“Steppe people seem not to have penetrated South Asia”

indo-iranian-sintashta-uralic-migrations

Open access structured abstract for The first horse herders and the impact of early Bronze Age steppe expansions into Asia from Damgaard et al. Science (2018) 360(6396):eaar7711.

Abstract (emphasis mine):

The Eurasian steppes reach from the Ukraine in Europe to Mongolia and China. Over the past 5000 years, these flat grasslands were thought to be the route for the ebb and flow of migrant humans, their horses, and their languages. de Barros Damgaard et al. probed whole-genome sequences from the remains of 74 individuals found across this region. Although there is evidence for migration into Europe from the steppes, the details of human movements are complex and involve independent acquisitions of horse cultures. Furthermore, it appears that the Indo-European Hittite language derived from Anatolia, not the steppes. The steppe people seem not to have penetrated South Asia. Genetic evidence indicates an independent history involving western Eurasian admixture into ancient South Asian peoples.

INTRODUCTION
According to the commonly accepted “steppe hypothesis,” the initial spread of Indo-European (IE) languages into both Europe and Asia took place with migrations of Early Bronze Age Yamnaya pastoralists from the Pontic-Caspian steppe. This is believed to have been enabled by horse domestication, which revolutionized transport and warfare. Although in Europe there is much support for the steppe hypothesis, the impact of Early Bronze Age Western steppe pastoralists in Asia, including Anatolia and South Asia, remains less well understood, with limited archaeological evidence for their presence. Furthermore, the earliest secure evidence of horse husbandry comes from the Botai culture of Central Asia, whereas direct evidence for Yamnaya equestrianism remains elusive.

RATIONALE
We investigated the genetic impact of Early Bronze Age migrations into Asia and interpret our findings in relation to the steppe hypothesis and early spread of IE languages. We generated whole-genome shotgun sequence data (~1 to 25 X average coverage) for 74 ancient individuals from Inner Asia and Anatolia, as well as 41 high-coverage present-day genomes from 17 Central Asian ethnicities.

damgaard-south-asia
Model-based admixture proportions for selected ancient and present-day individuals, assuming K = 6, shown with their corresponding geographical locations. Ancient groups are represented by larger admixture plots, with those sequenced in the present work surrounded by black borders and others used for providing context with blue borders. Present-day South Asian groups are represented by smaller admixture plots with dark red borders.

RESULTS
We show that the population at Botai associated with the earliest evidence for horse husbandry derived from an ancient hunter-gatherer ancestry previously seen in the Upper Paleolithic Mal’ta (MA1) and was deeply diverged from the Western steppe pastoralists. They form part of a previously undescribed west-to-east cline of Holocene prehistoric steppe genetic ancestry in which Botai, Central Asians, and Baikal groups can be modeled with different amounts of Eastern hunter-gatherer (EHG) and Ancient East Asian genetic ancestry represented by Baikal_EN.

In Anatolia, Bronze Age samples, including from Hittite speaking settlements associated with the first written evidence of IE languages, show genetic continuity with preceding Anatolian Copper Age (CA) samples and have substantial Caucasian hunter-gatherer (CHG)–related ancestry but no evidence of direct steppe admixture.

In South Asia, we identified at least two distinct waves of admixture from the west, the first occurring from a source related to the Copper Age Namazga farming culture from the southern edge of the steppe, who exhibit both the Iranian and the EHG components found in many contemporary Pakistani and Indian groups from across the subcontinent. The second came from Late Bronze Age steppe sources, with a genetic impact that is more localized in the north and west.

CONCLUSION
Our findings reveal that the early spread of Yamnaya Bronze Age pastoralists had limited genetic impact in Anatolia as well as Central and South Asia. As such, the Asian story of Early Bronze Age expansions differs from that of Europe. Intriguingly, we find that direct descendants of Upper Paleolithic hunter-gatherers of Central Asia, now extinct as a separate lineage, survived well into the Bronze Age. These groups likely engaged in early horse domestication as a prey-route transition from hunting to herding, as otherwise seen for reindeer. Our findings further suggest that West Eurasian ancestry entered South Asia before and after, rather than during, the initial expansion of western steppe pastoralists, with the later event consistent with a Late Bronze Age entry of IE languages into South Asia. Finally, the lack of steppe ancestry in samples from Anatolia indicates that the spread of the earliest branch of IE languages into that region was not associated with a major population migration from the steppe.

I think the wording of the abstract is weird, but consequent with their samples and results, so probably just clickbait / citebait for Indian journalists and social networks, or maybe a new attempt to ‘show respect for the sensibilities of Indians’ related to the artificially magnified “AIT vs. OIT” controversy, that is only present in India.

However, everything is possible, since it is brought to you by the same Danish group who proposed the Yamnaya ancestral component™, the CHG = Indo-European (and simultaneously EHG in Maykop = Anatolian??), and now also the CWC/R1a = Indo-European & Volosovo = Uralic

Here is the reaction of Narasimhan: Narasimhan has deleted the Tweet, it basically questioned the sentence that steppe people did not penetrate South Asia.

Related

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.

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