Around 7,400 years ago, the way of life in northwest Africa changed completely. Humans went from gathering and hunting to survive to producing their own food through agriculture. For years it has been debated what caused this step, a momentous evolution in the history of humanity.
Some researchers were betting on the idea that it was Neolithic farmers from Europe who brought the new way of life to North Africa. Others, however, argued that it was the African hunter-gatherers themselves who adopted agricultural practices.
Now, a genetic analysis carried out on ancient human remains found in Morocco has revealed that the food crop was introduced by immigrants from the Iberian Peninsula and the Levant and later adopted by local groups, according to the team of experts from Sweden, Spain and Morocco in an article published in the journal Nature.
“We found a remarkable population continuity in northwest Africa up to 7,500 years ago. There was a group of local foragers that had been living in isolation for at least 8,000 years, or perhaps much longer,” says Professor Mattias Jakobsson of Uppsala University, who led the study. And then something happened.
After being isolated for so long, northwest Africa received two large waves of migration in a period of just 1,000 years. One arrived following the northern Mediterranean coast, and the other followed the sea coast to the south.
“There is a foreign ancestry related to the first European farmers in the Maghreb in the remains from about 7,500 years ago,” says Dr. Luciana Simoes, indicating that it was these immigrants from Europe who introduced this new lifestyle.
“Inspired by their new neighbors, within a few hundred years, the local foragers began to change their way of life and turned to agriculture. The two groups lived together for at least another century,” adds Dr. Cristina Valdiosera, from the University of Burgos.
About 6,300 years ago, a new genetic ancestry appeared in human remains, probably as a consequence of the arrival of immigrants from the Levant at the same time that pastoralism was spreading through the region. The three ancestries merged during the Late Neolithic.
“This phenomenon has not been seen anywhere else in the world,” says Dr. Torsten Günther. “The genomic data generated in this study confirm what ceramic decoration already pointed out: a unidirectional diffusion from the Iberian coast to the Tingitana peninsula, around 7,500 years ago,” explains Dr. Rafael MartÃnez Sánches, from the University of Córdoba.
The researchers sequenced the genomes of nine individuals from four different archaeological sites spanning from the Epipaleolithic to the Middle Neolithic. “Filling in the key chronological gaps in the Maghreb was crucial to better understand how different subsistence strategies were acquired in the region,” concludes Dr Youssef Bokbot of Morocco’s L’Institut National des Sciences de l’Archéologie et du Patrimoine.
