Maternal lineages from Iron Age to present in Eastern Fennoscandia
S. Översti 1 , K. Majander 1,2,3 , E. Salmela 1,2 , K. Salo 4 , H. Etu-Sihvola 5 , L. Arppe 5 , S. Belskiy 6 , V. Laakso 7 , E. Mikkola 8 , M. Oinonen 5 K. Vuoristo 8 , A. Wessman 4 , W. Haak 2 , J. Krause 2 , J. Palo 9,10 , P. Onkamo 1,11
Introduction: aDNA has revealed that the Neolithization involve d a turnover of maternal lineages in Europe: haplogroup (hg) U, dominating in hunter-gatherers , was widely replaced by the farmer-associated hgs such as H. As a result, modern European populations show different proportions of these hgs. In Finland , mtDNA diversity resembles that observed in other populations, but holds relatively high frequency of U and shows internal substructure: U is more common in the north-east (NE) Finland and farmer-associated hgs in the south-west (SW). This pattern has been interpreted to reflect the arrival of agriculture from the south-west, most likely associated to the spread of the Corded Ware Culture c. 4,500 ya. Objectives: To provide insight into the past of Eastern Fennoscandia, complete mtDNA genomes from Iron Age to Medieval Era were obtained from Finland. These derived from five burial grounds, of which Levänluhta (300-800 AD, N=13), Luistari (600- 1130 AD, N=10) and Kirkkailanmäki (1100-1200 AD, N=16) are located in SW Finland, and Kylälahti (1200-1400 AD, N=14) and Tuukkala (1200-1400 AD, N=19) sites in south-eastern (SE) Finland.
Methods: Extraction of aDNA was performed as in Meyer et al. 2010 and mtDNA capture as in Dabney et al. 2013. Raw sequence data processing was performed with EAGER and Schmutzi. Statistical analyses were calculated in Arlequin 3.5.2.2.
Results: The 72 haplotypes obtained belong to hgs observed in modern Finns, but the frequencies differ both from the modern population and between studied sites: the SW sites showed higher frequency of U (60%) than the SE sites (19%) or the modern data (23 %). H showed an opposite trend: 52% in SE and 27% in SW. On sequence level, SW sites have higher affinity to the modern NE, while SE sites cluster with modern SW. Furthermore, within the SW sites the distribution of U subhaplogroups is uneven: Levänluhta has high frequency of U5a and Saami-related hg U5b1b1a whereas other SW sites show relatively high frequencies of U4. Conclusion: Our results suggest an interpretation that among the studied sites and modern Finns, there are varying levels of admixture of three ancestries: Saami (U5b1b1), possible non-Saami hunter-gatherers (U4, U5a) and farmers (H, J, T, K). The high prevalence of H in the eastern sites might reflect bidirectional arrival of the farming-associated populations into Finland, challenging the traditional assumption of the spread of agriculture from the south-west.
Luistari on tosin hiukan varhaisemmalta ajalta kuin nämä kaakon saitit