How to do modern phylogeography: Relationships between clans and genetic kin explain cultural similarities over vast distances

yakut-phylogeography

A preprint paper has been published in BioRxiv, Relationships between clans and genetic kin explain cultural similarities over vast distances: the case of Yakutia, by Zvenigorosky et al (2017).

Abstract:

Archaeological studies sample ancient human populations one site at a time, often limited to a fraction of the regions and periods occupied by a given group. While this bias is known and discussed in the literature, few model populations span areas as large and unforgiving as the Yakuts of Eastern Siberia. We systematically surveyed 31,000 square kilometres in the Sakha Republic (Yakutia) and completed the archaeological study of 174 frozen graves, assembled between the 15th and the 19th century. We analysed genetic data (autosomal genotypes, Y-chromosome haplotypes and mitochondrial haplotypes) for all ancient subjects and confronted it to the study of 190 modern subjects from the same area and the same population. Ancient familial links and paternal clan were identified between graves up to 1500 km apart and we provide new data concerning the origins of the contemporary Yakut population and demonstrate that cultural similarities in the past were linked to (i) the expansion of specific paternal clans, (ii) preferential marriage among the elites and (iii) funeral choices that could constitute a bias in any ancient population study.

Even if you are not interested in the cultural and anthropological evolution of this Turkic-speaking people of the Russian Far Eastern region, the method used is an excellent example of how to use archaeology and genetics (especially Y-DNA and mtDNA data) to obtain meaningful results when investigating ancient populations.

For quite some time, probably since the first renown admixture analyses of ancient DNA samples were published, we have been living under the impression that phylogeography, or simply archaeogenetics as it was called back in the day, is not needed.

Cavalli-Sforza’s assertion that the study of modern populations could offer a clear picture of past population movements is now considered wrong, and the study of Y-DNA and mtDNA haplogroups is today mostly disregarded as of secondary importance, even among geneticists. Whole genomic investigation (and especially admixture analyses) have been leading the new wave of overconfidence in genetic results, tightly joint with the ignorance of its shortcomings (and commercial interests based on desires of ethnic identification), and haplogroups are usually just reported with other, not entirely meaningful aspects of ancient DNA analyses.

While it is undeniable that admixture analyses are offering quite interesting results, they must be carefully balanced against known archaeological and linguistic knowledge. Phylogeography – and especially Y-DNA haplogroup assessment – is quite interesting in investigating kinship and clans in patrilocal communities – i.e. most communities in prehistoric and historic periods, unless proven otherwise.

Luckily enough, there are those researchers who still strive to obtain meaningful information from haplotypes. The article referenced in this post is quite interesting due to its phylogeographic method’s applicability to ancient cultures and peoples.

When some geneticists look at simplistic prehistoric maps, like those depicting Yamna, Afanasevo, Corded Ware, and Bell Beaker cultures together, they forget that 1) cultural regions are selected more or less arbitrarily (we only have certain scattered sites for each of these cultures); 2) economic or population contacts are difficult to ascertain and to represent graphically; and 3) time periods for archaeological sites are important – in fact, they are probably THE most important aspect in assessing how accurate a map (and its “arrows” of migration or exchange) represents reality.

A careful, detailed study like this one, if applied to the Pontic-Caspian steppe, would probably reveal how R1b subclades dominated steppe clans, beginning at least during the Suvorovo-Novodanilovka expansion to the west, and certainly representing the vast majority of lineages during the internal expansion in the Early Yamna period and its later expansion east and west of the steppe…

Featured image from the article, summing up Geography, Archaeology, and Genetics of Yakutia – including Y-DNA and mtDNA haplogroups from ancient populations.

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