Molecular systematics of pikas (genus Ochotona) inferred from mitochondrial DNA sequences.

摘要: The phylogenetic relationships among worldwide species of genus Ochotona were investigated by sequencing mitochondrial cytochrome b and ND4 genes. Parsimony neighbor-joining analyses the sequence data yielded congruent results that strongly indicated three major clusters: shrub-steppe group, northern mountain group. subgeneric classification needs to be revised because each two subgenera in present contains from To solve this taxonomic problem so taxon is monophyletic, i.e., represents a natural clade, could divided into subgenera, one for species, second third species. inferred tree suggests differentiation Palearctic Region was closely related gradual uplifting Tibet (Qinghai-Xizang) Plateau, as hypothesized previously, vicariance might have played role on On other hand, North American O. princeps, most likely dispersal event, which happened during Pliocene through opening Bering Strait. within group are worth noting instead monophyletic shrub-dwelling shrub dwellers steppe intermingled with other. Moreover, divergence sister tars steppe? dweller very low. These findings support hypothesis pikes entered environment several times morphological similarities due convergent evolution. (C) 2000 Academic Press.