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Wednesday, October 27, 2021

Local origins of the earliest Tarim Basin mummies (Zhang et al. 2021)

Over at Nature at this LINK. It's nice to see yet another huge surprise courtesy of ancient DNA. Please note that most of the ancients from this paper are already in the Global25 datasheets. Here's the abstract:

The identity of the earliest inhabitants of Xinjiang, in the heart of Inner Asia, and the languages that they spoke have long been debated and remain contentious 1. Here we present genomic data from 5 individuals dating to around 3000–2800 bc from the Dzungarian Basin and 13 individuals dating to around 2100–1700 bc from the Tarim Basin, representing the earliest yet discovered human remains from North and South Xinjiang, respectively. We find that the Early Bronze Age Dzungarian individuals exhibit a predominantly Afanasievo ancestry with an additional local contribution, and the Early–Middle Bronze Age Tarim individuals contain only a local ancestry. The Tarim individuals from the site of Xiaohe further exhibit strong evidence of milk proteins in their dental calculus, indicating a reliance on dairy pastoralism at the site since its founding. Our results do not support previous hypotheses for the origin of the Tarim mummies, who were argued to be Proto-Tocharian-speaking pastoralists descended from the Afanasievo 1,2 or to have originated among the Bactria–Margiana Archaeological Complex 3 or Inner Asian Mountain Corridor cultures 4. Instead, although Tocharian may have been plausibly introduced to the Dzungarian Basin by Afanasievo migrants during the Early Bronze Age, we find that the earliest Tarim Basin cultures appear to have arisen from a genetically isolated local population that adopted neighbouring pastoralist and agriculturalist practices, which allowed them to settle and thrive along the shifting riverine oases of the Taklamakan Desert.

Zhang, F., Ning, C., Scott, A. et al. The genomic origins of the Bronze Age Tarim Basin mummies. Nature (2021).

See also...

How the Shirenzigou nomads became Proto-Tocharians

Wednesday, October 20, 2021

Modern domestic horses came from the Eastern European steppe

Over at Nature at this LINK. I'm getting the impression that geneticists and the editors at Nature are really crap at geography. Obviously, this paper argues that modern domestic horses came from the Pontic-Caspian steppe, which is located very firmly in Eastern Europe. But, inexplicably, instead of actually saying this, the authors came up with the much more ambiguous term Western Eurasian steppes, and even put that in the title. I wonder why? Here's the paper abstract:

Domestication of horses fundamentally transformed long-range mobility and warfare 1. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling 2,3,4 at Botai, Central Asia around 3500 bc3. Other longstanding candidate regions for horse domestication, such as Iberia 5 and Anatolia 6, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes [my note: they actually mean the Pontic-Caspian steppe, which is located in Eastern Europe], especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 bc, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association 7 between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe [my note: the Yamnaya culture was located in Europe] around 3000 bc 8,9 driving the spread of Indo-European languages 10. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium bc Sintashta culture 11,12.

Librado, P., Khan, N., Fages, A. et al. The origins and spread of domestic horses from the Western Eurasian steppes. Nature (2021).

Update: I emailed one of the lead authors, Ludovic Orlando, asking him for a comment. Here it is:

Thanks for your interest in our research. We indeed struggled finding the term that would be most appropriate and this was discussed with our coauthors. The Pontic-Caspian steppe would seem the most obvious choice but my understanding is that this would include a large region, stretching from the most north-western side of the Black sea to the foothills of the Urals. This is larger than the signature recovered in our data. My understanding is that the Eastern European steppes would also stretch more northernly than the region that we narrowed down. Eastern European steppes was also not immediately clear, even for European scholars such as myself. Therefore, it did not seem that there were any terms that were ready-made for truly qualifying our findings. We thus went for Western Eurasian steppes in the main title, and sticked to more precise locations such as the Don-Volga region in the main text. I guess that this is one of those cases where the activities of past herders did not exactly follow some geographic terms that would only be defined thousands of years later.

However, the Pontic-Caspian steppe and the Eastern European steppe are in fact terms that describe the western end of the Eurasian steppe. So they should be totally interchangeable with the term Western Eurasian steppes. Except, at least to me, they seem less ambiguous.

Ergo, the Eastern European steppe can't be more northerly than the Western Eurasian steppes, because it's the same thing. Moreover, the Pontic-Caspian steppe can't stretch further west than the Western Eurasian steppes, because, again, it's the same thing.

Indeed, the land north of the Eastern European/Western Eurasian steppes is called the forest steppe.

See also...

Friday, October 15, 2021

Coming soon?

This ISBA9 abstract seems to be highly relevant to the ultimate origins of the Yamnaya and Corded Ware peoples. Emphasis is mine:

Genomic signals of continuity and admixture in the Caucasus

Ghalichi Ayshin et al.

Situated between the Black and Caspian Sea, the Caucasus is a key geographic region that connects the Near East and the Eurasian Steppe, with a great ecological diversity of ecotones and landscapes rich in natural resources. A recent archaeogenetic study has shown that the genetically diverse Eneolithic and Bronze Age groups of the steppe and mountains correspond to eco-geographic zones in the Caucasus. However, the formation, interactions and population dynamics warrant further investigation. In this study we explore new genome-wide data of 68 individuals from 20 archaeological cultures across the Caucasus mountains, the piedmont and the steppe extending our temporal transect to 6000 years, doubling the number of available genomes from the region. We present the first genomic data from a Mesolithic individual (6100 calBCE) from the Northwest Caucasus that shows Eastern hunter-gatherer ancestry, Neolithic individuals from Georgia, as well as new data from genetically unexplored regions/cultures in the northeastern highlands and the dry steppe. We observe a degree of genetic continuity through time within the main mountain and steppe genetic groups, but also identify various episodes of gene flow between these and the neighboring regions. In the Late Eneolithic period, we find evidence of admixture from the south into the steppe groups, detectable through the presence of Anatolian_Neolithic-like ancestry. During the Bronze Age, we found in Steppe Maykop individuals a genetic link to West Siberian hunter-gatherers, a component that is absent from Yamnaya, North Caucasus and Catacomb groups, but reappears in Bronze Age individuals associated with the Lola culture.

I'm not quite sure what it's saying though. Is the Mesolithc individual from the Northwest Caucasus actually an Eastern European hunter-gatherer, or, as I'm expecting, a mixture between Caucasus and Eastern European hunter-gatherers? If the latter, then it's game over for the Out-of-Iran and Out-of-Armenia Indo-European hypotheses that have been so popular among academics in recent years.

The authors also mention the spread of Anatolian-related ancestry into the Eastern European steppe during the Late Eneolithic. They're probably referring to the phenomenon that gave rise to the so called Steppe Maykop outliers. The ISBA9 abstract PDF book is freely available here.

See also...

Understanding the Eneolithic steppe

Ancient DNA vs Ex Oriente Lux

A note on Steppe Maykop