From the paper:
The overwhelming majority of mtDNA clusters, identified in Czechs, were of the western-Eurasian origin. The frequency of eastern-Eurasian (Mongoloid) mtDNA lineages in this population constituted 1.8% (haplogroups A, N9a, and M). African lineage (with the frequency of 0.4%) belonging to haplogroup L2a and marked by the +13803HaeIII variant was also detected.
Low frequency of Mongoloid mtDNA variant in Letts and Lithuanians suggests that Mongoloid component was probably not typical of Balto-Slavic protogene pool. Thus, it seems reasonable that accumulation of Mongoloid mtDNA lineages in Slavs and their ancestors was intensified only in the last 4000 years.
The highest frequencies of the Mongoloid component are typical of the Russian populations from Russian Pomor’e and Northwestern region. These populations, however, differ in the mtDNA haplogroup composition. It was established that assimilation of the indigenous pre-Slavic population of Eastern Europe by true Slavs was of great importance to the process of the development of Russian population.
It is suggested that after the decay of Avar Khaganate the populations included into it were assimilated by Slavic tribes . It is thereby suggested that rather high frequencies of eastern-Eurasian mtDNA lineages observed in the gene pools of some populations of Western and Southern Slavs (especially on the territoryof former Avar Khaganate) can be considered as a consequence of the process described.
Concerning the population of Eastern Europe, it should be noted that the forest zone of Eastern Europe was the area of intense population admixture . It seems likely, that formation of the complex of Mongoloid traits happened not later than in Upper Paleolithic. For this reason, it is suggested that East Siberian populations could have much time for migration to Eastern Europe . The number of such migrations still remains unclear, since in the northwest of Eastern Europe Mongoloid component is detected 10 000–8000 years ago; in Dnepr–Donetsk tribes, 7000–6000 years ago, and on the territory of Ivanovo oblast (Sakhtysh), 6000–5000 years ago [35, 36]. The data on mtDNA variation in Russian populations are consistent with anthropological data, since they point to the substantial differences in the frequencies of Mongoloid mtDNA lineages between the Russian populations of the Russian North, Northwest, and the central/southern regions of the European part of Russia (Table 3). We hope that future investigations would provide
the possibility of analyzing the chronology of the development of the Mongoloid component diversity in the gene pools of Russians and other Slavic populations.
Russian Journal of Genetics, 10.1007/s11177-008-3016-9
On the origin of Mongoloid component in the mitochondrial gene pool of Slavs
B. A. Malyarchuk, M. A. Perkova and M. V. Derenko
Abstract The data on mitochondrial DNA (mtDNA) restriction polymorphism in Czech population (n = 279) are presented. It was demonstrated that in terms of their structure, mitochondrial gene pools of Czechs and other Slavic populations (Russians, Poles, Slovenians, and Bosnians) were practically indistinguishable. In Czechs, the frequency of eastern-Eurasian (Mongoloid) mtDNA lineages constituted 1.8%. The spread of eastern-Eurasian mtDNA lineages belonging to different ethnolinguistic groups in the populations of Europe was examined. Frequency variations of these DNA lineages in different Slavic groups was observed, with the range from 1.2 and 1.6% in Southern and Western Slavs, respectively, to 1.3 to 5.2% in Eastern Slavs, the Russian population of Eastern Europe. The highest frequency of Mongoloid component was detected in the mitochondrial gene pools of Russian populations from the Russian North and the Northwestern region of Russia. This finding can be explained in terms of assimilation of northern-European Finno-Ugric populations during the formation of the Russian population of these regions. The origin of Mongoloid component in the gene pools of different groups of Slavs is discussed.