title: Influence of introgression and geological processes on phylogenetic relationships of Western North American mountain suckers (Pantosteus, Catostomidae).
abstract: Intense geological activity caused major topographic changes in Western North America over the past 15 million years. Major rivers here are composites of different ancient rivers, resulting in isolation and mixing episodes between river basins over time. This history influenced the diversification of most of the aquatic fauna. The genus Pantosteus is one of several clades centered in this tectonically active region. The eight recognized Pantosteus species are widespread and common across southwestern Canada, western USA and into northern Mexico. They are typically found in medium gradient, middle-elevation reaches of rivers over rocky substrates. This study (1) compares molecular data with morphological and paleontological data for proposed species of Pantosteus, (2) tests hypotheses of their monophyly, (3) uses these data for phylogenetic inferences of sister-group relationships, and (4) estimates timing of divergence events of identified lineages. Using 8055 base pairs from mitochondrial DNA protein coding genes, Pantosteus and Catostomus are reciprocally monophyletic, in contrast with morphological data. The only exception to a monophyletic Pantosteus is P. columbianus whose mtDNA is closely aligned with C. tahoensis because of introgression. Within Pantosteus, several species have deep genetic divergences among allopatric sister lineages, several of which are diagnosed and elevated to species, bringing the total diversity in the group to 11 species. Conflicting molecular and morphological data may be resolved when patterns of divergence are shown to be correlated with sympatry and evidence of introgression.
authors.affiliation: WIDB 401, Department of Biology, Brigham Young University, Provo, Utah, United States of America; National Evolutionary Synthesis Center, Durham, North Carolina, United States of America.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Unmack
authors.affiliation: School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America; Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Dowling
authors.affiliation: WIDB 401, Department of Biology, Brigham Young University, Provo, Utah, United States of America.
authors.forename: Nina J
authors.initials: NJ
authors.lastname: Laitinen
authors.affiliation: School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America.
authors.forename: Carol L
authors.initials: CL
authors.lastname: Secor
authors.affiliation: Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Mayden
authors.affiliation: WIDB 401, Department of Biology, Brigham Young University, Provo, Utah, United States of America.
authors.forename: Dennis K
authors.initials: DK
authors.lastname: Shiozawa
authors.affiliation: Museum of Zoology, The University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: Gerald R
authors.initials: GR
authors.lastname: Smith
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D044822:Biodiversity; D003531:Cypriniformes / Q000145:classification* / Q000235:genetics*; D004272:DNA, Mitochondrial; D004777:Environment; D019143:Evolution, Molecular; D059647:Gene-Environment Interaction; D005843:Geography; D055593:Geological Phenomena; D006824:Hybridization, Genetic; D008969:Molecular Sequence Data; D009656:North America; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial