Phylogenetic utility of the mitochondrial cytochrome oxidase gene: molecular evolution of the Drosophila buzzatii species complex.

Phylogenetic relationships among eight species of the Drosophila buzzatii species complex (D. mulleri subgroup; D. repleta species group) and D. hamatofila were determined by sequencing the mitochondrial cytochrome oxidase subunit I, II, and III genes. The species examined included members of the martensis cluster (D. martensis, D. starmeri, D. venezolana), the buzzatii cluster (D. buzzatii, D. serido, D. borborema), and the stalkeri cluster (D. stalkeri, D. richardsoni). The molecular phylogeny was found to be congruent with the chromosomal inversion phylogeny. Analyzing the cytochrome oxidase subunits separately revealed that not all the subunits seem to have the same phylogenetic information content. Parameters are discussed that might explain these differences.