Genetic vs. morphological differentiation of Old World buzzards (genus Buteo, Accipitridae)

Here, a comprehensive phylogenetic investigation of Old World buzzards of the buteo-vulpinus complex and related taxa using morphological and genetic markers is presented. The morphometric analysis proved useful to discriminate taxa. Nevertheless, phylogenetic relationships cannot be resolved with these characters. Sequence comparisons between the control region and the pseudo-control region revealed that the latter is the most variable section of the mitochondrial genome. Consequently it was used as a marker sequence. In the genetic analysis, almost no sequence variability was found among taxa comprising the buteo-vulpinus complex as well as Buteo rufinus and Buteo oreophilus, suggesting gene flow and/or incomplete lineage sorting. Thus, rapid morphological differentiation in adaptation to different environments was not accompanied by genetic differentiation of the mitochondrial genomes of these taxa. In contrast, the East Palearctic taxa are well differentiated genetically. The 'superspecies' concept and taxonomic consequences of our results are discussed.