title: Phylogeographic and population genetic analyses reveal multiple species of Boa and independent origins of insular dwarfism.
abstract: Boa is a Neotropical genus of snakes historically recognized as monotypic despite its expansive distribution. The distinct morphological traits and color patterns exhibited by these snakes, together with the wide diversity of ecosystems they inhabit, collectively suggest that the genus may represent multiple species. Morphological variation within Boa also includes instances of dwarfism observed in multiple offshore island populations. Despite this substantial diversity, the systematics of the genus Boa has received little attention until very recently. In this study we examined the genetic structure and phylogenetic relationships of Boa populations using mitochondrial sequences and genome-wide SNP data obtained from RADseq. We analyzed these data at multiple geographic scales using a combination of phylogenetic inference (including coalescent-based species delimitation) and population genetic analyses. We identified extensive population structure across the range of the genus Boa and multiple lines of evidence for three widely-distributed clades roughly corresponding with the three primary land masses of the Western Hemisphere. We also find both mitochondrial and nuclear support for independent origins and parallel evolution of dwarfism on offshore island clusters in Belize and Cayos Cochinos Menor, Honduras.
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Daren C
authors.initials: DC
authors.lastname: Card
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Drew R
authors.initials: DR
authors.lastname: Schield
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Adams
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Corbin
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Blair W
authors.initials: BW
authors.lastname: Perry
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Audra L
authors.initials: AL
authors.lastname: Andrew
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Giulia I M
authors.initials: GI
authors.lastname: Pasquesi
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA.
authors.forename: Eric N
authors.initials: EN
authors.lastname: Smith
authors.affiliation: Department of Ecology & Evolutionary Biology, University of Arizona, P.O. Box 210088, Tucson, AZ 85721, USA.
authors.forename: Tereza
authors.initials: T
authors.lastname: Jezkova
authors.affiliation: Department of Biology, P.O. Box 1773, Dickinson College, Carlisle, PA 17013, USA.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Boback
authors.affiliation: Department of Biological Science, 800 South Tucker Drive, University of Tulsa, Tulsa, OK 74104, USA.
authors.forename: Warren
authors.initials: W
authors.lastname: Booth
authors.affiliation: Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX 76019, USA. Electronic address: todd.castoe@uta.edu.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Castoe
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D017821:Boidae / Q000145:classification / Q000235:genetics* / Q000502:physiology; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004392:Dwarfism / Q000473:pathology / Q000662:veterinary; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D058974:Phylogeography; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D004247:DNA
keywords: Bayesian species delimitation; Boidae; Population genomics; Population structure; RADseq