Between 5,000 and 6,000 years ago, many Neolithic societies declined throughout western Eurasia due to a combination of factors that are still largely debated. Here, we report the discovery and genome reconstruction of Yersinia pestis, the etiological agent of plague, in Neolithic farmers in Sweden, pre-dating and basal to all modern and ancient known strains of this pathogen. We investigated the history of this strain by combining phylogenetic and molecular clock analyses of the bacterial genome, detailed archaeological information, and genomic analyses from infected individuals and hundreds of ancient human samples across Eurasia. These analyses revealed that multiple and independent lineages of Y. pestis branched and expanded across Eurasia during the Neolithic decline, spreading most likely through early trade networks rather than massive human migrations. Our results are consistent with the existence of a prehistoric plague pandemic that likely contributed to the decay of Neolithic populations in Europe.
We have evolved in the interpretation of the plague from 1) a Corded Ware-driven disease, to 2) a steppe disease that was spread by Yamna and Corded Ware, and now 3) a (potentially) Trypillia-driven disease that spread to the west earlier than Yamna and Corded Ware, but probably also later east and west with both.
At least it still seems that the plague and its demographic consequences were a good reason for the expansion of Indo-Europeans and Uralians into Europe, as we thought…
Featured image, from the paper: “The predicted model of early dispersion of Y. pestis during Neolithic and Bronze Age was built by integrating phylogenetic information of Y. pestis strains from this period (Figure 1E), their divergence times (Figure 3), the geographic locations, carbon dating and genotypes of the individuals, and the archaeological record. The model suggests that early Y. pestis strains likely emerged and spread from mega-settlements in Eastern Europe (built by the Trypillia Culture) into Europe and the Eurasian steppe, most likely through human interaction networks. This was facilitated by wheeled and animal-powered transports, which are schematized in the map with red lines with arrows pointing in both senses. Our model builds upon a previous model (Andrades Valtuena et al., 2017) that proposed the spread of plague to be associated with large-scale human migrations (blue line).”
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.
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.
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.
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).
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.
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…
I find it interesting that many geneticists would question the simplistic approach to the Out of Africa model as it is often enunciated, but they would at the same time consider the current simplistic model of Yamna expansion essentially right; a model – if anyone is lost here – based on proportions of the so-called Yamnaya™ ancestral component, as found in a small number of samples, from four or five Eneolithic–Chalcolithic cultures spanning more than a thousand years.
These wrong interpretations have been now substituted by data from two new early samples from the Baltic, which cluster closely to Yamna, and which – based on the Y-DNA and PCA cluster formed by all Corded Ware samples – are likely the product of female exogamy with Yamna peoples from the neighbouring North Pontic region (as we are seeing, e.g. in the recent Nikitin et al. 2018).
NOTE. There is also another paper from Nikitin et al. (2017), with more ancient mtDNA, “Subdivisions of haplogroups U and C encompass mitochondrial DNA lineages of Eneolithic-Early Bronze Age Kurgan populations of western North Pontic steppe”. Link to paper (behind paywall). Most interesting data is summarized in the following table:
Even after the publication of Olalde et al. (2018) and Wang et al. (2018) – where expanding Yamna settlers and Bell Beakers are clearly seen highly admixed within a few generations, and are found spread across a wide Eurasian cline (sharing one common invariable trait, the paternally inherited haplogroup, as supported by David Reich) – fine-scale studies of population structure and social dynamics is still not a thing for many, even though it receives more and more advocates among geneticists (e.g. Lazaridis, or Veeramah).
NOTE. I have tried to explain, more than once, that the nature and origin of the so-called “Yamnaya ancestry” (then “steppe ancestry”, and now subdivided further as Steppe_EMBA and Steppe_MLBA) is not known with precision before Yamna samples of ca. 3000 BC, and especially that it is not necessarily a marker of Indo-European speakers. Why some people are adamant that steppe ancestry and thus R1a must be Indo-European is mostly related to a combination of grandaddy’s haplogroup, the own modern ethnolinguistic attribution, and an aversion to sharing grandpa with other peoples and cultures.
In the meantime, we are seeing the “Yamnaya proportion” question often reversed: “how do we make Corded Ware stem from Yamna, now that we believed it?”. This is a funny circular reasoning, akin to the one used by proponents of the Franco-Cantabrian origin of R1b, when they look now at EEF proportions in Iberian R1b-L23 samples. It seems too comic to be true.
R1a and steppe ancestry
The most likely origin of haplogroup R1a-Z645 is to be found in eastern Europe. Samples published in the last year support this region as a sort of cradle of R1a expansions:
I1819, Y-DNA R1a1-M459, mtDNA U5b2, Ukraine Mesolithic ca. 8825-8561 calBCE, from Vasilievka.
I0061, hg R1a1-M459 (xR1a1a-M17), mtDNA C1, ca. 6773-6000 calBCE (with variable dates), from Yuzhnyy Oleni Ostrov in Karelia.
Samples LOK_1980.006 and LOK_1981.024.01, of hg MR1a1a-M17, mtDNA F, Baikalic cultures, dated ca. 5500-5000 BC.
Sample I0433, hg R1a1-M459(xM198), mtDNA U5a1i, from Samara Eneolithic, ca. 5200-4000 BCE
Samples A3, A8, A9, of hg R1a1-M459, mtDNA H, from sub-Neolithic cultures (Comb Ware and Zhizhitskaya) at Serteyea, although dates (ca. 5th-3rd millennium BC) need possibly a revision (from Chekunova 2014).
NOTE. The fact that Europe is better sampled than North Asia, coupled with the finding of R1a-M17 in Baikalic cultures, poses some problems as to the precise origin of this haplogroup and its subclades. While the first (Palaeolithic or Mesolithic) expansion was almost certainly from Northern Eurasia to the west – due to the Mal’ta sample – , it is still unknown if the different subclades of R1a in Europe are the result of local developments, or rather different east—west migrations through North Eurasia.
Y-Full average estimates pointed to R1a-M417 formation ca. 6500 BC, TMRCA ca. 3500 BC, and R1a-Z645 formation ca. 3300 BC, TMRCA ca. 2900 BC, so the most likely explanation was that R1a-Z645 and its subclades – similar to R1b-L23 subclades, but slightly later) expanded quickly with the expansion of Corded Ware groups.
The presence of steppe ancestry in Ukraine Eneolithic sample I6561, of haplogroup R1a-M417, from Alexandria, dated ca. 4045-3974 calBCE, pointed to the forest steppe area and late Sredni Stog as the most likely territory from where the haplogroup related to the Corded Ware culture expanded.
However, the more recent Y-SNP call showing R1a-Z93 (L657) subclade rendered Y-Full’s (at least formation) estimates too young, so we have to rethink the actual origin of both subclades, R1a-Z93 (formation ca. 2900 BC, TMRCA ca 2700 BC), and R1a-Z283 (formation ca. 2900 BC, TMRCA ca. 2800 BC).
Contrary to what we thought before this, then, it is possible that the expansion of Khvalynsk-Novodanilovka chieftains through the steppes, around the mid-5th millennium BC, had something to do with the expansion of R1a-Z645 to the north, in the forest steppe.
We could think that the finding of Z93 in Alexandria after the expansion of Khvalynsk-Novodanilovka chiefs would make it more likely that R1a-Z645 will be found in the North Pontic area. However, given that Lower Mikhailovka and Kvitjana seem to follow a steppe-related cultural tradition, different to forest steppe cultures (like Dereivka and Alexandria), and that forest steppe cultures show connections to neighbouring northern and western forest regions, the rest of the expanding R1a-Z645 community may not be related directly to the steppe at all.
Adding a hypothetical split and expansion of Z645 subclades to the mid-/late-5th millennium could place the expansion of this haplogroup to the north and west, pushed by expanding Middle PIE-speaking steppe peoples from the east:
This is what Włodarczak (2017) says about the emergence of Corded Ware with ‘steppe features’ after the previous expansion of such features in Central Europe with Globular Amphorae peoples. He refers here to the Złota culture (appearing ca. 2900-2800 BC) in Lesser Poland, believed to be the (or a) transitional stage between GAC and Corded Ware, before the emergence of the full-fledged “Corded Ware package”.
So far, to the north of the Carpathian Mountains, including Polish lands, no graves indicating their relationship with communities of the steppe zone have been found. On the contrary, the funeral rites always display a local, central European nature. However, individual elements typical of steppe communities do appear, such as the “frog-like” arrangement of the body (Fig. 20), or items associated with Pit Grave milieux (cf. Klochko, Kośko 2009; Włodarczak 2014). A spectacular example of the latter is the pointed-base vessel of Pit Grave culture found at the cemetery in Święte, site 11 near Jarosław (Kośko et al. 2012). These finds constitute a confirmation of the importance of the relationships between communities of Pit Grave culture and Corded Ware culture. They are chronologically diverse, although most of them are dated to 2600-2400 BC – that is, to the “classic” period of Corded Ware culture.
However, when discussing the relationships with the steppe communities, Polish lands deserve particular attention since part of the groups inhabiting it belonged to the eastern province of Corded Ware culture (cf. Häusler 2014), which neighboured Pit Grave culture both from the east and south. In addition, there was a tradition of varied relationships with the north Pontic zone, which began to intensify from the second half of the 4th millennium BC (Kośko, Szmyt, 2009; Kośko, Klochko, 2009). These connections are especially readable in Małopolska and Kujawy (Kośko 2014; Włodarczak 2014). The emergence of the community of Globular Amphora culture in the north Pontic zone at the end of the 4th and the beginnings of the 3rd millennium BC (Szmyt 1999) became a harbinger of a cultural closening between the worlds of central Europe and the steppe.
The second important factor taking place at that time was the expansion of the people of Pit Grave culture in a westerly direction, along the Danube thoroughfare. As a result of this, also to the south of the Carpathian Mountains, e.g., along the upper Tisza River, a new “kurgan” cultural system was formed. As one outcome, the areas of central Europe, above all Małopolska, found themselves in the vicinity of areas inhabited by communities characterized by new principles of social organization and a new funeral rite. Around 2800 BC these changes became evident in different regions of Poland, with the most numerous examples being documented in south-eastern Poland and Kujawy. The nature of the funeral rite and the features of the material culture perceptible at that time do not have straight forward analogies in the world of north Pontic communities. In this respect, the “A-horizon” is a phenomenon of local, central European origin. The events preceding the emergence of the said horizon (that is, the expansion of the people of Pit Grave culture into the area north of the arc of the Carpathians) are nowadays completely unidentifiable and remain merely an interesting theoretical matter (cf. e.g., Kośko 2000). Therefore, analysis of the archaeological sources cannot confirm the first archaeogenetic analysis suggesting a bond between the communities of the Pit Grave culture and Corded Ware culture (e.g., Haak et al. 2015).
Artefacts of the “A-horizon”, i.e., shaft-hole axes, amphorae (Fig. 21), beakers, and pots with a plastic wavy strip (Fig. 7) are found in different funerary and settlement contexts, sometimes jointly with finds having characteristics of various cultures (e.g., in graves of Złota culture, or at settlements of Rzucewo culture). Hence, they primarily represent a chronological phase (c. 2800-2600 BC), one obviously related to the expansion of a new ideology.
Eastern CWC expansion
Before continuing tracing the Corded Ware culture’s main features, it is worth it to trace first their movement forward in time, as Corded Ware settlers, from Poland to the east.
The colonizing Neolithic waves are continued by the Circum-Baltic Corded Ware culture, closely related to the traditions of the Single Grave culture and traditions of the Northern European Lowlands. After ca. 2900 BC, certain cultural systems with ‘corded’ traits –genetically related to the catchment area of the south-western Baltic – appear in the drainages of the Nemen, Dvina, Upper Dnieper, and even the Volga. These communities are considered the vector of Neolithisation in the Forest Zone.
The picture in the Baltic (Pamariu / Rzucewo) and Finland (Battle Axe) is thus more or less clearly connected with early dates ca. 2900-2800 BC:
There is a clear interaction sphere between the eastern Gulf of Finland area – reaching from Estonia to the areas of present-day Finland and the Karelian Isthmus in Russia –, evidenced e.g. by the sharp-butted axes, derived from the Estonian Karlova axe.
Interesting in this regard is the expansion of the Corded Ware culture in Finland, into a far greater territory than previously thought, that is poorly represented in most maps depicting the extent of the culture in Europe. Here is summary of CWC findings in Finland, using images from Nordqvist and Häkäla (2014):
Middle Dnieper and Fatyanovo
The earliest Middle Dnieper remains are related to CWC graves between the Upper Vistula and the Bug, containing pottery with Middle Dnieper traits, dated probably ca. 2700 BC, which links it with the expansion of the A-horizon. In fact, during the period ca. 2800-2400 BC, the area of Lesser Poland (with its numerous kurgans and catacomb burials) is considered the western fringe of an area spreading to the east, to the middle Dniester and middle Dnieper river basins, i.e. regions bordering the steppe oecumene. This ‘eastern connection’ of funeral ritual, raw materials, and stylistic traits of artefacts is also identified in some graves of the Polish Lowlands (Włodarczak 2017).
The Fatyanovo (or Fatyanovo-Balanovo) culture was the easternmost group of the Corded Ware culture, and occupied the centre of the Russian Plain, from Lake Ilmen and the Upper Dnieper drainage to the Wiatka River and the middle course of the Volga. From the few available dates, the oldest ones from the plains of the Moskva river, and from the late Volosovo culture containing also Fatyanovo materials, and in combination they show a date of ca. 2700 BC for its appearance in the region. The Volosovo culture of foragers eventually disappeared when the Fatyanovo culture expanded into the Upper and Middle Volga basin.
The origin of the culture is complicated, because it involves at its earliest stage different Corded Ware influences in neighbouring sites, at least on the Moskva river plains (Krenke et al. 2013): some materials (possibly earlier) show Circum-Baltic and Polish features; other sites show a connection to western materials, in turn a bridge to the Middle Dnieper culture. This suggests that groups belonging to different groups of the corded ware tradition penetrated the Moscow region.
The split of subclades Z93 – Z283
If we take into account that the split between R1-Z93 and R1a-Z283 must have happened during the 5th millennium BC, we have R1a-Z93 likely around the middle Dnieper area (as supported by the Alexandria sample), and R1a-Z283 possibly to the north(-west), so that it could have expanded easily into Central Europe, and – through the northern, Baltic region – to the east.
Where exactly lies the division is unclear, but for the moment all reported Circum-Baltic samples with Z645 subclades seem to belong to Z282, while R1a samples from Sintashta/Potapovka (including the Poltavka outlier) point to Abashevo being dominated by R1a-Z93 subclades.
We have to assume, then, that an original east-west split betwen R1a-Z283 and R1a-Z93 turned, in the eastern migrations, into a north-south split between Z282 and Z93, where Finland and Battle Axe in general is going to show Z282, and Middle Dnieper – Abashevo Z93 subclades.
I can think of two reasons why this is important:
Depending on how Proto-Corded Ware peoples expanded, we may be talking about one community overcoming the other and imposing its language. Because either
clans of both Z93 and Z283 were quite close and kept intense cultural contacts around Dnieper-Dniester area; or
if the split is as early as the 5th millennium BC, and both communities separated then without contact, we are probably going to see a difference in the language spoken by both of them.
In any case, the main north-south division of eastern Corded Ware groups is pointing to an important linguistic division within the Uralic-speaking communities, specifically between a Pre-Finno-Ugric and a Pre-Samoyedic one, and potentially between Pre-Finno-Permic and Pre-Ugric.
These may seem irrelevant questions – especially for people interested only in Indo-European migrations. However, for those interested in the history of Eurasian peoples and languages as a whole, they are relevant: even those who support an ‘eastern’ origin of Proto-Uralic, like Häkkinen, or Parpola (who are, by the way, in the minority, because most Uralicists would point to eastern Europe well before the Yamna expansion), place the Finno-Ugric expansion with the Netted Ware culture as the latest possible Finno-Ugric immigrants in Fennoscandia.
The Netted Ware culture
The image below shows the approximate expansion of Corded Ware peoples of Battle Axe traditions in Finland, as well as neighbouring Fennoscandian territories, from ca. 2800 BC until the end of the 3rd millennium. A controversial 2nd (late) wave of the so-called Estonian Corded Ware is popular in texts about this region, but has not been substantiated, and it seems to be a regional development, rather than the product of migrations.
As we have seen, Fatyanovo represents the most likely cultural border zone between Circum-Baltic peoples reaching from the Russian Battle Axe to the south, and Middle Dnieper peoples reaching from Abashevo to the north. In that sense, it also represents the most likely border culture between north-western (mainly R1a-Z282) and south-eastern (R1a-Z93) subclades.
With worsening climatic conditions (cooler seasons) at the end of the 3rd millennium, less settlements are apparent in the archaeological record in Finland. After ca. 2000 BC, two CWC-related cultures remain: in the coast, the Kiukainen culture, derived from the original Circum-Baltic Corded Ware settlers, reverts to a subsistence economy which includes hunting and fishing, and keeps mainly settlements (from the best territories) along the coast. In the inland, Netted Ware immigrants eventually appear from the south.
The Netted Ware culture emerged in the Upper Volga–Oka region, derived from the Abashevo culture and its interaction with the Seima-Turbino network, and spread ca. 1900-1800 BC to the north into Finland, spreading into eastern regions previously occupied by cultures producing asbestos and organic-tempered wares (Parpola 2018).
NOTE. Those ‘contaminated’ by the Copenhagen fantasy map series may think that Volosovo hunter-gatherers somehow survived the expansion of Fatyanovo-Balanovo and Abashevo, hidden for hundreds of years in the forest, and then reappeared and expanded the Netted Ware culture. Well, they didn’t. At least not in archaeological terms, and certainly not with the genetic data we have.
If we combine all this information, and we think about these peoples in terms of Pre-Finno-Permic and Pre-Ugric languages developing side by side, we get a really interesting picture (see here for Proto-Fennic estimates):
The Battle Axe around the Baltic Sea – including the Gulf of Finland and Scandinavia – would be the area of expansion of Pre-Finno-Permic peoples, of R1a-Z283 subclades, which became later concentrated mainly on coastal regions;
the southern areas may correspond to Pre-Ugric peoples, which expanded later to the north with Netted Ware (see image below) – their precise subclades may be dependent on what will be found in Fatyanovo;
and Pre-Samoyedic peoples (of R1a-Z93 subclades) would have become isolated somewhere in the Cis- or (more likely) Trans-Urals region after 2000 BC, possibly from the interaction of the latest Balanovo stages and the Seima-Turbino phenomenon.
These communities in contact would have allowed for:
the known Indo-Iranian loanwords in Finno-Ugric to spread through a continuum of early dialects formed by Abashevo – Fatyanovo – Battle Axe groups;
the important Palaeo-Germanic loanwords in Finno-Saamic spreading with long-term contacts (from Pre-Germanic to the Proto-Germanic, and later North Germanic period) through the Baltic Sea, between Scandinavia and the Gulf of Finland;
and Tocharian contacts with Samoyedic (although limited, and in part controversial), which point to its early expansion to the east of the Ural Mountains.
On the other hand, if one is inclined to believe that R1a and steppe ancestry do represent Indo-European speakers… which language was spoken from the Gulf of Finland well into the north, the inland, and Karelia, and in Northern Russia, by Corded Ware peoples and their cultural heirs (like Kiukainen or Netted Ware) for almost three thousand years?
After the expansion of Bell Beaker peoples, the geographic distribution of late Corded Ware groups in the second half of the 3rd millennium, just before their demise – and before the expansion of Netted Ware to the north – , can be depicted thus as follows:
Territories in cyan must then represent, for some people who believe in an archaic Indo-Slavonic of sorts, the famous Fennoscandian Balto-Slavic to the north (before they were displaced by incoming Finno-Saamic peoples of hg N1c during the Iron Age and up to the Middle Ages); and the also famous Tundra-Forest Indo-Iranian in the Upper Volga area, a great environment for the development of the two-wheeled chariot…
But let’s leave the discussion on imaginary IE dialects for another post, and continue with the real question at hand.
A steppe funerary connection?
Back to Złota as a transitional culture, we have already seen how the corded ware vessels characteristic of the Classic CWC are related to Globular Amphora tradition, and show no break with this culture. It is usually believed that the funerary rites were adopted from steppe influence, too. That is probably right; but it does not mean that it came from Yamna or other coeval (or previous) steppe culture; at least not directly.
NOTE. A similar problem is seen when we read that Mierzanowice or Trzciniec show “Corded Ware” traits from a neighbouring CWC group, when CWC groups disappeared long before these cultures emerged. For cultural groups that are separated centuries from each other, an assertion as to their relationship needs specifics in terms of dates and material connection, or it is plainly wrong.
These are the funerary ritual features from Złota (later specialized in Corded Ware), as described by Włodarczak (2017):
Single burial graves; along with the habit of interring the deceased in multiple burial graves, but emphasizing their individual character by careful deposition of the body and personal nature of the grave goods.
Grave goods with materials and stylistiscs belonging to an older system (e.g. amber products); and others correlated to the ‘new world’ of the CWC, such as flint products made of the raw materials tipical of Lesser Poland’s CWC, copper ornaments, stone shaft-hole axes, bone and shell ornaments, and characteristic forms of vessels like beakers and amphoras.
Military goods, which would become prevalent in later periods, are present in a moderate number, compatible with their lesser importance.
There are also cases of the characteristic catacomb (“niche”) graves – with an entrance pit, a more extensive niche, and a narrow corridor leading to a vault – , as well as some individual cases of application of ochre and deformation of skulls.
It seems that the Złota funerary tradition was also “transitional”, like corded ware vessels, into the classical Corded Ware ideology. But “transitional” from what exactly? Yamna? Probably not.
The Lublin-Volhynia culture
One needs not look for a too distant culture to find similarities. Włodarczak (2017) points to CWC in south-eastern Poland and Kuyavia showing, by the time of the Yamna expansion, a funeral rite and features of the material culture without straightforward analogies in the world of north Pontic communities, and thus suggests that the “A-horizon” is a local phenomenon of central European origin.
This assertion is interesting, in so far as most Corded Ware samples investigated to date seem to come precisely from an East-Central territory near the Ukraine forest steppe, with a cluster already established by the end of the 5th millennium:
The following text is from Stanisław Wilk (2018), about the Lublin-Volhynian (and related) cemeteries at Wyciąże and Książnice:
Regardless of the differences between the two necropolises (such as the number of burials, the area which has been explored, the orientation and layout of burials), it seems that they have several key elements in common:
concentration of graves in separate cemeteries;
differentiation of burials with regard to sex (the principle of the ‘left ̶ right’ side, different burial goods for males and females);
stratification of graves with regard to the richness of their inventories (this mainly applied to copper artefacts);
occurrence of indicators of the richest male burials (a copper dagger in Wyciąże, a copper battle axe, a small axe and a chisel in Książnice);
allocation of a separate area for elite burials (the eastern burial area in Książnice, and the southeastern and north-central part of the necropolis in Wyciąże), as well as one for egalitarian burials (the western area in Książnice, and the south-central and western part of the cemetery in Wyciąże).
The above-mentioned characteristics prove that the patterns of social and religious behaviours from areas lying beyond the Carpathian Mountains exerted a strong influence on the two societies living in Lesser Poland.
Anna Zakościelna, while describing the similarities between the burial ritual of the late Polgár groups and cultures from areas on the Tisza river and the Lublin-Volhynia culture, claimed that:
a characteristic feature of the burial ritual of both cultures was practicing various group norms, which required different treatment of the deceased depending on their sex, age and social rank. As in the Lublin-Volhynia culture, the opposition ‘male – female’ can the most clearly be observed ̶ particularly, in the consistent positioning of males on the right, and females, on the left side. And, there is much indication that this ritual norm divided the deceased from early childhood (Sofaer Derevensky 1997: 877, Tab. 1; Lichter 2001: 276- 280, 322-323) (Zakościelna 2010: 227-228).
It seems that these observations can also be extended to the Wyciąże-Złotniki group.
Another question is whether the evidence of the influences of the copper civilization observed in both cemeteries emerged as a result of the literal copying of patterns from the south, or whether the latter were only a source of inspiration for local solutions.
Looking at this problem form the perspective of the details of burial ritual, between the Carpathian Basin and Lesser Poland, we can observe clear differences, among others, in the size of cemeteries and orientation of burials. While, in the Carpathian Basin there were large necropolises, consisting of several dozen burials located in rows, with the dominant orientation along the SE-NW and E-W axis (Lichter 2001: Abb. 123, 143; Kadrow 2008: 87); in Lesser Poland there were small cemeteries of several to a dozen or so burials, mostly oriented along the S-N axis (in the Lublin-Volhynia culture; Zakościelna 2010: 66), as well as S-E and NE-SW (in the Wyciąże-Złotniki group; Kaczanowska 2009: 77). Similarly, there are differences in the details of the burial goods. North of the Carpathians, there is a much smaller frequency of copper artefacts, particularly in the group of prestigious, heavy items (battle axes, axes and daggers), as well as a complete lack of objects made of gold. Want is more, the pottery found in the graves has a distinct local character, only supplemented by imitating or imports from areas beyond the Carpathians (Zakościelna 2006: 85; Nowak 2014: 273; a different opinion Kozłowski 2006: 57). Therefore, the suggestion made by Nowak seems right ̶ namely, that these influences were not caused by migrations of groups of the population living on the Tisza river to Lesser Poland, but were rather due to processes of selective cultural transmission (Nowak 2014: 273).
Therefore, the sharing of a similar funerary rite (as happened later between Lublin-Volhynia and Złota), although it shows a strong cultural connection with autochthonous cultures, is obviously not the same as sharing ancestors; and even if it were so, they would not need to be paternal ancestors. But it shows that important Corded Ware cultural traits are local developments, and it disconnects thus still more supposed CWC ‘steppe traits’ from steppe cultures, and connects them with the first steppe-related cultural wave that reached central Europe in the 5th millennium BC.
Prehistoric Pontic—Caspian links
How would a Lublin-Volhynia culture be related to the North Pontic area ca. 4500-3000 BC? We can enjoy the map series of Baltic—Pontic migrations by Viktor Klochko (2009), and make a wild guess:
In the second half of the 5th millennium BC (horizon 1), communities of the Tripolye culture, phases BI-BII, had contacts with the population of the late (IIa) phase of the Malice culture. The areas settled by both cultural complexes were located at a great distance from each other. The communities of the Tripolye culture adopted selected features of Malice ceramic production (fig 2). This seems to have resulted from marital exchange: on a moderate scale, Tripolye men sought out their wives in the area of the Malice culture and, according to patrilocal marriage customs, the women then moved to the Tripolye settlements, sporadically transferring ready-made ceramic products, so-called imports, to the Tripolye culture. Thus, the wives were responsible for the considerably more numerous imitations of the Malice ceramics and the long-lasting, though selective, traditions of Malice pottery passed down in their new environment. The patrilocal marriage customs involving the Malice women and the Tripolye men (never the other way round), and the fact that pottery was women’s domain, led to the unidirectional transfer of vessels, technology and norms of ceramic production from the Malice culture to the Tripolye culture.
The turn of the 5th and the 4th millennia and the early 4th millennium BC (horizon 2) witnessed the deepening interaction between the populations of the youngest (IIb) phase of the Malice culture and the classic (II) phase of the Lublin-Volhynia culture on the one hand and the communities of phase BII of the Tripolye culture on the other. The Danube and the Tripolye settlement complexes came into contact on the upper Dniester and between the Styr and the Horyn rivers in Volhynia. This helped to continue the previous forms of marital exchange, which resulted in further popularisation of the ceramics and the traditions of ceramic production typical of the Danube cultures, i.e. the Malice and the Lublin-Volhynia cultures, and also the Polgár culture, in the areas settled by the Tripolye cultural complex.
As the civilizational norms of the Eneolithic (Copper) Age became widespread in that period, the forms of interaction described above acquired new elements. The deepening internal diversification of the early Eneolithic communities of the Lublin-Volhynia culture led to a growing demand for prestige objects, which was met with import or imitation of copper artefacts, mainly those from the Carpathian Basin, and with flint tools produced from long blades. That type of flint production depended largely on new technologies derived from the Tripolye culture, as proven by such borrowings as troughlike retouch or the very idea and technology for the production of long flint blades in the Lublin-Volhynia culture. It seems that the influx of Tripolye settlers into flintbearing areas in Volhynia and on the upper Dniester, adjacent to the settlement centres of the late phase of the Malice culture and the Lublin-Volhynia culture, created sufficient conditions for the expanding influence of the Tripolye flint working on the communities of the Eneolithic Lublin-Volhynia culture.
In the mid-4th millennium BC (horizon 3), those forms of interaction between the Danube communities (the late phase of the Lublin-Volhynian culture) and the Tripolye communities (phase CI)were continued. Elements of the Danube pottery still grew in popularity in the Tripolye population, while selected features of the Tripolye flint working were adopted by the Lublin-Volhynia culture.
In that period, the population of the Funnel Beaker culture of the pre-classic and early classic phases (the beginnings of Gródek 1 and Bronocice III), until then absent from those areas, quite quickly drove out and replaced the Danube population in western Volhynia and the upper Dniester basin. This caused significant changes in the forms and intensity of the intercultural interaction, which became fully apparent already in the 2nd half of the 4th millennium BC.
In the following period (horizon 4), the population of the classic phase of the Funnel Beaker culture (Gródek 1, Bronocice III) settled more and more intensively the upper Dniester basin, up to the Hnyla Lypa river, and western Volhynia, up to the Styr river. East of those rivers, the Funnel Beaker settlers created considerable areas where they mixed with settlers from early phase CII of the Tripolye culture. Their coexistence, lasting there for many generations, resulted in deepening the interactions between members of both cultural complexes and in developing entirely new forms of relationships.
The intensifying interaction between the communities of the Funnel Beaker culture and the Tripolye culture, early phase CII, in the 2nd half of the 4th millennium BC (horizon 4) was an introduction to, and perhaps a condition for, even more frequent contacts in the next period, the first centuries of the 3rd millennium BC (horizon 5). In that case, the interaction was mainly triggered by multidirectional migrations of larger human groups, involving a significant part of the population of all cultures from the areas discussed here. The Tripolye communities of younger phase CII settled Volhynia, its eastern areas in particular, from the south and the south-east, while groups representing the younger phases of the Funnel Beaker culture (Gródek 2), often with Baden features (Bronocice IV and V), moved increasingly into the western part of that region. The Yamna communities expanded along the lower and central Danube to the west, whereas the populations of the late phase of the Baden culture took the opposite direction, reaching as far as Kiev in the northeast, and contributed to the cultural character of the Sofievka group.
The communities of the Globular Amphora culture migrated from the north-west, from eastern Poland, towards the Danube Delta and as far as the Dnieper in the east, while the multicultural population from the areas around the mouth of the Danube moved in the opposite direction, carrying with them cultural elements from Thrace, or even from Anatolia. Some of them returned to the starting point (to south-eastern Poland), bringing with them a new form of pottery, so-called Thuringian amphora, borrowed from the late Trypillian Usatovo group. This resulted in origins of the Złota culture, a cultural phenomenon that gave beginnings to the oldest Corded Ware culture. Inventories of both cultures contained the already mentioned Thuringian amphorae.
Here is a more recent assessment (2017) of the latest radiocarbon analyses of the available settlements of cultures in the area, published by Marek Novak (announced in a previous post), which gives the following data on Wyciąże-Złotniki, Lublin-Volhynia, and Wyciąże/Niedźwiedź:
This scheme unambiguously suggests both the overlapping and contiguous nature of cultural development in western Lesser Poland within the Middle Neolithic. The basic elements of this development are: 1) the Wyciąże-Złotniki group and the Lublin-Volhynian culture, until c. 3650–3550 cal BC; 2) the Funnel Beaker culture proper, which appeared c. 3750–3700c al BC, and existed until c. 3300–3250 cal BC, perhaps accompanied by the Wyciąże/Niedźwiedź materials from c. 3650–3550 cal BC; and 3) the Baden culture and the Funnel Beaker/Baden assemblages from 3100 and 3300–3100 cal BC, respectively, until 2850–2750 and 2850 cal BC, with – possibly – later Funnel Beaker culture and Wyciąże/ Niedźwiedź materials, existing until c. 3100 cal BC.
The final scheme shows that the Lublin-Volhynian culture could have coincided with the Wyciąże-Złotniki group. In view of the territorial relationship between them, relations from the point of view of material culture, primarily in the field of pottery, become particularly interesting. It is relatively easy to see clear similarities between these units. However, the most evident similarities apply only to some categories of ceramics, including, for example, vessels with Scheibenhenkel handles. What is more, in the period between the late 38th and early 36th centuries BC, the early Funnel Beaker and possibly early Baden influences are superimposed on this Lublin-Volhynian/Wyciąże-Złotniki ‘mix’.
[About Corded Ware: The] development of this unit in central Europe, including western Lesser Poland,  usually point to c. 2800 cal BC (Włodarczak 2006a). (…) the calibration curve makes it possible to alternatively refer several dates earlier than c. 3100 to c. 2850–2800 cal BC.
There is no direct archaeological link of Lublin-Volhynia-related groups with Corded Ware, beyond the fact that they shared homeland and Central European (‘steppe-related’) traits, as found in the Złota culture. But there is no direct link of Yamna with Corded Ware, either, whether in terms of culture or population.
So, given the evident link of R1a-Z93 and steppe ancestry with the forest steppe ca. 4000 BC, the surrounding North Pontic areas in contact along the Dniester, Dnieper, Bug, and Prut are the best candidates for the appearance of R1a-Z283: steppe cultures to the south and south-west; sub-Neolithic (Comb Ware) groups to the north in the forest zone; and Eneolithic groups to the west and north-west.
Seeing how ‘ancestral components’ and PCA cluster can change within a few generations, the question of the spread of R1a-Z645 subclades is still not settled by a single sample in Alexandria. However, based on the explosive expansions we are seeing from small territories, it would not be surprising to find R1a-Z93 and R1a-Z283 side by side in the same small area within the forest steppe.
NOTE. An archaeological link may not mean anything relevant in genetics, especially – as in this case – when no clear migration event has been traced to date. We have seen exactly that with Kristiansen’s proposal of a long-term genetic admixture of Yamna with Trypillia and GAC to form Corded Ware, which didn’t happen. The cultural and ideological connection of CWC peoples with Lublin-Volhynian tradition may be similar to the already known connection with GAC, and not mean anything in genetic finds; at least in terms of Y-DNA haplogroup.
We believed in the 2000s that Corded Ware represented the expansion of Late Proto-Indo-European, because the modern map of haplogroup R1a showed a distribution similar to how we thought the European and Indo-Iranian languages could have expanded. This has been proven wrong, and that’s what ancient DNA is for; not to confirm the own ideas or models, or to support modern ideologies.
It is impossible to know if R1a-Z645 comes from the steppe, forest steppe, or forest zone, until more samples are published. I don’t think there will be any big surprise, no matter where it is eventually found. By now, adding linguistic reconstruction to archaeological traits, and to the genetic data from Yamna and Corded Ware settlers, the only clear pattern is that patrilineal clans expanded, during the Final Eneolithic / Chalcolithic:
Late Proto-Indo-European with Yamna and R1b-L23 subclades, given the known genomic data from Khvalynsk, Yamna, Afanasevo, Bell Beaker, Catacomb, and Poltavka—Sintashta/Potapovka.
Uralic with Corded Ware and R1a-Z645 subclades, given the known genomic data from Fennoscandia and the Forest Zone.
Everything else is just wishful thinking at this moment.
The main objects of study in Corded Ware origins are necessarily the region where the oldest Corded Ware vessels appeared, Lesser Poland, as well as the adjacent (traditionally considered Proto-Corded Ware regions) Volhynia, Podolia, and upper Dniester river basin. These are some relevant points, continuing where I left the Eneolithic steppe developments (following Szmyt 1999, Rassamakin 1999, Kadrow 2008, Furholt 2014):
More frequent contacts were seen ca. 3500-3000 BC, with an interaction showing multidirectional migrations of larger human groups in the centuries around 3000 BC, involving a significant part of the population of central-east Europe.
The easternmost area of the Funnel Beaker culture had become more Baden-like with the expansion of the Baden culture in its western area ca. 3300-2900 BC (with findings up to 2600 BC), and these younger groups with Baden features moved increasingly into the western part of Volhynia.
The influence of the neighbouring Trypillian culture is seen in the eastern parts of Volhynia, from ca. 3000 BC, either from a younger phase CII (cf. Troyaniv, Koshilivtsy, Brînzeni, Zhvaniets, or Vychvatintsy) or later groups (cf. Gorodsk, Kasperivtsy, Sofievka, Horodiştea-Folteşti, Usatovo).
In the forest-steppe zone, herding and hunting activities intensified, while agricultural traditions were preserved, as shown by the Sofievka, Kasperivtsy, and Gorodsk groups. From the end of the 4th millennium BC mobile parts of the late Trypillian populations moved to the steppe zone, absorbing more and more steppe elements; among others, cord ornamentation (in Vykhvatintsy, Troyaniv, and Gorodsk groups), pottery forms (Vykhvatintsy, which served as prototype for the Thuringian Apmphorae, dispersed along the Dniester river, too), flat burials with bodies in contracted position on the left or right side (Vykhvatintsy, reminding of Polgár culture different male-female position, and later Corded Ware burials, and also Lower Mikhailovka, under a mound without stone constructions). At the end of the Trypillia culture, its agricultural system collapsed completely.
Slash and burn techniques of agriculture – especially those practiced by Trypillian and Funnel Beaker populations – must have intensified effects of natural growth of humidity (ca. 3400-2400), increasing fluvial activities in west Ukrainian river valleys, and increasing deforestation processes, which favoured pastoralism and nomadisation of the settlement system, and a consequent change of the social structure
At the same time, Yamna communities expanded along the lower and central Danube to the west, while the populations of the late phase of the Baden culture took the opposite direction and reached as far as Kiev in the north-east, contributing to the culture of the Sofievka group.
Globular Amphora communities migrated from the north-west, from eastern Poland, towards the Danube Delta and as far as the Dnieper in the east, destroying the primary structures of the communities in the supposed cradle territories of the Corded Ware culture. These communities found refuge and conditions for further development in south-eastern margin zone of the Funnel Beaker culture territories, penetrating at first the upper parts of the loess uplands like typical Funnel Beaker sites, but on the margins of their range, and also on areas avoided by Funnel Beaker settlement agglomerations. They brought with them the so-called Thuringian amphora up to Lesser Poland, borrowed from the late Trypillian Usatovo group. This resulted in the Złota culture, which eventually gave rise to the A-Amphorae.
In the end, we are left with this information about the oldest CWC (Furholt 2014):
The earliest radiocarbon-dated groups associated with the Corded Ware culture come from new single graves from Jutland in Denmark and Northern Germany, ca. 2900 BC. This Early Single Grave culture is associated with the appearance of individual graves (some time after the decline of the megalithic constructions), composed of a small round barrow and a new gender-differentiated burial practice emphasising male individuals orientated west-east (with regional exceptions), combined with the internment with new local battle-axe types (A-Axe). However, there is no single type of burial or burial custom in Corded Ware:
In southern Sweden the prevailing orientation is north-east – south-west, and south-north, contrary to the supposed rule male individuals are regularly deposited on their left and females on their right side.
In the Danish Isles and north-eastern Germany, the Final Neolithic / Single Grave Period is characterized by a majority of megalithic graves, with only some single graves from typical barrows. In south Germany, west-east and collective burials prevail, while in Switzerland no graves are found.
In Kujawia (south-eastern Poland), Hesse (Germany), or the Baltic, west-east orientation and gender differentiation cannot be proven statistically.
The oldest Corded Ware vessels (the A-Amphorae, which define the A-Horizon of the CWC) come probably from the Złota (or a related) group in Lesser Poland, where a mixed archaeological culture connecting Funnel Beaker, Baden, Globular Amphorae and Corded Ware appears ca. 2900-2600 BC. No cultural (typological) break is seen between earlier Globular Amphorae and the first Corded Ware Amphorae, but rather a continuum of traits and characteristics among the recovered vessels. This strengthens the connection of Corded Ware with Globular Amphorae peoples. The A-horizon expanded thus probably from Lesser Poland ca. 2800-2600, as seen in local contexts.
And of course we have a third way of defining Corded Ware individuals, which is the presence of herding, and thus a transition from hunter-gatherers to agropastoralists. This is how some Baltic Late Neolithic individuals with no archaeological data have been classified as members of the Corded Ware culture: Even though no cultural remains were extracted with the two ‘outlier’ individuals, their haplogroup and ancestry point to a direct origin in or around the steppe and forest-steppe region (yes, that risks circular reasoning).
Ukraine Neolithic cultures – mainly from Dereivka – show haplogroups R1b-V88, R1a1, and R1b-L754 (xP297, xM269), which is similar to the haplogroup distribution found in Ukraine Mesolithic, but apparently with an expanding group marked by haplogroup I2a2a1b1 (possibly I2a2a1b1b).
The first thing that stands out about Ukraine Eneolithic samples is that only two of them can be said to be really Ukraine Eneolithic (i.e. from “Sredni Stog”-related groups):
Corded Ware samples from Mittnik et al. (2018) offer very wide radiocarbon dates, so it is unclear which of them may be the oldest one. Most of them cluster closely to the older Ukraine Eneolithic sample I5876, but also to later steppe_MLBA samples i.e. Sintashta, Potapovka, and especially Srubna and Andronovo). This points to a genetic continuity from Pre-Corded Ware to Classic and late Corded Ware peoples. Therefore, much like Khvalynsk-Yamna and apparently many other Neolithic cultures, these peoples did not really admix; at least not with the male population.
Lucky for us, even though the culture remains undefined, haplogroup R1a-Z645 seems like a unifying trait, as I said long ago, so we only have to wait for more samples to trace their origin. Nevertheless, it is clear that Corded Ware may not have been as genetically homogeneous as Khvalynsk, Yamna and Yamna-related cultures, further supporting its archaeological complexity:
Jagodno1 and Jagodno2 (Silesia), dated ca. 2800 BC, show haplogroup G? and I/J? – compatible with an origin of CWC in common with Trypillia (which shows 3 samples of haplogroup G2a2b2a, and one E) and Ukraine Neolithic (showing the expansion of I2a2a1b1 subclades).
I7272, from Brandýsek (Czech Republic), dated ca. 2900-2200 BC shows haplogroup I2a2a2 (compatible with an origin in Ukraine Neolithic peoples – this haplogroup is also found in Yamna Kalmykia and in the Yamna Bulgaria outlier, i.e. late western samples from the Early Yamna culture).
NOTE. This precise subclade is only present to date in Chalcolithic samples from Iberia, which points (possibly like the Esperstedt family) to local Central European haplogroups integrated in a mixed Proto-Corded Ware population. The upper subclade I2a2a is found in Neolithic samples from Iberia, the British Isles, Hungary (Koros EN, ALPc), and also south-east European Mesolithic and Neolithic samples.
RISE1, from Oblaczkowo (Greater Poland), ca. 2865-2578 BC, shows haplogroup R1b1.
The Esperstedt family samples have been analysed as R1a-M417 (xZ645), although the supposed ‘xZ645’ has not been confirmed – not even in the risky new Y-calls from Wang et al. (2018) supplementary materials.
Maybe this heterogeneity is a problem of better defining the culture, but from what we can see the oldest CWC regions and the unifying ‘Corded Ware province’ – formed after ca. 2700 BC by Jutland and Northern Germany, the Netherlands, Saale, Bohemia, Austria and the Upper Danube regions – are for the moment not the most genetically homogeneous groups.
Homogeneity comes later – which we may tentatively identify with the expansion of the A-horizon from the northern Dnieper-Dniester and Lesser Poland area – , as seen around the Baltic (like the Battle Axe culture) with R1a-Z283 subclades, and around Sintashta (i.e. probably Abashevo – Balanovo) with R1a-Z93 subclades, which is compatible with the late spread of different Z645 groups (and potentially a unifying language) .
Unfortunately, due to poor preservation, mitochondrial haplotype calls were only obtained from the EBA individuals in this study. However, some interesting findings were observed. We find two adult local individuals with unique haplogroup lineages [H1a, H1e], and two juvenile individuals with haplogroup lineages [H2a and T1a] previously found exclusively in the CWC individuals analyzed here, all four dated to BA I showing that new lineages had already been established on Gotland at this time period. Another unique haplogroup lineage [K1b] is found in the child dated to BA III at Suderkvie, indicating continued migration to the island. Additionally, the two nonlocal individuals [LN II; ans010 and BA I; hgb010], were adding to the already existing haplogroup lineages [U5b and T2b, respectively] previously found in the PWC individuals analyzed here. The T2b lineage has also been found in the TRB individuals from the dolmen (Table S4).
Our ancestral contribution modeling for the maternal lineages showed that, among the models tested, the only models with a good fit were 55/45 CWC/TRB contribution (Fig. 6), or a 3-way mixture of 55% CWC, 40% TRB, and 5% PWC (Fig. S15). All other models had poor support, including the models with 100% contribution from either group present on Gotland in the preceding period. The PWC group had the weakest fit of all models which is quite surprising as the PWC was the only preceding group that was established on the island in the beginning of the LN period. Although separated temporally by more than 500 years, the individuals from the Hägur burial seems to have been well established in the Eksta area which previously was inhabited by PWC groups. However, the new haplogroup lineages [H1a and H2a] in the Hägur burial suggest some migration to Gotland in a period succeeding the PWC. Archaeologically, it is difficult to reconcile a 55/45 CWC/TRB contribution on Gotland as the temporal range of the TRB culture ends around c. 2700 cal BCE, and presently there is little archaeological evidence of assimilation of TRB and BAC/CWC on Gotland during the latter part of the MN period (e.g. Andersson, 2016). The apparent decline of human activity on the island post TRB, and also later postPWC is intriguing. As we do not see cultural assimilation of TRB and PWC on Gotland one can only speculate as to why TRB disapears from the archaeological record.
The introduction of new female lineages and the mtDNA haplogroup variation within these stone cist burials, together with an increase of nonlocal individuals, and a dietary shift, indicates that a demographic event has happened. The LN period shows traces of activity all over the island compared to the MN period with ten TRB, and eighteen PWC sites (e.g. Bägerfeldt, 1992; Luthander, 1988; Wallin, 2010; Österholm, 1989). This pattern seems to continue into the EBA as seen by the well-established local groups identified by their Sr-signals, as well as the monumental burials.
From the conclusions:
We find a shift in population demography compared to the preceding cultural developments on the island recorded from the Neolithic TRB, and sub-Neolithic PWC groups. We find that these burials were used by local groups that were well established in the regions where the burials were situated. These individuals also displayed a different dietary pattern than that noted for the preceding TRB and PWC groups on the island. We also detect sporadic reuse of the MN TRB dolmen in the LN period by nonlocal individuals, who also shows deviating dietary patterns to the LN/EBA individuals in the stone cist burials.
We see an increase of new mitochondrial lineages in the EBA individuals, of which some also were noted in the CWC reference dataset used in this study. Our modeling for maternal ancestry suggests a 3-way model of 55% CWC, 40% TRB, and 5% PWC. Given the broad absence of archaeological evidence for the typical BAC/CWC burials, as well as no archaeological evidence of assimilation of TRB and PWC during the latter part of the MN period on Gotland, it seems probable that the major process of admixture did not occur on the island. Instead, the data indicates an admixture process that occurred elsewhere and prior to migrating to Gotland. Thus, our results suggest later migration to the island during the LN period by people with a new economy, as well as new burial customs. A likely scenario, taking all these factors into account, is a sizable migration of people, with a ~50/50 (maternal) ancestry in TRB and CWC associated groups, possibly admixing with much smaller local groups of PWC associated individuals on the island.
A quite interesting study that supports the predicted greater mobility during the Nordic Early Bronze Age, compared to earlier periods.
Obviously, the use of previous CWC and TRB mtDNA samples (dated necessarily before 2300 BC) to assert that the picture found during the EBA (ca. 1700-1100 BC) is due to the admixture of both cultures is not tenable.
It was more likely a mixture of descendant populations in Scandinavia, after the arrival of the Bell Beaker elites (ca. 2400 BC) and their admixture with the local population, bringing maritime integration and unifying trends to Scandinavia.