Overview
G2a2a2 is used in this atlas as a schematic label for those M286 derived lineages that show a strong western Mediterranean focus, especially in Sardinia, Corsica and parts of coastal Italy and the central Mediterranean. High resolution studies of island and coastal populations reveal that some G2a2a lineages underwent local founder events and subsequent drift, producing clusters that are phylogenetically nested within the broader M286 tree but geographically concentrated in these regions. In research trees these clades are often represented by markers such as Y84562, FGC58133 and Z43083.
Demographically, G2a2a2 appears to trace a history distinct from the classic P303 derived farmer lineages that dominate continental European G2a. Instead it reflects a mixture of early Neolithic maritime diffusion, insular isolation and later historical movements around the Tyrrhenian and central Mediterranean basins. The signal is strongest on islands like Sardinia and southern Corsica, where M286 derived lineages reach higher frequencies than in most mainland European populations and form part of a broader pattern of genetic continuity from early farmers.
Geographic distribution
Population genetic surveys in Sardinia, Corsica and nearby coastal regions report M286 derived lineages at noticeably higher levels than in most of Europe, especially in rural or historically isolated communities. Detailed Y chromosome work points to multiple G2a2a1a2 L91 and related lineages that cluster in these islands and may have roots in early Neolithic or Chalcolithic settlers, later shaped by island specific drift. Beyond these islands, scattered G M286 lineages have been found along the Italian coasts, in parts of the Balkans and in North African littoral populations, consistent with repeated maritime contacts across the central Mediterranean.
In contrast, M286 is rare in central and northern Europe and tends to appear as isolated cases within otherwise P303 dominated G2a profiles. This reinforces the interpretation that the main demographic center of gravity for the G2a2a2 type clusters lies in the western and central Mediterranean rather than in the continental Neolithic corridor.
Ancient DNA
- Ancient DNA surveys of Neolithic and later Mediterranean sites have identified G lineages that in some cases carry downstream markers compatible with M286 related structure, including island and coastal contexts in Sardinia and southern Corsica.
- A synthesis of Mediterranean aDNA and modern Y chromosome variation highlights G-M286 alongside G-P15 and G-U8 as part of the set of Near Eastern derived lineages contributing to the genetic profile of southern European coastal populations.
- As coverage improves, more insular ancient genomes from the Tyrrhenian region are expected to clarify how much of the present day G2a2a2 like diversity descends from early farmers versus later Bronze Age and classical era movements.
Phylogeny & subclades
Within the G2a2a tree, the markers Y84562, FGC58133 and Z43083 define several closely allied branches that in high coverage trees form a western leaning half of the M286 radiation. G2a2a2 in this atlas groups these branches into a single conceptual clade in order to highlight their shared geographic focus and to avoid overwhelming users with numerous closely spaced twig level nodes. Sister branches within G2a2a are grouped under G2a2a1 and represent more Near Eastern centered M286 lineages, giving a simple two way split that captures the main demographic contrast within the clade.
- G2a2a2* basal western Mediterranean M286 lineages
- Sardinia Corsica centered M286 microclades
- Italian and central Mediterranean founder clusters associated with coastal communities
Notes & context
Like G2a2a1, G2a2a2 is an atlas oriented label rather than a single canonical research SNP name. It compresses several closely related M286 derived branches that show a strong western Mediterranean profile into one easier to interpret node. This makes it possible to discuss the role of M286 in insular Mediterranean demography without forcing readers to track many separate low level labels. Under the hood, these branches correspond to specific YFull and ISOGG nodes defined by combinations of markers such as Y84562, FGC58133 and Z43083.
References & external links