title: Phylogeography of Sardinian cave salamanders (genus Hydromantes) is mainly determined by geomorphology.
abstract: Detecting the factors that determine the interruption of gene flow between populations is key to understanding how speciation occurs. In this context, caves are an excellent system for studying processes of colonization, differentiation and speciation, since they represent discrete geographical units often with known geological histories. Here, we asked whether discontinuous calcareous areas and cave systems represent major barriers to gene flow within and among the five species of Sardinian cave salamanders (genus Hydromantes) and whether intraspecific genetic structure parallels geographic distance within and among caves. We generated mitochondrial cytochrome b gene sequences from 184 individuals representing 48 populations, and used a Bayesian phylogeographic approach to infer possible areas of cladogenesis for these species and reconstruct historical and current dispersal routes among distinct populations. Our results show deep genetic divergence within and among all Sardinian cave salamander species, which can mostly be attributed to the effects of mountains and discontinuities in major calcareous areas and cave systems acting as barriers to gene flow. While these salamander species can also occur outside caves, our results indicate that there is a very poor dispersal of these species between separate cave systems.
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-UMR n° 5554, CC 064, Université Montpellier II, Montpellier, France. yle@yleniachiari.it
authors.forename: Ylenia
authors.initials: Y
authors.lastname: Chiari
authors.forename: Arie
authors.initials: A
authors.lastname: van der Meijden
authors.forename: Mauro
authors.initials: M
authors.lastname: Mucedda
authors.forename: João M
authors.initials: JM
authors.lastname: Lourenço
authors.forename: Axel
authors.initials: A
authors.lastname: Hochkirch
authors.forename: Michael
authors.initials: M
authors.lastname: Veith
mesh_terms: D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D059552:Caves; D045303:Cytochromes b / Q000235:genetics; D003710:Demography; D051456:Gene Flow / Q000235:genetics*; D049810:Genetic Speciation; D014644:Genetic Variation; D005843:Geography; D007558:Italy; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D058974:Phylogeography; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014562:Caudata / Q000235:genetics* / Q000502:physiology
chemical_list: D045303:Cytochromes b