A 4,000-year genomic history of Bantu speakers from the Congo rainforest

Bantu-speaking populations began differentiating ~4,000 years ago in sub-Saharan Africa, preceding explosive population growth by about a millennium, based on 960 genomes including ancient Iroungou individuals.

• Why it matters: The Congo rainforest was central to the Bantu Expansion, but its demographic timeline and links to later population changes remain only partially resolved.
• What they did: The study inferred past population dynamics from 960 sub-Saharan African genomes, including four newly sequenced ancient individuals from Iroungou cave and 176 present-day individuals from Gabon.
• The result: Distinct southward dispersals shaped ancestry in Gabon and elsewhere, and both Bantu speakers and Congo rainforest hunter-gatherers show a major demographic crisis ~1,500 years ago coinciding with an archaeological hiatus.