Newly-released data based on decades of research into ancient DNA samples has shed new light on the once-murky origins of the Swahili people.
The peer-reviewed study from the University of South Florida (USF) published in Nature explains that the Swahili people are an ethnic and cultural group from the east African coast, characterized by their common language of Kiswahili and their shared predominant religion of Islam.
According to the University of Pennsylvania's East Africa Living Encyclopedia (EALE) archeological evidence suggests the Swahili have inhabited eastern Africa since the 1st century CE. There is evidence of the Swahili having engaged in trade via the Indian Ocean as early as the 7th century, and the presence of Islam has been traced back to the 8th century CE, per the USF study.
Today, millions of east Africans living on the coast identify as Swahili, although according to the study in Nature, this identity is often secondary to their town of origin or traditional social status.
Balancing Africanness with the Persian connection
Until recently, however, a definite throughline from medieval Swahili culture to the Swahili people of today eluded scientists and the general public.
“This research has been my life’s work – this journey to recover the past of the Swahili and restore them to rightful citizenship,” said Chapurukha Kusimba, author of the study and USF professor of anthropology. “These findings bring out the African contributions, and indeed, the Africanness of the Swahili, without marginalizing the Persian and Indian connection.”
The Persian and Indian connection of which he speaks refers to the idea that the Shirazi people of Iran settled along the Swahili Coast and were responsible for the spread of Islam.
"Accounts of Shirazi roots were central to the narrative constructed by mid-20th century colonialist archaeologists," the study explains, "who interpreted second-millennium coastal eastern African sites as built by Persian and Arab settlers, and focused on connections with the broader Indian Ocean world."
Archaeologists, however, are not solely responsible for what some now call the "Shirazi myth." Subgroups of Swahili people have claimed to be of Persian descent for centuries, as such ancestry could be a mark of high social status. However, as is explained in Early Swahili History Reconsidered, an article that appeared in a 2000 edition of The International Journal of African Historical Studies, the reality of Swahili religion and culture are not compatible with Persian ancestry. Among other things, the Swahili language is decidedly native to Africa (not connected to the Iranian language family), the cultural practices attributed to the Shirazi can also be traced to other African peoples and the Swahili have historically practiced Sunni Islam, rather than Shia Islam which is practiced by Iranians.
“Our results do not provide simple validation for the narratives previously advanced in archaeological, historical or political circles,” Kusimba said. “Instead, they contradict and complicate those narratives.”
A mother's influence
Kusimba and his fellow researchers took a careful scientific approach to solve the puzzle of the Swahili people's origins. They generated ancient DNA samples from the skeletal remains of 80 individuals across six different coastal and island towns. The people studied lived between 1250 and 1800 CE.
Researchers compared the ancient DNA to that of present-day coastal Swahili speakers. They also compared the DNA data with anthropological statistics and information they could glean from extant texts.
They found evidence of people of Persian and African ancestry intermingling beginning around 1000 CE, which is consistent with extant chronicles of the region. This timing also matches the archeological evidence from the time, which indicates widespread cultural transformation and the adoption of Islam.
The study highlights the fact that, per the DNA data, it was predominantly male Persians procreating with female Africans. Critically, however, the archeological and anthropological evidence indicates that children adopted language and culture from their mothers, thus preserving their native African language and traditions. Notably, Arabic loanwords are the single largest non-local element in Kiswahili, and Persian loanwords make up approximately 3% of the vocabulary as well.
“There is always tension between anthropology and genetics surrounding the interpretation of the material,” Kusimba said. “But working with my colleagues from Harvard, Rice University and University of York to ensure that the anthropological explanation accommodated the genetic data analysis without being simplistic has been so rewarding.”