Overview
G-U1 forms another major branch of the P303-derived European and Near Eastern Neolithic expansions. While not as numerically dominant as L497, U1 is far more widely distributed and appears across Europe, the Near East and the Caucasus. Its structure suggests an early Holocene diversification likely rooted in the Anatolia–Caucasus interaction zone.
U1 encompasses several subclades associated with both continental and maritime Neolithic expansions. Its presence in the Balkans, Italy, France and the Caucasus indicates repeated episodes of regional founder effects.
Geographic distribution
Modern distributions of U1 show peaks in the Caucasus, eastern Anatolia, Greece, southern Italy, central Europe and the western Mediterranean. In the Caucasus, U1 displays high diversity, consistent with deep roots. In Europe, it appears at modest but widespread levels, often representing residual early farmer ancestry.
In the Mediterranean, U1 occurs in island populations and coastal areas historically connected to Aegean and eastern Mediterranean maritime networks.
Ancient DNA
- Early Neolithic Balkan and Aegean individuals sometimes carry U1-related lineages.
- Mediterranean Neolithic sites—particularly in southern Italy and the western Mediterranean—show occasional U1 derivatives.
- Caucasus samples from late prehistoric periods show deep U1 diversity, suggesting long-term presence independent of European expansions.
Phylogeny & subclades
U1 divides into U1a and U1b, each with further substructure. U1a appears more Mediterranean/European; U1b shows deeper Caucasus–Anatolia diversity. Both branches contain microclades representing regional founder effects.
The U1 phylogeny suggests an early split between Mediterranean and Caucasus-centered lineages, followed by Holocene radiations tied to Neolithic movements.
- G-U1a (Mediterranean–European branches)
- G-U1b (Caucasus/Near Eastern-centered diversity)
- Numerous WGS-defined microclades
Notes & context
U1 is important for capturing the diversity of P303 expansions beyond the central European core. It provides strong evidence for early Neolithic maritime and overland diffusion pathways and helps distinguish multiple independent founder events across Europe, Anatolia and the Caucasus.
References & external links