Proto-Indo-European homeland south of the Caucasus?

User Camulogène Rix at Anthrogenica posted an interesting excerpt of Reich’s new book in a thread on ancient DNA studies in the news (emphasis mine):

Ancient DNA available from this time in Anatolia shows no evidence of steppe ancestry similar to that in the Yamnaya (although the evidence here is circumstantial as no ancient DNA from the Hittites themselves has yet been published). This suggests to me that the most likely location of the population that first spoke an Indo-European language was south of the Caucasus Mountains, perhaps in present-day Iran or Armenia, because ancient DNA from people who lived there matches what we would expect for a source population both for the Yamnaya and for ancient Anatolians. If this scenario is right the population sent one branch up into the steppe-mixing with steppe hunter-gatherers in a one-to-one ratio to become the Yamnaya as described earlier- and another to Anatolia to found the ancestors of people there who spoke languages such as Hittite.

The thread has since logically become a trolling hell, and it seems not to be working right for hours now.

Reich’s proposal based on ancestral components to explain the formation of a people and language is a continuation of their emphasis on ancestry to explain cultures and languages. It seems quite interesting to see this happen again, given their current trend to surreptitiously modify their previous ‘Yamnaya ancestry’ concept and Yamnaya millennia-long R1a-R1b community (that supposedly explains a Yamna -> Corded Ware -> Bell Beaker migration) to a more general ‘steppe people’ sharing a ‘steppe ancestry’ who spoke a ‘steppe language’.

steppe-ancestry
Interesting arrows of dispersal of steppe ancestry, from Yamna -> Corded Ware -> Bell Beaker, from David Reich’s new book (yes, from 2018, number one bestseller in Amazon.com).

This new idea based on ancestral components suffers thus from the same essential methodological problems, which equate it – yet again – to pure speculation:

  1. It is a conclusion based on the genomic analysis of few individuals from distant regions and different periods, and – maybe more disturbingly – on the lack of steppe ancestry in the few samples at hand.
  2. Wait, what? Steppe ancestry? So they are trying to derive potential genetic connections among specific prehistoric cultures with a poorly depicted genetic sketch, based on previous flawed concepts (instead of on anthropological disciplines), which seems a rather long stretch for any scientist, whether they are content with seeing themselves as barbaric scientific conquerors of academic disciplines or not. In other words, statistics is also science (in fact, the main one to assert anything in almost any scientific field), and you cannot overcome essential errors (design, sampling, hypothesis testing) merely by using a priori correct statistical methods. Results obtained this way constitute a statistical fallacy.

  3. Even if the sampling and hypothesis testing were fine, to derive anthropological models from genomic investigation is completely wrong. Ancestral component ≠ population.
  4. To include not only potential migrations, but also languages spoken by these potential migrants? It’s sad that we have a need to repeat it, but if ancestral component ≠ population, how could ancestral component = language?

The Proto-Indo-European-speaking community

This is what we know about the formation of a Proto-Indo-European community (i.e. a community speaking a reconstructible Proto-Indo-European language) in the Pontic-Caspian steppe, which is based on linguistic reconstruction and guesstimates, tracing archaeological cultures backwards from cultures known to have spoken ancient (proto-)languages, and helping both disciplines with anthropological models (for which ancient genomics is only helping select certain details) of migration or – rarely – cultural diffusion:

NOTE. The following dates are obviously simplified. Read here a more detailed linguistic assessment based on phonology.

neolithic_steppe-anatolian-migrations
Most likely Pre-Proto-Anatolian migration with Suvorovo-Novodanilovka chiefs in the North Pontic steppe and the Balkans.
  • ca. 5000 BC. Early Proto-Indo-European (or Indo-Uralic) spoken probably during the formation and development of a loose Early Khvalynsk – Sredni Stog I cultural-historical community over the Pontic-Caspian steppe region, whose indigenous population probably had mainly Caucasus hunter-gatherer ancestry.
  • ca. 4500 BC. Khvalynsk probably speaking Middle Proto-Indo-European expands, most likely including Suvorovo-Novodanilovka chiefs into the North Pontic steppe, and probably expanding R1b-M269 lineages for the first time.
  • ca. 4000 BC. Separated communities develop, including North Pontic cultures probably gradually dominated by R1a-Z645 (potentially speaking Proto-Uralic); and Khvalynsk (and Repin) cultures probably dominated by R1b-L23 lineages, most likely developing a Late Proto-Indo-European already separated from Proto-Anatolian.
  • ca. 3500 BC. A Proto-Corded Ware population dominated by R1a-Z645 expands to the north, and slightly later an early Yamna community develops from Late Khvalynsk and Repin, expanding to the west of the Don River, and to the east into Afanasevo. This is most likely the period of reduction of variability and expansion of subclades of R1a-Z645 and R1b-L23 that we expect to see with more samples.
  • ca. 3000 BC. Expansion of Corded Ware migrants in northern Europe, and Yamna migrants along the Danube and into the Balkans, with further reduction and expansion of certain subclades.
  • ca. 2500 BC. Expansion of Bell Beaker migrants dominated by R1b-L51 subclades in Europe, and late Corded Ware migrants in east Yamna expanding R1a-Z93 subclades.

All these events are compatible with language reconstruction in mainstream European schools since at least the 1980s, supported by traditional archaeological research of the past 20 years, and is being confirmed with Genomics.

For those willingly lost in a myriad of new dreams boosted by the shallow comment contained in David Reich’s paragraph on CHG ancestry, even he does not doubt that the origin of Late Proto-Indo-European lies in Yamna, to the north of the Caucasus, based on Anthony’s (2007) account:

yamnaya-migrations-reich
Both images from the book, posted by Twitter user Jasper at https://twitter.com/jaspergregory.

NOTE: By the way, David Anthony, one of the main sources of information for Reich’s group, never considered Corded Ware to have received Yamna migrants, and althought he changed his model due to the conclusions of the 2015 papers, he has recently changed his model again to adapt it to the inconsistencies found in phylogeography.

CHG ancestry and PIE homeland south of the Caucasus

As for the potential origins of CHG ancestry in early Proto-Indo-European speakers, I already stated clearly my opinion quite recently. They may be attributed to:

Just to be clear, an expansion of Proto-Anatolian to the south, through the Caucasus, cannot be discarded today. It will remain a possibility until Maykop and more Balkan Chalcolithic and Anatolian-speaking samples are published.

However, an original Early Proto-Indo-European community south of the Caucasus seems to me highly unlikely, based on anthropological data, which should drive any conclusion. From what I could read, here are the rather simplistic arguments used:

  • Gimbutas and Maykop: Maykop was thought to be (in Gimbutas’ times) a rather late archaeological culture, directly connected to a Transcaucasian Copper Age culture ca. 2400-2300 BC. It has been demonstrated in recent years that this culture is substantially older, and even then language guesstimates for a Late PIE / Proto-Anatolian would not fit a migration to the north. While our ignorance may certainly be used to derive far-fetched conclusions about potential migrations from and to it, using Gimbutas (or any archaeological theory until the 1990s) today does not make any sense. Still less if we think that she favoured a steppe homeland.

NOTE. It seems that the Reich Lab may have already access to Maykop samples, so this suggested Proto-Indo-European – Maykop connection may have some real foundation. Regardless, we already know that intense contacts happened, so there will be no surprise (unless Y-DNA shows some sort of direct continuity from one to the other).

  • Gamkrelidze & Ivanov: they argued for an Armenian homeland (and are thus at the origin of yet another autochthonous continuity theory), but they did so to support their glottalic theory, i.e. merely to support what they saw as favouring their linguistic model (with Armenian being the most archaic dialect). The glottalic theory is supported today – as far as I know – mainly by Kortlandt, Jagodziński, or (Nostraticist) Bomhard, but even they most likely would not need to argue for an Armenian homeland. In fact, their support of a Graeco-Aryan group (also supported by Gamkrelidze & Ivanov) would be against this, at least in archaeological terms.
  • Colin Renfrew and the Anatolian homeland: This conceptual umbrella of language spreading with farming everywhere has changed so much and so many times in the past 20 years, with so many glottochronological and archaeological estimates circulating, that you can support anything by now using them. Mostly used today for abstract models of long-lasting language contacts, cultural diffusion, and constellation analogies. Anyway, he strives to keep up-to-date information to revise the model, that much is certain:
  • Glottochronology, phylogenetic trees, Swadesh list analysis, statistical estimates, psychics, pyramid power, and healing crystals: no, please, no.
Science Magazine
“A first line of evidence comes from linguistic analysis based on quantitative lexical data, which returned a tree compatible with the Anatolian hypothesis

In principle, unlike many other recent autochthonous continuity theories, I doubt there can be much racial-based opposition anywhere in the world to an origin of Proto-Indo-European in the Middle East, where the oldest civilizations appeared – apart, obviously, from modern Northeast and Northwest Caucasian, Kartvelian, or Semitic speakers, who may in turn have to revisit their autochthonous continuity theories radically…

Nevertheless, it is obvious that prehistoric (and many historic) migrations are signalled by the reduction in variability and expansion of certain Y-DNA haplogroups, and not just by ancestral components. That is generally accepted, although the reasons for this almost universal phenomenon are not always clear.

In fact, Proto-Anatolian and Common Anatolian speakers need not share any ancestral component, PCA cluster, or any other statistical parameter related to steppe populations, not even the same Y-DNA haplogroups, given that approximately three thousand years might have passed between their split from an Indo-Hittite community and the first attested Anatolian-speaking communities…We must carefully follow their tracks from Anatolia ca. 1500 BC to the steppe ca. 4500 BC, otherwise we risk creating another mess like the Corded Ware one.

In my opinion, the substantial contribution of EHG ancestry and R1a-M417 lineages to the Pontic-Caspian steppe (probably ca. 6500 BC) from Central or East Eurasia is the most recent sizeable genomic event in the region, and thus the best candidate for the community that expanded a language ancestral to Proto-Indo-European – whether you call it Pre-Proto-Indo-European, Pre-Indo-Uralic, or Eurasiatic, depending on your preferences.

An early (and substantial) contribution of CHG ancestry in Khvalynsk relative to North Pontic cultures, if it is found with new samples, may actually be a further proof of the Caucasian substrate of Proto-Indo-European proposed by Kortlandt (or Bomhard) as contributing to the differentiation of Middle PIE from Uralic. Genomics could thus help support, again, traditional disciplines in accepting or rejecting academic controversial theories.

Conclusion

In the case of an Early PIE (or Indo-Uralic) homeland, genomic data is scarce. But all traditional anthropological disciplines point to the Pontic-Caspian steppe, so we should stick to it, regardless of the informal suggestion written by a renown geneticist in one paragraph of a book conceived as an introduction to the field.

It seems we are not learning much from the hundreds of peer-reviewed, statistically (superficially, at least) sound genetic papers whose anthropological conclusions have been proven wrong by now. A lot of people should be spending their time learning about the complex, endless methods at hand in this kind of research – not just bioinformatics – , instead of fruitlessly speculating about wild unsubstantiated proposals.

As a final note, I would like to remind some in the discussion, who seem to dismiss the identification of CHG with Proto-Indo-European by supporting a “R1a-R1b” community for PIE, of their previous commitment to ancestral components in identifying peoples and languages, and thus their support to Reich’s (and his group’s) fundamental premises.

You cannot have it both ways. At least David Reich is being consistent.

Related:

Agricultural origins on the Anatolian plateau

anatolia-neolithic-agriculture

New paper (behind paywall) Agricultural origins on the Anatolian plateau, by Baird et al. PNAS (2018), published ahead of print (March 19).

Abstract (emphasis mine):

This paper explores the explanations for, and consequences of, the early appearance of food production outside the Fertile Crescent of Southwest Asia, where it originated in the 10th/9th millennia cal BC. We present evidence that cultivation appeared in Central Anatolia through adoption by indigenous foragers in the mid ninth millennium cal BC, but also demonstrate that uptake was not uniform, and that some communities chose to actively disregard cultivation. Adoption of cultivation was accompanied by experimentation with sheep/goat herding in a system of low-level food production that was integrated into foraging practices rather than used to replace them. Furthermore, rather than being a short-lived transitional state, low-level food production formed part of a subsistence strategy that lasted for several centuries, although its adoption had significant long-term social consequences for the adopting community at Boncuklu. Material continuities suggest that Boncuklu’s community was ancestral to that seen at the much larger settlement of Çatalhöyük East from 7100 cal BC, by which time a modest involvement with food production had been transformed into a major commitment to mixed farming, allowing the sustenance of a very large sedentary community. This evidence from Central Anatolia illustrates that polarized positions explaining the early spread of farming, opposing indigenous adoption to farmer colonization, are unsuited to understanding local sequences of subsistence and related social change. We go beyond identifying the mechanisms for the spread of farming by investigating the shorter- and longer-term implications of rejecting or adopting farming practices.

anatolia-neolithic
Map of central Anatolia showing the principal sites mentioned in the text.

Interesting excerpts:

The persistence of foraging and rejection of farming at Pınarbaşı is also worthy of further consideration. Pınarbaşı’s longevity as a settlement locale in the early Holocene appears to have been based on hunting of wild mammals, wetland exploitation, and significant focus on nut exploitation, all afforded by its ecotonal setting between the hills, plain, and wetland. Perhaps this existing diversity, including nutritious storable plant resources, was a key factor in a lack of interest in adopting cultivation. Another factor may have been a conscious desire to maintain traditional identities and long-standing distinctions with other communities, in part reflected in its particular way of life and its specific connections with particular elements in landscape, for example the almond and terebinth woodlands whose harvests underwrote the continuity of the Pınarbaşı settlement.

The variability in response to the possibilities of early food production in a relatively small geographical area demonstrated here is notable and provides an example useful in evaluating the spread of farming in other regions. It shows the possible role of indigenous foragers, the potential patchwork and diffuse nature of the spread of farming, the lack of homogeneity likely in the communities caught up in the process, the probability of significant continuities in local cultural traditions within the process, and the potentially long-term stable adaptation offered by lowlevel food production. The strength of identities linked to exploitation of particular foods and particular parts of the landscape may have been a major factor contributing to rejection or adoption of food production by indigenous foragers.

The results are also relevant for understanding the processes that underpinned the initial development of farming within the Fertile Crescent itself: that is, the region in which the wild progenitors of the Old World founder crops and stock animals are found. Recent research has rejected the notion of a core area for farming’s first appearance in southwest Asia and demonstrated that farming developed in diverse ways over the Fertile Crescent zone from the southern Levant to the Zagros, very analogous to the situation just described for Central Anatolia (2). Cultivation, herding, and domestication developed in that region, and it seems inescapable that exchange of crops and herded animals occurred between communities (2), involving a spread of farming within the Fertile Crescent, leading eventually to the Neolithic farming package that was so similar across the region and which spread into Europe (5). Central Anatolia was clearly linked to the Fertile Crescent, with significant evidence of exchange and some shared cultural traditions from at least the Epipaleolithic (22). The evidence presented here demonstrates very clearly the movement of crops between settlements and regions in early phases of the Neolithic through exchange, and thus allows us to identify episodes of crop exchange that were probably taking place within the Fertile Crescent itself, but are difficult, if not impossible, to distinguish due to the presence of crop progenitors across much of the region.

A very interesting read in combination with 14C-radiometric data and climatic conditions showing potential triggers of dispersal of Neolithic lifeways from Turkey to Southeast Europe, e.g. Dispersal of Neolithic Lifeways: Absolute Chronology and Rapid Climate Change in Central and West Anatolia, by Lee Clare & Bernhard Weninger, in The Neolithic in Turkey, Vol.6 (2014), Edited by Mehmet Özdogan, Nezih Basgelen, Peter Kuniholm.

anatolian-neolithic-aegean
The Late Neolithic (6600-6000 cal. BC) witnesses the rapid westward dispersal of Neolithic communities, apparently reaching the Aegean in the space of a very short time (ca. 6600 cal. BC). This process is linked to the demand of individuals, groups, and communities for less vulnerable conditions in the face of climate fluctuation associated with RCC. Coastal areas not only offered respite from more frequently occurring physical impacts (extreme winters and high drought risk) in inner Anatolia, they may also have provided refuge for weaker (more vulnerable) social groups (…).

Featured image, from the latter: “In the Early Pottery Neolithic (7000-6600 cal. BC) there occurs a clear break with precedeing (PPN) traditions, attested by abandonment and decreasing size of settlements, albeit that evidence for migration of groups westwards towards the Aegean is still ambiguous (black arrows: human migrations; white arrows: Anatolian obsidian)”

See also:

Pleistocene North African genomes link Near Eastern and sub-Saharan African human populations

taforalt-samples

Pleistocene North African genomes link Near Eastern and sub-Saharan African human populations, by van de Loosdrecht et al. Science (2018).

Abstract

North Africa is a key region for understanding human history, but the genetic history of its people is largely unknown. We present genomic data from seven 15,000-year-old modern humans from Morocco, attributed to the Iberomaurusian culture. We find a genetic affinity with early Holocene Near Easterners, best represented by Levantine Natufians, suggesting a pre-agricultural connection between Africa and the Near East. We do not find evidence for gene flow from Paleolithic Europeans into Late Pleistocene North Africans. The Taforalt individuals derive one third of their ancestry from sub-Saharan Africans, best approximated by a mixture of genetic components preserved in present-day West and East Africans. Thus, we provide direct evidence for genetic interactions between modern humans across Africa and Eurasia in the Pleistocene.

Excerpts:

We analyzed the genetic affinities of the Taforalt individ-uals by performing principal component analysis (PCA) and model-based clustering of worldwide data (Fig. 2). When pro-jected onto the top PCs of African and West Eurasian popu-lations, the Taforalt individuals form a distinct cluster in an intermediate position between present-day North Africans (e.g., Amazighes (Berbers), Mozabite and Saharawi) and East Africans (e.g., Afar, Oromo and Somali) (Fig. 2A). Consist-ently, we find that all males with sufficient nuclear DNA preservation carry Y haplogroup E1b1b1a1 (M-78; table S16). This haplogroup occurs most frequently in present-day North and East African populations (18). The closely related E1b1b1b (M-123) haplogroup has been reported for Epipaleolithic Natufians and Pre-Pottery Neolithic Levantines (“Levant_N”) (16). Unsupervised genetic clustering also suggests a connection of Taforalt to the Near East. The three major components that comprise the Taforalt genomes are maximized in early Holocene Levantines, East African hunter-gatherer Hadza from north-central Tanzania, and West Africans (K = 10; Fig. 2B). In contrast, present-day North Africans have smaller sub-Saharan African components with minimal Hadza-related contribution (Fig. 2B).

Taforalt harboring an ancestry that contains additional affinity with South, East and Central African outgroups. None of the present-day or ancient Holocene African groups serve as a good proxy for this unknown ancestry, because adding them as the third source is still insufficient to match the model to the Taforalt gene pool.

Mitochondrial consensus sequences of the Taforalt indi-viduals belong to the U6a (n = 6) and M1b (n = 1) haplogroups (15), which are mostly confined to present-day populations in North and East Africa (7). U6 and M1 have been proposed as markers for autochthonous Maghreb ancestry, which might have been originally introduced into this region by a back-to-Africa migration from West Asia (6, 7). The occurrence of both haplogroups in the Taforalt individuals proves their pre-Holocene presence in the Maghreb.
(…) the diversification of haplogroup U6a and M1 found for Taforalt is dated to ~24,000 yBP (fig. S23), which is close in time to the earliest known appearance of the Iberomaurusian in Northwest Africa (25,845-25,270 cal. yBP at Tamar Hat (26)).

taforalt-admixture
A summary of the genetic profile of the Taforalt individuals. (A) The top two PCs calculated from present-day African, Near Eastern and South European individuals from 72 populations. The Taforalt individuals are projected thereon (red-colored circles). Selected present-day populations are marked by colored symbols. Labels for other populations (marked by small grey circles) are provided in fig. S8. (B) ADMIXTURE results of chosen African and Middle Eastern populations (K = 10). Ancient individuals are labeled in red color. Major ancestry components in Taforalt are maximized in early Holocene Levantines (green), West Africans (purple) and East African Hadza (brown). The ancestry component prevalent in pre-Neolithic Europeans (beige) is absent in Taforalt.

The relationships of the Iberomaurusian culture with the preceding MSA, including the local backed bladelet technologies in Northeast Africa, and the Epigravettian in southern Europe have been questioned (13). The genetic profile of Taforalt suggests substantial Natufian-related and sub-Saharan African-related ancestries (63.5% and 36.5%, respec-tively), but not additional ancestry from Epigravettian or other Upper Paleolithic European populations. Therefore, we provide genomic evidence for a Late Pleistocene connection between North Africa and the Near East, predating the Neolithic transition by at least four millennia, while rejecting a potential Epigravettian gene flow from southern Europe into northern Africa within the resolution of our data.

It seems that the Taforalt gene pool (ca. 13000-12000 BC) cannot be explained by a connection with Upper Palaeolithic Europeans, but a more archaic admixture, so the authors cannot prove a migration through the Strait of Gibraltar or Sicily.

Nevertheless, these results apparently suggest:

  • That there is no contact before ca. 12000 BC through the Strait of Gibraltar; therefore the Sicilian route I support for the migration of R1b-V88 lineages is still the most likely one.
  • That the North African connection with Natufians is quite old – for which we already had modern Y-DNA investigation – , and therefore unlikely to be related to the Afroasiatic expansion.

I am glad I had some more time this week to read at least some interesting parts of the published papers, because the information to process is becoming insanely huge…

Related:

Iberian prehistoric migrations in Genomics from Neolithic, Chalcolithic, and Bronze Age

iberia-neolithic-bronze-age

New open access paper Four millennia of Iberian biomolecular prehistory illustrate the impact of prehistoric migrations at the far end of Eurasia, by Valdiosera, Günther, Vera-Rodríguez, et al. PNAS (2018) published ahead of print.

Abstract (emphasis mine)

Population genomic studies of ancient human remains have shown how modern-day European population structure has been shaped by a number of prehistoric migrations. The Neolithization of Europe has been associated with large-scale migrations from Anatolia, which was followed by migrations of herders from the Pontic steppe at the onset of the Bronze Age. Southwestern Europe was one of the last parts of the continent reached by these migrations, and modern-day populations from this region show intriguing similarities to the initial Neolithic migrants. Partly due to climatic conditions that are unfavorable for DNA preservation, regional studies on the Mediterranean remain challenging. Here, we present genome-wide sequence data from 13 individuals combined with stable isotope analysis from the north and south of Iberia covering a four-millennial temporal transect (7,500–3,500 BP). Early Iberian farmers and Early Central European farmers exhibit significant genetic differences, suggesting two independent fronts of the Neolithic expansion. The first Neolithic migrants that arrived in Iberia had low levels of genetic diversity, potentially reflecting a small number of individuals; this diversity gradually increased over time from mixing with local hunter-gatherers and potential population expansion. The impact of post-Neolithic migrations on Iberia was much smaller than for the rest of the continent, showing little external influence from the Neolithic to the Bronze Age. Paleodietary reconstruction shows that these populations have a remarkable degree of dietary homogeneity across space and time, suggesting a strong reliance on terrestrial food resources despite changing culture and genetic make-up.

iberia-admixture
(A) f4 statistics testing affinities of prehistoric European farmers to either early Neolithic Iberians or central Europeans, restricting these reference populations to SNP-captured individuals to avoid technical artifacts driving the affinities. The boxplots in A show the distributions of all individual f4 statistics belonging to the respective groups. The signal is not sensitive to the choice of reference populations and is not driven by hunter-gatherer–related admixture (Datasets S4 and S5). (B) Estimates of ancestry proportions in different prehistoric Europeans as well as modern southwestern Europeans. Individuals from regions of Iberia were grouped together for the analysis in A and B to increase sample sizes per group and reduce noise

Conclusion:

We present a comprehensive biomolecular dataset spanning four millennia of prehistory across the whole Iberian Peninsula. Our results highlight the power of archaeogenomic studies focusing on specific regions and covering a temporal transect. The 4,000 y of prehistory in Iberia were shaped by major chronological changes but with little geographic substructure within the Peninsula. The subtle but clear genetic differences between early Neolithic Iberian farmers and early Neolithic central European farmers point toward two independent migrations, potentially originating from two slightly different source populations. These populations followed different routes, one along the Mediterranean coast, giving rise to early Neolithic Iberian farmers, and one via mainland Europe forming early Neolithic central European farmers. This directly links all Neolithic Iberians with the first migrants that arrived with the initial Mediterranean Neolithic wave of expansion. These Iberians mixed with local hunter-gatherers (but maintained farming/pastoral subsistence strategies, i.e., diet), leading to a recovery from the loss of genetic diversity emerging from the initial migration founder bottleneck. Only after the spread of Bell Beaker pottery did steppe-related ancestry arrive in Iberia, where it had smaller contributions to the population compared with the impact that it had in central Europe. This implies that the two prehistoric migrations causing major population turnovers in central Europe had differential effects at the southwestern edge of their distribution: The Neolithic migrations caused substantial changes in the Iberian gene pool (the introduction of agriculture by farmers) (6, 9, 11, 13, 24), whereas the impact of Bronze Age migrations (Yamnaya) was significantly smaller in Iberia than in north-central Europe (24). The post-Neolithic prehistory of Iberia is generally characterized by interactions between residents rather than by migrations from other parts of Europe, resulting in relative genetic continuity, while most other regions were subject to major genetic turnovers after the Neolithic (4, 6, 7, 9, 25, 48). Although Iberian populations represent the furthest wave of Neolithic expansion in the westernmost Mediterranean, the subsequent populations maintain a surprisingly high genetic legacy of the original pioneer farming migrants from the east compared with their central European counterparts. This counterintuitive result emphasizes the importance of in-depth diachronic studies in all parts of the continent.

Related:

On the potential origin of Caucasus hunter-gatherer ancestry in Eneolithic steppe cultures

An interesting open genomic question is the origin and spread of Caucasus hunter-gatherer (CHG) ancestry in steppe populations during the Eneolithic.

My broad theory regarding the appearance of this ancestral component is based on:

Two recently published papers ivestigating the Don Region may shed some light on this issue:

Plant food subsistence in the human diet of the Bronze Age Caspian and Low Don steppe pastoralists: archaeobotanical, isotope and 14C data, by Shishlina, Bobrov, Simakova, et al. Veget Hist Archaeobot (2018).

EDIT (16/3/2018): You can now read or download the paper at Academia.edu.

Abstract:

The paper presents the result of analysis of charred food on the interior part of the vessels from the graves of the East Manych and West Manych Catacomb archaeological cultures (2500–2350 cal bc). The phytolith and pollen analyses identified pollen of wild steppe plants and phytoliths of domesticated gramineous plants determined as barley phytoliths. Direct 14С dating of one of the samples demonstrates that barley spikelets and stems were used in funeral rites by local steppe communities. However, there are no data suggesting that steppe inhabitants of the Lower Don Region were engaged in agriculture in the mid-3000 bc. Supposedly, barley could have reached the steppes through seasonal migrations of mobile pastoralists to the south, use of North Caucasus grasslands in the economic system of seasonal moves and exchange with local people. Nevertheless, presence of carbonized barley seeds in the occupation layers at North Caucasus settlements of 4000–3000 bc requires confirmation by direct 14С dating of such samples.

catacomb-sites-peschany
Location of sites. 1: Ulan IV; 2: Peschany IV and V; 3: Shakhaevskaya 1; 4: Zunda-Tolga 2; 5: Lesnoye; 6: Chidgom; 7: Meshoko; 8: Chishkho; 9: Svobodnoye

Dynamics of Chemical and Microbiological Soil Properties in the Desert–Steppe Zone of the Southeast Russian Plain during the Second Part of the Holocene (4000 BC–XIII century AC), Kashirskaya, Khomutova, Kuznetsova, et al. Arid Ecosyst (2018) 8(1):38-46.

Abstract:

The results of studies of the chemical and microbiological properties of the soils buried under the barrows of the Eneolithic, Bronze, and Middle Ages periods of the southeast of the Russian Plain are presented. It was shown that the climate of the region in the Eneolithic period (4200–4100 BC) and in the Middle Ages (700 years ago) was more humid in comparison to the present time. The third millennium BC was characterized by a gradual increase of the climate aridity. Its peak was at the end of the III millennium BC. The number and biomass of microbial cells was maximal in soils buried in periods of high atmospheric humidity (4200–4100 and 3000–2800 BC) and sharply decreased during the aridization period in the second half of the III millennium BC. In general, the variability of indicators of microbocenosis conditions of desert–steppe buried soils of all ages from the burial mounds correlated with the centuries-old dynamics of the climate.

steppe-humidity-periods
Number of microbial cells in buried soils of different ages and modern background soil.

It is well known that access to more food – as in favorable crops and cattle feeding – may cause demographic explosions, and the second article – together with recent genomic data – may be yet another proof of that.

Until now, pastoralism seemed to be the main subsistence economy for most steppe groups. It seems that earlier Eneolithic contacts of certain steppe groups with settlements of the Northern Caucasus might have been not just to obtain prestige goods though, but – if proper radiocarbon dating confirms it – also implied essential goods, and maybe more stable seasonal exchange systems.

Such stable economic exchanges might have therefore included bidirectional exogamy practices, justifying the sizeable genomic contribution from the Caucasus.

At this point this is just another good theory to take into account.

Related:

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

southeast-asia-reich

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

Abstract (emphasis mine):

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

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

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

See also:

Population replacement in Early Neolithic Britain, and new Bell Beaker SNPs

copper-age-late-bell-beaker

New (copyrighted) preprint at BioRxiv, Population Replacement in Early Neolithic Britain, by Brace et al. (2018).

Abstract (emphasis mine):

The roles of migration, admixture and acculturation in the European transition to farming have been debated for over 100 years. Genome-wide ancient DNA studies indicate predominantly Anatolian ancestry for continental Neolithic farmers, but also variable admixture with local Mesolithic hunter-gatherers. Neolithic cultures first appear in Britain c. 6000 years ago (kBP), a millennium after they appear in adjacent areas of northwestern continental Europe. However, the pattern and process of the British Neolithic transition remains unclear. We assembled genome-wide data from six Mesolithic and 67 Neolithic individuals found in Britain, dating from 10.5-4.5 kBP, a dataset that includes 22 newly reported individuals and the first genomic data from British Mesolithic hunter-gatherers. Our analyses reveals persistent genetic affinities between Mesolithic British and Western European hunter-gatherers over a period spanning Britain’s separation from continental Europe. We find overwhelming support for agriculture being introduced by incoming continental farmers, with small and geographically structured levels of additional hunter-gatherer introgression. We find genetic affinity between British and Iberian Neolithic populations indicating that British Neolithic people derived much of their ancestry from Anatolian farmers who originally followed the Mediterranean route of dispersal and likely entered Britain from northwestern mainland Europe.

Also, Genetiker has updated Y-SNP calls from new data published from the Harvard group.

The R1b lineages that expanded from (Yamna->) East Bell Beakers -> Western Europe are more and more clearly of R1b-L151 subclades, as expected.

Quite interesting are the early samples from Poland, of R1b1a1a2a2-Z2103 and R1b1a1a2a1a-L151 lineages – , which may point (different to the more homogeneous L151 distribution in Western Europe) to a mix in both original (east-west) Yamna groups. This could tentatively be used to explain the Graeco-Aryan influence that some linguists see in Balto-Slavic (or its superstrate).

That link would then be quite early, to account for an influence during the Yamna settlements in Hungary, before its expansion as East Bell Beakers, but we haven’t seen a clearly differentiated subgroup (yet) in Archaeology, Anthropology, or Genomics within the Hungarian Yamna/East Bell Beaker community, so I am not convinced. It could be just that different scattered subclades mixed with the general L151 population pop up (following old Yamna lineages, or having being added along the way), as expected in an expansion over such a great territory – as if some scattered samples of R1a, I1, I2, J, etc. were found.

We need more early samples from south-eastern Europe and the steppe during the Chalcolithic to ascertain the composition and migration paths of the different Yamna settlers.

Other interesting findings are the early (Proto-)Bell Beaker samples of haplogroup R1b with no steppe ancestry from Spain – which some autochthonous continuists wanted to believe was a proof of some kind – , which are actually R1b-V88, a haplogroup known to have expanded throughout Europe quite early. In fact, this subclade has been recently shown to have most likely expanded through the Green Sahara region, and is potentially linked to the expansion of Afro-Asiatic.

See also:

Corded Ware culture contacts in the Baltic Sea region linked to immigrant potters

chalcolithic_early_corded_ware

Article behind paywall Tracing grog and pots to reveal neolithic Corded Ware Culture contacts in the Baltic Sea region (SEM-EDS, PIXE) by Larsson et al., J. Archaeol. Sci. (2018) 91:77-91.

Abstract (emphasis mine):

The Neolithic Corded Ware Culture (CWC) complex spread across the Baltic Sea region ca. 2900/2800–2300/2000 BCE. Whether this cultural adaptation was driven by migration or diffusion remains widely debated. To gather evidence for contact and movement in the CWC material culture, grog-tempered CWC pots from 24 archaeological sites in southern Baltoscandia (Estonia and the southern regions of Finland and Sweden) were sampled for geochemical and micro-structural analyses. Scanning electron microscopy with energy dispersive spectrometry (SEM-EDS) and particle-induced X-ray emission (PIXE) were used for geochemical discrimination of the ceramic fabrics to identify regional CWC pottery-manufacturing traditions and ceramic exchange. Major and minor element concentrations in the ceramic body matrices of 163 individual vessels and grog temper (crushed pottery) present in the ceramic fabrics were measured by SEM-EDS. Furthermore, the high-sensitivity PIXE technique was applied for group confirmation. The combined pot and grog matrix data reveal eight geochemical clusters. At least five geochemical groups appeared to be associated with specific find locations and regional manufacturing traditions. The results indicated complex inter-site and cross-Baltic Sea pottery exchange patterns, which became more defined through the grog data, i.e., the previous generations of pots. The CWC pottery exhibited high technological standards at these latitudes, which, together with the identified exchange patterns and the existing evidence of mobility based on human remains elsewhere in the CWC complex, is indicative of the relocation of skilled potters, possibly through exogamy. An analytical protocol for the geochemical discrimination of grog-tempered pottery, and its challenges and possibilities, is presented.

corded-ware-finland
Meolithic Corded Ware Culture sites studied in the Baltic Sea region

We are seeing a growing complexity for the definition of the Corded Ware culture in anthropological models that help us understand genomic data, including its precise origins and expansion, and indeed for the question of the expansion of ancient Uralic languages in the region.

Related:

Demographic research of Neolithic, Chalcolithic, and Bronze Age Europe

europe-demographic

I mentioned in the Indo-European demic diffusion model the need to assess absolute and relative population growth – as well as other demographic changes – to interpret genomic data from the different European regions studied.

One article I referred to was Demographic traces of technological innovation, social change and mobility: from 1 to 8 million Europeans (6000–2000 BCE), by Johannes Müller.

Excerpts (emphasis mine):

  • The neolithization of Northern and Northwestern Europe (probably with new forms of slash-and-burn agriculture; Feeser et al. 2012; Schier 2009) was also one of the causes for the population increase observed.
  • The introduction of the plough and developing technologies (e.g. the introduction of the wheel) (cf. Mischka 2011) might also be causes of rising population figures from ca. 3500–3000 BC.
  • The establishment of subcontinental value systems, such as the Corded Ware and Bell-Beaker phenomena (Czebreszuk/Szmyt 2003; Furholt 2004), in contrast to regional identities, might have triggered different reactions in different areas, leading to fluctuating population levels.
  • The introduction of Bronze Age ideologies, including bronze as a technology, triggered the spread of Neolithic and Bronze Age societies to vast areas of Europe (e.g. Earle/Kristiansen 2010).A major population increase is observed in both the areas already settled as well as in new areas of interest.
europe-population-neolithic
Absolute population values in Europe and the Near East from 6500–1500 BCE (interpolation line: spline).

In our population estimations for Central Europe and Scandinavia, population increases are associated with the periods from 5500–5000 BCE (LBK) and 3500–3000 BCE (middle and late Funnelbeaker Culture), but not for the period from 2500–2000 BCE (Bell Beaker). Consequently, this would possibly indicate forms of immigration for the first two periods and a form of interregional networking (e.g. through marriage) for the latter. But as also for the first cases on the supra-regional level (which our enquiries investigated), no other area with a significant population decrease could be observed, therefore “proof” for larger population displacement is not given. For such inquiries, studies on a more regional level are probably necessary. Nevertheless, for the Bell Beaker period I would like to exclude the possibility of large population influxes at least to Central Europe and South Scandinavia as the population values show no indication of such an event (cf. Fig. 10). In consequence, supra-regional networks or population-exchanges between smaller regions might be responsible for the isotope values.

One could interpret from the graphics, including known anthropological and genomic data, that:

  • The population growth corresponding to the Corded Ware expansion from ca. 3300 into Central Europe was seen initially with the introduction of new technology, but then stalled – probably with population replacement during the A-horizon of the Corded Ware culture.
  • The Yamna expansion into South-East Europe must have included some population replacement, i.e. influx into progressively deserted areas (such as that of the Cucuteni-Trypillia culture), since it did not leave traces of population growth.
  • The impact of the expansion of East Bell Beakers from ca. 2500 BC is clear in South-East Europe, and especially in Western Europe – taking into account the whole population growth in Europe. In Central Europe and Scandinavia the overall impact of BB migration was more limited, which suggests some degree of population replacement.

Also important to interpret genomic data are the actual economic and social differences in the different periods and cultures – usually growing after the introduction of farming. A good example is the scarce data from Khvalynsk, where the sample of haplogroup R1b (most likely of subclade M269) shows – apart from a closer position in PCA to Yamna – a a high-status burial, similar to high-status individuals buried under kurgans in later Yamna graves. This man was therefore probably a founder of an elite group of patrilineally-related families, which dominated in the following Yamna culture, which explains the clear expansion of this haplogroup’s subclades from this region.

europe-population-inequality
Figures from Rebellion and Inequality in Archaeology (2017), by Johannes Müller

Other interesting papers on European demographics by Johannes Müller include:

Check out also works by Marko Porčić (such as Radiocarbon test for demographic events in written and oral history) or Stephen Shennan.

EDIT (17 Feb 2018): For how variation in the effective population size governs genetic diversity, see:

Featured image, from the main article: “The distribution of agrarian regions in Europe and the Near East in relation to the supra-regions as defined in this study: Near East (NE) about 2.400.000 km2; South East Europe (SEE) about 1.087500 km2; Central Europe and South Scandinavia (CE/SSc) about 1.613.000 km2. Europe includes 10.050.000 km2 (without Iceland)”.

See also:

The concept of “Outlier” in Human Ancestry (III): Late Neolithic samples from the Baltic region and origins of the Corded Ware culture

corded-ware-regions-main

I have written before about how the Late Neolithic sample from Zvejnieki seemed to be an outlier among Corded Ware samples (read also the Admixture analysis section on the IEDDM), due to its position in PCA, even more than its admixture components or statistical comparison might show.

In the recent update to Northern European samples in Mittnik et al. (2018), an evaluation of events similar to the previous preprint (2017) is given:

Computing D-statistics for each individual of the form D(Baltic LN, Yamnaya; X, Mbuti), we find that the two individuals from the early phase of the LN (Plinkaigalis242 and Gyvakarai1, dating to ca. 3200–2600 calBCE) form a clade with Yamnaya (Supplementary Table 7), consistent with the absence of the farmer-associated component in ADMIXTURE (Fig. 2b). Younger individuals share more alleles with Anatolian and European farmers (Supplementary Table 7) as also observed in contemporaneous Central European CWC individuals2.

baltic-region-mittnik
Sampling locations and dating of 38 ancient Northern European samples introduced in this study. Chronology based on calibrated radiocarbon dates or relative dating

My interpretation of the Zvejnieki sample ca. 2880 BC (and thus also of the only Baltic LN sample forming a close cluster with it) as ‘outlier’ seems thus reinforced as more samples come in. My explanation based on exogamy is one possibility for the region. After all, great mobility and exogamy practices are universally accepted for the Corded Ware territory, and Yamna migrants had settled up along the Prut precisely around this period (ca. 3100-2900 BC), so this kind of relation between Yamna and Baltic samples is to be expected.

NOTE: Information on the Late Neolithic burial of Zvejnieki is scarce, since it is an isolated find in radiocarbon analysis, among Mesolithic burials. You can read more about it from Ilga Zagorska’s studies, such as The use of ochre in Stone Age burials of the East Baltic (2008), The persistent presence of the dead: recent excavations at the hunter-gatherer cemetery at Zvejnieki (Latvia) (Antiquity 2013), or Dietary freshwater reservoir effects and the radiocarbon ages of prehistoric human bones from Zvejnieki, Latvia (J. Archaeol. Sci. 2016).

Samples of Baltic “Late Neolithic / Corded Ware culture”

The only two samples clustering more closely to Yamna cluster also closely to the three previous samples from Khvalynsk in Samara (labelled ‘Steppe Eneolithic’ in the paper), which makes one wonder how strongly connected were cultures from the forest and forest-steppe zones before the expansion of Corded Ware and Yamna settlers.

NOTE: Apart from the scarcity of samples available, which is common in genetic studies, the description of both additional ‘outlier’ samples of the Baltic Late Neolithic – isolated finds based mainly on radiocarbon analysis – leaves a lot to the imagination, because of the lack of cultural context and potential problems with dating methods:

Plinkaigalis 242, >40 year old female (OxA-5936, 4280 ± 75 BP, 3260–2630 calBCE). The burial site is located in the plains of central Lithuania on the eastern bank of the river Šušvė on the outskirts of the Plinkaigalis village, approximately 400 m southeast of an Iron age hill fort and settlement. The burial site was discovered in 1975 when local residents started digging for gravel in the western part of the hill. The same year site was granted a legal protection with archaeological excavations carried out for eight straight years in a row (1977-1984). During the eight years of fieldwork a total of 373 graves (364 inhumation and 9 cremation graves) with all but two of them dating to 3rd to 8th c. AD were uncovered. The two exceptional graves (no. 241, 242) were uncovered in the northern part of the burial site and C14 dated to the Late Neolithic.

Gyvakarai 1, 35-40 year old male (Poz-61584, 4030 ± 30 BP, 2620–2470 calBCE). The burial site is located in the northern part of Lithuania on the steep gravelly bank (elevation up to 79 m a. s. l.) of the rivulet Žvikė, 500 m to the south from where, in the wet grassland valley, it meets the main stem river Pyvesa. The site was discovered in 2000 when local residents started digging for gravel in the central part of the gravelly bank. The same year rescue excavations were conducted in the surrounding area of the highly disturbed grave resulting in discovery of a single grave C14 dated to the Late Neolithic.

EDIT (16 FEB 2018): A commentator noted that Gyvakaray1 was also studied for Yersinia pestis, a disease which appears to have expanded first to the west from the steppe, and then to the east, so it is possible that its position in PCA related to Plinkaigalis242 shows a connection to late Yamna settlers or East Bell Beaker migrants.

pca-mittnik
File modified by me from Mittnik et al. (2018) to include the approximate position of the most common ancestral components, and an identification of potential outliers. Zoomed-in version of the European Late Neolithic and Bronze Age samples. “Principal components analysis of 1012 present-day West Eurasians (grey points, modern Baltic populations in dark grey) with 294 projected published ancient and 38 ancient North European samples introduced in this study (marked with a red outline).

NOTE: I haven’t had the time and patience to work with my virtual computer on the PCA of these new samples – my CPU is reaching everyday its limit and my fans work half the time – , so I don’t know exactly which of them is Plinkaigalis242 and which Gyvakarai1, I just made a wild guess (based on ADMIXTURE) that the earlier Plinkaigalis242 forms a common ‘outlier’ group with Zvejnieki; if they are reversed or otherwise wrong in the image, please correct me. It will be much appreciated.

We can see from the additional samples in Mittnik et al. (2018) that the common cluster formed by most Baltic LN samples in PCA (most of them with clear cultural context among Late Neolithic or Corded Ware material, unlike the two ‘outliers’ and Gyvakarai1) is among Ukraine Eneolithic samples, European Corded Ware samples, and also Mesolithic-Neolithic samples from the Baltic. This is a logical find in light of the mainstream opinion that the expansion of the third horizon of the Corded Ware culture seems to have begun in the Dnieper-Dniester region (a corridor of steppe, steppe-forest, and forest zones) ca. 3300 BC.

baltic-samples
PCA and ADMIXTURE analysis reflecting three time periods in Northern European prehistory. a Principal components analysis of 1012 present-day West Eurasians (grey points, modern Baltic populations in dark grey) with 294 projected published ancient and 38 ancient North European samples introduced in this study (marked with a red outline). Population labels of modern West Eurasians are given in Supplementary Fig. 7 and a zoomed-in version of the European Late Neolithic and Bronze Age samples is provided in Supplementary Fig. 8. b Ancestral components in ancient individuals estimated by ADMIXTURE (k = 11)

Corded Ware culture origins

If we take the most recent reliable radiocarbon analyses of material culture, and interpretations based on them of Corded Ware as a ‘complex’ similar to Bell Beaker (accepted more and more by disparate academics such as Anthony or Klejn), it seems that the controversial ‘massive’ Corded Ware migration must have begun somehow later than previously thought, which leaves these early Baltic samples still less clearly part of the initial Corded Ware culture, and more as outliers waiting for a more precise cultural context among Late Neolithic changes in the region.

Their situation in PCA among Khvalynsk (Samara), Baltic Mesolithic, East Hunger-Gatherer samples, Yamna and Eneolithic Ukraine leaves us without enough information to understand their actual origin.

EDIT (3 FEB 2018): In the first edition of my IEDDM paper I based the potential expansion of the Corded Ware culture mainly on Piezonka’s detailed analyses of the evolution of Mesolithic and Neolithic cultures in the forest-steppe and Forest Zone, and on later phylogeographic finds, since there were no samples from these regions in this interesting period. I revised it in the second edition to accomodate the model to the Indo-Uralic proto-language supported by the Leiden school, and identified it with a a close Neolithic-Chalcolithic steppe community based on common language guesstimates and – after the latest revision of Mathieson et al. (2017) – on the appearance of steppe admixture in the steppe.

However, if traditional Uralicists are right in supposing a loose Neolithic community in the Forest Zone, and Kristiansen is right in supposing long-lasting contacts in the Dniester-Dnieper region, we might actually be seeing with these ‘outliers’ the first proof that Neolithic samples from the forest-steppe and Forest Zone of the 4th millenium – unrelated to the Corded Ware culture – clustered closely to Khvalynsk, Sredni Stog, or Yamna samples, which is compatible with Piezonka’s accounts of intercultural contacts.

Martin Furholt‘s assessment of the origin of the A-horizon of the Corded Ware culture would put the early dates of Late Neolithic in the Baltic coinciding with or just before the initial expansion of Corded Ware migrants. For example, here are some excerpts (emphasis mine) from Re-evaluating Corded Ware Variability in Late Neolithic Europe (2014), in Proceedings of the Prehistoric Society (you can read it free at Academia.edu):

Radiocarbon analysis

Acceptance of the results of radiometric dating meant that the concept of the so called ‘A-Horizon’ also had to be reformulated. If we are dealing with such a phase at all, it is not a classic typological period that is defined by a uniform material culture inventory, but rather a set of types which show a wide distribution, but which are always integrated into a locally specific and thus regionally variable context.

The situation resembles that of the Bell Beakers, where a few supra-regional types are associated with local forms of ‘Begleitkeramik’ (i.e. pottery that accompanies Bell Beakers: Strahm 1995; Besse 1996).

The distribution data indicate that this set of forms (namely the A-Beaker, ‘A-Amphora’, and A-Battle Axe, as well as Herringbone-decorated Beakers) was to be found over much of Europe around 2700 BC, and that the currency of these forms was not short: they seem to have been used continuously during the Final Neolithic, perhaps even until 2000 BC (Fig. 3; Furholt 2004). Analysis of the radiometric and dendrochronological determinations also indicates that the A-Horizon is not the earliest Corded Ware phase. Instead, it appears to follow an apparent earlier phase in Poland during which Corded Ware pottery was in use from as early as 2900 BC (Furholt 2003; 2008a; Wödarczak 2006; Ullrich 2008).

corded-ware-chronology
Chronological model following from radiocarbon dating. Mark the contrast to the traditional model of the A-horizon as the earliest phase and a successive increase in regional variability later on

Corded Ware and Yamna/Bell Beaker

While widening networks and a change in the mechanism of exchange appears to have contributed to the emergence of the Corded Ware archaeological phenomenon, and also the contemporaneous Yamnaya graves (Harrison & Heyd 2007) and the following Bell Beaker and Early Bronze Age phenomena, it remains to be seen exactly what factors contributed to the development of these systems. It may be that there were changes in subsistence practices, perhaps involving a rising importance of animal herding that subsequently required higher mobility (for a discussion see Dörfler & Müller 2008), but considering the obvious diversity in subsistence patterns present in different Corded Ware groups, such an explanation would seem appropriate for the transformation in some regions, but surely not for the eastern hunterfisher-gatherer groups of the Baltic (Bläuer & Kantanen 2013). Also, trade with amber and copper might have played its role, but there are so far no indications for a significant rise in quantity or reach of these two materials in connection with Corded Ware graves or settlements (Furholt 2003, 125–7).

The impacts of animal traction and the wagon are also to be taken into account, as they are present since 3400 BC (Mischka 2011) but does at least not play any visible role in Corded Ware burial rituals, very much in contrast to the previous periods (Johannsen & Laursen 2010). There is no evidence for horse riding, but the domesticated horse seems to be present in central Europe since before 3000 BC (Becker 1999) and have also been found in Corded Ware settlements (Becker 2008), but again the evidence of domesticated horses is much more abundant in the period before 3000 BC.

So, concerning amber and copper exchange, or the impact of the wheel and animal traction, there is the recurrent motive of stronger evidence for the period before 3000 BC than during or in connection to Corded Ware finds after 2700 BC.

corded-ware-groups-europe-chronology
Summary table for the chronological positions (extent of name plus vertical lines) of the most important traditional archaeological ‘cultures’, ‘Groups’ or pottery styles discussed in this paper. Note that the definitions of those units are far from consistent or comparable, because they derive from different national and regional research traditions. Bold letters indicate a unit connected to the Corded Ware phenonomenon

Conclusion

The evidence strongly points towards a long period of coalescence from 3000 to 2700 BC, when several innovations in burial customs, pottery, and tool types sprung forth from different places and subsequently spread via different networks of exchange and interaction. These surely showed a significant rise in scale, reach, and impact on local practices, but the same is true for the contemporary Globular Amphora and Yamnaya ‘Cultures’. This exchange resulted, roughly spoken, in a phenomenon like the A-Horizon.

(…)

Thus, it seems reasonable to explain the wide regional reach of those Corded Ware elements as the result of a general increase in mobility and thus an increase in the spatial extension of regional networks, triggered by the long-term effects of technological innovations and connected economic and social transformations in Europe since 3400 BC. It is the increase in mobility and regional networks that is new to the European Neolithic Societies after this time, and it is not only the Corded Ware elements, that are spread through these channels but also Yamnaya, Globular Amphorae, Bell Beaker ‘Cultures’, and copper and bronze artefacts in later periods. Those are archaeological classification units, heuristic tools for the ordering of finds, while brushing over variability and overlapping traits, and so they should not be confused with real social groups.

corded-ware-regions-network
Network analysis based on the quantitative occurrence of Corded Ware pottery forms, pottery ornamentation styles, tools, weapons and ornaments as stated in Table 1, based on the catalogues given in Table 2, line thickness representing similarity

As a summary, we can say that there is still much work to be done on the origins and expansion of the Corded Ware culture, and that speculative interpretations of recent genetic papers (especially since 2015), based solely on scarce genetic finds, are not doing much in favour of sound anthropological models by connecting directly Yamna to Corded Ware (and the latter to Bell Beaker), as the multiple new anthropological ‘steppe’ models (and their unending revisions due to the gradual corrections from ‘Yamnaya’ to ‘steppe’ admixture in genetic papers) are showing.

Featured image, from Furholt’s article: Map of the Corded Ware regions discussed for central Europe. The dark shading indicates those regions where Corded Ware burial rituals are present regularly.

Related: