Molecular phylogeny of the chipmunks inferred from mitochondrial cytochrome b and cytochrome oxidase II gene sequences

There are currently 25 recognized species of the chipmunk genus Tamias. In this study we sequenced the complete mitochondrial cytochrome b (cyt b) gen e of 23 Tamias species. We analyzed the cyt b sequence and then analyzed a combined data set of cyt b along with a previous data set of cytochrome oxi dase subunit II (COII) sequence. Maximum-likelihood was used to further tes t the fit of models of evolution to the cyt b data. Other sciurid cyt b seq uence was added to examine the evolution of Tamias in the context of other sciurids. Relationships among Tamias species are discussed, particularly th e possibility of a current sorting event among taxa of the southwestern Uni ted States and the extreme divergences among the three subgenera (Neotamias , Eutamias, and Tamias). (C) 2001 Academic Press.