Overview
Haplogroup R-Y4371 is a downstream branch of R-Z94 that emerged during a period of major demographic restructuring across Central Asia. Its formation overlaps with the southward expansion of steppe derived groups into the oasis civilizations of Bactria and Margiana. Y4371 occupies a key phylogenetic position that connects the primary Z94 expansions with later Iron Age Indo Iranian populations. Its downstream diversity indicates long term continuity within populations living between southern Central Asia and the Iranian Plateau. Y4371 includes multiple regionally structured branches, each of which corresponds to populations historically linked to Iranian speaking groups. Some subclades show strong representation among Pashtuns and northeastern Iranian ethnic groups. Others appear in Tajiks, Pamiris and isolated populations of Turkmenistan and northern Afghanistan. This pattern suggests that Y4371 accompanied both nomadic and sedentary phases of Indo Iranian development, contributing to the paternal background of culturally diverse but genetically connected populations. Modern distributions show Y4371 in Afghanistan, Iran, Tajikistan and Turkmenistan, with additional frequencies in Pakistan and parts of the Caucasus. Its presence in isolated mountain communities reflects ancient demographic stability across regions that historically served as contact zones between the steppe and Southwest Asia. Y4371 remains highly informative for reconstructing the population history of eastern Iranian peoples.