Overview
Haplogroup R-Y33b is an important downstream branch within the R-M73 phylogeny and occupies a central position in the early population history of the Altai and eastern Kazakh forest-steppe zone. Emerging during the middle Holocene, Y33b appears to have arisen among groups experiencing early transitions from purely foraging economies toward more regionally structured subsistence systems. Its time depth places it in a period when early ceramic traditions and localized resource intensification were becoming prominent in Inner Asia. R-Y33b demonstrates a moderate level of internal diversity and forms several microbranches associated with different ecological niches across the Altai Mountains and northern Xinjiang. These patterns suggest that Y33b-bearing populations may have been semi-nomadic or seasonally mobile, following riverine and forest-edge resources. Archaeological assemblages in the region, such as those related to early Altai Neolithic cultures, show continuity in stone-tool traditions and semi-sedentary settlement patterns that align with the genetic persistence suggested by this lineage. Modern instances of R-Y33b are rare but appear in localized groups from the eastern Altai, western Mongolia, and parts of northern Xinjiang. Its survival into the present reflects the endurance of deeply rooted paternal lines that persisted despite later demographic transformations linked to early Indo-European and later Turkic expansions. Y33b is therefore a highly informative lineage for reconstructing early Holocene forager ancestry across the Inner Asian mountain corridor.