Within months, it will be finally confirmed that both Late Repin offshoots – Early Yamnaya and Afanasievo – spread with clans that were dominated by R1b-L23 patrilineages. Succeeding migration events, likely coupled with internal founder effects under the most successful clans, left Indo-Tocharian-speaking clans as an almost uniform community in terms of Y-chromosome haplogroups, with their most recent common ancestor traceable to the 5th millennium BC.
Before that, it seems that the Indo-Anatolian-speaking Early Khvalynsk community was slightly more diverse. In particular, the success of R1b-V1636 lineages is apparent in the Khvalynsk-Novodanilovka expansion, since it is … Read the rest “Proto-Indo-European kinship system and patrilineality”
Open access Close inbreeding and low genetic diversity in Inner Asian human populations despite geographical exogamy, by Marchi et al. Scientific Reports (2018) 8:9397.
Abstract (emphasis mine):
When closely related individuals mate, they produce inbred offspring, which often have lower fitness than outbred ones. Geographical exogamy, by favouring matings between distant individuals, is thought to be an inbreeding avoidance mechanism; however, no data has clearly tested this prediction. Here, we took advantage of the diversity of matrimonial systems in humans to explore the impact of geographical exogamy on genetic diversity and inbreeding. We collected ethno-demographic data for 1,344 individuals
… Read the rest “Close inbreeding and low genetic diversity in Inner Asian human populations despite geographical exogamy”