Entwined African and Asian genetic roots of medieval peoples of the Swahili coast

AI interpretationAI-generated

Ancient DNA reveals how African and Asian roots intertwined on the medieval Swahili coast.

This study analyzed ancient DNA from 80 individuals who lived in Swahili coastal and inland towns between 1250 and 1800 AD. Many coastal individuals had over half African ancestry, mainly from female ancestors, plus a large Asian component. About 80–90% of that Asian DNA came from Persian men. Mixing began around 1000 AD, coinciding with Islam's spread. Before 1500 AD, Asian ancestry was mostly Persian-related; afterward, it became more Arabian. Later interactions further changed the ancestry of today's Swahili coast people.

• African and Asian peoples began mixing by about 1000 AD, coinciding with the large-scale adoption of Islam.
• Most Asian DNA (80–90%) came from Persian men, while African ancestry was largely from female ancestors.
• Before 1500 AD, Asian ancestry was mainly Persian-related; after 1500 AD, it shifted toward Arabian sources.

Sample interpretation

The dataset includes 82 ancient individuals from six coastal towns and one inland town, with 28 Y-chromosome haplogroups resolved. The largest site sample is I24975 (n=48), followed by I17405 (n=13) and I7943 (n=8). Y haplogroups include E-V43, J-CTS463, J-Z28162, E-FGC39408, and E-Z1788 (each n=2). Mitochondrial haplogroups are predominantly African, led by L3e3a (n=8), L0a2a2a (n=6), and L3d1a1a (n=6), reflecting the strong female African contribution.

For genealogy enthusiasts

For ancestry enthusiasts, this study shows that the Swahili coast was a true genetic crossroads: African maternal lines met Persian paternal lines around 1000 AD, later joined by Arabian influences. It highlights how trade, religion, and migration shaped one of Africa's most cosmopolitan medieval societies.