Insights on speciation patterns in the genus Iberochondrostoma (Cyprinidae): Evidence from mitochondrial and nuclear data

In this paper, the patterns of cladogenesis in the cyprinid fish genus Iberochondrostoma were analysed using a mitochondrial (cytochrome b) and a nuclear (beta-actin) gene fragment. The two genes yielded discordant results. While the cytochrome b gene yielded a fully dichotomous tree, where all species of the genus are monophyletic, the much slower beta-actin gene yielded star-like relationships. However, when information from both genes was considered together, the data suggested the persistence of a very large central unit from which at least two peripheral clades arose at different times. This pattern which is akin to peripatric speciation was shown to be compatible with the paleogeographical information available. It is suggested that combining the techniques of phylogeny and phylogeography and the use of multiple markers varying in their rate of evolution may enrich our understanding of speciation and evolution of clades beyond species level.