Overview
G2a2 represents the major internal radiation of G2a and is the ancestral trunk for nearly all G2a lineages that expanded with early farming cultures. Defined by markers such as PF3147 and PF3150, it encompasses both the G2a2a and G2a2b megaclades. Its formation timeframe places G2a2 within the Late Pleistocene–Early Holocene transition, aligning with climatic amelioration and the earliest stages of sedentism in the Near East.
While G2a2 itself is rarely reported in its basal form, it provides the phylogenetic anchor for G2a2b—a lineage that became the dominant paternal signature of Early Neolithic farmers who migrated out of Anatolia into Southeast Europe and onward into Central Europe and the western Mediterranean.
Geographic distribution
Basal G2a2 is extremely rare today and found almost exclusively in the Near East and occasionally in the Caucasus. Most modern individuals who fall under the G2a2 umbrella belong to downstream branches such as G2a2b (L30/S126) and its many subclades. These descendant branches are distributed across Europe, the Near East, and parts of the Caucasus and Mediterranean.
The stratified geographic pattern—strong diversity in West Asia and more structured clades in Europe—mirrors the Neolithic farmer expansion model. Basal G2a2 likely persisted in small populations of early Holocene agriculturalists and pre-agricultural communities in the northern Fertile Crescent.
Ancient DNA
- Early Neolithic individuals from Anatolia and the Aegean, whose descendants formed the core of European Neolithic populations, almost all fall under G2a2-derived lineages.
- Basal G2a2 itself has not yet been directly identified in ancient remains, likely due to the dominance and preservation bias of G2a2b sublineages.
- The presence of multiple deep G2a2-derived clades in early Neolithic contexts supports the interpretation of G2a2 as a structured lineage population already diversified in the Near East before the spread of farming.
Phylogeny & subclades
G2a2 splits mainly into G2a2a (M286) and G2a2b (L30/S126). The latter undergoes substantial downstream radiation into numerous Neolithic-associated clades. G2a2 functions largely as a non-terminal node in the tree: a key ancestral stage connecting deeper G2a diversity with the explosive Neolithic expansions that characterize G2a2b.
- G2a2a-M286 (older West Asian-centered branch)
- G2a2b-L30/S126 (dominant Neolithic farmer lineage)
- Multiple unnamed basal micro-branches (WGS-defined)
Notes & context
G2a2 is a necessary phylogenetic reference point in order to map the hierarchical descent of the dense G2a tree. Its importance lies in anchoring the transition from early Holocene diversification in West Asia to the major Neolithic expansions documented across Europe. Without the G2a2 node, the downstream Neolithic signatures of G2a2b and P303-derived clades cannot be contextualized.
References & external links