Overview
G2a2b1 is a less common and partly unresolved branch situated just upstream of and parallel to the major G2a2b2a expansions. Although historically grouped under L91 and M406 markers, modern WGS sequencing reveals that G2a2b1 contains a heterogeneous set of early-branching Mediterranean and Near Eastern lineages that diverged before the dominant P303 radiation.
This lineage reflects a pre-P303, early Holocene population stratum likely associated with initial coastal and highland farming groups in the eastern Mediterranean. Its scattered but ancient distribution pattern suggests it played a role in the earliest phases of Aegean–Anatolian society formation prior to the large-scale expansions that shaped later Neolithic Europe.
Geographic distribution
G2a2b1 appears at low but widespread frequencies across the Aegean, Anatolia, Cyprus, the Levant and occasionally in coastal Italy and Iberia. Small pockets in the Caucasus and northern Mesopotamia contain early basal examples. In Europe, it is rare and mostly restricted to coastal enclaves linked to early maritime expansions.
Ancient DNA
- A small minority of Aegean Neolithic samples show upstream G2a2b1 signals.
- Some early Near Eastern Neolithic individuals may belong to proto-G2a2b1, predating the main P303 expansions.
- Western Mediterranean Neolithic samples occasionally show ambiguous P303-/L91-adjacent markers consistent with early G2a2b1 ancestry.
Phylogeny & subclades
G2a2b1 is phylogenetically upstream of G2a2b2a and forms a side-branch off the main L30 framework. Its internal structure is shallow, containing regionally mixed microclades, many of which require further resolution. It acts as a fossil record for pre-P303 G2a2b diversity.
- G2a2b1* basal
- Mediterranean microclades
- Near Eastern early farmer microclades
Notes & context
G2a2b1 provides rare insight into the earliest phase of G2a2b diversification. It predates the P303-dominated expansions and helps distinguish early eastern Mediterranean genetic layers from the dominant later Neolithic farmer waves. For the atlas, including G2a2b1 is essential for mapping the pre-LBK and pre-Cardial paternal landscape.
References & external links