Human evolution in Siberia: from frozen bodies to ancient DNA

Abstract

Background: The Yakuts contrast strikingly with other populations from Siberia due to their cattle- and horse-breeding economy as well as their Turkic language. On the basis of ethnological and linguistic criteria as well as population genetic studies, it has been assumed that they originated from South Siberian populations. However, many questions regarding the origins of this intriguing population still need to be clarified (e.g. the precise origin of paternal lineages and the admixture rate with indigenous populations). This study attempts to better understand the origins of the Yakuts by performing genetic analyses on 58 mummified frozen bodies dated from the 15th to the 19th century, excavated from Yakutia (Eastern Siberia).

Results: High quality data were obtained for the autosomal STRs, Y-chromosomal STRs and SNPs and mtDNA due to exceptional sample preservation. A comparison with the same markers on seven museum specimens excavated 3 to 15 years ago showed significant differences in DNA quantity and quality. Direct access to ancient genetic data from these molecular markers combined with the archaeological evidence, demographical studies and comparisons with 166 contemporary individuals from the same location as the frozen bodies helped us to clarify the microevolution of this intriguing population.

Conclusion: We were able to trace the origins of the male lineages to a small group of horse-riders from the Cis-Baïkal area. Furthermore, mtDNA data showed that intermarriages between the first settlers with Evenks women led to the establishment of genetic characteristics during the 15th century that are still observed today.

Figure 1

Location of Yakutia and its districts. Geographic location of the three districts in Central Yakutia where the excavations were performed. 1: Tattinsky, 2: Churapchinsky, 3: Khangalassky.

Figure 2

Frozen bodies. Three frozen bodies from Yakutia a few minutes after the opening of the graves [57]. 1: Kémus Buluussé (Khangalasssky), 2: Kyys Ounouoga (Churapchinsky), 3: Okhtoubout 3 (Churapchinsky).

Figure 3

MDS plot of genetic distances between populations on the basis of Y- STRs. MDS plot based on pairwise Fst values calculated from Y-chromosomal STRs. a_Yakuts: ancient Yakuts, PD_Yakuts: present day Yakuts (97 samples, data not shown, available upon request), Buryats_W: Buryats [75], Evenks_P: Evenks [50], Evenks_X: Evenks [76], a_EG: ancient Mongols from Egyin Gol [47], PD_EG: present day Mongols from Egyin Gol [48], Kazakhs [77], H_Kirghiz and L_Kirghiz: Kirghiz [77], Mongols_K: Mongols [78], Mongols_W: Mongols [75], Moscow: Russians (Jobling, YHRD database: http://www.ystr.org/index.html), Uyghurs_PL: Uyghurs [77], Uyhgurs_Z: Uyghurs [79].

Figure 4

Median Joining network based on Y-chromosomal haplotype. Median Joining network based on Y-chromosomal haplotypes belonging to the haplogroup N1c. Black: ancient Yakuts, Blue: present day Yakuts, Orange: Evenks. Green for Other populations included in the computations: Buryats [75,80], Evenks [80,81], Mongols [76,80], Tuvans [43,80], Uyghurs [76,80] and Altaians, Evens, Kalmyks, Khakassians, Koryaks, Shors, Sojots, Tofalars, and Yakuts from Derenko et al. [80].

Figure 5

MDS plot of genetic distances between populations on the basis of mtDNA. MDS plot based on Fst values of mtDNA HVS-1 sequences. Yak_a: ancient Yakuts, Yak_c: ancient Yakuts from the Christian period, PD_Yakuts: present day Yakuts (this study). Altaï [82], Buryats [4], Evenks [50], Egyin Gol: [48], Kazakhs [23], Kirghiz [23], Koryaks [83], Mansis [22], Mongols [48], Oroqens [65], Tuvans [3], Uyghurs [23,26], Uzbeks [84], W_Siberia: West Siberians [85].