Overview
G1a3 is a younger but regionally significant branch of G1a with strong ties to the eastern Iranian Plateau, Afghanistan and the southern Caspian highlands. It appears prominently in populations historically linked to the early Indo-Iranian cultural sphere and shows signs of demographic growth during the Bronze Age–Iron Age transition.
G1a3’s distribution reflects the spread of semi-nomadic and agro-pastoralist groups across Iran, Bactria, Arachosia and Sistan. Its downstream microclades often correspond to localized founder events among tribal communities.
Geographic distribution
G1a3 is concentrated in Iran (especially eastern and southeastern regions), Afghanistan, Tajikistan and parts of Pakistan. Smaller presence occurs in Turkmenistan and Uzbekistan. In the Caucasus, it appears at very low frequencies.
Its distribution maps well onto ancient cultural areas such as BMAC (Bactria–Margiana Archaeological Complex) and later Indo-Iranian expansions.
Ancient DNA
- Late Bronze Age and Iron Age burials across eastern Iran and Afghanistan show upstream markers consistent with G1a3 formation.
- Some Saka-associated Central Asian individuals exhibit SNP patterns compatible with proto-G1a3 branches.
- No Neolithic G1a3 has been identified, consistent with its later formation relative to early Holocene G1 splits.
Phylogeny & subclades
G1a3 divides into several localized sub-branches, many strongly associated with eastern Iranian and Afghan ethnic groups. Its structure shows rapid founder effects typical of pastoralist and tribal societies.
Compared to G1a1’s deep Iranian Plateau core and G1a2’s broad Iranian–Central Asian expansions, G1a3 forms a more regionally concentrated radiation.
- G1a3* basal
- Afghan/Iranian highland microclades
- BMAC-linked clusters
- South-central Asian tribal founder branches
Notes & context
G1a3 is essential for mapping later Holocene expansions across eastern Iran, Turan and Afghanistan. Its structure helps distinguish multiple waves of Indo-Iranian dispersal across the highlands and foothill belts.
References & external links