title: Phylogeny and phylogeography of the Liolaemus darwinii complex (Squamata: Liolaemidae): evidence for introgression and incomplete lineage sorting.
abstract: Although mitochondrial DNA markers have several properties that make them suitable for phylogeographic studies, they are not free of difficulties. Phylogeographic inferences within and between closely related species can be mislead by introgression and retention of ancestral polymorphism. Here we combine different phylogenetic, phylogeographic, and population genetic methods to extract the maximum information from the Liolaemus darwinii complex. We estimate the phylogeographic structure of L. darwinii across most of its distributional range, and we then estimate relationships between L. darwinii and the syntopic species L. laurenti and L. grosseorum. Our results suggest that range expansion of these lineages brought them into secondary contact in areas where they are presently in syntopy. Here we present the first evidence for introgression in lizards from temperate South America (of L. danwinii mitochondrial DNA into L. laurenti and L. grosseorum), and for incomplete lineage sorting (between L. darwinii and L. laurenti). We show that a combination of methods can provide additional support for inferences derived from any single method and thus provide more robust interpretations and narrow the range of plausible hypotheses about mechanisms and processes of divergence. Additional studies are needed in this group of lizards and in other codistributed groups to determine if Pleistocene climatic changes could be a general factor influencing the evolutionary history of a regional biota.
authors.affiliation: Department of Integrative Biology, and M. L. Bean Life Science Museum, Brigham Young University, 401 WIDB, Provo, Utah 84602, USA. mariana_morando@hotmail.com
authors.forename: Mariana
authors.initials: M
authors.lastname: Morando
authors.forename: Luciano J
authors.initials: LJ
authors.lastname: Avila
authors.forename: Jay
authors.initials: J
authors.lastname: Baker
authors.forename: Jack W
authors.initials: JW
authors.lastname: Sites
mesh_terms: D000818:Animals; D001118:Argentina; D001483:Base Sequence; D045303:Cytochromes b / Q000235:genetics; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006824:Hybridization, Genetic / Q000235:genetics*; D016013:Likelihood Functions; D008116:Lizards / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D045303:Cytochromes b