Overview
Haplogroup R-FT15373 represents a downstream but phylogenetically meaningful branch of R2a, forming during the middle Holocene as populations across South Asia and Southwest Asia experienced increasing demographic structuring. This time period is associated with the spread of settled agriculture, the emergence of long distance trade networks and the consolidation of regionally distinct cultural groups. FT15373 appears to have diverged from upstream R2a populations that were already widespread across the Iranian Plateau, Turan and northern South Asia. The lineage today is distributed at low but detectable frequencies in Iran, Pakistan and India, particularly in populations with deep historical continuity in highland regions. This pattern suggests that R-FT15373 likely emerged in or near the eastern Iranian highlands before diffusing into adjacent territories. Unlike the more expansive R2a branches found prominently in the Ganges basin or Deccan Plateau, FT15373 remained confined to smaller founder groups and did not experience large scale demographic expansion. The age estimates indicate that R-FT15373 existed during the period leading into the Chalcolithic urban precursors of the Indus region and the early metallurgical traditions of Southwest Asia. Although ancient DNA samples directly linked to FT15373 are not yet known, upstream R2a signals in early Iranian and Pakistani archaeological contexts strongly support the ecological and geographic plausibility of the lineage's early presence. Its survival into the modern era highlights the deep and complex structure of R2a, particularly its western branches which contrast sharply with the large expansions seen farther east. FT15373 therefore serves as a genetic relic of early Holocene regional differentiation.