title: Molecular systematics and evolution of Regina and the thamnophiine snakes.
abstract: Snakes of the tribe Thamnophiini represent an ecologically important component of the herpetofauna in a range of habitats across North America. Thamnophiines are the best-studied colubrids, yet little is known of their systematic relationships. A molecular phylogenetic study of 32 thamnophiine species using three complete mitochondrial genes (cytochrome b, NADH dehydrogenase subunit 2, and 12S ribosomal DNA) recovered a well-supported phylogeny with three major clades: a garter snake group, a water snake group, and a novel semifossorial group. The historically contentious genus Regina, which contains the crayfish-eating snakes, is polyphyletic. The phylogeographic pattern of Thamnophis is consistent with an hypothesis of at least one invasion of northern North America from Mexico.
authors.affiliation: Section of Evolution and Ecology, University of California, One Shields Avenue, Davis, California 95616, USA. malfaro@midway.uchicago.edu
authors.forename: M E
authors.initials: ME
authors.lastname: Alfaro
authors.forename: S J
authors.initials: SJ
authors.lastname: Arnold
mesh_terms: D000818:Animals; D001483:Base Sequence; D003573:Cytochrome b Group / Q000235:genetics; D017931:DNA Primers; D004275:DNA, Ribosomal / Q000235:genetics; D019143:Evolution, Molecular; D016013:Likelihood Functions; D008969:Molecular Sequence Data; D009245:NADH Dehydrogenase / Q000235:genetics; D009690:Nucleic Acid Conformation; D016133:Polymerase Chain Reaction; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D012911:Snakes / Q000145:classification* / Q000235:genetics*; D013045:Species Specificity
chemical_list: D003573:Cytochrome b Group; D017931:DNA Primers; D004275:DNA, Ribosomal; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D009245:NADH Dehydrogenase