The Finnic Peoples of Russia: Genetic Structure Inferred from Genome-Wide and Y-Chromosome Data

Abstract

Background: Eastern Finnic populations, including Karelians, Veps, Votes, Ingrians, and Ingrian Finns, are a significant component of the history of Finnic populations, which have developed over ~3 kya. Yet, these groups remain understudied from a genetic point of view. Methods: In this work, we explore the gene pools of Karelians (Northern, Tver, Ludic, and Livvi), Veps, Ingrians, Votes, and Ingrian Finns using Y-chromosome markers (N = 357) and genome-wide autosomes (N = 67) and in comparison with selected Russians populations of the area (N = 763). The data are analyzed using statistical, bioinformatic, and cartographic methods. Results: The autosomal gene pool of Eastern Finnic populations can be divided into two large categories based on the results of the PCA and ADMIXTURE modeling: (a) "Karelia": Veps, Northern, Ludic, Livvi, and Tver Karelians; (b) "Ingria": Ingrians, Votes, Ingrian Finns. The Y-chromosomal gene pool of Baltic Finns is more diverse and is composed of four genetic components. The "Northern" component prevails in Northern Karelians and Ingrian Finns, the "Karelian" in Livvi, Ludic, and Tver Karelians, the "Ingrian-Veps" in Ingrians and Veps (a heterogeneous cluster occupying an intermediate position between the "Northern" and the "Karelian" ones), and the "Southern" in Votes. Moreover, our phylogeographic analysis has found that the Y-haplogroup N3a4-Z1927 carriers are frequent among most Eastern Finnic populations, as well as among some Northern Russian and Central Russian populations. Conclusions: The autosomal clustering reflects the major areal groupings of the populations in question, while the Y-chromosomal gene pool correlates with the known history of these groups. The overlap of the four Y-chromosomal patterns may reflect the eastern part of the homeland of the Proto-Finnic gene pool. The carriers of the Y-haplogroup N3a4-Z1927, frequent in the sample, had a common ancestor at ~2.4 kya, but the active spread of N3a4-Z1927 happened only at ~1.7-2 kya, during the "golden" age of the Proto-Finnic culture (the archaeological period of the "typical" Tarand graves). A heterogeneous Y-chromosomal cluster containing Ingrians, Veps, and Northern Russian populations, should be further studied.

Keywords: Finnic people; Ingrian Finns; Ingrians; Karelians; Veps; Votes; Y-chromosome; ancestral components; gene pool; genome-wide SNPs.

Figure 1

Approximate dispersal of the Eastern Finnic populations over the past 2.5 kya: A—from the 4th–3rd centuries BC to 3rd–4th centuries AD: archaeological culture of the Iron Age (“typical” Tarand graves, [15] (p. 175)); B—from the 3rd–4th to 9–11th centuries AD: the expansion of the Finnic area: the Korela tribes are being formed [19] (p. 11); C—the 9–11th centuries AD: active Finnic migrations of the tribes related to ancient Beloozero Ves’ (the alleged ancestors of modern Veps), Chud and Zavoloch Chud [17] (p. 4); D—from the end of the 1st millennium AD, but especially in the 12–15th century AD: (a) migrations of the ancestors of Ingrians from the area of the Korela tribes and the formation of Ingrians [23] (pp. 8–13), [24] (pp. 2–6); (b) Northern and Eastern migrations of Ves’ tribes and Southeastern migrations of Korela tribes and the formations of Ludic and Livvi Karelians [22] (pp. 93–94); (c) Northeastern migrations of Korela tribes after the Orekhov treaty of 1323 with Sweden and the formation of South Karelian proper [21] (pp. 170–172); E—the 17th century AD: after the T’avzino treaty of 1595 and especially the Stolbovo treaty of 1617 with Sweden, (a) mass migrations of the ancestors of Northern Karelian proper (Northern Karelian migrations), and of Tikhvin, Valdai, and Tver Karelians (Southern Karelian migrations) from the Swedish to the Russian territory [25] (pp. 176–177) and (b) the migrations of the ancestors of Ingrian Finns to the new lands of Sweden (the province of Ingria): the “Savakot” Finns from the Savo parish, the “Äyrämöiset” Finns from the Äyräpää parish, and possibly Finns from some other territories of modern Finland [26] (pp. 469–471). Dotted maroon line (“RAHK”): the southern boundary of attested Finnic toponyms [27] (p. 32).

Figure 2

Position of Finnic populations in the genetic space of Northeastern Europe (multidimensional scaling plot for 18 populations based on 25 Y-chromosomal haplogroups, stress 0.07, alienation 0.09).

Figure 3

Geographical distribution of the four main patterns of the studied Finnic gene pools in Northern Europe (A–D). The map (E) is an averaged map showing the four patterns, while the map (F) shows the overlap of four patterns.

Figure 4

Phylogeny, dating, and distribution maps for the haplogroup N3a4. The maps are arranged according to the phylogenetic tree and the TMRCA-agess of N3a4 branches (see [43]).

Figure 5

Gene pools of Finnic populations studied and of some adjacent Russian groups in the principal component (PC) genetic space constructed from autosomal markers: (A) PC1*PC2, (B) PC1*PC3, (C) PC2*PC3. Small dots represent individual genomes; big dots represent the centroids (centers of population clouds).

Figure 6

Average values of ancestral components in the studied populations at K = 6 (A) and K = 22 (B).