考古学：北西アフリカにおける農耕の起源

Neolithic migrants from Iberia and Levant may have brought farming to northwest Africa, suggests an analysis of ancient genomic data published in this week’s Nature. The research helps to resolve a long-held debate over the origins of farming in this part of the world.

Around 7,400 years ago, modern humans living in northwestern Africa transitioned from a foraging to a farming-based lifestyle, but the mechanism driving this shift has been unclear. Some studies suggest that farming was adopted by these communities without any mixing with the neighbours, from whom they learned about it. Other studies hypothesize that settlers from Iberia mixed with or replaced local populations and thereby introduced farming.

To help resolve this issue, Mattias Jakobsson and colleagues sequenced the genomes of nine individuals, from three previously unsampled archaeological sites in Morocco, dating from around 7,600 and 5,700 years ago. They conclude that farming was introduced by Iberian migrants during the Early Neolithic. The newcomers brought new methods, domesticated animals and pottery traditions that were rapidly adopted by local Maghrebi groups, the authors propose. A further wave of migration then occurred during the Middle Neolithic, when travellers from the Levant introduced pastoralism. Subsequently, the three different ancestries — Maghrebi, European and Levant — all blended together. This scenario is different from other regions, such as Europe and sub-Saharan Africa, where local hunter-gatherers were replaced or assimilated by the incoming farmers.

The research points to a more complex and dynamic pattern of human migration and intermixing than was previously recognized in Morocco, say Louise Humphrey and Abdeljalil Bouzouggar in an accompanying News & Views article.