A steppe lineage of eastern Europe and South Asia
Haplogroup R1a, defined by M420, is the eastern counterpart to R1b within the great R lineage. It is common across eastern Europe, reaches high frequencies among Slavic-speaking populations and in parts of Central and South Asia, and is closely tied to the Bronze Age expansions of steppe populations that reshaped the genetics of both Europe and Asia.
R1a is common across eastern Europe, where it is a dominant lineage among many Slavic-speaking populations, and it extends into Scandinavia and central Europe at lower frequencies. It is also frequent in parts of Central Asia and reaches high frequencies among some populations of the Indian subcontinent, particularly in the north. This double centre of gravity — eastern Europe and South Asia — is characteristic of the lineage.
Like R1b, the branches of R1a that matter most today are associated with the Bronze Age expansions of steppe pastoralists. Ancient DNA links R1a strongly to steppe-associated populations, and its spread both westward into Europe and southeastward towards South Asia is a central thread in current accounts of how these movements reshaped Eurasian ancestry. Dating of the key branches continues to be refined.
R1a divides into major branches with distinct distributions: one is characteristic of eastern European and Slavic populations, while another is associated with Central and South Asia. This split reflects the divergence of steppe-descended populations that moved in different directions, and downstream lineages carry sharper regional and sometimes population-specific signals.
An R1a result points to ancestry connected to the steppe expansions, most often eastern European or South and Central Asian. The main branches are immediately informative about which of these applies, and downstream testing refines the result further, often to a regionally useful level.
Live counts by country are shown on this page once the map data loads.