Systematics and evolution of the herpetological fauna from Neotropical areas

Abstract

The present proposal aims to continue and expand the ongoing multidisciplinary research on the systematic and evolution of the herpetological fauna from Neotropical areas, as well as on the aspects of historical biogeography of neotropical reptile, amphibian and small mammal faunas. We intend to: 1) expand the karyological data so far gathered to include new species and localities for Brazilian lizards, amphibians and rodents, in order to better understand their chromosomal evolution with a great effort to use methodologies that allow the identification of useful characters for phylogenetic analyses; 2) complete the ongoing studies on taxonomy, karyotypes and DNA sequencing (molecular) about the herpetological fauna of the São Francisco river, with special attention to gather intra and interspecific rates of divergences for endemic taxes; 3) study the heterocrony of the genus Calyptommatus and aspects of ontogeny of the Gymnophthalmini, collecting data that should guide a broad future study on the developmental biology of the group. The inclusion of this new approach may provide useful information to the understanding of the genetic mechanisms that controls the limb reduction present in several lineages of Gymnophthalmidae; 4) proceed with the collection of karyotypes and DNA sequences data on lizards of genus Leposoma to better understand the phylogeny of its species and the high level of genetic diversity within the genus; investigate the origin of parthenogenesis of clones in L.percarinatum and compare with that of clones of Gymnophthalmus underwoodii; 5) add more data (morphological, karyological and molecular) to the study of the phylogenetic relationships within the family Gymnophthalmidae, to obtain a robust hypothesis based on multiple data sets for a more complete sample of genera; 6) increase the sampling for lizards of genera Gymnodactylys, Coleodactylus and Mabuya to allow phylogenetic and historical biogeography studies using morphological, karyological and molecular data; 7) conduct preliminary comparative studies on selected taxes of herps and small rodents with discontinuous distribution on Amazon and Atlantic forests and on rainforest remnants in the northeastern Caatingas, in order to obtain approximate times of divergence for different groups in these forested areas. These estimations will be compared to those gathered for populations of lizard's genus Gymnodactylus from island and mainland areas, and to those of disjunctive populations in the dunes of São Francisco river. (AU)