Science | The Mysteries of the Bantu Expansion

Between a third and a half of the population of sub-Saharan Africa speaks a Bantu language. For a long time, it was believed that this linguistic success was akin to the lure of Latin in the past – and English now. Genetic studies show that it is in fact a migration without common measure in history, which for 2000 years has caused the disappearance of dozens of hunter-gatherer societies.

Mathieu Perreault
The Press

Bantu expansion

4,000 years ago, farmers on the border between Cameroon and Nigeria began to migrate south-east along the coast, then east through the equatorial forest. 2000 years ago, they arrived in Kenya, then in southern Africa. A third wave of migration – south and east – also took place between the XI^and and XIV^and centuries, just before the arrival of the first Europeans.

“There are more than 500 Bantu languages,” says Cymone Fourshey, a historian specializing in east-central Africa at Brucknell University in Pennsylvania. “We talked for a long time about Bantu expansion, but we weren’t sure if there were really population movements. But we now know with genetics that there are close links between populations living in central, eastern and southern Africa. »

Bantu languages ​​are also at the origin of very frequent intonations among African-Americans, according to Akinwumi Ogundiran, anthropologist at the University of North Carolina at Charlotte. He has published several studies on the cultural links between pre-colonial and present-day Africa.

Bantu expansion wiped out, either through assimilation or displacement, dozens of hunter-gatherer populations over the centuries. “There do not appear to have been any wars related to the Bantu expansion,” says M^me Fourshey. I personally believe that there has been a crossbreeding with the local populations on the cultural level, but the dominant idea in anthropology reflects the linguistic uniformity that we observe. »

Justinian’s Plague

The idea of ​​a final wave of Bantu expansion, just before the arrival of Europeans, was until recently controversial because it may resemble the “empty land” myth propagated by English settlers in South Africa. to justify their appropriation of the territory.

Last year, a study published in Science Advances demonstrated that there was a demographic collapse between the IV^and and VII^and centuries in the Congo. “We think it may be linked to the plague of Justinian which weakened the Byzantine Empire”, explains Étienne Patin, geneticist at the Institut Pasteur. He is co-author of the study Science having definitively established genetic links between the various Bantu speakers of the continent.

In southern Africa, there is a gap of about 1,000 years in the typical archaeological traces of Bantu-speaking populations, who generally introduced agriculture to the regions where they arrived, according to Koen Bostoen. This linguist from the University of Ghent, Belgium, is one of the most prolific authors in the study of the Bantus.

“But it’s not clear if it’s a lack of excavation effort, or if there’s been a population collapse like in central Africa. Personally, I think there has been a continuous Bantu presence for 2000 years in southern Africa. In eastern Africa, the Bantu have, 1000 years ago, invested ecological niches where they were previously absent, such as the highlands, notes M^me Fourshey.

A Portuguese Catechism

The idea of ​​a Bantu civilization was born during the first Portuguese explorations in the XVI^and century, when interpreters recruited from the west coast of Africa were able to communicate with people from the east coast. A Bantu Jesuit catechism from the early 17th century^and century is also part of the collection of the British Library in London.

“But Eastern Bantu speakers, for example, can generally understand each other, like a Frenchman and an Italian, sometimes even like an Italian and a Spaniard,” explains Ms.^me Grollmund.

Belgians are over-represented among specialists in the expansion of Bantu, due to the colonization of the Congo. “The English and the French had a lot of civilizations to study, but we only had the Congo, so we bet everything on the Bantu,” explains Pierre de Maret, an anthropologist emeritus at the Free University of Brussels, who was among the authors of the study Science Advances by 2021. About half of graduate students at Bantu institutes in Belgium are African, but often when they return to Africa, they take up senior government positions, according to Mr. de Maret.

Like the Austronesians

The Bantu expansion is unique in human history, according to Mr. Patin. “The only possible comparison is the Austronesian migration from Taiwan 5,000 years ago. But there is much more linguistic and cultural diversity among the different populations resulting from the Austronesian migration. This wave of migration in the Pacific and the Indian Ocean reached Madagascar 1700 years ago and Easter Island 1300 years ago.

The Kingdom of Kongo

One of the most important states in the Bantu-speaking sphere is the Kingdom of Kongo, which appeared in the XIV^and century in Angola. “It was the first African Catholic kingdom, if we exclude Ethiopia,” explains Mr. de Maret. There have been several Bantu states for 1000 years, some the size of France. But there was no general political ensemble. Another important kingdom is that of Zimbabwe, which flourished between the XI^and and XIV^and centuries.

Going forward, one of the important questions to investigate is the reason for the lack of Bantu westward migration, according to de Maret. The “proto-Bantu” was born on the border between Cameroon and Nigeria, but Nigeria is not Bantu. Another priority is to do other genetic analyses, such as those that led to the publication of Science of 2017, this time with other Bantu-speaking populations, believes Isabelle Ribot, a bioanthropologist from the University of Montreal who has worked on proto-Bantu prehistoric sites in northwestern Cameroon.