Phylogenetic studies on Liolaemus (Sauria: Tropiduridae): An interpretation based on molecular data and a biochemical test of a biogeographic hypothesis
Date of Award
Doctor of Philosophy (Ph.D.)
First Committee Member
Jay M. Savage - Committee Chair
Although the wide-ranging iguanid lizard genus Liolaemus has undergone a dramatic radiation within the South American region (over 100 species are recognized) most of the taxonomic attention paid to the genus has been at the level of distinguishing local populations. This study uses allozymic data, loci as the characters and alleles as character states, to elucidate phylogenetic relationships among Liolaemus sensu lato species. The data were analyzed by PAUP 3.0 (Phylogenetic Analysis Using Parsimony Swofford, 1990) to yield the most parsimonious phylogenetic relationships for Liolaemus. The unordered option of PAUP was used to build the tree, which was then rooted by outgroup analysis. Vilcunia silvanae, Ctenoblepharis adspersus and Phymaturus palluma were used as outgroup taxa. The cladistic analysis supports the monophyly of Liolaemus sensu lato, including V. silvanae, and the subdivision of Liolaemus sensu lato into two genera: Liolaemus sensu stricto; and Eulaemus. Based on the Liolaemus phylogeny a vicariance biogeography analysis was performed. The study includes analysis of a proposed biogeographic model (Solbrig, 1976) for southern South America. Brooks parsimony analysis was used for constructing the Liolaemus area cladogram under Assumption 0 and Assumption 1. Both assumptions gave differing results except when irreversibility was imposed to the data. The Liolaemus area cladogram does not allow corroboration of Solbrig's biogeographic model. Five major points relative to the origin and evolution of Liolaemus are emphasized: (1) The common ancestor of Liolaemus was distributed throughout the southern Nothofagus forest, central Argentina and central and northern Chile, from where it was vicariated by the geological and climatic events of the Tertiary; (2) Eulaemus evolved after the origin of Patagonia; (3) A Liolaemus sensu stricto and northern Eulaemus species group post Pleistocene radiation has taken place; (4) Northern Patagonia and Southern Patagonia (Cei, 1979) have a separate evolutionary history; (5) The High Andes for Liolaemus sensu stricto is not the same area historically as the High Andes of the northern Eulaemus species group.
Young-Downey, Ana Rosa, "Phylogenetic studies on Liolaemus (Sauria: Tropiduridae): An interpretation based on molecular data and a biochemical test of a biogeographic hypothesis" (1998). Dissertations from ProQuest. 3512.