Sciurid phylogeny and the paraphyly of Holarctic ground squirrels (Spermophilus)

    Authors

    M. D. Herron; T. A. Castoe;C. L. Parkinson

    Comments

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    Abbreviated Journal Title

    Mol. Phylogenet. Evol.

    Keywords

    Bayesian phylogeny; cytochrome b; marmotini; Sciuridae; Spermophilus; squirrels; taxonomy; MITOCHONDRIAL CYTOCHROME-B; RIBOSOMAL-RNA GENES; MOLECULAR PHYLOGENY; WORLD SQUIRRELS; DNA-SEQUENCES; NUCLEOTIDE SUBSTITUTION; EVOLUTIONARY; GENETICS; MAXIMUM-LIKELIHOOD; JAW MUSCLES; RODENTIA; Biochemistry & Molecular Biology; Evolutionary Biology; Genetics &; Heredity

    Abstract

    The squirrel family, Sciuridae, is one of the largest and most widely dispersed families of mammals. In spite of the wide distribution and conspicuousness of this group, phylogenetic relationships remain poorly understood. We used DNA sequence data from the mitochondrial cytochrome b gene of 114 species in 21 genera to infer phylogenetic relationships among sciurids based on maximum parsimony and Bayesian phylogenetic methods. Although we evaluated more complex alternative models of nucleotide substitution to reconstruct Bayesian phylogenies, none provided a better fit to the data than the GTR + G + I model. We used the reconstructed phylogenies to evaluate the current taxonomy of the Sciuridae. At essentially all levels of relationships, we found the phylogeny of squirrels to be in substantial conflict with the current taxonomy. At the highest level, the flying squirrels do not represent a basal divergence, and the current division of Sciuridae into two subfamilies is therefore not phylogenetically informative. At the tribal level, the Neotropical pygmy squirrel, Sciurillus, represents a basal divergence and is not closely related to the other members of the tribe Sciurini. At the genus level, the sciurine genus Sciurus is paraphyletic with respect to the dwarf squirrels (Microsciurus), and the Holarctic ground squirrels (Spermophilus) are paraphyletic with respect to antelope squirrels (Ammospermophilus), prairie dogs (Cynomys), and marmots (Marmota). Finally, several species of chipmunks and Holarctic ground squirrels do not appear monophyletic, indicating a need for reevaluation of alpha taxonomy. (C) 2003 Elsevier Inc. All rights reserved.

    Journal Title

    Molecular Phylogenetics and Evolution

    Volume

    31

    Issue/Number

    3

    Publication Date

    1-1-2004

    Document Type

    Article

    Language

    English

    First Page

    1015

    Last Page

    1030

    WOS Identifier

    WOS:000221443400019

    ISSN

    1055-7903

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