Overview
G2a2b1a31 is modeled in the atlas as a coastal Mediterranean branch whose deep ancestry lies in the broader Anatolian M406 radiation, while its visible demographic expansion fits the late Hellenistic to Roman and late antique periods. The lineage is associated with populations that lived in port towns, river mouths and coastal plains, especially on the northern and central Mediterranean shores. Rather than representing a single archaeological culture, it reflects the composite demographic layer created when Anatolian rooted paternal lines became integrated into multiethnic maritime societies.
From a population history perspective, G2a2b1a31 illustrates the secondary dispersal phase of G2a2b1a, where already diversified Anatolian lineages were redistributed by imperial logistics, merchant diasporas and coastal urbanization. The branch underscores how later mobility waves could carry relatively rare paternal lines over long distances while still producing only modest frequencies in each local population.
Geographic distribution
In a generalized present day pattern, G2a2b1a31 type lineages are most often recorded in coastal Italy, the Adriatic shore, southern France and parts of eastern Spain. They appear at lower frequencies in coastal North Africa and in islands such as Corsica, Sardinia and Sicily. Very small occurrences in the Levant and western Anatolia correspond to back links to the ancestral Near Eastern domain. Inland Europe usually shows much lower presence, consistent with a maritime diffusion model rather than deep continental spread.
Ancient DNA
- Late Hellenistic and Roman period individuals from Italian coastal cities often display G-M406 derived haplogroups, some of which are plausibly ancestral to internal nodes represented here as G2a2b1a31.
- Burials from Roman ports on the French and Spanish Mediterranean coasts show M406 related signatures that mirror the maritime connectivity implied by this branch.
- No single ancient specimen can be firmly assigned to FT79013 in current literature, so the branch timeline in this atlas is reconstructed from general patterns of M406 distribution and coastal demographic history.
Phylogeny & subclades
Within the atlas framework, G2a2b1a31 is plotted as a mid level node under G2a2b1a, downstream of FGC5081 type trunks that are already widely distributed across the eastern Mediterranean and Europe. Internal structure is divided into a western Mediterranean clade, an Adriatic clade and a small eastern remnant clade. The divergence of these internal subbranches is timed to late classical and early medieval centuries, which corresponds well with known episodes of coastal urban growth, regional fragmentation and the formation of new local elites.
- G-FT79013* basal coastal core with strongest representation in central and southern Italy
- G-FT79013a western Mediterranean branch that appears in eastern Spain and southern France
- G-FT79013b Adriatic microcluster associated with coastal Croatia and Montenegro
- G-FT79013c sparse North African and island derived offshoots that testify to limited but real south shore connectivity
Notes & context
This clade is used in the atlas as a detailed internal node to represent a specific coastal Mediterranean pattern within the broader G-M406 radiation. Its naming and exact SNP set should be understood as model based and may not correspond one to one to any single named cluster in external databases. The demographic narrative is conservative and relies on well known coastal mobility patterns, without assigning this lineage to any single historical ethnic or linguistic identity.
References & external links