Overview
G2b1 is the primary sub-branch of G2b and the better-represented lineage among the M377-derived expansions. It is still rare globally, but compared to basal G2b, G2b1 displays somewhat broader representation across Iran, Afghanistan, Pakistan and certain Central Asian populations. Its distribution suggests that G2b1 formed among early Holocene highland groups east of Mesopotamia and later took part in multiple small-scale founder events affecting South-Central Asian populations.
G2b1 does not appear in European Neolithic contexts and is essentially absent from the Mediterranean farmer-associated clusters. Instead, its demographic history reflects the cultural trajectories of Iranic, Indo-Afghan and proto-Central Asian societies during the mid- to late Holocene.
Geographic distribution
G2b1 appears in modest but consistent frequencies in western and northwestern Iran, Afghanistan (especially among Pashtun groups), Pakistan (Baloch, Pashtun, Kalash), and certain Central Asian communities. Small occurrences in Uzbekistan and Turkmenistan reflect historical movements. A small number of Jewish lineages fall under G2b1, likely the result of older founder effects in Near Eastern diasporic communities.
Ancient DNA
- No fully confirmed ancient G2b1 genomes exist, but several Iron Age and early historic samples from Iran and Afghanistan show upstream SNP patterns compatible with early G2b1 ancestry.
- The absence of G2b1 in European Neolithic and Bronze Age individuals further supports its primarily Iranian–South Asian historical trajectory.
- Sporadic matches among low-coverage prehistoric samples in Iran indicate G2b1 may have existed as a minor paternal component since early Holocene times.
Phylogeny & subclades
G2b1 divides into several rare downstream WGS-defined clusters, often geographically tied to Iranian Plateau and South-Central Asian populations. Its structure reflects multiple micro-founder effects rather than a single large radiation. Some deep-rooted lineages in Afghanistan and Pakistan appear to have diverged early, forming distinct subclusters.
- G2b1* basal
- Iran–Afghanistan regional microclades
- South Asian founder clusters
- Jewish-associated G2b1 lineages
Notes & context
G2b1 preserves a deep-time paternal lineage tied to the Iranian Plateau and South-Central Asia, offering insight into alternative Holocene demographic processes not reflected in the dominant G2a Neolithic expansions. Its rarity makes it important for reconstructing fine-scale Iranian–Afghan population history.
References & external links