central Europe, e.g. in samples from the Únětice and Tumulus culture.

About the Bronze Age sample, we have at last official confirmation of haplogroup R1a1a (sadly no subclade*) at the very beginning of the Trzciniec period – in a region between western (Iwno) and eastern (Strzyżów) groups related to Mierzanowice – , which has to be put in relation with the samples from the final Trzciniec period in the Baltic published in Mittnik et al. (2018).

EDIT (8 OCT 2018): More specific subclades have been published, including a R1a-Z280 lineage for the Bronze Age sample (see spreadsheet).

This confirms the early resurge of R1a-Z645 (probably R1a-Z282) lineages at the core of the developing East European Bronze Age, a province of the European Bronze Age that emerged from evolving Bell Beaker groups in Poland.

bell-beakers-poland-kujawy
Arrival of Bell Beakers in Poland after ca. 2400 BC, and their origin in other BBC centres (Czebreszuk and Szmyt 2011).

I don’t have any hope that the Balto-Slavic evolution through BBC Poland → Mierzanowice/Iwno → Trzciniec → Lusatian cultures is going to be confirmed any time soon, until we have a complete trail of samples to follow all the way to historic Slavs of the Prague culture. However, I do think that the current data on central-east Europe – and the recent data we are receiving from north-east Europe and the Iranian steppes, at odds with the Indo-Slavonic alternative – supports this model.

I guess that, in the end, similar to how the Yamna vs. Corded Ware question is being solved, the real route of expansion of Proto-Balto-Slavic (supposedly spoken ca. 1500-1000 BC) is probably going to be decided by the expansion of either R1a-M458 (from the west) or R1a-Z280 lineages (from the east), because the limited precision of genetic data and analyses available today are going to show ‘modern Slavic’-like populations from the whole eastern half of Europe for the past 4,000 years…

Related

Globular Amphora not linked to Pontic steppe migrants – more data against Kristiansen’s Kurgan model of Indo-European expansion

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New open access article, Genome diversity in the Neolithic Globular Amphorae culture and the spread of Indo-European languages, by Tassi et al. (2017).

Abstract:

It is unclear whether Indo-European languages in Europe spread from the Pontic steppes in the late Neolithic, or from Anatolia in the Early Neolithic. Under the former hypothesis, people of the Globular Amphorae culture (GAC) would be descended from Eastern ancestors, likely representing the Yamnaya culture. However, nuclear (six individuals typed for 597 573 SNPs) and mitochondrial (11 complete sequences) DNA from the GAC appear closer to those of earlier Neolithic groups than to the DNA of all other populations related to the Pontic steppe migration. Explicit comparisons of alternative demographic models via approximate Bayesian computation confirmed this pattern. These results are not in contrast to Late Neolithic gene flow from the Pontic steppes into Central Europe. However, they add nuance to this model, showing that the eastern affinities of the GAC in the archaeological record reflect cultural influences from other groups from the East, rather than the movement of people.

globular-amphora-pca-admixture
(a) Principal component analysis on genomic diversity in ancient and modern individuals. (b) K = 3,4 ADMIXTURE analysis based only on ancient variation. (a) Principal component analysis of 777 modern West Eurasian samples with 199 ancient samples. Only transversions considered in the PCA (to avoid confounding effects of post-mortem damage). We represented modern individuals as grey dots, and used coloured and labelled symbols to represent the ancient individuals. (b) Admixture plots at K = 3 and K = 4 of the analysis conducted only considering the ancient individuals. The full plot is shown in electronic supplementary material, figure S7. The ancient populations are sorted by a temporal scale from Pleistocene to Iron Age. The GAC samples of this study are displayed in the box on the right.

Excerpt, from the discussion:

In its classical formulation, the Kurgan hypothesis, i.e. a late Neolithic spread of proto-Indo-European languages from the Pontic steppes, regards the GAC people as largely descended from Late Neolithic ancestors from the East, most likely representing the Yamna culture; these populations then continued their Westward movement, giving rise to the later Corded Ware and Bell Beaker cultures. Gimbutas [23] suggested that the spread of Indo-European languages involved conflict, with eastern populations spreading their languages and customs to previously established European groups, which implies some degree of demographic change in the areas affected by the process. The genomic variation observed in GAC individuals from Kierzkowo, Poland, does not seem to agree with this view. Indeed, at the nuclear level, the GAC people show minor genetic affinities with the other populations related with the Kurgan Hypothesis, including the Yamna. On the contrary, they are similar to Early-Middle Neolithic populations, even geographically distant ones, from Iberia or Sweden. As already found for other Late Neolithic populations [18], in the GAC people’s genome there is a component related to those of much earlier hunting-gathering communities, probably a sign of admixture with them. At the nuclear level, there is a recognizable genealogical continuity from Yamna to Corded Ware. However, the view that the GAC people represented an intermediate phase in this large-scale migration finds no support in bi-dimensional representations of genome diversity (PCA and MDS), ADMIXTURE graphs, or in the set of estimated f3-statistics.

globular-amphora-hunter-gatherer-farmer-yamnaya
Scheme summarizing the five alternative models compared via ABC random forest. We generated by coalescent simulation mtDNA sequences under five models, differing as to the number of migration events considered. The coloured lines represent the ancient samples included in the analysis, namely Unetice (yellow line), Bell Beaker (purple line), Corded Ware (green line) and Globular Amphorae (red line) from Central Europe, Yamnaya (light blue line) and Srubnaya (brown line) from Eastern Europe. The arrows refer to the three waves of migration tested. Model NOMIG was the simplest one, in which the six populations did not have any genetic exchanges; models MIG1, MIG2 and MIG1, 2 differed from NOMIG in that they included the migration events number 1, 2 (from Eastern to Central Europe, respectively before and after the onset of the GAC), or both. Model MIG2, 3 represents a modification of MIG2 model also including a back migration from Central to Eastern Europe after the development of the Corded Ware culture.

Together with Globular Amphora culture samples from Mathieson et al. (2017), this suggests that Kristiansen’s Indo-European Corded Ware Theory is wrong, even in its latest revised models of 2017.

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The background shading indicates the tree migratory waves proposed by Marija Gimbutas, and personally
checked by her in 1995. The symbols refer to the ancient populations considered in the ABC analysis

On the other hand, the article’s genetic finds have some interesting connections in terms of mtDNA phylogeography, but without a proper archaeological model it is difficult to explain them.

mtdna-yamnaya-gac-corded-ware-bell-beaker
Haplogroup frequencies were obtained for Early Neolithic (EN), Middle Neolithic (MN), Chalcolithic (CA), and Late Neolithic (LN). The color assigned to each haplogroup is represented on the lower right part of each plot. Haplogroup frequencies were plotted geographically using QGIS v2.14.

Text and images from the article under Creative Commons Attribution 4.0 license.

Discovered first via Bernard Sécher’s blog.

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