V23

Origins and Evolution

mtDNA haplogroup V23 is a downstream lineage within haplogroup V, deriving from the V2 branch that is associated with post-Last Glacial Maximum (LGM) re-expansions from southwestern European refugia. Given the parent clade V2 is dated to roughly 12 kya in western Europe, V23 is plausibly a slightly younger subclade that formed in the early Holocene (around 9 kya). Its emergence fits the pattern of postglacial diversification of maternal lineages as small founder groups recolonized temperate Europe and later experienced demographic processes (drift, local founder effects, and low-frequency dispersals).

Subclades (if applicable)

At present, V23 appears to be a relatively narrow lineage with few reported deep sub-branches in the published literature and public phylogenies; most available evidence treats V23 as a terminal or near-terminal clade within V2. Where present, internal diversity is low, which is consistent with a recent origin relative to major V subclades and with limited population size in the groups that carried it. Future high-resolution whole-mtDNA sequencing and sampling in undersurveyed regions (Iberia, Sardinia, the Caucasus) could reveal further substructure.

Geographical Distribution

The observed distribution of V23 is patchy and low-frequency, reflecting its status as a rare subclade of V2. Modern and limited ancient occurrences align with areas known to carry V2 derivatives:

• Western Iberia (Spain, Portugal) and adjacent southwestern France — consistent with refugial and postglacial recolonization pathways.
• Mediterranean islands (notably Sardinia and other island populations) where founder effects and long-term isolation amplify rare maternal lineages.
• Northern Europe (scattered occurrences, including Saami and other indigenous northern groups) where V lineages were carried northward during postglacial expansions and later demographic events.
• Caucasus and adjacent Near East pockets — low-frequency occurrences likely reflecting ancient gene flow or later mobility between southern Europe and the Caucasus.
• North African Berber groups (sporadic) — consistent with known low-level west Mediterranean mtDNA exchanges.

Overall, frequencies are low in all regions; occurrences likely reflect ancient postglacial dispersal routes, island founder events, and subsequent drift rather than large-scale demographic expansions.

Historical and Cultural Significance

Because V23 is rare, its direct association with specific archaeological cultures is mostly inferential. The broader V2/V pattern ties it to post-LGM hunter-gatherer re-expansions from southwestern refugia, and these maternal lineages later became incorporated into Neolithic and later cultural horizons. Reasonable cultural associations include:

• Mesolithic hunter-gatherer contexts: V-lineages are often detected among European Mesolithic and early Holocene remains, reflecting the postglacial recolonization phase.
• Early Neolithic/Cardial-related groups: Low-frequency transmission into farming populations through admixture is plausible, particularly along Mediterranean coasts.
• Bell Beaker and later Bronze Age contexts: Sporadic occurrences in Bell Beaker-associated remains or in later Bronze Age samples are possible but would represent assimilation rather than primary lineage carriers for these cultures.

In sum, V23 most plausibly represents a maternal legacy of pre-Neolithic and early Holocene populations that was subsequently absorbed into a variety of cultural groups as Europe experienced the Neolithic transition and later movements.

Conclusion

mtDNA V23 is a narrowly distributed, low-frequency descendant of V2 whose pattern fits a southwestern European origin and early Holocene formation. Its restricted diversity and patchy presence in Iberia, Mediterranean islands, parts of northern Europe, the Caucasus and North Africa reflect founder events, drift, and localized dispersals rather than broad population replacements. Additional whole-mitogenome sequencing and expanded ancient DNA sampling would clarify its exact phylogenetic placement, age, and historical migrations.