A mitochondrial cytochrome B phylogeny of the Alectoris partridges.

Nucleotide sequences of the entire mitochondrial cytochrome b gene were used to study patterns of molecular evolution and phylogenetic relationships of the seven extant species of Alectoris partridges. Among Alectoris, transition substitutions were not saturated and 80% of nucleotide variability and informative parsimony substitutions were at third positions of codons. Transitions contributed most of interspecific genetic divergence. Phylogenetic analyses of the mtDNA sequences supported the existance of three main evolutionary events and were concordant with relationships reconstructed using allozyme data. The first splitting separated north African A. barbara and Arabian A. melanocephala from the other Alectoris. Following, western A. rufa and A. graeca separated from eastern species. Recent speciation events originated A. chukar, A magna, and A. philbyi. A tentative calibration of rates of nucleotide evolution suggests that Alectoris speciated between ca. 6 and 2 million years ago. Consistent resolution of relationships among recent species of Alectoris may require the addition of sequences from genes evolving faster than cytochrome b.