Genetic evidence confirms a western African origin for the Bantu expansion across sub‑Saharan Africa

By the early 1990s, some scholars began to question whether Bantu languages and material culture spread through large‑scale migration or through more gradual cultural exchange. Could these innovations have been adopted by local hunter‑gatherer groups without massive population movements?

Advances in genetic analysis helped to settle this debate. DNA is shared in predictable amounts with relatives—about 50% with full siblings, 12.5% with first cousins, 3.3% with second cousins, and so on. Although these fractions become tiny as one goes back further in time, sophisticated statistical techniques can still detect underlying population patterns.

Indeed, a 2009 study of 2,432 Africans revealed that Bantu‑speaking peoples from western, central and southern regions are far more genetically similar than geography alone would predict. In 2024, a larger team sequenced genomes from 1,763 Africans and found that genetic diversity peaks among western Bantu speakers, with diversity dropping off as distance from that region increases. “This is a classic signature of a population expanding outward from a source,” explains coauthor Carina Schlebusch, a geneticist at Uppsala University in Sweden.

Mysterious roots

Although linguistic and genetic data both point to western Africa—particularly the Grassfields region of Cameroon—as the Bantu homeland, definitive archaeological proof remains scarce. At the best‑studied site in the Grassfields, the Shum Laka rock shelter, pottery fragments date to 7,000‑6,000 years ago and become common by 5,000‑4,000 years ago. The earliest vessels bear simple incisions and stamps; later examples show marks from carved or braided tools rolled over wet clay. These findings are suggestive but not conclusive evidence of early Bantu ancestors.

South of Cameroon, in the Congo rainforest—one of the first destinations for Bantu speakers—archaeologist Alexandre Livingstone Smith of Belgium’s Royal Museum for Central Africa conducted boat surveys along the Congo River between 2010 and 2023 as part of a team led by linguist Birgit Ricquier. In several villages Smith uncovered pottery shards that match the western style and date to roughly 2,300‑2,000 years ago. “That would be the potential first Bantu settlers of the forest,” he says.

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