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:

The preferred northwest passage to Scandinavia

Pontus Skoglund writes (and shares publicly) his perspective on early postglacial migrations of hunter-gatherers into Scandinavia, in Northwest Passage to Scandinavia (Nat. Ecol. Evol.): an initial migration from the south and a second coastal migration north of the Scandinavian ice sheet.

He sums up the recently published Open Access paper Population genomics of Mesolithic Scandinavia: Investigating early postglacial migration routes and high-latitude adaptation, by Günther, Malmström , Svensson, Omrak, et al. PLoS Biol (2018) 16(1): e2003703, based on preprint at BioRxiv Genomics of Mesolithic Scandinavia reveal colonization routes and high-latitude adaptation (2017).

Abstract:

Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the Last Glacial Maximum (LGM). However, the routes and genetic composition of these postglacial migrants remain unclear. We sequenced the genomes, up to 57× coverage, of seven hunter-gatherers excavated across Scandinavia and dated from 9,500–6,000 years before present (BP). Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east–west genetic gradient that opposes the pattern seen in other parts of Mesolithic Europe. Our results suggest two different early postglacial migrations into Scandinavia: initially from the south, and later, from the northeast. The latter followed the ice-free Norwegian north Atlantic coast, along which novel and advanced pressure-blade stone-tool techniques may have spread. These two groups met and mixed in Scandinavia, creating a genetically diverse population, which shows patterns of genetic adaptation to high latitude environments. These potential adaptations include high frequencies of low pigmentation variants and a gene region associated with physical performance, which shows strong continuity into modern-day northern Europeans.

The ice sheet distribution – which did not improve nuch for thousands of years – was clearly the greatest barrier for potential migrations in the region.

baltic-sea-10000-bc
Baltischer Süßwassersee Vorläufer der Ostsee vor 12.000 Jahren, by Juschki and Koyos at Wikipedia

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:

Genetic prehistory of the Baltic Sea region and Y-DNA: Corded Ware and R1a-Z645, Bronze Age and N1c

baltic-region-mittnik

Open Access The genetic prehistory of the Baltic Sea region, by Mittnik et al., Nature Communications 9: 442 (2018), based on preprint The Genetic History of Northern Europe, at BioRxirv.

As you can see, it follows my predictions in terms of haplogroups, and sadly the same trend to substitute ‘Yamna’ for ‘steppe’ while keeping linguistic interpretations unchanged…

Important excerpts for the Indo-European question (emphasis mine):

Mesolithic to Neolithic

In the archaeological understanding, the transition from Mesolithic to Neolithic in the Eastern Baltic region does not coincide with a large-scale population turnover and a stark shift in economy as seen in Central and Southern Europe. Rather, it is signified by a change in networks of contacts and the use of pottery, among other material, cultural and economic changes. Our results suggest continued admixture between groups in the south of the Eastern Baltic region, who are more closely related to WHG, and northern or eastern groups, more closely related to EHG. Neolithic social networks from the Eastern Baltic to the River Volga could also explain similarities of the hunter-gatherer pottery styles, although morphologically analogous ceramics might also have developed independently due to similar functionality. The genetic evidence for a change in networks and possibly even a large-scale population movement is most pronounced in the Middle Neolithic in individuals attributed to the CCC. The distribution of this culture overlaps in the north with the Narva culture and extends further north to Finland and Karelia. Its spread in the Eastern Baltic is linked with a significant change in imported raw materials, artefacts, and the appearance of village-like settlements15.

Neolithic to Chalcolithic

We see a further population movement into the regions surrounding the Baltic Sea with the CWC in the Late Neolithic that was accompanied by the first evidence of extensive animal husbandry in the Eastern Baltic. The presence of ancestry from the Pontic-Caspian Steppe among Baltic CWC individuals without the genetic component from north-western Anatolian Neolithic farmers must be due to a direct migration of steppe pastoralists that did not pick up this ancestry in Central Europe. It suggests import of the new economy by an incoming steppe-like population independent of the agricultural societies that were already established to the south and west of the Baltic Sea. The presence of direct contacts to the steppe could lend support to a linguistic model that sees an early branching of Balto-Slavic from a Proto-Indo-European language, for which the west Eurasian steppe was proposed as a homeland. However, as farmer ancestry is found in later Eastern Baltic individuals, it is likely that considerable individual mobility and a network of contact throughout the range of the CWC facilitated its spread eastward, possibly through exogamous marriage practices. Conversely, the appearance of mitochondrial haplogroup U4 in the Central European Late Neolithic after millennia of absence could indicate female gene-flow from the Eastern Baltic, where this haplogroup was present at high frequency.

baltic-neolithic
PCA and ADMIXTURE analysis reflecting Late Neolithic 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 ancient North European samples introduced in this study (marked with a red outline). b Ancestral components in ancient individuals estimated by ADMIXTURE (k = 11)
baltic-samples-neolithic
Zoomed-in version of the European Late Neolithic PCA.

So, we see that no farmer ancestry is found in the Baltic (unlike in Western Yamna), that PCA of Late Neolithic is closer to Corded Ware samples from Europe (or to earlier samples from the region) and not to Yamna, as suggested at first by the Zvejnieki individual.

There obviously was exogamy – which may in fact justify the findings in PCA close to Yamna (like the Zvejnieki sample), although researchers obviate that.

Also, as expected, no R1b-M269 in the Baltic (during the Corded Ware period), most are R1a with the majority showing subclade R1a-Z645 (and others poor SNP coverage), which support the reduction in haplogroup diversity to this very subclade during the expansion of Corded Ware peoples, as I predicted it would happen.

Bronze Age

Local foraging societies were, however, not completely replaced and contributed a substantial proportion to the ancestry of Eastern Baltic individuals of the latest LN and Bronze Age. This ‘resurgence’ of hunter-gatherer ancestry in the local population through admixture between foraging and farming groups recalls the same phenomenon observed in the European Middle Neolithic and is responsible for the unique genetic signature of modern-day Eastern Baltic populations.

We suggest that the Siberian and East Asian related ancestry in Estonia, and Y-haplogroup N in north-eastern Europe, where it is widespread today, arrived there after the Bronze Age, ca. 500 calBCE, as we detect neither in our Bronze Age samples from Lithuania and Latvia. As Uralic speaking populations of the Volga-Ural region show high frequencies of haplogroup N, a connection was proposed with the spread of Uralic language speakers from the east that contributed to the male gene pool of Eastern Baltic populations and left linguistic descendants in the Finno-Ugric languages Finnish and Estonian. A potential future direction of research is the identification of the proximate population that contributed to the arrival of this eastern ancestry into Northern Europe.

I predicted that haplogroup N arrived probably to the region west of the Urals with the Sejma-Turbino phenomenon, and that it expanded quite late, probably through founder effects. A late arrival to the region leaves obviously (safe for these researchers and others working with old ideas) only the Corded Ware culture (represented by steppe admixture and mainly haplogroup R1a-Z645) as the vector of expansion of Uralic languages, which show obviously a dialectalization process and regional expansion much older than 500 BC…

It is funny to see how people keep trying to identify R1a with ‘Yamnaya’, now ‘steppe’, but always Indo-European (an ethnolinguistic term, mind you) supposedly because of the ‘Yamnaya’ (now ‘steppe’) admixture, but the only ‘mark’ of Uralic languages for the same researchers in the same paper using this very concept is nevertheless, paradoxically, haplogroup N, with an assumption explicitly based on prevalence in modern populations

This admixture vs. haplogroup question for language and culture identification in genetic papers is really gettting messed up with new data, now in a contortionist-like way…

Images and text: Content of the paper is licensed under CC-by 4.0.

See also:

Something is very wrong with models based on the so-called ‘Yamnaya admixture’ – and archaeologists are catching up (II)

A new article by Leo S. Klejn tries to improve the Northern Mesolithic Proto-Indo-European homeland model of the Russian school of thought: The Steppe hypothesis of Indo-European origins remains to be proven, Acta Archaeologica, 88:1, 193–204.

Abstract:

Recent genetic studies have claimed to reveal a massive migration of the bearers of the Yamnaya culture (Pit-grave culture) to the Central and Northern Europe. This migration has supposedly lead to the formation of the Corded Ware cultures and thereby to the dispersal of Indo-European languages in Europe. The article is a summary presentation of available archaeological, linguistic, genetic and cultural data that demonstrates many discrepancies in the suggested scenario for the transformations caused by the Yamnaya “invasion” some 5000 years ago.

Excerpts:

Both teams [Reich/Anthony, and Willerslev/Kristiansen] interpreted this resemblance in the same way: as evidence of mass migration of the Yamnaya culture from the steppes into the Central and Northern Europe, resulting in the formation of the Corded Ware cultures, and these are universally recognised as Indo-European. Since earlier in this part of Europe existed a different pool of genomes, geneticists presumed that the Yamnaya migration alone had brought the Indo-European languages into Europe. It is difficult to say to what extent the pre-convictions of the involved archaeologists influenced these conclusions, or whether the results of the genetic studies attracted archaeologists with such beliefs.

Mismatch of cultural manifestations

First, we might question the idea of the Yamnaya culture as a unity rather than a loose conglomerate of cultures. Merpert (1974) divided it into nine local groups but did not recognise them as separate cultures. However, in 1975 I suggested that Nerushay (Budzhak) monuments should be recognised as a distinct culture (Klejn 1975), although still as a part of the same broader steppe community.

This was accepted by other specialists (Ivanova 2012; 2013; 2014). Generally, in the western branch of this community, a mixture of the eastern rites of interment with local, Balkan ceramics can be observed. It should be noted that hitherto all genetic samples were taken from eastern material (in the vicinity of Samara in the Volga basin and Kalmykia), while the central thesis concerns the intrusion of the western branch of this community (Budzhak culture) into Europe.

yamnaya-corded-ware.connection
The spread of cultural-historical communities of the Yamnaya culture and the location of the Budzhak culture. GAC – Globular Amphora culture; CWC – Corded Ware culture. After Ivanova 2013.

Simultaneity of cultures

The Yamnaya culture (Chernykh & Orlovskaya 2004a; Heyd 2011; Frȋnculeasa et al. 2015) appears not to be the predecessor of the Corded Ware cultures but is contemporary with them. The Corded Ware cultures appeared also around the turn between the fourth and third millennium BC (Stöckli 2001; Furholt 2003). Their derivation from the Yamnaya seems, therefore, to be less probable. This is evidenced by the fact that the corded beakers or amphorae found in the Budzhak culture are not the prototypes of the corded beakers or amphorae found in more northern territories, but seem instead to be an outcome of contemporaneous contacts (Ivanova 2014; Klejn 2017c).

Discrepancies across the haplogroups

Even more remarkable is the variation in the distribution of types of Y chromosome. In the Yamnaya population, R1b is not just a single occurrence (there are about seven known occurrences) while in the Corded Ware population a different clade of R1b is found and R1a is predominant (several instances). Thus the postulate of unbroken succession finds no support!

yamna-into-corded-ware
Distribution of artefacts and customs of the Yamnaya culture in the area of the Corded Ware cultures. After Bátora 2006.

Paradoxical gradient

In the tables presented in the article by Reichs’ team (Haak et al. 2015) the genetic pool connecting the Yamnaya culture with the Corded Ware people is shown to be more intense in Northern Europe (Norway and Sweden) and decreases gradually from the North to the South (Fig. 6). It is weakest around the Danube, in Hungary, i. e. areas neighbouring the western branch of the Yamnaya culture! This is the reverse image to what the proposed hypothesis by the geneticists would lead us to expect. It is true that this gradient is traced back from the contemporary materials, but it was already present during the Bronze Age (Klejn 2015a).

The author also uses questionable interpretations from selected articles to advance his (as of today) untenable positions regarding a Mesolithic origin of the reconstructible Proto-Indo-European language.

1. Glottochronology, for a PIE origin:

If based on the data of glottochronology (taking into account all disputes) the period of initial dispersal is to be dated to the 7th-5th millennium BC.

2. Doubts on the origin of R1b-L51 subclades expressed in Genetic differentiation between upland and lowland populations shapes the Y-chromosomal landscape of West Asia, by Balanovsky et al. (2017), Human Genetics 136, 4. 437-450:

The currently available dataset does not contradict the hypothesis that R-GG400 marks a link between the East European steppe dwellers and West Asians, though the route and even direction of this migration is disputable. It does, however, demonstrate that present-day West European R1b chromosomes do not originate from the Yamnaya populations analyzed in (Haak et al. 2015; Mathieson et al. 2015) and raises the question of their origin. A Bronze Age origin is more likely than a Neolithic one (Balaresque et al. 2010), but further ancient DNA studies may be necessary to identify this source.

Just yesterday I read the post The retraction paradox: Once you retract, you implicitly have to defend all the many things you haven’t yet retracted, by Andrew Gelman. While – in my opinion – the post does not live up to its title, it poses an interesting question, as to how ad logicam (fallacy fallacy) is often used today in research: One author proposes something that is later demonstrated to be wrong, so everything they wrote or write can be said ipso facto to be wrong…especially if they accept that it was wrong.

This is usual with amateur geneticists (those who don’t publish, and are therefore not subjected to criticism): if anyone is wrong (whether in Archaeology or Genetics), then they are wrong in everything else. It seems to me that Klejn’s theses against recent genetic results rest on the same assumption: The Yamna -> Corded Ware migration model is wrong, ergo the Yamna homeland model is wrong.

I guess this same fallacy is what a lot of angered geneticists (whether professional or amateurs) are going to use to dismiss Klejn’s criticism, trying to focus on what he clearly does not grasp – about genomic data of Yamna peoples and their expansion – to disregard his doubts on genetic interpretations entirely.

I have warned many times about how simplistic interpretations of genetic data would cause a general mistrust in the field, and that archaeologists won’t take the discipline seriously, no matter how many articles get published in famous research tabloids like Nature or Science…

Those who dismiss this warning lightly seem to forget the fate of other recent “scientific breakthroughs” which were initially so promising that Humanities appeared to matter no more, like glottochronology for Linguistics and, to some extent, that of radiocarbon analysis for Archaeology.
EDIT: see here a recent example of discusion on discrepancies between archaeological and 14C-based chronologies, whereby ‘scientific data’ obviously needs archaeological context for a meaningful interpretation

Featured image: The direction of the supposed migration of the bearers of the Yamnaya culture into the area of the Corded Ware cultures. After Haak et al. 2015.

NOTE: I obviously don’t agree with Klejn’s main model: he criticises the Proto-Indo-European steppe homeland, and more specifically the expansion of Yamna peoples with R1b-L23 subclades, which I support. But, probably because of his “pre-convictions” (as he puts it when describing proponents of the steppe hypotheses) about the Proto-Indo-European homeland in Northern Europe during the Mesolithic, he was one of the first renown archaeologists to criticise the obvious inconsistencies in the genetic model of migrations based exclusively on the “Yamnaya ancestral component” concept, and to provoke the necessary reaction from (until then) overconfident geneticists, and he deserves credit for that.

In my opinion, the Russian school’s “Northern European Mesolithic” homeland model – as I have said before – could be based on the appearance of EHG ancestry, or maybe on the expansion of haplogroup R1b with post-Swiderian cultures, but the timeframe proposed is too early for any reconstructible parent proto-language, even for Indo-Uralic.

Related:

Archaeological origins of Early Proto-Indo-European in the Baltic during the Mesolithic

zaliznyak-old-european

New article by Leonid Zaliznyak, Mesolithic origins of the first Indo-European cultures in Europe according to the archaeological data (also available in Russian).

The article refers to the common Meso-Neolithic basis of Ukrainian ancient Indo-European cultures (Mariupol, Serednii Stih) and Central Europe (Funnel Beaker and Globular Amphorae cultures) of the fourth millennium BC. Archaeological materials show that the common cultural and genetic substrate of the earliest Indo-Europeans in Europe was forming from the sixth to the fourth millennia BC due to migration of the Western Baltic Mesolithic population to the east through Poland and Polissia to the Dnipro River middle region and further to the Siverskyi Donets River.

I already spoke about the view of the Russian school, and its interpretation of the origin of Proto-Indo-European (and potentially Indo-Uralic) in North-Eastern European Mesolithic. While the genetic interpretation seemed quite off in Klejn’s last article discussing Genetics, Zaliznyak improves the archaeological model to some extent.

This model is partially compatible with the expansion of R1b lineages and the Villabruna cluster with migrating peoples of post-Swiderian cultures into eastern Europe. However – as seems to be often the case with linguists of post-Soviet countries (maybe because of the greater influence of Nostraticists there) – proto-language dates are pushed further back in time than is warranted by usual guesstimates, and thus the model is way off as it approaches the Neolithic, and especially beyond that time.

As you can see, a Post-Swiderian expansion of (a language ancestral to) Proto-Indo-European (e.g. Pre-Indo-Uralic) is compatible with the Indo-European demic diffusion model. On the other hand, it is very difficult to assert anything about that period in terms of language change or evolution, because of scarce and obscured archaeological finds, and because of different admixture waves found in east Europe (in the Pontic-Caspian steppe, forest-steppe, and Forest Zone) during the Palaeolithic-Mesolithic – and even during the Mesolithic-Neolithic – transition.

It is therefore impossible today to ascertain if it was a community of western (R1b) or eastern (R1a) Eurasian lineages who spread Pre-Indo-Uralic; or which combination of WHG:ANE (if any) might have yielded EHG ancestry (and thus how a Pre-Indo-Uralic language might have developed from the influence of west and east Eurasian communities); or how later waves of ANE and CHG ancestry found in steppe populations (during the Neolithic) might have brought cultural change to the communities, or even if they accompanied the more recent R1a-M417 subclades (or haplogroup Q) found in the region…

zaliznyak-post-swiderian
Spreading of Post-Swiderian and Post-Krasnosillian sites in Mesolithic of Eastern Europe in the 8th millennia BC. See the article for an explanation of all details.

This Russian (or post-Soviet, or East European) school of thought, which is mainly based on their traditional archaeological models, tries to use new genetic data to obtain plausible archaeological-linguistic models of Indo-European expansion. Nevertheless, this improved model is likely to cause some quick dismissals and be made fun of by certain amateur geneticists.

It is curious, though, that some people are quick to judge archaeologists trying to fit new data to their traditional models – which seems like the right way of obtaining sound models for prehistoric human migrations -, but are on the other hand extremely confident about any new model based solely on genetics and their personal desires: very strong confirmation (and rejection) bias at play, indeed.

For example, how could Sredni Stog be Late Indo-European-speaking, if the best candidate for a Late Indo-European-speaking community (the Yamna culture) is almost fully unrelated? For some, simply because of the ‘Yamnaya ancestral component’.

In spite of many naysayers – amateur geneticists who hate archaeological models not fitting their dreams – , it seems that otherwise extremely disparate Indo-European schools of thought (like the German, American, and Spanish schools, the British, and even Leiden, the French, and to some extent the East European school) are converging in Linguistics, while in Archaeology Heyd’s model of Yamna migration (independent of the Corded Ware culture) is being accepted as mainstream with help from aDNA analysis – now also partially by Anthony, at last.

Only researchers of a single workgroup (very popular today, it seems) – tend to diverge from the general unifying trend, following mostly their interpretations of new genetic papers in a funny vicious circle, that is creating a growing bubble of misinformation with no substantive basis (apart from the controversial existence of a Kurgan people).

Let’s see how this ends up, if new genetic algorithms can truly revolutionise Archaeology and Linguistics, or if academic models will keep proving right over misinterpretations from recent genetic papers…

Featured image, from the article, “The settling of the early Indo-Europeans in the period from the 4th to the 2nd millennia BC”.

Related:

Coexistence of two different populations in Gotland during the Middle Neolithic

neolithic

New insights on cultural dualism and population structure in the Middle Neolithic Funnel Beaker culture on the island of Gotland, by Fraser et al., in Journal of Archaeological Science: Reports (2017).

Abstract (emphasis mine):

In recent years it has been shown that the Neolithization of Europe was partly driven by migration of farming groups admixing with local hunter-gatherer groups as they dispersed across the continent. However, little research has been done on the cultural duality of contemporaneous foragers and farming populations in the same region. Here we investigate the demographic history of the Funnel Beaker culture [Trichterbecherkultur or TRB, c. 4000–2800 cal BCE], and the sub-Neolithic Pitted Ware culture complex [PWC, c. 3300–2300 cal BCE] during the Nordic Middle Neolithic period on the island of Gotland, Sweden. We use a multidisciplinary approach to investigate individuals buried in the Ansarve dolmen, the only confirmed TRB burial on the island. We present new radiocarbon dating, isotopic analyses for diet and mobility, and mitochondrial DNA haplogroup data to infer maternal inheritance. We also present a new Sr-baseline of 0.71208 ± 0.0016 for the local isotope variation. We compare and discuss our findings together with that of contemporaneous populations in Sweden and the North European mainland.

The radiocarbon dating and Strontium isotopic ratios show that the dolmen was used between c. 3300–2700 cal BCE by a population which displayed local Sr-signals. Mitochondrial data show that the individuals buried in the Ansarve dolmen had maternal genetic affinity to that of other Early and Middle Neolithic farming cultures in Europe, distinct from that of the contemporaneous PWC on the island. Furthermore, they exhibited a strict terrestrial and/or slightly varied diet in contrast to the strict marine diet of the PWC. The findings indicate that two different contemporary groups coexisted on the same island for several hundred years with separate cultural identity, lifestyles, as well as dietary patterns.

gotland-funnel-beaker-culture
“Map indicating distribution of TRB-North group megalithic tombs (Blomqvist, 1989; Midgley, 2008; Sjögren, 2003; Tilley, 1999) and PWC areas (Larsson, 2009) modified from (Malmström et al., 2009). Swedish megalithic TRB burial sites included in the analyses: 1. Gökhem passage grave, Falköping, Västergötland, 2. Alvastra dolmen, Östergötland, 3. Mysinge passage grave, Resmo, Öland, 4. Ansarve dolmen, Tofta, Gotland, and 5. the Ostorf TRB burial ground, Mecklenburg-Vorpommern, Germany.”

If you are interested in knowing more details about settlements on the island, I recommend you to read Early Holocene human population events on the island of Gotland in the Baltic Sea (9200-3800 cal. BP), by Jan Apel, downloadable here.

It is important to remember cases like this one when speaking about the steppe as representing a single culture and people, speaking the same language, no matter the period in question and the archaeological cultures involved…

Related:

Featured image: Diachronic map of Early Neolithic migrations ca. 5000-4000 BC.

Related:

Expansion of peoples associated with spread of haplogroups: Mongols and C3*-F3918, Arabs and E-M183 (M81)

iron-age-migrations

The expansion of peoples is known to be associated with the spread of a certain admixture component, joint with the expansion and reduction in variability of a haplogroup. In other words, few male lineages are usually more successful during the expansion.

Known examples include:

Two recent interesting papers add prehistoric cases of potential expansion of cultures associated with haplogroups:

1. Whole Y-chromosome sequences reveal an extremely recent origin of the most common North African paternal lineage E-M183 (M81), by Solé-Morata et al., Scientific Reports (2017).

Abstract:

E-M183 (E-M81) is the most frequent paternal lineage in North Africa and thus it must be considered to explore past historical and demographical processes. Here, by using whole Y chromosome sequences from 32 North African individuals, we have identified five new branches within E-M183. The validation of these variants in more than 200 North African samples, from which we also have information of 13 Y-STRs, has revealed a strong resemblance among E-M183 Y-STR haplotypes that pointed to a rapid expansion of this haplogroup. Moreover, for the first time, by using both SNP and STR data, we have provided updated estimates of the times-to-the-most-recent-common-ancestor (TMRCA) for E-M183, which evidenced an extremely recent origin of this haplogroup (2,000–3,000 ya). Our results also showed a lack of population structure within the E-M183 branch, which could be explained by the recent and rapid expansion of this haplogroup. In spite of a reduction in STR heterozygosity towards the West, which would point to an origin in the Near East, ancient DNA evidence together with our TMRCA estimates point to a local origin of E-M183 in NW Africa.

haplogroup-E-M183-subclade-distribution
Distribution of E-M183 subclades among North Africa, the Near East and the Iberian Peninsula. Pie chart sectors areas are proportional to haplogroup frequency and are coloured according to haplogroup in the schematic tree to the right. n: sample size. Map was generated using R software.

An interesting excerpt, from the discussion:

Regarding the geographical origin of E-M183, a previous study suggested that an expansion from the Near East could explain the observed east-west cline of genetic variation that extends into the Near East. Indeed, our results also showed a reduction in STR heterozygosity towards the West, which may be taken to support the hypothesis of an expansion from the Near East. In addition, previous studies based on genome-wide SNPs reported that a North African autochthonous component increase towards the West whereas the Near Eastern decreases towards the same direction, which again support an expansion from the Near East. However, our correlations should be taken carefully because our analysis includes only six locations on the longitudinal axis, none from the Near East. As a result, we do not have sufficient statistical power to confirm a Near Eastern origin. In addition, rather than showing a west-to-east cline of genetic diversity, the overall picture shown by this correlation analysis evidences just low genetic diversity in Western Sahara, which indeed could be also caused by the small sample size (n = 26) in this region. Alternatively, given the high frequency of E-M183 in the Maghreb, a local origin of E-M183 in NW Africa could be envisaged, which would fit the clear pattern of longitudinal isolation by distance reported in genome-wide studies. Moreover, the presence of autochthonous North African E-M81 lineages in the indigenous population of the Canary Islands, strongly points to North Africa as the most probable origin of the Guanche ancestors. This, together with the fact that the oldest indigenous inviduals have been dated 2210 ± 60 ya, supports a local origin of E-M183 in NW Africa. Within this scenario, it is also worth to mention that the paternal lineage of an early Neolithic Moroccan individual appeared to be distantly related to the typically North African E-M81 haplogroup30, suggesting again a NW African origin of E-M183. A local origin of E-M183 in NW Africa > 2200 ya is supported by our TMRCA estimates, which can be taken as 2,000–3,000, depending on the data, methods, and mutation rates used.

The TMRCA estimates of a certain haplogroup and its subbranches provide some constraints on the times of their origin and spread. Although our time estimates for E-M78 are slightly different depending on the mutation rate used, their confidence intervals overlap and the dates obtained are in agreement with those obtained by Trombetta et al Regarding E-M183, as mentioned above, we cannot discard an expansion from the Near East and, if so, according to our time estimates, it could have been brought by the Islamic expansion on the 7th century, but definitely not with the Neolithic expansion, which appeared in NW Africa ~7400 BP and may have featured a strong Epipaleolithic persistence. Moreover, such a recent appearance of E-M183 in NW Africa would fit with the patterns observed in the rest of the genome, where an extensive, male-biased Near Eastern admixture event is registered ~1300 ya, coincidental with the Arab expansion. An alternative hypothesis would involve that E-M183 was originated somewhere in Northwest Africa and then spread through all the region. Our time estimates for the origin of this haplogroup overlap with the end of the third Punic War (146 BCE), when Carthage (in current Tunisia) was defeated and destroyed, which marked the beginning of Roman hegemony of the Mediterranean Sea. About 2,000 ya North Africa was one of the wealthiest Roman provinces and E-M183 may have experienced the resulting population growth.

2. The Y-chromosome haplogroup C3*-F3918, likely attributed to the Mongol Empire, can be traced to a 2500-year-old nomadic group, by Zhang et al., Journal of Human Genetics (2017)

Abstract:

The Mongol Empire had a significant role in shaping the landscape of modern populations. Many populations living in Eurasia may have been the product of population mixture between ancient Mongolians and natives following the expansion of Mongol Empire. Geneticists have found that most of these populations carried the Y-haplogroup C3* (C-M217). To trace the history of haplogroup (Hg) C3* and to further understand the origin and development of Mongolians, ancient human remains from the Jinggouzi, Chenwugou and Gangga archaeological sites, which belonged to the Donghu, Xianbei and Shiwei, respectively, were analysed. Our results show that nine of the eleven males of the Gangga site, two of the eight males of Chengwugou site and all of the twelve males of Jinggouzi site were found to have mutations at M130 (Hg C), M217 (Hg C3), L1373 (C2b, ISOGG2015), with the absence of mutations at M93 (Hg C3a), P39 (Hg C3b), M48 (Hg C3c), M407 (Hg C3d) and P62 (Hg C3f). These samples were attributed to the Y-chromosome Hg C3* (Hg C2b, ISOGG2015), and most of them were further typed as Hg C2b1a based on the mutation at F3918. Finally, we inferred that the Y-chromosome Hg C3*-F3918 can trace its origins to the Donghu ancient nomadic group.

mongol-expansion-y-dna-haplogroup
The development of Mongolia and the frequencies of haplogroup C3* in modern Eurasians. a The development of Mongolia. b The frequencies of haplogroup C3 in modern Eurasians. The dotted line represents the approximate boundary between the Xiongnu and the Donghu. The black and grey arrows denote the migration of the Donghu and Mongolians, respectively

Featured image: Diachronic map of Iron Age migrations ca. 750-250 BC.

Related:

Review article about Ancient Genomics, by Pontus Skoglund and Iain Mathieson

ancient-genomics-holocene-migrations

A preprint article by two of the most prolific researchers in Human Ancestry is out, and they request feedback: Ancient genomics: a new view into human prehistory and evolution, by Skoglund and Mathieson (2017). Right now, it is downloadable on Dropbox.

Abstract:

The first decade of ancient genomics has revolutionized the study of human prehistory and evolution. We review new insights based on ancient genomic data, including greatly increased resolution of the timing and structure of the out-of-Africa event, the diversification of present-day non-African populations, and the earliest expansions of those populations into Eurasia and America. Prehistoric genomes now document patterns of population continuity and change on every inhabited continent–in particular the effect of agricultural expansions in Africa, Europe and Oceania–and record a history of natural selection that shapes present-day phenotypic diversity. Despite these advances, much remains unknown, in particular about the genomic histories of Asia–the most populous continent, and Africa–the continent that contains the most genetic diversity. Ancient genomes from these and other regions, integrated with a growing understanding of the genomic basis of human phenotypic diversity, will be in focus during the next decade of research in the field.

The paper may be highly recommended as an introduction for anyone interested in the field of Human Ancestry in general.

However, its short summary of steppe ancestry expansion (where the Corded Ware culture predominates) is still reminiscent of the infamous “Yamnaya -> Corded Ware -> Bell Beaker” model set forth by the 2015 Nature articles on the subject, and Kristiansen’s Indo-European Corded Ware theory.

Here is an excerpt (emphasis mine):

The next substantial change is closely related to ancestry that by around 5000 BP extended over a region of more than 2000 miles of the Eurasian steppe, including in individuals associated with the Yamnaya Cultural Complex in far-eastern Europe (1; 38) and with the Afanasievo culture in the central Asian Altai mountains (1). This “steppe” ancestry is itself a mixture between ancestry that is related to Mesolithic hunter-gatherers of eastern Europe and ancestry that is related to both present-day populations (38) and Mesolithic hunter-gatherers (46) from the Caucasus mountains, and also to the populations of Neolithic (11), and Copper Age (56) Iran. Steppe ancestry appeared in southeastern Europe by 6000 BP (72), northeastern Europe around 5000 BP (47) and central Europe at the time of the Corded Ware Complex around 4600 BP (1; 38). These dates are reasonably tight constraints, because in each case there is no evidence of steppe ancestry in individuals immediately preceding these dates (47; 72). Gene flow on the steppe was extensive and bidirectional, as shown by the eastward flow of Anatolian Neolithic ancestry– reaching well into central Eurasia by the time of the Andronovo culture ~3500 BP (1)–and the westward flow of East Asian ancestry–found in individuals associated with the Iron Age Scythian culture close to the Black Sea ~2500 BP (143).

Copper and Bronze Age population movements (14; 78 Martiniano, 2017 #8761; 85; 112), as well as later movements in the Iron Age and Historical period (70; 119) further distributed steppe ancestry around Europe. Present-day western European populations can be modeled as mixtures of these three ancestry components (Mesolithic hunter-gatherer, Anatolian Neolithic and Steppe) (38; 57). In eastern Europe, further shifts in ancestry are the result of additional or distinct gene flow from Anatolia throughout the Neolithic and Bronze Age in the Aegean (42; 51; 55; 72; 87), and gene flow from Siberian-related populations in Finland and the Baltic region (38). East-west gene flow also brought new ancestry–related to populations from 265 Copper Age Iran–to the Levant during the Copper and Bronze ages (39; 56).

The geographic structure of these population transformations gave rise to population structure of present-day Europe. For example Anatolian Neolithic ancestry is highest in southern European populations like Sardinians, and lowest in northern European populations (38). Steppe ancestry is at high frequency in north-central Europeans and low in the south. Isolation-by-distance may have contributed to these patterns to some extent, but the contribution must have been small. In much of Europe, extreme population discontinuity was the norm.

Featured image: from the article, “Major Holocene population movements and expansions that have been demonstrated using ancient DNA.”

Related:

Something is very wrong with models based on the so-called ‘steppe admixture’ – and archaeologists are catching up

steppe-admixture

Russian archaeologist Leo Klejn has published an article Discussion: Are the Origins of Indo-European Languages Explained by the Migration of the Yamnaya Culture to the West?, which includes the criticism received from Wolfgang Haak, Iosif Lazaridis, Nick Patterson, and David Reich (mainly on the genetic aspect), and from Kristian Kristiansen, Karl-Göran Sjögren, Morten Allentoft, Martin Sikora, and Eske Willerslev (mainly on the archaeological aspect).

I will not post details of Klejn’s model of North-South Proto-Indo-European expansion – which is explained in the article, and relies on the north-south cline of ‘steppe admixture’ in the modern European population -, since it is based on marginal anthropological methods and theories, including glottochronological dates, and archaeological theories from the Russian school (mainly Zalyzniak), which are obviously not mainstream in the field of Indo-European Studies, and (paradoxically) on the modern distribution of ‘steppe admixture’…

The most interesting aspects of the article are the reactions to the criticism, some of which can be used from the point of view of the Indo-European demic diffusion model, too. It is sad, however, that they didn’t choose to answer earlier to Heyd’s criticism (or to Heyd’s model, which is essentially also that of Mallory and Anthony), instead of just waiting for proponents of the least interesting models to react…

The answer by Haak et al.:

Klejn mischaracterizes our paper as claiming that practitioners of the Corded Ware culture spoke a language ancestral to all European Indo-European languages, including Greek and Celtic. This is incorrect: we never claim that the ancestor of Greek is the language spoken by people of the Corded Ware culture. In fact, we explicitly state that the expansion of steppe ancestry might account for only a subset of Indo-European languages in Europe. Klejn asserts that ‘a source in the north’ is a better candidate for the new ancestry manifested in the Corded Ware than the Yamnaya. While it is indeed the case that the present-day people with the greatest affinity to the Corded Ware are distributed in north-eastern Europe, a major part of the new ancestry of the Corded Ware derives from a population most closely related to Armenians (Haak et al., 2015) and hunter-gatherers from the Caucasus (Jones et al., 2015). This ancestry has not been detected in any European huntergatherers analysed to date (Lazaridis et al., 2014; Skoglund et al., 2014; Haak et al., 2015; Fu et al., 2016), but made up some fifty per cent of the ancestry of the Yamnaya. The fact that the Corded Ware traced some of its ancestry to the southern Caucasus makes a source in the north less parsimonious.

In our study, we did not speculate about the date of Proto-Indo-European and the locations of its speakers, as these questions are unresolved by our data, although we do think the genetic data impose constraints on what occurred. We are enthusiastic about the potential of genetics to contribute to a resolution of this longstanding issue, but this is likely to require DNA from multiple, as yet unsampled, ancient populations.

Klejn response to that:

Allegedly, I had accused the authors of tracing all Indo-European languages back to Yamnaya, whereas they did not trace all of them but only a portion! Well, I shall not reproach the authors for their ambiguous language: it remains the case that (beginning with the title of the first article) their qualifications are lost and their readers have understood them as presenting the solution to the whole question of the origins of Indo-European languages.

(…) they had in view not the Proto-Indo-European before the separation of the Hittites, but the language that was left after the separation. Yet, this was still the language ancestral to all the remaining Indo-European languages, and the followers of Sturtevan and Kluckhorst call only this language Proto-Indo-European (while they call the initial one Indo-Hittite). The majority of linguists (specialists in Indo-European languages) is now inclined to this view. True, the breakup of this younger language is several hundred years more recent (nearly a thousand years later according to some glottochronologies) than the separation of Anatolian languages, but it is still around a thousand years earlier than the birth of cultures derived from Yamnaya.
More than that, I analysed in my criticism both possibilities — the case for all Indo-European languages spreading from Yamnaya and the case for only some of them spreading from Yamnaya. In the latter case, it is argued that only the languages of the steppes, the Aryan (Indo- Iranian) are descended from Yamnaya, not the languages of northern Europe. Together with many scholars, I am in agreement with the last possibility. But, then, what sense can the proposed migration of the Yamnaya culture to the Baltic region have? It would bring the Indo-Iranian proto-language to that region! Yet, there are no traces of this language on the coasts of the Baltic!

My main concern is that, to my mind, one should not directly apply conclusions from genetics to events in the development of language because there is no direct and inevitable dependence between events in the life of languages, culture, and physical structure (both anthropological and genetic). They can coincide, but often they all follow divergent paths. In each case the supposed coincidence should be proved separately.

The authors’ third objection concerns the increase of the genetic similarity of European population with that of the Yamnaya culture. This increases in the north of Europe and is weak in the south, in the places adjacent to the Yamnaya area, i.e. in Hungary. This gradient is clearly expressed in the modern population, but was present already in the Bronze Age, and hence cannot be explained by shifts that occurred in the Early Iron Age and in medieval times. However, the supposed migration of the Yamnaya culture to the west and north should imply a gradient in just the opposite direction!

Regarding the arguments of Kristiansen and colleagues:

[They argue that] in two early burials of the Corded Ware culture (one in Germany, the other in Poland) some single attributes of Yamnaya origin have been found.

(…) if this is the full extent of Yamnaya infiltration into central Europe—two burials (one for each country) from several thousands (and from several hundreds of early burials)—then it hardly amounts to large-scale migration.

Quite recently we have witnessed the success of a group of geneticists from Stanford University and elsewhere (Poznik et al., 2016). They succeeded in revealing varieties of Y-chromosome connected with demographic expansions in the Bronze Age. Such expansion can give rise to migration. Among the variants connected with this expansion is R1b, and this haplogroup is typical for the Yamnaya culture. But what bad luck! This haplogroup connected with expansion is indicated by the clade L11, while the Yamnaya burials are associated with a different clade, Z2103, that is not marked by expansion. It is now time to think about how else the remarkable results reached by both teams of experienced and bright geneticists may be interpreted.

Regarding the work of Heyd,

(…) with regard to the barrow burials of the third millennium BC in the basin of the Danube, although they have been assigned to the Yamnaya culture, I would consider them as also belonging to
another, separate culture, perhaps a mixed culture: its burial custom is typical of the Yamnaya, but its pottery is absolutely not Yamnaya, but local Balkan with imports of distinctive corded beakers (Schnurbecher). I would not be surprised if
Y-chromosome haplogroups of this population were somewhat similar to those of the Yamnaya, while mitochondrial groups were indigenous. As yet, geneticists deal with great blocks of populations and prefer to match them to very large and generalized cultural blocks, while archaeology now analyses more concrete and smaller cultures, each of which had its own fate.

Iosif Lazaridis shares more thoughts on the discussion in his Twitter account:

As we mentioned in Haak, Lazaridis et al. (2015), the Yamnaya are the best proximate source for the new ancestry that first appears with the Corded Ware in central Europe, as it has the right mix of both ANE (related to Native Americans, MA1, and EHG), but also Armenian/Caucasus/Iran-like southern component of ancestry. The Yamnaya is a westward expansive culture that bears exactly the two new ancestral components (EHG + Caucasus/Iran/Armenian-like).
As for the Y-chromosome, it was already noted in Haak, Lazaridis et al. (2015) that the Yamnaya from Samara had Y-chromosomes which belonged to R-M269 but did not belong to the clade common in Western Europe (p. 46 of supplement). Also, not a single R1a in Yamnaya unlike Corded Ware (R1a-dominated). But Yamnaya samples = elite burials from eastern part of the Yamnaya range. Both R1a/R1b found in Eneolithic Samara and EHG, so in conclusion Yamnaya expansion still the best proximate source for the post-3,000 BCE population change in central Europe. And since 2015 steppe expansion detected elsewhere (Cassidy et al. 16, Martiniano et al. 17, Mittnik et al. 17, Mathieson et al. 17, Lazaridis et al. 2016 (South Asia) and …?…

I love the smell of new wording in the morning… viz. Yamnaya best proximate source for Corded Ware, Corded Ware might account for only a subset of Indo-European languages, Corded Ware representing Aryan languages (probably Klejn misinterprets what the authors mean, i.e. some kind of Indo-Slavonic or Germano-Balto-Slavic group)…

We shall expect more and more ambiguous rewording and more adjustments of previous conclusions as new papers and new criticisms appear.

Related:

Featured image from the article: Distribution of the ‘Yamnaya’ genetic component in the populations of Europe (data taken from Haak et al., 2015). The intensity of the colour corresponds to the contribution of this component in various modern populations