Mitochondrial DNA divergence
Among the 213 individuals sampled, 49 different haplotypes were detected. The haplotype network is complex (Fig. 5) and composed of five main haplogroups that correspond to i) Blue Nile basin (including the Didessa R.), ii) Genale R. (Indian Ocean basin), iii) Gojeb R. (Omo-Turkana basin), iv) Birbir R. (White Nile basin), and v) Sore R. (White Nile basin) (Fig. 5). A few samples from the Didessa R. and Birbir R. were close to central putative haplotypes interconnecting the analyzed haplogroups. Genetic p -distances between the geographic basins varied from 0.009±0.003 to 0.031±0.005 (Supplementary Table S9). No haplotype sorting between sympatric generalized and thick-lipped ecomorphs within each basin was revealed (Fig. 5).