Overview
Haplogroup R-Y40 is a mid Holocene descendant of the R-M73 lineage that likely formed among forager groups inhabiting the southern Siberian forest steppe and the transitional ecotones around the eastern Altai. This lineage arose during a time when human groups were increasingly experimenting with broader seasonal mobility, multi layered subsistence strategies and more complex social organization. Y40 therefore represents populations positioned between fully nomadic hunter lifestyles and increasingly structured seasonal forager networks. The phylogenetic structure of R-Y40 indicates at least several early branching events, pointing to a demographic scenario where multiple localized groups maintained genetic separation over long periods. Archaeological parallels include persistent microlithic tool cultures, bone harpoon technologies and well documented fishing stations along the Ob and Katun rivers. These correspondences support the interpretation of Y40 as a lineage embedded in a long lasting forager tradition unaffected by early pastoralist expansions. Today, R-Y40 survives in low frequencies in parts of southern Siberia and among isolated communities around the Altai Sayan region. Its distribution suggests that the lineage persisted in ecological refugia not heavily impacted by the major Bronze Age expansions or by the subsequent Indo European and Turkic population waves. This makes R-Y40 an important genetic witness to the deep demographic layering that predates major steppe pastoralist transformations.