Overview
Haplogroup R2-M479 is one of the two principal branches of haplogroup R and forms a distinct Upper Paleolithic paternal lineage with its deepest roots in southern Central Asia, Iran and South Asia. Unlike R1, which experienced massive Bronze Age expansions across Eurasia, R2 followed a different demographic trajectory characterized by regional continuity, localized founder effects and moderate expansions during the Neolithic and later historical periods. R2 has long been associated with populations of northern and eastern Iran, Afghanistan, Pakistan and the Indian subcontinent, and its distribution reflects ancient interactions between Iranian plateau communities and early South Asian populations. R2 likely developed among hunter gatherer groups living in regions situated between the Iranian plateau and South Central Asia during the terminal Pleistocene. As agriculture spread into these regions during the Neolithic, R2-bearing populations contributed to several early settled communities in eastern Iran, Balochistan and the Indus Valley region. Later expansions into the Indian subcontinent occurred during periods associated with Chalcolithic cultures, regional early states and historic era movements within South Asia. The majority of modern R2 chromosomes fall into the R2a (R-M124) branch, which experienced significant growth during the late Holocene and today forms one of the major paternal lineages in parts of South Asia. More basal forms of R2 are rare, providing important insight into the earliest phases of R diversification and movements across southwestern Asia.