Genetic evidence supports the long-standing view that Bantu languages and technologies spread across sub-Saharan Africa through population movement rather than solely through cultural exchange among communities that remained in place. Studies of thousands of African genomes point to western Africa as the source of a population expansion, while archaeological research in Cameroon and the Congo rainforest is beginning to identify sites that may document the earliest stages of that movement.
By the 1990s, some scholars had begun questioning whether migration was responsible for spreading Bantu languages and technologies. They proposed that cultural practices might instead have spread while people stayed in the same regions, with hunter-gatherer communities passing new techniques, languages, and customs from one group to another.
Genetic methods, including those used to analyze people’s ancestry, helped clarify the debate. People share DNA with their relatives: Siblings share an average of 50 percent, cousins 12.5 percent, and more distant relatives 3.3 percent, with the percentages declining as the time since a shared ancestor increases. Statistical methods can nevertheless reveal relationships and population patterns across long periods.
In 2009, an analysis of 2,432 Africans found that Bantu-speaking peoples in western, central, and southern Africa were more closely related to one another than their geographic distances would suggest. In 2024, another team analyzed the genomes of 1,763 Africans. The researchers found that Bantu speakers in West Africa had the greatest genetic diversity, and that diversity declined with increasing distance from the region.
“This is a typical feature of population expansion from one place to another,” explains study co-author Karina Schlebusch, a geneticist at Uppsala University in Sweden.
Approximately 350 million people in sub-Saharan Africa speak one of approximately 500 Bantu languages, ranging from Swahili in eastern Africa to Xhosa spoken in southern Africa. Credit: Wikimedia Commons
Uncertain archaeological origins
Although linguistic and genetic evidence identifies the Grassfields region of western Africa, particularly Cameroon, as the homeland of the Bantu people, definitive archaeological evidence remains limited.
At Shum Raka, a rock shelter that is the Grassfields’ best-studied archaeological site, researchers have found pottery fragments dating from 7,000 to 6,000 years ago. The pottery became more abundant between 5,000 and 4,000 years ago. Early bowls and jars were decorated simply with incisions and stamps; later examples may show marks made by carvings or knitting tools rolled across wet clay. However, these finds have not yet provided conclusive evidence of Bantu ancestry.
Archaeologists have also searched for evidence in southern Cameroon’s Congo rainforest, one of the first areas reached by Bantu-speaking populations. Several times between 2010 and 2023, Alexandre Livingston-Smith, an archaeologist at the Royal Museum of Central Africa in Belgium, traveled by boat along the Congo River as part of a team led by linguist Birgit Rikkier.
In many villages, Livingston-Smith found pottery sherds dating from 2,300 to 2,000 years ago. Their style was consistent with pottery found farther west. “That would be the first potential Bantu forest settlers,” Smith said.
Source: arstechnica.com