Swahili People’s African and Asian Ancestry Revealed by Ancient DNA

A new study of ancient DNA has revealed the shared African and Asian ancestry of the Swahili people that inhabit the Indian Ocean coast of east Africa.

Swahili culture

Swahili culture bloomed in the medieval period. The Swahili people embraced a unique mix of religion – Islam – and language – Kiswahili (an African Bantu language that uses Arabic loanwords) – which spread along the huge coastal region that runs from present-day Somalia to Mozambique.

Millions of people still recognize themselves as Swahili, often as a secondary identity that sits alongside family history or social status. But working out whether Swahili culture also featured a unique genetic mix has proved difficult without ancient DNA samples.

A new study that brings together data from 156 skeletal samples buried across 7 burial sites in east Africa has revealed the genetic history of the Swahili people.

One of the excavations was organized by Professor Stephanie Wynne-Jones from the University of York, who commented on the study’s findings: “DNA from the burial sites we have been studying shows African and Persian ancestry. The Persian line came from men, suggesting they were forming relationships with African women.”

From Persia to Arabia

DNA samples taken from the digs were analyzed by the Reich Laboratory at Harvard University, which determined that African and Persian people began to have children together around the year 1000. The DNA identified was from their descendants, who still made up a substantial proportion of the area’s population 500 years later.

The researchers were able to trace the path of historical trade routes through their analysis. While early samples showed a large proportion of DNA coming from Asian sources, of which 80–90% were Persian men, DNA sources became increasingly Arabian after the year 1500 as interactions between this region and Africa increased.

Professor Jeffrey Fleisher, from Rice University, and one co-author of the study, said: “Oral histories of the Swahili who live in East Africa have often told us of their Persian ancestry, which for many years researchers have believed was a way for the Swahili people to use their Persian and other foreign trade links for political gain, but our data reveals that these oral records were correct, showing how important it is to take oral traditions seriously.”

Wynne-Jones said that the findings suggested that the way academia thinks about Swahili culture needs to be less “binary”: “It shows that people were moving and establishing deep connections and families in the Indian Ocean region, and that Persian migrants would have been part of the cosmopolitan world created by coastal African societies.”

Reference: Brielle ES, Fleisher J, Wynne-Jones S et al. Entwined African and Asian genetic roots of medieval peoples of the Swahili coast. Nature. 2023. doi: 10.1038/s41586-023-05754-w.

This article is a rework of a press release issued by the University of York. Material has been edited for length and content.