Genetic Structure of the Western and Eastern African Sahel/Savannah Belt and the Role of Nomadic Pastoralists as Inferred from the Variation of D-loop mtDNA sequences

Authors

Martina Čížková, Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech RepublicFollow
Pavel Munclinger, Department of Zoology, Faculty of Science, Charles University, Prague, Czech RepublicFollow
Mame Yoro Diallo, Département d’Histoire, Faculté des Lettres et Sciences humaines, Université Cheikh Anta Diop de Dakar, SenegalFollow
Iva Kulichová, Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech RepublicFollow
Mohammed Gassim Mokhtar, Arabic Department, Faculty of Arts, University of Kordofan, Al-Ubayyid, SudanFollow
Alioune Deme, Département d’Histoire, Faculté des Lettres et Sciences humaines, Université Cheikh Anta Diop de Dakar, SenegalFollow
Luísa Pereira, a) Institute of Molecular Pathology and Immunology at the University of Porto b) Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal c) Faculdade de Medicina da Universidade do Porto, Porto, PortugalFollow
Viktor Černý, Institute of Archaeology of the Academy of Sciences of the Czech Republic, Czech RepublicFollow

Document Type

Article

Anticipated Volume

89

Anticipated Issue

4

Abstract

The objective of this study is to provide deeper knowledge of the maternal genetic structure and demographic history of the human population of the dynamic Sahel/Savannah belt, the extensive region lying between the Sahara and tropical rainforests, spanning from the Atlantic Ocean to the Red Sea coast. The study aims to confirm or disconfirm archaeological and linguistic data indicating that the region’s populations underwent diversification as a result of the spread of agropastoral food-producing subsistence lifestyles, over time dividing the region into separate areas of nomadic pastoralism on the one hand, and sedentary farming on the other. In order to perform both descriptive and coalescence analyses from the Sahel/Savannah belt’s entire region, including western and eastern rather than just central populations studied previously, we generated a new mtDNA dataset not only having almost 2,000 samples (875 of which were newly collected); but also encompassing whole mtDNA D-loop segment rather than only the previously studied HVS-1. While comparing our analyses with previous results from the Lake Chad Basin (central Sahel/Savannah Belt) we revealed similar intra-population diversity measures (i.e., lower values of measures in pastoralists than farmers). However, the new dataset pointed to significant differences in mating strategies between western as compared to the eastern pastoralists: our results suggest higher gene flow between the Arabic pastoralists and neighboring farmers in the eastern than between the Fulani pastoralists and their sedentary neighbors in the western part of the Sahel/Savannah Belt. The findings are discussed in the light of archaeological and linguistic data, allowing us to postulate that the genetic differentiation of Fulani pastoralists from the common western African agropastoral gene pool occurred at around the same time as the arrival of the Arabic pastoralists to eastern Africa. However, it seems that while the process of divergence of the Fulani pastoralists in the west was accompanied by a loss of Fulani females to other populations, the Arab pastoralists’ immigration to the Sahel/Savannah belt conversely resulted in some gain of local females into this Arab population.

Recommended Citation

Čížková, Martina; Munclinger, Pavel; Diallo, Mame Yoro; Kulichová, Iva; Mokhtar, Mohammed Gassim; Deme, Alioune; Pereira, Luísa; and Černý, Viktor, "Genetic Structure of the Western and Eastern African Sahel/Savannah Belt and the Role of Nomadic Pastoralists as Inferred from the Variation of D-loop mtDNA sequences" (2018). Human Biology Open Access Pre-Prints. 129.
https://digitalcommons.wayne.edu/humbiol_preprints/129