Overview
Haplogroup R-Y35 is a mid Holocene branch of the R-M73 lineage and represents a population layer that flourished across the northern foothills of the Altai and the adjacent western Siberian forest corridor. Its formation occurred during a period of regional ecological stabilization when Holocene warming produced more predictable seasonal cycles and opened new microhabitats for hunter fisher groups. Archaeologically, this period corresponds to the widespread adoption of refined lithic industries, early bone and antler tool specialization and pronounced riverine resource utilization. Genetically, R-Y35 shows moderate downstream structuring, indicating that several localized forager groups carried this paternal line during the middle Holocene. These groups appear to have occupied the river valleys linking the Altai, the upper Irtysh basin and northern Xinjiang, forming semi sedentary or seasonally mobile clusters. The phylogenetic diversity within Y35 suggests prolonged demographic stability rather than rapid expansions, implying that groups bearing this lineage maintained cultural continuity across multiple millennia. Modern traces of R-Y35 are sparse but appear among populations inhabiting the forest steppe boundary of southwestern Siberia and sporadically in the eastern Altai. These occurrences reflect the survival of deeply rooted Holocene lineages despite major demographic overshifts caused by Bronze Age steppe cultures and later waves of Indo European and Turkic influence. R-Y35 provides an essential genetic anchor for reconstructing mid Holocene population structures in the Altai Siberian transitional zone.