Overview
Haplogroup R-M73 is one of the oldest surviving branches of the R1b lineage outside Europe and plays a critical role in understanding the early expansion of R1b across central and northern Asia. This lineage likely emerged among Upper Paleolithic or early Holocene hunter gatherers inhabiting the Altai region, southern Siberia and parts of western Central Asia. R-M73 represents a pre agricultural paternal signature that persisted among mobile groups long before the rise of Neolithic societies in Europe and the Near East. Unlike R-M269, which experienced a dramatic demographic expansion during the Bronze Age, R-M73 followed a much more localized and regionally stable path. Its presence in ancient and modern populations of the Kazakh steppe, the Altai Mountains and parts of Siberia suggests long term continuity among pastoral or semi nomadic groups. Its distribution also overlaps with areas inhabited historically by early Turkic and proto Iranian groups, although its deep origin predates these ethnolinguistic horizons. R-M73 is also phylogenetically important because it demonstrates that R1b diversity was originally far broader and more geographically dispersed than the later M269 expansions would imply. Together with its sister branch M478, it provides evidence that early R1b lineages were well established across the steppe belt long before Bronze Age cultural transformations.