We know that the Caucasus Mountains formed a persistent prehistoric barrier to cultural and population movements. Nevertheless, an even more persistent frontier to population movements in Europe, especially since the Neolithic, is the Pontic-Caspian steppe – forest-steppe ecotone.
Like the Caucasus, this barrier could certainly be crossed, and peoples and cultures could permeate in both directions, but there have been no massive migrations through it. The main connection between both regions (steppe vs. forest-steppe/forest zone) was probably through its eastern part, through the Samara region in the Middle Volga.
The chances of population expansions crossing this natural barrier anywhere else seem quite limited, with a much less porous crossing region in the west, through the Dnieper-Dniester corridor.
A Persistent ecological and cultural frontier
It is very difficult to think about any culture that transgressed this persistent ecological and cultural frontier: many prehistoric and historical steppe pastoralists did appear eventually in the neighbouring forest-steppe areas during their expansions (e.g. Yamna, Scythians, or Turks), as did forest groups who permeated to the south (e.g. Comb Ware, GAC, or Abashevo), but their respective hold in foreign biomes was mostly temporary, because their cultures had to adapt to the new ecological environment. Most if not all groups originally from a different ecological niche eventually disappeared, subjected to renewed demographic pressure from neighbouring steppe or forest populations…
Before the emergence of pastoralism, the cultural contacts of the Pontic region (i.e. forest-steppes) with the Baltic were intense. In fact, the connection of the north Pontic area with the Baltic through the Dnieper-Dniester corridor and the Podolian-Volhynian region is essential to understand the spread of peoples of post-Maglemosian and post-Swiderian cultures (to the south), hunter-gatherer pottery (to the north), TRB (to the south), Late Trypillian groups (north), GAC (south), or Comb Ware (south) (see here for Eneolithic movements), and finally steppe ancestry and R1a-Z645 with Corded Ware (north). After the complex interaction of TRB, Trypillia, GAC, and CWC during the expansion of late Repin, this traditional long-range connection is lost and only emerges sporadically, such as with the expansion of East Germanic tribes.
A barrier to steppe migrations into northern Europe
One may think that this barrier was more permeable, then, in the past. However, the frontier is between steppe and forest-steppe ecological niches, and this barrier evolved during prehistory due to climate changes. The problem is, before the drought that began ca. 4000 BC and increased until the Yamna expansion, the steppe territory in the north Pontic region was much smaller, merely a strip of coastal land, compared to its greater size ca. 3300 BC and later.
This – apart from the cultural and technological changes associated with nomadic pastoralism – justifies the traditional connection of the north Pontic forest-steppes to the north, broken precisely after the expansion of Khvalynsk, as the north Pontic area became gradually a steppe region. The strips of north Pontic and Azov steppes and Crimea seem to have had stronger connections to the Northern Caucasus and Northern Caspian steppes than with the neighbouring forest-steppe areas during the Upper Palaeolithic, Mesolithic, and Neolithic.
NOTE. We still don’t know the genetic nature of Mikhailovka or Ezero, steppe-related groups possibly derived from Novodanilovka and Suvorovo close to the Black Sea (which possibly include groups from the Pannonian plains), and how they compare to neighbouring typically forest-steppe cultures of the so-called late Sredni Stog groups, like Dereivka or partly Kvityana.
Despite the Pontic-Caspian steppes and forest-steppes neighbouring each other for ca. 2,000 km, peoples from forested and steppe areas had an obvious advantage in their own regions, most likely due to the specialization of their subsistence economy. While this is visible already in Palaeolithic and Mesolithic hunter-gatherers, the arrival of the Neolithic package in the Pontic-Caspian region incremented the difference between groups, by spreading specialized animal domestication. The appearance of nomadic pastoralism adapted to the steppe, eventually including the use of horses and carts, made the cultural barrier based on the economic know-how even stronger.
Even though groups could still adapt and permeate a different territory (from steppe to forest-steppe/forest and vice-versa), this required an important cultural change, to the extent that it is eventually complicated to distinguish these groups from neighbouring ones (like north-west Pontic Mesolithic or Neolithic groups and their interaction with the steppes, Trypillia-Usatovo, Scythians-Thracians, etc.). In fact, this steppe – forest-steppe barrier is also seen to the east of the Urals, with the distinct expansion of Andronovo and Seima-Turbino/Andronovo-like horizons, which seem to represent completely different ethnolinguistic groups.
As a result of this cultural and genetic barrier, like that formed by the Northern Caucasus:
1) No steppe pastoralist culture (which after the emergence of Khvalynsk means almost invariably horse-riding, chariot-using nomadic herders who could easily pasture their cows in the huge grasslands without direct access to water) has ever been successful in spreading to the north or north-west into northern Europe, until the Mongols. No forest culture has ever been successful in expanding to the steppes, either (except for the infiltration of Abashevo into Sintashta-Potapovka).
2) Corded Ware was not an exception: like hunter-gatherer pottery before it (and like previous population movements of TRB, late Trypillia, GAC, Comb Ware or Lublin-Volhynia settlers) their movements between the north Pontic area and central Europe happened through forest-steppe ecological niches due to their adaptation to them. There is no reason to support a direct connection of CWC with true steppe cultures.
3) The so-called “Steppe ancestry” permeated the steppe – forest-steppe ecotone for hundreds of years during the 5th and early 4th millennium BC, due to the complex interaction of different groups, and probably to the aridization trend that expanded steppe (and probably forest-steppe) to the north. Language, culture, and paternal lineages did not cross that frontier, though.
EDIT (4 FEB 2019): Wang et al. is out in Nature Communications. They deleted the Yamna Hungary samples and related analyses, but it’s interesting to see where exactly they think the trajectory of admixture of Yamna with European MN cultures fits best. This path could also be inferred long ago from the steppe connections shown by the Yamna Hungary -> Bell Beaker evolution and by early Balkan samples:
Mitochondrial genomes from all three individuals belong to the U5a2d haplogroup. (…) The mitochondrial U5a2d haplogroup is consistent with earlier published results for ancient individuals from Scandinavia, U5a being the most common within SHG. Of the 16 Mesolithic individuals from Scandinavia published prior to our study, seven belong to the U5a haplogroup, nine share the U2 and U4 haplogroups
We divided the SHG group into two groups: SHGa and SHGb (ancient individuals found in contemporary Norway and Sweden, respectively). We based this on both the geographical distribution and the previous studies demonstrating the close relation of SHGa to EHG group and SHGb to WHG group. To further explore the demography within the SHG group, we compared the ancestry of BLE individuals within SHGa and SHGb groups. This comparison revealed a high relative shared drift between BLE individuals and the SHGb group
The results from Huseby Kiev allow us to finally connect the SHG group with the eastern pressure blade technology. However, the higher genetic affinity between Huseby Kiev individuals and the WHG group challenges the earlier suggested tie between eastern technology and EHG genetics. Our results suggest either early cultural transmission, or a more complex course of events involving both non- and co-dependent cultural and genetic admixture.
Seeing how culture is indeed usually associated with the expansion of a certain population, especially at such an early date, I guess this similarity with WHG of incoming eastern peoples comes from an originally EHG population expanding into a mainly WHG area in the west (similar to what happens e.g. with Bell Beakers), or being replaced later by a WHG population which adopted the culture (similar to what happened with late Corded Ware populations in central-east Europe after the expansion of Bell Beakers).
Unlike later periods, it will always be difficult to judge such ancient population movements with few samples covering thousands of years… Probably specific Y-DNA haplogroups would help differentiate between both expanding populations from east and west.
To understand the population history and context of dairy pastoralism in the eastern Eurasian steppe, we applied genomic and proteomic analyses to individuals buried in Late Bronze Age (LBA) burial mounds associated with the Deer Stone-Khirigsuur Complex (DSKC) in northern Mongolia. To date, DSKC sites contain the clearest and most direct evidence for animal pastoralism in the Eastern steppe before ca. 1200 BCE.
Most LBA Khövsgöls are projected on top of modern Tuvinians or Altaians, who reside in neighboring regions. In comparison with other ancient individuals, they are also close to but slightly displaced from temporally earlier Neolithic and Early Bronze Age (EBA) populations from the Shamanka II cemetry (Shamanka_EN and Shamanka_EBA, respectively) from the Lake Baikal region. However, when Native Americans are added to PC calculation, we observe that LBA Khövsgöls are displaced from modern neighbors toward Native Americans along PC2, occupying a space not overlapping with any contemporary population. Such an upward shift on PC2 is also observed in the ancient Baikal populations from the Neolithic to EBA and in the Bronze Age individuals from the Altai associated with Okunevo and Karasuk cultures.
(…) two individuals fall on the PC space markedly separated from the others: ARS017 is placed close to ancient and modern northeast Asians, such as early Neolithic individuals from the Devil’s Gate archaeological site (22) and present-day Nivhs from the Russian far east, while ARS026 falls midway between the main cluster and western Eurasians.
Upper Paleolithic Siberians from nearby Afontova Gora and Mal’ta archaeological sites (AG3 and MA-1, respectively) (25, 26) have the highest extra affinity with the main cluster compared with other groups, including the eastern outlier ARS017, the early Neolithic Shamanka_EN, and present-day Nganasans and Tuvinians (Z > 6.7 SE for AG3). Main cluster Khövsgöl individuals mostly belong to Siberian mitochondrial (A, B, C, D, and G) and Y (all Q1a but one N1c1a) haplogroups.
Previous studies show a close genetic relationship between WSH populations and ANE ancestry, as Yamnaya and Afanasievo are modeled as a roughly equal mixture of early Holocene Iranian/ Caucasus ancestry (IRC) and Mesolithic Eastern European hunter-gatherers, the latter of which derive a large fraction of their ancestry from ANE. It is therefore important to pinpoint the source of ANE-related ancestry in the Khövsgöl gene pool: that is, whether it derives from a pre-Bronze Age ANE population (such as the one represented by AG3) or from a Bronze Age WSH population that has both ANE and IRC ancestry.
The amount of WSH contribution remains small (e.g., 6.4 ± 1.0% from Sintashta). Assuming that the early Neolithic populations of the Khövsgöl region resembled those of the nearby Baikal region, we conclude that the Khövsgöl main cluster obtained ∼11% of their ancestry from an ANE source during the Neolithic period and a much smaller contribution of WSH ancestry (4–7%) beginning in the early Bronze Age.
Apparently, then, the first individual with substantial WSH ancestry in the Khövsgöl population (ARS026, of haplogroup R1a-Z2123), directly dated to 1130–900 BC, is consistent with the first appearance of admixed forest-steppe-related populations like Karasuk (ca. 1200-800 BC) in the Altai. Interestingly, haplogroup N1a1a-M178 pops up (with mtDNA U5a2d1) among the earlier Khövsgöl samples.
I will repeat what I wrote recently here: Samoyedic arrived in the Altai with Karasuk and hg R1a-Z645 + Steppe_MLBA-like ancestry, admixed with Altai populations, clustering thus within an Ancient Altai cline. Only later did N1a1a subclades infiltrate Samoyedic (and Ugric) populations, bringing them closer to their modern Palaeo-Siberian cline. The shared mtDNA may support an ancestral EHG-“Siberian” cline, or else a more recent Afanasevo-related origin.
Also interesting, Q1a2 subclades and ANE ancestry making its appearance everywhere among ancestral Eurasian peoples, as Chetan recently pointed out.
(…) the spread of agriculture in Europe was a result of the demic diffusion of early Anatolian farmers, it was discovered that the spread of agriculture to South Asia was mediated by a genetically completely different farmer population in the Zagros mountains in contemporary Iran (IF). The ANI-ASI cline itself was interpreted as a mixture of three components genetically related to Iranian agriculturalists, Onge and Early and Middle Bronze Age Steppe populations (Steppe_EMBA).
The first ever autosomal aDNA from South Asia comes from Northern Pakistan (Swat Valley, early Iron Age). This study presented altogether 362 aDNA samples from the broad South and Central Asia and contributes substantially to our understanding of the evolutionary past of South and Central Asia. The study redefines the three genetic strata that form the basis of the Indian Cline. The Indus Periphery (IP) component is composed of (varying proportions of): first, IF, second, Ancient Ancestral South Asians (AASI), which represents an ancient branch of human genetic variation in Asia arising from a population split contemporaneous with the splits of East Asian, Onge and Australian Aboriginal ancestors and third, West_Siberian Hunter gatherers (WS_HG).
The authors argue that IP could have formed the genetic base of the Indus Valley Civilization (IVC). Upon the collapse of the IVC IP contributes to the formation of both ASI and ANI. ASI is formed as IP admixes further with AASI. ANI in turn forms when IP admixes with the incoming Middle and Late Bronze Age Steppe (Steppe_MLBA) component, (rather than the Steppe_EMBA groups suggested earlier)
Dating of the arrival of the Austro-Asiatic speakers in South Asia-based on Y chromosome haplogroup O2a1-M95 expansion estimates yielded dates between 3000 and 2000 BCE . However, admixture LD decay-based approach on genome-wide data suggests the admixture between South Asian and incoming Austro-Asiatic speakers occurred slightly later between 1800 and 0 BCE (Tätte et al. submitted). It is interesting that while the mtDNA variants of the Mundas are completely South Asian, the Y chromosome variation is dominated at >60% by haplogroup O2a which is phylogeographically nested in East Asian-specific paternal lineages.
In India, the speakers of Tibeto-Burman (TB) languages live in the Seven Sisters States in Northeast India and in the very north of the country. Genetically they show a clear East Asian origin and around 20% of subsequent admixture with South Asians within the last 1000 years.The genetic flavour of East Asia in TB is different from that in Munda speakers as the best surrogates for the East Asian admixing component are contemporary Han Chinese.
I found the simplistic migration maps especially interesting to illustrate ancient population movements. The emergence of EHG is supposed to involve a WHG:ANE cline, though, and this isn’t clear from the map. Also, there is new information on what may be at the origin of WHG and Anatolian hunter-gatherers.
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 was reading The Bronze Age Landscape in the Russian Steppes: The Samara Valley Project (2016), and I was really surprised to find the following excerpt by David W. Anthony:
The Samara Valley links the central steppes with the western steppes and is a north-south ecotone between the pastoral steppes to the south and the forest-steppe zone to the north [see figure below]. The economic contrast between pastoral steppe subsistence, with its associated social organizations, and forest-zone hunting and fishing economies probably explains the shifting but persistent linguistic border between forest-zone Uralic languages to the north (today largely displaced by Russian) and a sequence of steppe languages to the south, recently Turkic, before that Iranian, and before that probably an eastern dialect of Proto-Indo-European (Anthony 2007). The Samara Valley represents several kinds of borders, linguistic, cultural, and ecological, and it is centrally located in the Eurasian steppes, making it a critical place to examine the development of Eurasian steppe pastoralism.
Khokhlov (translated by Anthony) further insists on the racial and ethnic divide between both populations, Abashevo to the north, and Poltavka to the south, during the formation of the Abashevo – Sintashta-Potapovka community that gave rise to Proto-Indo-Iranians:
Among all cranial series in the Volga-Ural region, the Potapovka population represents the clearest example of race mixing and probably ethnic mixing as well. The cultural advancements seen in this period might perhaps have been the result of the mixing of heterogeneous groups. Such a craniometric observation is to some extent consistent with the view of some archaeologists that the Sintashta monuments represent a combination of various cultures (principally Abashevo and Poltavka, but with other influences) and therefore do not correspond to the basic concept of an archaeological culture (Kuzmina 2003:76). Under this option, the Potapovka-Sintashta burial rite may be considered, first, a combination of traits to guarantee the afterlife of a selected part of a heterogeneous population. Second, it reflected a kind of social “caste” rather than a single population. In our view, the decisive element in shaping the ethnic structure of the Potapovka-Sintashta monuments was their extensive mobility over a fairly large geographic area. They obtained knowledge of various cultures from the populations with whom they interacted.
Interesting is also this excerpt about the predominant population in the Abashevo – Sintashta-Potapovka admixture (which supports what Chetan said recently, although this does not seemed backed by Y-DNA haplogroups found in the richest burials), coupled with the sign of incoming “Uraloid” peoples from the east, found in both Sintashta and eastern Abashevo:
The socially dominant anthropological component was Europeoid, possibly the descendants of Yamnaya. The association of craniofacial types with archaeological cultures in this period is difficult, primarily because of the small amount of published anthropological material of the cultures of steppe and forest belt (Balanbash, Vol’sko-Lbishche) and the eastern and southern steppes (Botai-Tersek). The crania associated with late MBA western Abashevo groups in the Don-Volga forest zone were different from eastern Abashevo in the Urals, where the expression of the Old Uraloid craniological complex was increased. Old Uraloid is found also on a single skull of Vol’sko-Lbishche culture (Tamar Utkul VII, Kurgan 4). Potentially related variants, including Mongoloid features, could be found among the Seima-Turbino tribes of the forest-steppe zone, who mixed with Sintashta and Abashevo. In the Sintashta Bulanova cemetery from the western Urals, some individuals were buried with implements of Seima-Turbino type (Khalyapin 2001; Khokhlov 2009; Khokhlov and Kitov 2009). Previously, similarities were noted between some individual skulls from Potapovka I and burials of the much older Botai culture in northern Kazakhstan (Khokhlov 2000a). Botai-Tersek is, in fact, a growing contender for the source of some “eastern” cranial features.
The wave of peoples associated with “eastern” features can be seen in genetics in the Sintashta outliers from Narasimhan et al. (2018), and it probably will be eventually seen in Abashevo, too. These may be related to the Seima-Turbino international network – but most likely it is directly connected to Sintashta through the starting Andronovo and Seima-Turbino horizons, by admixing of prospective groups and small-scale back-migrations.
Corded Ware – Yamna similarities?
So, if peoples of north-eastern Europe have been assumed for a long time to be Uralic speakers, what is happening with the Corded Ware = IE obsession? Is it Gimbutas’ ghost possessing old archaeologists? Probably not.
It is about certain cultural similarities evident at first sight, which have been traditionally interpreted as a sign of cultural diffusion or migration. Not dissimilar to the many Bell Beaker models available, where each archaeologist is pushing certain differences, mixing what seemed reasonable, what still might seem reasonable, and what certainly isn’t anymore after the latest ancient DNA data.
The initial models of Gimbutas, Kristiansen, or Anthony – which are known to many today – were enunciated in the infancy of archaeological studies in the regions, during and just after the fall of the USSR, and before many radiocarbon dates that we have today were published (with radiocarbon dating being still today in need of refinement), so it is only logical that gross mistakes were made.
We have similar gross mistakes related to the origins of Bell Beakers, and studying them was certainly easier than studying eastern data.
Gimbutas believed – based mainly on Kurgan-like burials – that Bell Beaker formed from a combination of Yamna settlers with the Vučedol culture, so she was not that far from the truth.
The expansion of Corded Ware from peoples of the North Pontic forest-steppe area, proposed by Gimbutas and later supported also by Kristiansen (1989) as the main Indo-European expansion – , is probably also right about the approximate origins of the culture. Only its ‘Indo-European’ nature is in question, given the differences with Khvalynsk and Yamna evolution.
Anthony only claimed that Yamna migrants settled in the Balkans and along the Danube into the Hungarian steppes. He never said that Corded Ware was a Yamna offshoot until after the first genetic papers of 2015 (read about his newest proposal). He initially claimed that only certain neighbouring Corded Ware groups “adopted” Indo-European (through cultural diffusion) because of ‘patron-client’ relationships, and was never preoccupied with the fate of Corded Ware and related cultures in the east European forest zone and Finland.
So none of them was really that far from the true picture; we might say a lot people are more way off the real picture today than the picture these three researchers helped create in the 1990s and 2000s. Genetics is just putting the last nail in the coffin of Corded Ware as a Yamna offshoot, instead of – as we believed in the 2000s – to Vučedol and Bell Beaker.
So let’s revise some of these traditional links between Corded Ware and Yamna with today’s data:
Even more than genetics – at least until we have an adequate regional and temporary sampling – , archaeological findings lead what we have to know about both cultures.
It is essential to remember that Corded Ware, starting ca. 3000/2900 BC in east-central Europe, has been proposed to be derived from Early Yamna, which appeared suddenly in the Pontic-Caspian steppes ca. 3300 BC (probably from the late Repin expansion), and expanded to the west ca. 3000.
The question at hand, therefore, is if Corded Ware can be considered an offshoot of the Late PIE community, and thus whether the CWC ethnolinguistic community – proven in genetics to be quite homogeneous – spoke a Late PIE dialect, or if – alternatively – it is derived from other neighbouring cultures of the North Pontic region.
NOTE. The interpretation of an Indo-Slavonic group represented by a previous branching off of the group is untenable with today’s data, since Indo-Slavonic – for those who support it – would itself be a branch of Graeco-Aryan, and Palaeo-Balkan languages expanded most likely with West Yamna (i.e. R1b-L23, mainly R1b-Z2103) to the south.
The convoluted alternative explanation would be that Corded Ware represents an earlier, Middle PIE branch (somehow carrying R1a??) which influences expanding Late PIE dialects; this has been recently supported by Kortlandt, although this simplistic picture also fails to explain the Uralic problem.
❔ Kurgans: The Yamna tradition was inherited from late Repin, in turn inherited from Khvalynsk-Novodanilovka proto-Kurgans. As for the CWC tradition, it is unclear if the tumuli were built as a tradition inherited from North and West Pontic cultures (in turn inherited or copied from Khvalynsk-Novodanilovka), such as late Trypillia, late Kvityana, late Dereivka, late Sredni Stog; or if they were built because of the spread of the ‘Transformation of Europe’, set in motion by the Early Yamna expansion ca. 3300-3000 BC (as found in east-central European cultures like Coţofeni, Lizevile, Șoimuș, or the Adriatic Vučedol). My guess is that it inherits an older tradition than Yamna, with an origin in east-central Europe, because of the mound-building distribution in the North Pontic area before the Yamna expansion, but we may never really know.
❌ Burial rite: Yamna features (with regional differences) single burials with body on its back, flexed upright knees, poor grave goods, common orientation east-west (heads to the west) inherited from Repin, in turn inherited from Khvalynsk-Novodanilovka. CWC tradition – partially connected to Złota and surrounding east-central European territories (in turn from the Khvalynsk-Novodanilovka expansion) – features single graves, body in fetal position, strict gender differentiation – men on the right, women on the left -, looking to the south, graves with standardized assemblages (objects representing affirmation of battle, hunting, and feasting). The burial rites clearly represent different ideologies.
❌ Corded decoration: Corded ware decoration appears in the Balkans during the 5th millennium, and represents a simple technique whereby a cord is twisted, or wrapped around a stick, and then pressed directly onto the fresh surface of a vessel leaving a characteristic decoration. It appears in many groups of the 5th and 4th millennium BC, but it was Globular Amphorae the culture which popularized the drinking vessels and their corded ornamentation. It appears thus in some regional groups of Yamna, but it becomes the standard pottery only in Corded Ware (especially with the A-horizon), which shows continuity with GAC pottery.
❌ Economy: Yamna expands from Repin (and Repin from Khvalynsk-Novodanilovka) as a nomadic or semi-nomadic purely pastoralist society (with occasional gathering of wild seeds), which naturally thrives in the grasslands of the Pontic-Caspian, lower Danube and Hungarian steppes. Corded Ware shows agropastoralism (as late Eneolithic forest-steppe and steppe groups of eastern Europe, such as late Trypillian, TRB, and GAC groups), inhabits territories north of the loess line, with heavy reliance of hunter-gathering depending on the specific region.
❌ Cattle herding: Interestingly, both west Yamna and Corded Ware show more reliance on cattle herding than other pastoralist groups, which – contrasted with the previous Eneolithic herding traditions of the Pontic-Caspian steppe, where sheep-goats predominate – make them look alike. However, the cattle-herding economy of Yamna is essential for its development from late Repin and its expansion through the steppes (over western territories practising more hunter-gathering and sheep-goat herding economy), and it does not reach equally the Volga-Ural region, whose groups keep some of the old subsistence economy (read more about the late Repin expansion). Corded Ware, on the other hand, inherits its economic strategy from east European groups like TRB, GAC, and especially late Trypillian communities, showing a predominance of cattle herding within an agropastoral community in the forest-steppe and forest zones of Volhynia, Podolia, and surrounding forest-steppe and forest regions.
❔ Horse riding: Horse riding and horse transport is proven in Yamna (and succeeding Bell Beaker and Sintashta), assumed for late Repin (essential for cattle herding in the seas of grasslands that are the steppes, without nearby water sources), quite likely during the Khvalynsk expansion (read more here), and potentially also for Samara, where the predominant horse symbolism of early Khvalynsk starts. Corded Ware – like the north Pontic forest-steppe and forest areas during the Eneolithic – , on the other hand, does not show a strong reliance on horse riding. The high mobility and short-term settlements characteristic of Corded Ware, that are often associated with horse riding by association with Yamna, may or may not be correct, but there is no need for horses to explain their herding economy or their mobility, and the north-eastern European areas – the one which survived after Bell Beaker expansion – did certainly not rely on horses as an essential part of their economy.
NOTE: I cannot think of more supposed similarities right now. If you have more ideas, please share in the comments and I will add them here.
✅ EHG: This is the clearest link between both communities. We thought it was related to the expansion of ANE-related ancestry to the west into WHG territory, but now it seems that it will be rather WHG expanding into ANE territory from the Pontic-Caspian region to the east (read more on recent Caucasus Neolithic, on , and on Caucasus HG).
NOTE. Given how much each paper changes what we know about the Palaeolithic, the origin and expansion of the (always developing) known ancestral components and specific subclades (see below) is not clear at all.
❔ CHG: This is the key link between both cultures, which will delimit their interaction in terms of time and space. CHG is intermediate between EHG and Iran N (ca. 8000 BC). The ancestry is thus linked to the Caucasus south of the steppe before the emergence of North Pontic (western) and Don-Volga-Ural (eastern) communities during the Mesolithic. The real question is: when we have more samples from the steppe and the Caucasus during the Neolithic, how many CHG groups are we going to find? Will the new specific ancestral components (say CHG1, CHG2, CHG3, etc.) found in Yamna (from Khvalynsk, in the east) and Corded Ware (probably from the North Pontic forest-steppe) be the same? My guess is, most likely not, unless they are mediated by the Khvalynsk-Novodanilovka expansion (read more on CHG in the Caucasus).
❌ WHG/EEF: This is the obvious major difference – known today – in the formation of both communities in the steppe, and shows the different contacts that both groups had at least since the Eneolithic, i.e. since the expansion of Repin with its renewed Y-DNA bottleneck, and probably since before the early Khvalynsk expansion (read more on Yamna-Corded Ware differences contrasting with Yamna-Afanasevo, Yamna-Bell Beaker, and Yamna-Sintashta similarities).
NOTE 1. Some similarities between groups can be seen depending on the sampled region; e.g. Baltic groups show more similarities with southern Pontic-Caspian steppe populations, probably due to exogamy.
NOTE 2. We have this information on the differences in “steppe ancestry” between Yamna and Corded Ware, compared to previous studies, because now we have more samples of neighbouring, roughly contemporaneous Eneolithic groups, to analyse the real admixture processes. This kind of fine scale studies is what is going to show more and more differences between Khvalynsk-Yamna and Sredni Stog-Corded Ware as more data pours in. The evolution of both communities in archaeology and in PCA (see below) is probably witness to those differences yet to be published.
❌ R1: Even though some people try very hard to think in terms of “R1” vs. (Caucasus) J or G or any other upper clade, this is plainly wrong. It is possible, given what we know now, that Q1a2-M242 expanded ANE ancestry to the west ca. 13000 BC, while R1b-P279 expanded WHG ancestry to the east with the expansion of post-Swiderian cultures, creating EHG as a WHG:ANE cline. The role of R1a-M459 is unknown, but it might be related to any of these migrations, or others (plural) along northern Eurasia (read more on the expansion of R1b-P279, on Palaeolithic Q1a2, and on R1a-M417).
NOTE. I am inclined to believe in a speculative Mesolithic-Early Neolithic community involving Eurasiatic movements accross North Eurasia, and Indo-Uralic movements in its western part, with the last intense early Uralic-PIE contacts represented by the forming west (Mariupol culture) and east (Don-Volga-Ural cultures, including Samara) communities developing side by side. Before their known Eneolithic expansions, no large-scale Y-DNA bottleneck is going to be seen in the Pontic-Caspian steppe, with different (especially R1a and R1b subclades) mixed among them, as shown in North Pontic Neolithic, Samara HG, and Khvalynsk samples.
Corded Ware and ‘steppe ancestry’
If we take a look at the evolution of Corded Ware cultures, the expansion of Bell Beakers – dominated over most previous European cultures from west to east Europe – influenced the development of the whole European Bronze Age, up to Mierzanowice and Trzciniec in the east.
The only relevant unscathed CWC-derived groups, after the expansion of Sintashta-Potapovka as the Srubna-Andronovo horizon in the Eurasian steppes, were those of the north-eastern European forest zone: between Belarus to the west, Finland to the north, the Urals to the east, and the forest-steppe region to the south. That is, precisely the region supposed to represent Uralic speakers during the Bronze Age.
This inconsistency of steppe ancestry and its relation with Uralic (and Balto-Slavic) peoples was observed shortly after the publication of the first famous 2015 papers by Paul Heggarty, of the Max-Planck Institute for Evolutionary Anthropology (read more):
Haak et al. (2015) make much of the high Yamnaya ancestry scores for (only some!) Indo-European languages. What they do not mention is that those same results also include speakers of other languages among those with the highest of all scores for Yamnaya ancestry. Only these are languages of the Uralic family, not Indo-European at all; and their Yamnaya-ancestry signals are far higher than in many branches of Indo-European in (southern) Europe. Estonian ranks very high, while speakers of the very closely related Finnish are curiously not shown, and nor are the Saami. Hungarian is relevant less directly since this language arrived only c. 900 AD, but also high.
These data imply that Uralic-speakers too would have been part of the Yamnaya > Corded Ware movement, which was thus not exclusively Indo-European in any case. And as well as the genetics, the geography, chronology and language contact evidence also all fit with a Yamnaya > Corded Ware movement including Uralic as well as Balto-Slavic.
Both papers fail to address properly the question of the Uralic languages. And this despite — or because? — the only Uralic speakers they report rank so high among modern populations with Yamnaya ancestry. Their linguistic ancestors also have a good claim to have been involved in the Corded Ware and Yamnaya cultures, and of course the other members of the Uralic family are scattered across European Russia up to the Urals.
NOTE. Although the author was trying to support the Anatolian hypothesis – proper of glottochronological studies often published from the Max Planck Institute – , the question remains equally valid: “if Proto-Indo-European expands with Corded Ware and steppe ancestry, what is happening with Uralic peoples?”
For my part, I claimed in my draft that ancestral components were not the only relevant data to take into account, and that Y-DNA haplogroups R1a and R1b (appearing separately in CWC and Yamna-Bell Beaker-Afanasevo), together with their calculated timeframes of formation – and therefore likely expansion – did not fit with the archaeological and linguistic description of the spread of Proto-Indo-European and its dialects.
In fact, it seemed that only one haplogroup (R1b-M269) was constantly and consistenly associated with the proposed routes of Late PIE dialectal expansions – like Anthony’s second (Afanasevo) and third (Lower Danube, Balkan) waves. What genetics shows fits seamlessly with Mallory’s association of the North-West Indo-European expansion with Bell Beakers (read here how archaeologists were right).
More precise inconsistencies were observed after the publication of Olalde et al. (2017) and Mathieson et al. (2017), by Volker Heyd in Kossinna’s smile (2017). Letting aside the many details enumerated (you can read a summary in my latest draft), this interesting excerpt is from the conclusion:
Simple solutions to complex problems are never the best choice, even when favoured by politicians and the media. Kossinna also offered a simple solution to a complex prehistoric problem, and failed therein. Prehistoric archaeology has been aware of this for a century, and has responded by becoming more differentiated and nuanced, working anthropologically, scientifically and across disciplines (cf. Müller 2013; Kristiansen 2014), and rejecting monocausal explanations. The two aDNA papers in Nature, powerful and promising as they are for our future understanding, also offer rather straightforward messages, heavily pulled by culture-history and the equation of people with culture. This admittedly is due partly to the restrictions of the medium that conveys them (and despite the often relevant additional detail given as supplementary information, which is unfortunately not always given full consideration).
While I have no doubt that both papers are essentially right, they do not reflect the complexity of the past. It is here that archaeology and archaeologists contributing to aDNA studies find their role; rather than simply handing over samples and advising on chronology, and instead of letting the geneticists determine the agenda and set the messages, we should teach them about complexity in past human actions and interactions. If accepted, this could be the beginning of a marriage made in heaven, with the blessing smile of Gustaf Kossinna, and no doubt Vere Gordon Childe, were they still alive, in a reconciliation of twentieth- and twenty-first-century approaches. For us as archaeologists, it could also be the starting point for the next level of a new archaeology.
The question was made painfully clear with the publication of Olalde et al. (2018) & Mathieson et al. (2018), where the real route of Yamna expansion into Europe was now clearly set through the steppes into the Carpathian basin, later expanded as Bell Beakers.
We analyzed teeth from two individuals 63 recovered from Dzudzuana Cave, Southern Caucasus, from an archaeological layer previously dated to ~27-24kya (…). Both individuals had mitochondrial DNA sequences (U6 and N) that are consistent with deriving from lineages that are rare in the Caucasus or Europe today. The two individuals were genetically similar to each other, consistent with belonging to the same population and we thus analyze them jointly.
(…) our results prove that the European affinity of Neolithic Anatolians does not necessarily reflect any admixture into the Near East from Europe, as an Anatolian Neolithic-like population already existed in parts of the Near East by ~26kya. Furthermore, Dzudzuana shares more alleles with Villabruna-cluster groups than with other ESHG (Extended Data Fig. 5b), suggesting that this European affinity was specifically related to the Villabruna cluster, and indicating that the Villabruna affinity of PGNE populations from Anatolia and the Levant is not the result of a migration into the Near East from Europe. Rather, ancestry deeply related to the Villabruna cluster was present not only in Gravettian and Magdalenian-era Europeans but also in the populations of the Caucasus, by ~26kya. Neolithic Anatolians, while forming a clade with Dzudzuana with respect to ESHG, share more alleles with all other PGNE (Extended Data Fig. 5d), suggesting that PGNE share at least partially common descent to the exclusion of the much older samples from Dzudzuana.
Our co-modeling of Epipaleolithic Natufians and Ibero-Maurusians from Taforalt confirms that the Taforalt population was mixed, but instead of specifying gene flow from the ancestors of Natufians into the ancestors of Taforalt as originally reported, we infer gene flow in the reverse direction (into Natufians). The Neolithic population from Morocco, closely related to Taforalt is also consistent with being descended from the source of this gene flow, and appears to have no admixture from the Levantine Neolithic (Supplementary Information 166 section 3). If our model is correct, Epipaleolithic Natufians trace part of their ancestry to North Africa, consistent with morphological and archaeological studies that indicate a spread of morphological features and artifacts from North Africa into the Near East. Such a scenario would also explain the presence of Y-chromosome haplogroup E in the Natufians and Levantine farmers, a common link between the Levant and Africa.
(…) we cannot reject the hypothesis that Dzudzuana and the much later Neolithic Anatolians form a clade with respect to ESHG (P=0.286), consistent with the latter being a population largely descended from Dzudzuana-like pre-Neolithic populations whose geographical extent spanned both Anatolia and the Caucasus.Dzudzuana itself can be modeled as a 2-way mixture of Villabruna-related ancestry and a Basal Eurasian lineage.
In qpAdm modeling, a deeply divergent hunter-gatherer lineage that contributed in relatively unmixed form to the much later hunter-gatherers of the Villabruna cluster is specified as contributing to earlier hunter-gatherer groups (Gravettian Vestonice16: 35.7±11.3% and Magdalenian ElMiron: 60.6±11.3%) and to populations of the Caucasus (Dzudzuana: 199 72.5±3.7%, virtually identical to that inferred using ADMIXTUREGRAPH). In Europe, descendants of this lineage admixed with pre-existing hunter-gatherers related to Sunghir3 from Russia for the Gravettians and GoyetQ116-1 from Belgium for the Magdalenians, while in the Near East it did so with Basal Eurasians. Later Europeans prior to the arrival of agriculture were the product of re-settlement of this lineage after ~15kya in mainland Europe, while in eastern Europe they admixed with Siberian hunter-gatherers forming the WHG-ANE cline of ancestry [See PCA above]. In the Near East, the Dzudzuana-related population admixed with North African-related ancestry in the Levant and with Siberian hunter-gatherer and eastern non-African-related ancestry in Iran and the Caucasus. Thus, the highly differentiated populations at the dawn of the Neolithic were primarily descended from Villabruna Cluster and Dzudzuana-related ancestors, with varying degrees of additional input related to both North Africa and Ancient North/East Eurasia whose proximate sources may be clarified by future sampling of geographically and temporally intermediate populations.
Interesting excerpts from the supplementary materials:
From our analysis of Supplementary Information section 3, we showed that these sources are indeed complex, and only one of these (WHG, represented by Villabruna) appears to be a contributor to all the remaining sources. This should not be understood as showing that hunter-gatherers from mainland Europe migrated to the rest of West Eurasia, but rather that the fairly homogeneous post-15kya population of mainland Europe labeled WHG appear to represent a deep strain of ancestry that seems to have contributed to West Eurasians from the Gravettian era down to the Neolithic period.
Villabruna is representative of the WHG group. We also include ElMiron, the best sample from the Magdalenian era as we noticed that within the WHG group there were individuals that could not be modeled as a simple clade with Villabruna but also had some ElMiron-related ancestry. Ddudzuana is representative of the Ice Age Caucasus population, differentiated from Villabruna by Basal Eurasian ancestry. AG3 represents ANE/Upper Paleolithic Siberian ancestry, sampled from the vicinity of Lake Baikal, while Russia_Baikal_EN related to eastern Eurasians and represents a later layer of ancestry from the same region of Siberia as AG3 Finally, Mbuti are a deeply diverged African population that is used here to represent deep strains of ancestry (including Basal Eurasian) prior to the differentiation between West Eurasians and eastern non-Africans that are otherwise not accounted for by the remaining five sources. Collectively, we refer to this as ‘Basal’ or ‘Deep’ ancestry, which should be understood as referring potentially to both Basal Eurasian and African ancestry.
It has been suggested that there is an Anatolia Neolithic-related affinity in hunter-gatherers from the Iron Gates. Our analysis confirms this by showing that this population has Dzudzuana-related ancestry as do many hunter-gatherer populations from southeastern Europe, eastern Europe and Scandinavia. These populations cannot be modeled as a simple mixture of Villabruna and AG3 but require extra Dzudzuana-related ancestry even in the conservative estimates, with a positive admixture proportion inferred for several more in the speculative ones. Thus, the distinction between European hunter-gatherers and Near Eastern populations may have been gradual in pre-Neolithic times; samples from the Aegean (intermediate between those from the Balkans and Anatolia) may reveal how gradual the transition between Dzudzuana-like Neolithic Anatolians and mostly Villabruna-like hunter-gatherers was in southeastern Europe.
Villabruna: This type of ancestry differentiates between present-day Europeans and non-Europeans within West Eurasia, attaining a maximum of ~20% in the Baltic in accordance with previous observations and with the finding of a later persistence of significant hunter-gatherer ancestry in the region. Its proportion drops to ~0% throughout the Near East. Interestingly, a hint of such ancestry is also inferred in all North African populations west of Libya in the speculative proportions, consistent with an archaeogenetic inference of gene flow from Iberia to North Africa during the Late Neolithic.
ElMiron: This type of ancestry is absent in present-day West Eurasians. This may be because most of the Villabruna-related ancestry in Europeans traces to WHG populations that lacked it (since ElMiron-related ancestry is quite variable within European hunter-gatherers). However, ElMiron ancestry makes up only a minority component of all WHG populations sampled to date and WHG-related ancestry is a minority component of present-day Europeans. Thus, our failure to detect it in present day people may be simply be too little of it to detect with our methods.
Dzudzuana: Our analysis identifies Dzudzuana-related ancestry as the most important component of West Eurasians and the one that is found across West Eurasian-North African populations at ~46-88% levels. Thus, Dzudzuana-related ancestry can be viewed as the common core of the ancestry of West Eurasian-North African populations. Its distribution reaches its minima in northern Europe and appears to be complementary to that of Villabruna, being most strongly represented in North Africa, the Near East (including the Caucasus) and Mediterranean Europe. Our results here are expected from those of Supplementary Information section 3 in which we modeled ancient Near Eastern/North African populations (the principal ancestors of present-day people from the same regions) as deriving much of their ancestry from a Dzudzuana-related source. Migrations from the Near East/Caucasus associated with the spread of the Neolithic, but also the formation of steppe population introduced most of the Dzudzuana-related ancestry present in Europe, although (as we have seen above) some such ancestry was already present in some pre-agricultural hunter-gatherers in Europe.
AG3: Ancestry related to the AG3 sample from Siberia has a northern distribution, being strongly represented in both central-northern Europe and the north Caucasus.
Russia_Baikal_EN: Ancestry related to hunter-gatherers from Lake Baikal in Siberia (postdating AG3) appears to have affected primarily northeastern European populations which have been previously identified as having East Eurasian ancestry; some such ancestry is also identified for a Turkish population from Balıkesir, likely reflecting the Central Asian ancestry of Turkic speakers which has been recently confirmed directly in an Ottoman sample from Anatolia.
So, to try and sum up:
Dzudzuana shares ancestry with ‘Common West Eurasian’ (CWE). the ancestor cluster of Villabruna.
Dzudzuana diverges from CWE because of a Basal Eurasian ancestry contribution [which supports that Basal Eurasian ancestry was a deep Middle Eastern lineage].
Dzudzuana is closest to Anatolia Neolithic, and close to Gravettian.
Aurignacian: First West Eurasians arrive ca. 36,000 BP, Goyet cluster expands probably with C1a2 lineages.
After that, the early or ‘unmixed’ Villabruna cluster (‘hidden’ somewhere probably east of Europe, either North Eurasia or South Eurasia), lineages unknown (possibly IJ), contributes to:
Gravettian (ca. 30,000 BP): Věstonice cluster expands, probably with IJ lineages.
A (hidden) ‘Common West Eurasian’ population.
Dzudzuana ca. 26,000 BP derived from Common West Eurasian (curiously, haplogroup G seems to split in today’s subclades ca. 26,000 BP).
During the Gravettian (ca. 26,000 BP), an Anatolian Neolithic-like population exists already in the Near East. Both Věstonice and this Anatolian HG are close to Dzudzuana; in turn, Dzudzuana from CWE.
Magdalenian (ca. 20,000 BP): El Mirón cluster expands, probably with more specific I lineages.
Bølling-Allerød warming period (ca. 14,000 BP): ‘late’ Villabruna cluster or WHG (=CWE with greater affinity to Near Eastern populations) expands, probably spreading with R1b in mainland Europe and to the east (admixing with Siberian HG), creating the WHG — ANE ancestry cline, as reflected in Iron Gates HG, Baltic HG, etc.
[Here we have the possible “bidirectional gene flow between populations ancestral to Southeastern Europeans of the early Holocene and Anatolians of the late glacial or a dispersal of Southeastern Europeans into the Near East” inferred from Anatolian hunter-gatherers]
The paper talks about possibilities for Common West Eurasian:
Migration from mainland Europe to Near East or vice versa (not very likely);
Migration from a geographically intermediate Ice Age refugium in southeast Europe, Anatolia, or the circum-Pontic region that explain post-glacial affinity of post-glacial Levantine and Anatolian populations.
I would say that the distinct CHG vs. Dzudzuana ancestry puts CHG probably to the south, within the Iranian Plateau, during the Gravettian, expanding probably later.
Also important, Ancestral North African probably accompanied by haplogroup E. Early expansion of North Africans into the Near East further confirms the impossibility of Afroasiatic (much younger) to be associated with these expansions, and confirms that the still unclear Green Sahara migrations are the key.
Anatolian hunter-gatherers experienced climatic changes during the last glaciation and inhabited a region that connects Europe to the Near East. However, interactions between Anatolia and Southeastern Europe in the later Upper Palaeolithic/Epipalaeolithic are so far not well documented archaeologically. Interestingly, a previous genomic study showed that present-day Near-Easterners share more alleles with European hunter-gatherers younger than 14,000 BP (‘Later European HG’) than with earlier ones (‘Earlier European HG’). With ancient genomic data available, we could directly compare the Near-Eastern hunter-gatherers (AHG and Natufian) with the European ones. As is the case for present-day Near-Easterners, the Near-Eastern hunter-gatherers share more alleles with the Later European HG than with the Earlier European HG, shown by the significantly positive statistic D(Later European HG, Earlier European HG; AHG/Natufian, Mbuti). Among the Later European HG, recently reported Mesolithic hunter-gatherers from the Balkan peninsula, which geographically connects Anatolia and central Europe (‘Iron Gates HG’), are genetically closer to AHG when compared to all the other European hunter-gatherers, as shown in the significantly positive statistic D(Iron_Gates_HG, European hunter-gatherers; AHG, Mbuti/Altai). Iron Gates HG are followed by Epigravettian and Mesolithic individuals from Italy and France (Villabruna and Ranchot respectively) as the next two European hunter-gatherers genetically closest to AHG. Iron Gates HG have been suggested to be genetically intermediate between WHG and eastern European hunter-gatherers (EHG) with an additional unknown ancestral component.
We find that Iron Gates HG can be modeled as a three-way mixture of Near-Eastern hunter-gatherers (25.8 ± 5.0 % AHG or 11.1 ± 2.2 % Natufian), WHG (62.9 ± 7.4 % or 78.0 ± 4.6 % respectively) and EHG (11.3 ± 3.3 % or 10.9 ± 3 % respectively). The affinity detected by the above D-statistic can be explained by gene flow from Near-Eastern hunter-gatherers into the ancestors of Iron Gates or by a gene flow from a population ancestral to Iron Gates into the Near-Eastern hunter-gatherers as well as by a combination of both. To distinguish the direction of the gene flow, we examined the Basal Eurasian ancestry 5 component (α), which is prevalent in the Near East but undetectable in European hunter-gatherers. Following a published approach, we estimated α to be 24.8 ± 5.5 % in AHG and 38.5 ± 5.0 % in Natufians, consistent with previous estimates for the latter. Under the model of unidirectional gene flow from Anatolia to Europe, 6.4 % is expected for α of Iron Gates by calculating (% AHG in Iron Gates HG) × (α in AHG). However, Iron Gates can be modeled without any Basal Eurasian ancestry or with a non-significant proportion of 1.6 ± 2.8 %, suggesting that unidirectional gene flow from the Near East to Europe alone is insufficient to explain the extra affinity between the Iron Gates HG and the Near-Eastern hunter-gatherers. Thus, it is plausible to assume that prior to 15,000 years ago there was either a bidirectional gene flow between populations ancestral to Southeastern Europeans of the early Holocene and Anatolians of the late glacial or a dispersal of Southeastern Europeans into the Near East. Presumably, this Southeastern European ancestral population later spread into central Europe during the post-last-glacial maximum (LGM) period, resulting in the observed late Pleistocene genetic affinity between the Near East and Europe.
While ancestry is not always relevant to distinguish certain population movements (see here), especially – as in this case – when there are few samples (thus neither geographically nor chronologically representative) and no previous model to test, it seems that ancestry and Y-DNA show a great degree of continuity in Anatolia since the Palaeolithic until the Neolithic, at least in the sampled regions. C1a2 appears in Europe since ca. 40,000 years ago (viz. Kostenki, Goyet, Vestonice, etc., and later emerges again in the Balkans after the Anatolian Neolithic expansion, probably a resurge of European groups).
The potential transition of a G2a-dominated agricultural society – that is later prevalent in Anatolian and European farmers – may have therefore happened during the Aceramic III period (ca. 8000 BC), a process of haplogroup expansion probably continuing through the early part of the Pottery Neolithic, as the society based on kinship appeared (Rosenberg and Erim-Özdoğan 2011). There is still much to know about the spread of ceramic technology and southwestern Asia domesticate complex, though.
Without a proper geographical sampling, representative of previous and posterior populations, it is impossible to say. But the expansion of R1b-L754 through Anatolia to form part of the Villabruna cluster (and also the Iron Gates HG) seems perfectly possible with this data, although this paper does not help clarify the when or how. We have seen significant changes in ancestry happen within centuries with expanding populations admixing with locals. Palaeolithic sampling – like this one – shows few individuals scattered geographically over thousands of km and chronologically over thousands of years…