There is a general consensus that Homo sapiens originated in Africa. But there are many uncertainties and competing theories about where, when and how.

In an article published in NatureAn international research team led by McGill University and the University of California, Davis, suggests, based on modern genomic data from around the continent, that humans migrated from the same region and lived in different parts of Africa. for hundreds of thousands of years they have been intermingled and intermingled. This view contradicts some of the dominant theories about the origin of man in Africa.

Competing theories about the origin of man in Africa

One theory states that there was a single central ancestral population in Africa about 150,000 years ago from which other populations diverged. Another proposes that this central ancestral population was the result of modern humans mixing with Neanderthal-like hominids (human-like creatures), leading to a leap forward in human evolution thought to have taken place in Eurasia.

“At various times, people who accepted the classical model of a single origin of Homo sapiens suggested that humans first arose in East or South Africa,” says Brenna Henn, a population geneticist in the University’s Department of Anthropology and Genome. California, Davis. and co-author of the study.

“However, it has been difficult to reconcile these theories with archaeological evidence and limited fossil records of human habitation from places as far away as Morocco, Ethiopia, and South Africa, which suggest that Homo sapiens could have been found throughout the continent in ancient times, at least 300,000 years ago.”

Therefore, the research team took a different approach.

Available genomic data suggest otherwise.

In the first systematic test of these competing anthropological models on genetic data, the team worked back from modern genomic material of 290 individuals from four geographically and genetically diverse African groups, tracking similarities and differences between populations over the past millions of years and gaining insight. Genetic relationships, relationships and human evolution across the continent.

These groups were: Nama (Hoe-San from South Africa); Mende (from Sierra Leone); Humuses (new descendants of a group of hunter-gatherers from Ethiopia); as well as Amhara and Oromo (farmers from East Africa). The researchers also included some Eurasian genetic material to include traces of colonial invasions and African mixing.

“We used a new algorithm to quickly test hundreds of possible scenarios. Genes that oscillated between populations in different parts of the continent over hundreds of thousands of years provided a much better explanation for the genetic diversity we see today,” adds Human Genetics at McGill University. Simon Gravel, associate professor and co-author of the paper.

“We wrote this algorithm to understand how genetic disease risk varies in different populations, which led us to dive deeper into human origins. It was really interesting to combine applied and basic research in this way.”