Genetic differentiation and phylogenetic relationships among Palearctic mice (Rodentia, Muridae)
Mezhzherin, S.V.
Genetika 33(1): 78-86
1997
ISSN/ISBN: 0016-6758 PMID: 9162690 Document Number: 475902
Genetic differentiation of 18 Palearctic mouse species (genera Sylvaemus, Mus, Apodemus, Micromys, and Rattus) with respect to 31 biochemical loci was estimated to define the taxonomic status of these genera. On the basis of genetic data, two independent centers of origin of species belonging to the family Muridae were identified. The first is the Indo-African center, from which the modern Sylvaemus species and Palearctic representatives of Mus originated in the Pleistocene (1.0-2.0 million years ago). Genera Micromys and Apodemus, which diverged in early Pliocene (about 7 million years ago), trace their origin to the same center. From the second center, located in Southeast Asia, Rattus species radiated. The genetic divergence of taxa issuing from these two centers attains the level characteristic of differentiation between families and dates back to the late Miocene (over 10 million years ago). Species were compared pairwise to determine the percent of fixed gene differences (Pfd) between them. Analysis of Pfd distribution confirmed distinct periodicity of speciation in mice and revealed two speciation peaks. The first, at the level of genera, occurred in the Pliocene, and the second, at the species level, in the Pleistocene.