The rise of the patriarchs: circumpolar edition

For whatever reason I missed this paper which came out in July in AJHG, Human Y Chromosome Haplogroup N: A Non-trivial Time-Resolved Phylogeography that Cuts across Language Families. Basically it blows up sample size and utilizes NGS techniques (whole-genome) to resolve some questions around haplogroup N, and in particular the M46/TAT subclade which exhibits a peculiar geographic distribution, from the shores of the Baltic to easternmost Siberia.

I actually blogged about this as far back as 2003, so it’s a long term mystery. There’s no autosomal rhyme or reason to the frequency of this lineage. Yes, there is a vague Uralic affinity, but this Y chromosomal variant is higher in the Lithuanians than the Finns, and found in peoples as distant as the Koryaks. One of the major early questions was whether it was a marker that indicated east-west movement, or west-east movement. In other words, was it associated Siberian ancestry in Finns and affiliated people, or did it indicate European ancestry in Siberian people?

If the results in this paper are correct the likely answer is: none of the above. The core TAT lineage looks like it underwent an explosion ~5,000 years ago. This is around the same time as Northern Europeans and Siberians as we understand them were coming into being. So the TAT lineage didn’t come with a specific people, it was part of the process which made the people. I’ll quote from the discussion:

Overall, a considerable proportion of men inhabiting much of the Arctic and temperate zones of western and eastern Eurasia share N3a3’6 lineages that date back to the mid-Holocene (4.5–5.0 kya). This common patrilineal ancestry unites widely different linguistic phyla, including Indo-European, particularly Balto-Slavic, branches of the Altaic, such as the Mongolic, Turkic, Tungusic, and Chu- kotko-Kamchatkan branches, as well as the Balto-Finnic branch of the Finno-Ugric.

The autosomal genome-wide data is clear, pretty much all the Finnic peoples in Europe seem to have a small (to various degrees, with Finns proper the least), but clear, signal of admixture that is Siberian. It is tempting to associate this with the men who carried TAT into these populations, but observe that the Lithuanians seem to be lacking in this signature. Y chromosomes and autosomes are not always in alignment, but recall that many Siberians have some West Eurasian ancestry, some of it likely quite ancient, and carry R1a1a Y chromosomes. The past was more complex than we had assumed, and the relationship between movements of men and languages is likely not so straightforward in the inferences we can make. It may be that the Siberian admixture into Finnic peoples, and their linguistic identity, post-dates the arrival of TAT into the far north of Europe.

One of the aspects of the explosion of many Y chromosomal lineages 4-5,000 years ago is how much they don’t associate well with ethno-linguistic boundaries. The “Indo-Aryan” R1a1a in South Asia is very common in some low caste South Indian tribal populations. The R1b brought by the Corded-Ware culture, which presumably transmitted Indo-European languages, is at very high frequency among the non-Indo-European Basques, as well as groups such as Sardinians, who were Indo-Europeanized only in Classical Antiquity. The Y lineages seem to expanded far beyond the totality of the cultural unit.

Genetics is giving us lots of data. But there are no theoretical bones to scaffold this flesh.