Fig. 4: Formation of the SP gene pool.

a, Contours indicate the averaged MOBEST maximum probability at search time 1,950 years before present for 20 individuals from Niederwünsch (denoting the mean prediction of the geographic regions where the ancestors of these individuals originated). This is supplemented by five lines of evidence: (A) ancient and present-day groups from the Baltics show the highest genetic similarity to SP individuals; (B) Bronze Age and Iron Age individuals from Estonia, Ingria and Karelia are less related to SP individuals than groups from Lithuania and Latvia; (C) populations in Western Russia feature too high proportions of Steppe and/or Siberian ancestry; (D) SP individuals are enriched in EEF and depleted in WHG ancestry compared with Bronze Age and Iron Age populations from the Baltics; (E) Putative migration directions inferred using pairwise mean sIBD sharing values between SP sites⁷⁷ (n > 2). Made with Natural Earth. b, Comparison of linguistic split times (left) and genetic admixture dates in SP groups (right). Divergence date distributions for the Balto-Slavic and Slavic subgroups were extracted from a sample of 37,004 trees⁷⁸. Genetic admixture dates were obtained using DATES. Error bars indicate 2 × s.d. H, historical. c, Sex-biased admixture in four MP and four SP populations. Shown are non-local ancestry proportions on the autosomes, X chromosome and the Y chromosome (Y-chromosome haplogroups R1a, N and I2 for SP populations; E, G, J and T for MP populations). Points denote qpAdm (autosomes and X chromosome) or maximum likelihood (Y chromosome) estimates. Estimates were obtained as described in Supplementary Notes 7.2 using ancient source groups. The corresponding data can be found in Supplementary Table 47. Error bars indicate 2 × s.d. ♂ indicates an excess of non-local males in the admixture process; ♀ indicates a non-local female bias. The size of the symbols denotes the strength of the sex bias (with |z| > 2 being considered significant).