Overview
E-Z3604 is one of the principal downstream branches of E-U209 and serves as a key signature of major Bantu-associated demographic expansions across West Central and Central Africa. Its formation period corresponds to a stage in the late Holocene when mobile agriculturalists were progressively expanding into the tropical forest zones, adapting to new ecological niches and establishing the earliest Iron Age cultural complexes. E-Z3604 is highly diverse internally and marks a lineage that underwent multiple phases of growth, likely aligned with both early dispersals from the Nigeria–Cameroon region and later expansions deeper into the Congo Basin. Its wide spatial distribution and strong subclade differentiation make it one of the most diagnostic haplogroups for tracking early Bantu movement and settlement patterns.
Geographic distribution
E-Z3604 exhibits a broad geographic footprint encompassing Cameroon, Gabon, the Republic of the Congo, Equatorial Guinea and northern Angola. It is widely found across the DR Congo, particularly along the Congo River and its tributary systems, including the Kasai, Sangha and Ubangi basins. Eastern branches extend into Uganda, Rwanda, Burundi and western Kenya, marking the spread from the Congo Basin toward the Great Lakes region. Southern subclades appear in Zambia and northern Mozambique. The lineage is also represented in African-descendant populations throughout the Americas, reflecting historical population movements from coastal Central Africa.
Ancient DNA
- Although direct ancient-DNA evidence remains unavailable for E-Z3604 due to poor preservation conditions in tropical regions, indirect indicators strongly associate the lineage with Iron Age demographic expansions.
- Archaeological cultures characterized by pottery, iron smelting and early agriculture in Cameroon, Gabon and the western Congo Basin show strong parallels with the modern spatial distribution of Z3604 clades.
- The timeline of E-Z3604 diversification coincides with the development of complex trade and interaction networks across the equatorial forest belt.
Phylogeny & subclades
The phylogenetic structure of E-Z3604 is deep and comprises multiple regional radiations. A western cluster is centered around Cameroon and Gabon, marking some of the earliest waves of population movement originating from the U209 nucleus. A major central cluster stretches across the DR Congo, mirroring demographic flows along river corridors penetrating the rainforest interior. Eastern clusters appear in the Great Lakes region, while southern branches extend toward Angola and Zambia. The internal diversity suggests a long period of gradual expansion with several pulses of increased population growth, likely tied to ecological changes, agricultural developments and evolving cultural systems.
- E-Z3604* basal
- West-Cameroon/Gabon cluster
- Congo Basin–riverine macrocluster
- Great Lakes expansion branch
- Southern Central African extension
Notes & context
E-Z3604 is regarded as a major lineage for reconstructing the central phases of Bantu-associated population expansions. Due to limited sampling across the Congo Basin and surrounding regions, its full substructure has yet to be uncovered. Continued high-coverage sequencing from understudied populations is expected to significantly expand the known tree and refine tmrca estimates for its major clusters. As a widely dispersed and internally diverse lineage, E-Z3604 is essential for understanding demographic transitions across tropical Africa during the last 3,000 years.
References & external links