Overview
E-Z1723 is a significant downstream branch of E-Z1725 that represents an important layer of paternal diversity within West Africa. Emerging during the middle Holocene, E-Z1723 developed during a transformative era that saw increased settlement density, early domestication practices and the formation of proto–Niger–Congo communities. Although smaller in overall frequency compared to the massive E-Z1724 sub-branch, E-Z1723 is notable for its strong regional structuring, especially within the Nigeria–Cameroon highlands and surrounding forest–savanna transition zones. Its time to most recent common ancestor aligns with societal changes driven by intensified agriculture, regional trade routes and the earliest phases of metallurgical production in West Africa.
Geographic distribution
The distribution of E-Z1723 is centered primarily in Nigeria and Cameroon, especially among groups occupying upland and transitional ecological zones. It is observed in moderate frequencies among Igbo, Yoruba, Bantoid-speaking communities of western Cameroon, and several ethnolinguistic groups in the Benue–Cross River region. Its presence decreases as one moves west toward Ghana and east toward Central Africa, though traces of downstream branches can be found in Gabon and the western Congo Basin through secondary migrations. In African diaspora populations, E-Z1723 appears occasionally but is less common than E-Z1724 or E-Z2336 due to its more localized historical distribution.
Ancient DNA
- Ancient DNA assignments for West African Holocene populations remain scarce, but chronological modelling places E-Z1723 diversification in a period contemporaneous with the establishment of early settled communities along the forest–savanna frontier.
- Its coalescence around 2,300–3,000 years ago overlaps with archaeological horizons characterized by early iron metallurgy, increasing village complexity and intensified interregional exchange networks.
- Phylogenetic patterns imply that E-Z1723 lineages subdivided within a relatively contained geographic area before undergoing moderate secondary expansions.
Phylogeny & subclades
E-Z1723 forms a moderately sized phylogenetic subtree under E-Z1725, with several downstream branches showing clear micro-regional differentiation. The lineage contains both older basal splits and younger star-like expansions that reflect periods of stable local population growth. Many subclades exhibit high clustering within specific ethnic groups, indicating strong community-level continuity and limited paternal gene flow across certain cultural boundaries. The overall phylogeny suggests that E-Z1723 expanded largely through incremental, localized demographic processes rather than large-scale migrations.
- E-Z1723* (rare basal forms)
- Region-specific microclades concentrated in Cameroon highlands
- Branches found primarily in Nigerian forest–savanna transition groups
- Occasional downstream clades appearing in Central African populations
Notes & context
E-Z1723 provides an important window into the demographic and cultural landscape of pre-Bantu West Africa. Unlike some E-U175 lineages that underwent continent-spanning expansions, E-Z1723 represents a more geographically defined paternal layer that persisted through several millennia. Its strong regional signatures make it valuable for fine-scale historical genetic analyses and for tracing lineage continuity among communities in Nigeria and Cameroon. While not as globally dispersed as some sister clades, its internal diversity contributes significantly to understanding the formation of early agricultural societies in West Africa.
References & external links