Overview
Haplogroup R-Y43 represents a downstream branch of the R-M73 lineage that emerged among Holocene forager populations spread across the northern Altai and the adjacent forest-steppe regions. The formation of Y43 is tied to a period when postglacial ecosystems reached stabilized productivity, allowing human groups to maintain predictable seasonal cycles centered on fishing, ungulate hunting and berry harvesting across varied microenvironments. The phylogenetic signature of Y43 reveals a lineage with modest downstream branching, indicating that early populations remained demographically stable and regionally rooted. Archaeological parallels include microlithic blade industries, polished bone implements and riverbank habitation structures typical of mid Holocene forest-steppe foragers. Y43 shows no evidence of participating in the expansive demographic pulses seen in Bronze Age steppe cultures, reinforcing its identification as an older forager-associated lineage. Today, R-Y43 is exceedingly rare but persists in small pockets of southwestern Siberia and occasionally among individuals with deep Altai ancestry. The rarity of the lineage highlights the overwhelming demographic replacement brought by pastoralist expansions from the steppe but also underscores the resilience of small forager communities who preserved isolated pockets of earlier Holocene genetic diversity.