The phylogenetic systematics of blue‐tailed skinks (Plestiodon) and the family Scincidae
Blue‐tailed skinks (genus Plestiodon) are a common component of the terrestrial herpetofauna throughout their range in eastern Eurasia and North and Middle America. Plestiodon species are also frequent subjects of ecological and evolutionary research, yet a comprehensive,
well‐supported phylogenetic framework does not yet exist for this genus. We construct a comprehensive molecular phylogeny of Plestiodon using Bayesian phylogenetic analyses of a nine‐locus data set comprising 8308 base pairs of DNA, sampled from 38 of the 43 species in
the genus. We evaluate potential gene tree/species tree discordance by conducting phylogenetic analyses of the concatenated and individual locus data sets, as well as employing coalescent‐based methods. Specifically, we address the placement of Plestiodon within the evolutionary
tree of Scincidae, as well as the phylogenetic relationships between Plestiodon species, and their taxonomy. Given our sampling of major Scincidae lineages, we also re‐evaluate ‘deep’ relationships within the family, with the goal of resolving relationships that have
been ambiguous in recent molecular phylogenetic analyses. We infer strong support for several scincid relationships, including a major clade of ‘scincines’ and the inter‐relationships of major Mediterranean and southern African genera. Although we could not estimate the
precise phylogenetic affinities of Plestiodon with statistically significant support, we nonetheless infer significant support for its inclusion in a large ‘scincine’ clade exclusive of Acontinae, Lygosominae, Brachymeles, and Ophiomorus. Plestiodon
comprises three major geographically cohesive clades. One of these clades is composed of mostly large‐bodied species inhabiting northern Indochina, south‐eastern China (including Taiwan), and the southern Ryukyu Islands of Japan. The second clade comprises species inhabiting
central China (including Taiwan) and the entire Japanese archipelago. The third clade exclusively inhabits North and Middle America and the island of Bermuda. A vast majority of interspecific relationships are strongly supported in the concatenated data analysis, but there is nonetheless significant
conflict amongst the individual gene trees. Coalescent‐based gene tree/species tree analyses indicate that incongruence amongst the nuclear loci may severely obscure the phylogenetic inter‐relationships of the primarily small‐bodied Plestiodon species that inhabit
the central Mexican highlands. These same analyses do support the sister relationship between Plestiodon marginatus Hallowell, 1861 and Plestiodon stimpsonii (Thompson, 1912), and differ with the mitochondrial DNA analysis that supports Plestiodon elegans (Boulenger, 1887) + P. stimpsonii.
Finally, because the existing Plestiodon taxonomy is a poor representation of evolutionary relationships, we replace the existing supraspecific taxonomy with one congruent with our phylogenetic results.
© 2012 The Linnean Society of London, Zoological Journal of the Linnean
Society, 2012, 165, 163–189.
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Document Type: Research Article
Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, California 94720-3160, USA
Institute of Natural and Environmental Sciences and Museum of Human and Nature, University of Hyogo, Yayoigaoka, Sanda, Hyogo 669-1546, Japan
Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, México 04510, Distrito Federal, México
Museo de Zoología, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México 09230, Distrito Federal, México
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
Publication date: 01 May 2012