More evidence on the recent arrival of haplogroup N and gradual replacement of R1a lineages in North-Eastern Europe

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A new article (in Russian), Kinship Analysis of Human Remains from the Sargat Mounds, Baraba forest-steppe, Western Siberia, by Pilipenko et al. Археология, этнография и антропология Евразии Том 45 № 4 2017, downloadable at ResearchGate.

Abstract:

We present the results of a paleogenetic analysis of nine individuals from two Early Iron Age mounds in the Baraba forest -teppe, associated with the Sargat culture (fi ve from Pogorelka-2 mound 8, and four from Vengerovo-6 mound 1). Four systems of genetic markers were analyzed: mitochondrial DNA, the polymorphic part of the amelogenin gene, autosomal STR-loci, and those of the Y-chromosome. Complete or partial data, obtained for eight of the nine individuals, were subjected to kinship analysis. No direct relatives of the “parent-child” type were detected. However, the data indicate close paternal and maternal kinship among certain individuals. This was evidently one of the reasons why certain individuals were buried under a single mound. Paternal kinship appears to have been of greater importance. The diversity of mtDNA and Y-chromosome lineages among individuals from one and the same mound suggests that kinship was not the only motive behind burying the deceased people jointly. The presence of very similar, though not identical, variants of the Y chromosome in different burial grounds may indicate the existence of groups such as clans, consisting of paternally related males. Our conclusions need further confi rmation and detailed elaboration. Keywords: Paleogenetics, ancient DNA, kinship analysis, mitochondrial DNA, uniparental genetic markers, STR-loci, Y-chromosome, Baraba forest-steppe, Sargat culture, Early Iron Age.

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From the older study of the same region (Baraba, numbered 4) “Location of ancient human groups with a high frequency of mtDNA haplogroups U5, U4 and U2e lineages. The area of Northern Eurasian anthropological formation is marked by yellow region on the map (References: 1. Bramanti et al., 2009; 2. Malmstrom et
al., 2009; 3. Krause et al., 2010; 4. this study)”

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Chronological time scale of Bronze Age Cultures from the Baraba region
This is the same team that brought an ancient mtDNA study of different cultures within the Baraba steppe-forest region (from the Open Access book Population Dynamics in Prehistory and Early History).

The Baraba steppe-forest is a region between the Ob and Irtysh rivers (about 800 km from west to east), stretching over 200 km from the taiga zone in the north to the steppes in the south.

The new study brings a more recent picture of the region, from the Iron Age Sargat culture, ca. 500 BC – 500 AD, with five samples of haplogroup N and two samples of haplogroup R1a.

R1a lineages in the region probably derive from the previous expansion of Andronovo and related cultures, which had absorbed North Caspian steppe populations and their Late Indo-European culture.

N subclades prevalent in certain modern Eurasian populations are probably derived from the expansion of the Seima-Turbino phenomenon.

While samples are scarce, Y-DNA data keeps showing the same picture I have spoken about more than once:

N subclades (potentially originally speaking Proto-Yukaghir languages) gradually replacing haplogroup R1a (originally probably speaking Uralic languages), probably through successive founder effects (such as the bottlenecks found in Finland), which left their Uralic culture and ethnolinguistic identification intact.

Therefore, late Corded Ware groups of North-Eastern Europe (in the Forest Zone and the Baltic), mainly of R1a-Z645 subclades, probably never adopted Late Indo-European languages.

Related:

New preprint papers on Finland’s population history and disease, skin pigmentation in Africa, and genetic variation in Thailand hunter-gatherers

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New and interesting research these days in BioRxiv:

Haplotype sharing provides insights into fine-scale population history and disease in Finland, by Martín et al. (2017):

Finland provides unique opportunities to investigate population and medical genomics because of its adoption of unified national electronic health records, detailed historical and birth records, and serial population bottlenecks. We assemble a comprehensive view of recent population history (≤100 generations), the timespan during which most rare disease-causing alleles arose, by comparing pairwise haplotype sharing from 43,254 Finns to geographically and linguistically adjacent countries with different population histories, including 16,060 Swedes, Estonians, Russians, and Hungarians. We find much more extensive sharing in Finns, with at least one ≥ 5 cM tract on average between pairs of unrelated individuals. By coupling haplotype sharing with fine-scale birth records from over 25,000 individuals, we find that while haplotype sharing broadly decays with geographical distance, there are pockets of excess haplotype sharing; individuals from northeast Finland share several-fold more of their genome in identity-by-descent (IBD) segments than individuals from southwest regions containing the major cities of Helsinki and Turku. We estimate recent effective population size changes over time across regions of Finland and find significant differences between the Early and Late Settlement Regions as expected; however, our results indicate more continuous gene flow than previously indicated as Finns migrated towards the northernmost Lapland region. Lastly, we show that haplotype sharing is locally enriched among pairs of individuals sharing rare alleles by an order of magnitude, especially among pairs sharing rare disease causing variants. Our work provides a general framework for using haplotype sharing to reconstruct an integrative view of recent population history and gain insight into the evolutionary origins of rare variants contributing to disease.

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Migration rates and haplotype sharing within Finland and between neighboring countries. A) Map of regional Finnish, Swedish, and Estonian birthplaces Purple triangle indicates St. Petersburg, Russia. Hungary not shown. 1 Finnish, Swedish, and Estonian region labels are shown in Table S3. B) Principal components analysis (PCA) of unrelated individuals, colored by birth region as shown in A) if available or country otherwise. C-D) Migration rates inferred with EEMS. Values and colors indicate inferred rates, for example with +1 (shades of blue) indicating an order of magnitude more migration at a given point on average, and shades of orange indicating migration barriers. C) Migration rates among municipalities in Finland. D) Migration rates within and between Finland, Sweden, Estonia, and St. Petersburg, Russia. Available under a CC-BY 4.0 International license.

Interesting to understand this paper is the whole research published by the Institute for Molecular Medicine Finland (FIMM): their website contains detailed research on Finland’s recent genetic history.

NOTE: The featured image of this article contains three figures from the FIMM (License CC-BY 4.0). Left: Position of the points represents the locations of 1042 Finnish individuals. By clustering the individuals into two groups based on genome data we see a split between eastern (blue) and western (red) parts. Individuals who show considerable relatedness to both groups have been colored with cyan. Both parents of each individual were born close to each other and based on the parents’ birth years we can infer that we are looking at the genetic structure present in Finland before 1950s. Center: An estimated borderline of the Treaty of Nöteborg on top of the map from the left. The border line is drawn between Jääski (28.92 N, 61.04 E) and Pyhäjoki (24.26 N, 64.46 E). Right: The settlement border divides Finland into the early settlement region (to west and south of the border) and the late settlement region (to east and north of the border) (Jutikkala 1933, s. 91). We see that Southern Savo (in south-eastern part of the early settlement) is among the only parts of the early settlement region that is dominated by the eastern genetic group. Information from Matti Pirinen and Sini Kerminen, 24.5.2017.

An Unexpectedly Complex Architecture for Skin Pigmentation in Africans, by Martin et al (2017):

Fewer than 15 genes have been directly associated with skin pigmentation variation in humans, leading to its characterization as a relatively simple trait. However, by assembling a global survey of quantitative skin pigmentation phenotypes, we demonstrate that pigmentation is more complex than previously assumed with genetic architecture varying by latitude. We investigate polygenicity in the Khoe and the San, populations indigenous to southern Africa, who have considerably lighter skin than equatorial Africans. We demonstrate that skin pigmentation is highly heritable, but that known pigmentation loci explain only a small fraction of the variance. Rather, baseline skin pigmentation is a complex, polygenic trait in the KhoeSan. Despite this, we identify canonical and non-canonical skin pigmentation loci, including near SLC24A5, TYRP1, SMARCA2/VLDLR, and SNX13 using a genome-wide association approach complemented by targeted resequencing. By considering diverse, under-studied African populations, we show how the architecture of skin pigmentation can vary across humans subject to different local evolutionary pressures.

Contrasting maternal and paternal genetic variation of hunter-gatherer groups in Thailand, by Kutanan et al. (2017):

The Maniq and Mlabri are the only recorded nomadic hunter-gatherer groups in Thailand. Here, we sequenced complete mitochondrial (mt) DNA genomes and ~2.364 Mbp of non-recombining Y chromosome (NRY) to learn more about the origins of these two enigmatic populations. Both groups exhibited low genetic diversity compared to other Thai populations, and contrasting patterns of mtDNA and NRY diversity: there was greater mtDNA diversity in the Maniq than in the Mlabri, while the converse was true for the NRY. We found basal uniparental lineages in the Maniq, namely mtDNA haplogroups M21a, R21 and M17a, and NRY haplogroup K. Overall, the Maniq are genetically similar to other negrito groups in Southeast Asia. By contrast, the Mlabri haplogroups (B5a1b1 for mtDNA and O1b1a1a1b and O1b1a1a1b1a1 for the NRY) are common lineages in Southeast Asian non-negrito groups, and overall the Mlabri are genetically similar to their linguistic relatives (Htin and Khmu) and other groups from northeastern Thailand. In agreement with previous studies of the Mlabri, our results indicate that the Malbri do not directly descend from the indigenous negritos. Instead, they likely have a recent origin (within the past 1,000 years) by an extreme founder event (involving just one maternal and two paternal lineages) from an agricultural group, most likely the Htin or a closely-related group.

Related:

Collapse of the European ice sheet caused chaos in northern and eastern Europe until about 8000 BC

deglaciation-europe-east

A new paper with open access has appeared in Quaternary Science Reviews, authored by Patton et al.: Deglaciation of the Eurasian ice sheet complex, which offers a new model investigating the retreat of this ice sheet and its many impacts.

According to the comments of professor Alun Hubbard, the paper’s second author and a leading glaciologist:

To place it in context, this is almost 10 times the current rates of ice lost from Greenland and Antarctica today. What’s fascinating is that not all Eurasian ice retreat was from surface melting alone. Its northern and western sectors across the Barents Sea, Norway and Britain terminated directly into the sea. They underwent rapid collapse through calving of vast armadas of icebergs and undercutting of the ice margin by warm ocean currents.

Some speculate that at some points during the European deglaciation, this river system had a discharge twice that of the Amazon today. Based on our latest reconstruction of this system, we have calculated that its catchment area was similar to that of the Mississippi. It was certainly the largest river system to have ever drained the Eurasian continent.

One thing that we show pretty well in this study is that our simulation is relevant to a range of different research disciplines, not only glaciology. It can even be useful for archaeologists who look at human migration routes, and are interested to see how the European environment developed over the last 20,000 years.

Interesting is its effect on population movements in eastern Europe, including the steppe, the forest-steppe, and the Forest Zone, during the Younger Dryas period and thereafter.

Another, recent build-up article on this model also by Patton and cols. of december 2016, in the same journal, is The build-up, configuration, and dynamical sensitivity of the Eurasian ice-sheet complex to Late Weichselian climatic and oceanic forcing. A summary is found at the University of Tromso website.

Discovered via News at Phys.org.

Featured image: Younger Dryas period, from the article.