Genetic history of North Africa

The genetic history of North Africa encompasses the genetic history of the people of North Africa. The most important source of gene flow to North Africa from the Neolithic Era onwards was from Western Asia, while the Sahara desert to the south and the Mediterranean Sea to the north were also important barriers to gene flow from sub-Saharan Africa and parts of Europe in prehistory. However, North Africa is connected to Western Asia via the Isthmus of Suez and the Sinai peninsula, while at the Straits of Gibraltar, North Africa and Europe are separated by only 15 km (9 mi), similarly Malta, Sicily, Canary Islands, Lampedusa and Crete are close to the coasts of North Africa.

North Africa is a genetically heterogenous and diverse region, and is characterized by its diverse ethnic groups, the main ones being Arabs, Berbers and Copts (in Egypt).^[1] North African populations show a complex and heterogeneous genetic structure that has been described as an amalgam of at least four different ancestral components from the Middle East, sub-Saharan Africa, Europe and also indigenous North Africans who are distinct from these three.^[2] Although North Africa has experienced gene flows from the surrounding regions, it has also experienced long periods of genetic isolation.^[3] Some genetic studies have been criticised for their interpretation and categorisation of African genetic data.^{[4][5][6][7][8][9][10]}

Current scientific debate is concerned with determining the relative contributions of different periods of gene flow to the current gene pool of North Africans. Anatomically modern humans are known to have been present in North Africa during the Middle Paleolithic (300,000 years ago), as attested by the by Jebel Irhoud 1.^[11] Without morphological discontinuity, the Aterian was succeeded by the Iberomaurusian industry, whose lithic assemblages bore close relations with the Cro-Magnon cultures of Europe and Western Asia, rather than to the contemporary cultures of sub-Saharan Africa or the Horn of Africa.^[12] The Iberomaurusian industry was succeeded by the heavily West Asian influenced Capsian industry (8000 BC to 2700 BC) in the eastern part of North Africa (Egypt, Libya, Tunisia, eastern Algeria, Malta).

DNA studies of Iberomaurusian peoples at Taforalt, Morocco dating to around 15,000 years ago have found them to have a distinctive Maghrebi ancestry unrelated to European Cro-Magnon groups, formed from a mixture of Near Eastern and African ancestry, which is still found as a part of the genome of modern Northwest Africans.^[13] Later during the Neolithic, from around 7,500 years ago onwards, there was a migration into Northwest Africa of European Neolithic Farmers from the Iberian Peninsula (who had originated in Anatolia several thousand years prior), as well as pastoralists from the Levant, both of whom also significantly contributed to the ancestry of modern Northwest Africans.^[14]

After migrating to North Africa in the 1st millennium BC, Semitic Phoenician settlers from the cities of Tyre and Sidon in the Levant established over 300 coastal colonies throughout the region (as well as the Iberian Peninsula, Sicily, Malta, Sardinia etc) and built a powerful empire that controlled most of the region from the 8th century BC until the middle of the 2nd century BC.^[15] A recent study has found that nearly 40% of modern Maghrebi males carry the paternal marker E-M81, which is thought to have expanded from the Levant into North Africa.^[16]

In the 7th century AD, the region was conquered by Muslim Umayyad Arabs from the Arabian Peninsula. Under the relatively brief Arab-Umayyad conquest and the later arrival of nomadic Bedouin, Levantine Arabs and Arabized peoples from the Near East in Western Asia and the arrival of some Sephardi Jews and Iberian Muslims fleeing the Spanish Catholic Reconquista of Iberia, a partial population mix or fusion have taken place and have resulted in some genetic diversity among some North Africans.^[17] The Trans-Saharan slave trade has resulted in increased levels of Sub-Saharan African ancestry in North Africans in Medieval and modern times relative to earlier periods.^[18]

A recent study from 2017 suggested that the Arab migrations to the Maghreb was mainly a demographic process that heavily implied gene flow and remodeled the genetic structure of the Maghreb, rather than a mere cultural replacement as claimed by older studies.^[19] Another study found out that the majority of J-M267 (Eu10) chromosomes in the Maghreb are due to the recent gene flow caused by the Arab migrations to the Maghreb in the first millennium CE as both southern Qahtanite and northern Adnanite Arabs added to the heterogenous Maghrebi ethnic melting pot. The Eu10 chromosome pool in the Maghreb is derived not only from early Neolithic dispersions but to a much greater extent from recent expansions of Arab tribes from the Arabian Peninsula.^[20] While acknowledging the genetic impact of Arabization of Northwest Africa during the Islamic period, other authors have suggested that earlier migration processes, such as the arrival of Neolithic famers from Europe, were ultimately more genetically impactful.^[18]