Folk wanderings in "the Heartland"

Gene ExpressionBy Razib KhanJul 7, 2009 5:15 PM


Sign up for our email newsletter for the latest science news

In the early 20th century the geographer Halford Mackinder posited that the key to world domination lay in the control of the Eurasian Heartland. This was in sharp contrast to Alfred Mahan's emphasis on the role of naval power. Whatever the applicability of these geopolitical frameworks in the modern era, it is interesting to observe their precedents in the ancient and medieval world. The rise of Rome was facilitated by the Mediterranean essential role as a conduit for communication and trade which connected the cities which were the foci of the Empire. Easy transport of cheap grain from Egypt or Sicily to Rome or Constantinople allowed these cities to scale up to enormous proportions. In contrast Han China did not have the advantage of the same natural endowments of water transport, which might explain the greater emphasis on primary production and local provisioning within the Chinese state. But after the fall of Rome and Han China Eurasia witnessed the first of repeated eruptions from the steppe of nomadic peoples. In the West the Huns and Avars stitched together diverse confederacies predicated on extracting rents from the shrunken post-Roman world. In the East the heirs of the Xiongnu swept over the North China plain, and drove the Han elite south of the Yangtze. In the 6th century there arose a Turk empire which stretched from the Caspian to Manchuria, the collapse of which sent the various tribes streaming across the frontiers of what was at the time becoming the Islamic world. The subsequent rise of the Mongols is well known, the last and most ferocious in a long line of roving nomadic bands whose power was finally checked only by the rise of gunpowder states. But the period between 500 and 1500 A.D. is only a thin slice of history, and does not reflect the whole story. Herodotus tells us of the Scythians, who ravaged the Middle East and Europe. The Romans later defeated Sarmatians on the plains of Pannonia. Even further back in history we know of the Indo-Aryan Mittani in Syria, while there are hints of a relationship between nomadic societies on the steppe of Eurasia and later settled populations in Eastern Europe, Iran & India. Because of the lack of literacy in most of the world before 500 B.C. we must rely on archaeology to connect the vaguest of these dots. But the new field of ancient DNA allows us to go a step beyond "Pots not Peoples" and reconstruct phylogenies across space and time. Two new papers address some issues relating to the Eurasian Heartland and its genetic history, Pigment phenotype and biogeographical ancestry from ancient skeletal remains: inferences from multiplexed autosomal SNP analysis and Ancient DNA provides new insights into the history of south Siberian Kurgan people. There is a great deal of overlap in the substance and data because the same groups produced these two papers. Here are the abstracts:

In the present study, a multiplexed genotyping assay for ten single nucleotide polymorphisms (SNPs) located within six pigmentation candidate genes was developed on modern biological samples and applied to DNA retrieved from 25 archeological human remains from southern central Siberia dating from the Bronze and Iron Ages. SNP genotyping was successful for the majority of ancient samples and revealed that most probably had typical European pigment features, i.e., blue or green eye color, light hair color and skin type, and were likely of European individual ancestry. To our knowledge, this study reports for the first time the multiplexed typing of autosomal SNPs on aged and degraded DNA. By providing valuable information on pigment traits of an individual and allowing individual biogeographical ancestry estimation, autosomal SNP typing can improve ancient DNA studies and aid human identification in some forensic casework situations when used to complement conventional molecular markers.


To help unravel some of the early Eurasian steppe migration movements, we determined the Y-chromosomal and mitochondrial haplotypes and haplogroups of 26 ancient human specimens from the Krasnoyarsk area dated from between the middle of the second millennium BC. to the fourth century AD. In order to go further in the search of the geographic origin and physical traits of these south Siberian specimens, we also typed phenotype-informative single nucleotide polymorphisms. Our autosomal, Y-chromosomal and mitochondrial DNA analyses reveal that whereas few specimens seem to be related matrilineally or patrilineally, nearly all subjects belong to haplogroup R1a1-M17 which is thought to mark the eastward migration of the early Indo-Europeans. Our results also confirm that at the Bronze and Iron Ages, south Siberia was a region of overwhelmingly predominant European settlement, suggesting an eastward migration of Kurgan people across the Russo-Kazakh steppe. Finally, our data indicate that at the Bronze and Iron Age timeframe, south Siberians were blue (or green)-eyed, fair-skinned and light-haired people and that they might have played a role in the early development of the Tarim Basin civilization. To the best of our knowledge, no equivalent molecular analysis has been undertaken so far.

This is a complex and volatile topic fraught with nationalism. While Western European maritime nation-states were preoccupied with their Age of Discovery, the Empire of the Czars was expanding into Siberia. Just as the Chinese state attempts to obscure the complex ethnic history of Xinjiang, so the Russians, and in particular the Soviets, would recruit ethnologists, historians and archaeologists in the service of their own colonialist narrative. A white European presence in Siberia and the Russian Far East was seen by some as less objectionable if it could be argued that in fact the Turkic-Mongolian peoples who have the current status as indigenes are themselves settlers who superseded a previous Europoid population in the region. Standard physical anthropological methods did yield results which suggested that populations of European provenance were resident within the heart of Asia thousands of years ago. Where did they go? To some extent they remain in the substratum, as the Uighurs of Xinjiang exhibit a range of physical types, and their genes show them to be a hybrid population. The historical records are also good enough that we know that in the period between 500 and 1500, and especially in the second half, much of Central Asia shifted from Indo-European speech and culture to Turkic. The change was not total, Turks and non-Turks still coexist in in many regions, with the dominant non-Turkic group being Tajiks, Central Asian Persian speakers (there are even remnants of ancient peoples such as the Sogdians). 2,000 years ago in the Tarim Basin there flourished a group known as Tocharians, who spoke their own unique Indo-European language, served as conduits for Buddhism to China, and whose self-depictions make it rather clear that they were of generally European appearance. Though to me the pre-genetic archaelogical and anthropological evidence is strong, the prestige of natural science adds glamor to these inferences, and some precision. Additionally, genes often persist through time down to the modern era, while cultural traits such as language may be totally erased. This is surely what has happened in the case of the Uighers, who are culturally Turks, and so by origin a Mongolian people, but whose genes make it clear that they have substantial pre-Turkic ancestry (also see my post on Anatolian Turks). Previous groups have extracted ancient DNA from Central Asian remains, but these two papers have a wider range of data, as well as some temporal diversity (Bronze Age to Late Antique). I have highlighted the region of Siberia from which the samples of interest were derived:

And here is a figure from the first paper which shows how the ancient samples from Krasnoyarsk relate to modern populations (aDNA = ancient DNA):

The ancient samples span the Bronze Age to the 4th century A.D. Note that they're clearly close to European populations, but, there is already some admixture with groups of East Asian origin. In the second paper there are two maps which show the distributions of genetic variants which were found in the ancient DNA samples in extant modern populations. That is, they looked for the variants which they identified in their Krasnoyarsk samples in modern databases and then plotted them spatially. These two maps show the distribution of the matches for Y and mtDNA lineages.

The distributions of both male and female lineages seem to span the same regions (with minor exceptions); roughly, the Heartland and in particular its western margins. It may seem a rather bizarre historical coincidence that the Russian expansion to the east in the early modern era recapitulated Bronze Age migrations, but this is a case where geography is destiny. Of course the spatial relationships in the current period does not necessarily reflect the reality in the past. Perhaps there was a massive migration west of populations in the past few thousand years, reflecting the expansion of the Slavs, which brought the haplotypes found among the Europoid populations of the Altai. I am in particular intrigued by the fact that it seems that the Eastern European variants are common in the former East Germany, but not in the former West Germany. There are some historical data which suggest that the medieval German drive to the east which pushed the boundaries of the German language past the Elbe occurred in the context of Germanization of the indigenous Slavic and Baltic populations (see God's War: A New History of the Crusades). The authors of these papers note that almost all of the males from these ancient remains are carriers of the R1a haplogroup. R1a are a family of haplotypes which are of great historical interest. Some geneticists, such as Spencer Wells, have suggested that its current distribution is the result of the expansion of the Indo-European peoples. This is a position which is hotly debated, and it seems that the current thinking is that R1a has a much deeper history across most of Eurasia than the last 5,000 years, and so its current distribution is not a reflection of recent population movements (in particular, the significance of its distribution in India hinges strongly on whether the Indian branches have recent common ancestry with the Eastern European ones, or if the connections go back to the Ice Age). But, what is clear from these data are that the R1a lineages in the ancient samples are copiously represented among the modern Slavs. Additionally, it seems that one of the variants is also matched a 2,000 year old Tocharian specimen, suggesting a connection between the remains in Krasnoyarsk and the Tocharians. The Krasnoyarsk samples are of the Andronovo culture. It was noted in the second paper that the samples from later periods, when the Andronovo gave way to successor cultural complexes, the proportion of European ancestry dropped in relation to East Asian ancestry. The ancestry was easy to ascertain as there are several pigmentation genes where West Eurasians and East Asians exhibit disjoint frequencies, so they are perfectly ancestrally informative. In terms of complexion the predominantly East European appearance of the Krasnoyarsk samples is clear, recent SNPs implicated in light skin, hair and eyes are all found among them. One of the samples which was positive for an East Asian maternal lineage turned out to have a typical European genotype in terms of pigmentation, emphasizing the importance of assaying multiple loci when making inferences about an individual's ancestry. Finally, here's the conclusion from the second paper:

To conclude, in this work we demonstrated that some carriers of the Kurgan culture, believed to be Indo-European speakers, were also carriers of the R1a1 haplogroup. These data lend further support to the idea that R1a1 might be a marker to the migration patterns of the early Indo-Europeans, an idea also supported by the recent article of Haak et al. (2008) in which individuals of the Corded Ware Culture, a culture commonly associated with Indo-European, might bore R1a1 Y-chromosome (as we deduced from their Y-STR typing results). The modern distribution of lineages is the outcome of many millennia of population movements and therefore the assumption of a Proto-Indo-European speaker's homeland in Kurgan region should be taken with great caution. Nevertheless, our study opens possibilities for new debates. We also showed for the Wrst time that Bronze and Iron Ages south Siberian populations displayed "European" physical appearance, thus corroborating physical anthropological records. Another conclusion that can tentatively be inferred from the data presented here is that the Andronovo culture might be the eastern spread of the Kurgan culture and might be related to Tocharian speakers in the Tarim Basin.

I haven't mentioned the Kurgans yet. If you want a survey of a model of how Kurgans from the steppes of Eurasian spread Indo-European languages I recommend The Horse, the Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World. These data strongly suggest that even in the Bronze Age the Eurasian steppe was connected by peoples with close relationships, cultural and genetic, from Siberia to the Black Sea. This dynamic is a necessary precondition for any of the speculative theories which purport to explain the distribution of contemporary language families. But, it is important I think to note that many of the lineages extracted from the Andronovo burial grounds are not found in Western Europe or across much of Southern Asia, where Indo-European languages are dominant. In Spain we have evident from the Roman period, as well as the modern Basques, which suggest that much of the peninsula was "Indo-Europeanized" via Latinization. But Gaul and Britain were populated by Celtic peoples who spoke Indo-European languages. In India there are a few individuals who share an Andronovo haplotype, and that is certainly suggestive, but Iran, land of the Aryans, is a blank spot. The Andronovo are presumed by many to the precursors of the Indo-Iranian peoples, so this might be a case where "Pots not Peoples" is actually valid! This is just scratching the surface. Thank god there's no prospect of Kennewick Man in the land of Putin. H/T:Polish Genetics and Anthropology Blog. Cite: Int J Legal Med (2009) 123:315-325 DOI 10.1007/s00414-009-0348-5 & Hum Genet DOI 10.1007/s00439-009-0683-0

1 free article left
Want More? Get unlimited access for as low as $1.99/month
Already a subscriber? Log In or Register
1 free articleSubscribe
Want unlimited access?

Subscribe today and save 70%


Already a subscriber? Log In or Register
More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 70% off the cover price when you subscribe to Discover magazine.

Copyright © 2021 Kalmbach Media Co.