Incongruence of mitochondrial and nuclear gene trees in the carabid beetles Ohomopterus

We studied the molecular phylogeny of the carabid subgenus Ohomopterus (genus Carabus) using two mtDNA regions (16SrRNA and ND5) and three nuclear DNA regions (wingless, phosphoenolpyruvate carboxykinase, and an anonymous locus). We revisited the previously reported incongruence between the distribution of mtDNA markers and morphologically defined species (Su et al., 1996, J. Mol. Evol., 43:662-671) which they attributed to \"type switching\", a concerted change in many morphological characters that results in the repeated evolution of a particular morphological type. Our mtDNA gene tree obtained from 44 individuals representing all 15 currently recognized species of Ohomopterus revealed that haplotypes isolated from individuals of a single \"species\" were frequently separated into distant clades, confirming the previous report. The three nuclear markers generally conformed better with the morphologically defined species. The phylogenetic signal in mtDNA and nuclear DNA data differed stron...