A molecular phylogenetic study of Hylopetes (Rodentia: Sciuridae) inferred from mitochondrial cytochrome-b gene

To elucidate the phylogenetic relationships of Hylopetes, the complete cytochrome-b gene sequences (1,140 bp) were determined from degraded museum specimens for phylogenetic study. The large genetic differences (18.1% to 20.7%) separate Eoglaucomys from Hylopetes as a distinct genus. Phylogenetic relationships reconstructed with maximum parsimony, maximum likelihood, and Bayesian methods show that all Hylopetes were genetically clustered as two major groups, the Indochinese Hylopetes group including H. alboniger and H. phayrei, and the Sundaic group consisting of H. lepidus, H. nigripes, and H. spadiceus. The close genetic relationship and the recent divergence suggest that the Indochinese group rapidly extended to their present distributions with the uplifting of the Himalayas last few million years ago, whereas the oceanic tectonic movements during the Pliocene-Pleistocene resulted in the current geographical distributions of the Sundaic group through alteration of dispersal across the islands of the Sunda Shelf.