The peopling of sub-Saharan Africa: The case study of Cameroon

This study analyzes the distribution of ten protein genetic polymorphisms i n eighteen populations from the most densely inhabited areas of Cameroon. T he languages spoken belong to three different Linguistic families [Afro-Asi atic (AA), Nilo-Saharan (NS) and Niger-Kordofanian (NK)]. The analysis of v ariation of allele frequencies indicates that the level of genetic interpop ulation differentiation is rather low (F-st = 0.011 +/- 0.006) but statisti cally significant (p < 0.001). This result is not unexpected because of the relatively small geographic area covered by our survey. This value is also significantly fewer than the one estimated for other groups of African pop ulations. Among the factors responsible for this, we discuss the possible r ole of gene flow There is a considerable genetic differentiation among the AA populations of north Cameroon as is to be expected because they all orig inated from the first agriculturists of the fanning "savanna complex." The Podowko and Uldeme are considerably different from all the other AA groups, probably due to the combined effect of genetic drift and isolation. In the case of the Wandala and Massa, our analyses suggest that genetic admixture with allogeneous groups (especially with the Kanuri) played an important r ole in determining their genetic differentiation from other AA speaking gro ups. The Bantu speaking populations (Bakaka, Bamileke Bassa and Ewondo, NK family, Benue Congo subfamily) settled in western and southern Cameroon are more tightly clustered than AA speaking groups. This result shows that the linguistic affinity among these four populations coincides with a substant ial genetic similarity despite their different origin. Finally, the Fulbe a re genetically distinct from all the populations that belong to their same linguistic phylum (NK), and closer to the neighboring Fall and Tupuri, east ern Adamawa speaking groups of north Cameroon. (C) 1999 Wiley-Liss, Inc.