The Ancestors Of Northwest Africans

The genetic forebears of Northwest Africans are Iberian and Levantine first farmers, and earlier European and Middle Eastern hunter-gatherers. Sub-Saharan introgression eventually came later, not sooner than the metal ages.

In northwestern Africa, lifestyle transitioned from foraging to food production around 7,400 years ago but what sparked that change remains unclear. Archaeological data support conflicting views: (1) that migrant European Neolithic farmers brought the new way of life to North Africa or (2) that local hunter-gatherers adopted technological innovations. The latter view is also supported by archaeogenetic data. 

Here we fill key chronological and archaeogenetic gaps for the Maghreb, from Epipalaeolithic to Middle Neolithic, by sequencing the genomes of nine individuals (to between 45.8- and 0.2-fold genome coverage). 

Notably, we trace 8,000 years of population continuity and isolation from the Upper Palaeolithic, via the Epipaleolithic, to some Maghrebi Neolithic farming groups. However, remains from the earliest Neolithic contexts showed mostly European Neolithic ancestry. We suggest that farming was introduced by European migrants and was then rapidly adopted by local groups. During the Middle Neolithic a new ancestry from the Levant appears in the Maghreb, coinciding with the arrival of pastoralism in the region, and all three ancestries blend together during the Late Neolithic. Our results show ancestry shifts in the Neolithization of northwestern Africa that probably mirrored a heterogeneous economic and cultural landscape, in a more multifaceted process than observed in other regions.

Luciana G. Simões, et al., "Northwest African Neolithic initiated by migrants from Iberia and Levant" Nature (June 7, 2023) (open access). Razib Khan summarizes the results as follows:

Basically, the ancestors of the Berbers seem to be a mix of indigenous people whose ancestors were Eurasians who arrived during the Last Glacial Maximum, Early European Farmers (Anatolian) and Levantine farmers/pastoralists, in that order of timing, but reverse order of contribution. To me it is interesting that there is no Sub-Saharan African ancestry in the earliest populations, indicating that the Sahara was really not habitable for humans for much of the Ice Age.