Phylogeography and populational genetic structure of spiders species (Arachnida, Araneae)

Abstract

In South America there are two important rain forests, the Amazon and the Atlantic forest, separated by a zone of open vegetation, which has been considered a restriction for species migrations. However, as vegetation maps show some connections between these forests and probably they were continuous in the past, interesting phylogeographic patterns can be found for species found in the two areas. Paleontological as well as geomorphological studies suggest that the two biomes were separated with the climate changes of the Pleistocene. Recently, some findings have supported this hypothesis, although studies are still scarce in Brazil and only a few taxa have been already investigated. This project aims to study the population structure and phylogeography of Araneus venatrix, three species of Aglaoctenus and Nephila clavipes and using sequences of the mitochondrial gene cytochrome oxidase I (COI) and amplification of microsatellites. These species are found in the Amazon and in the Atlantic Forest, being suitable for such for evolutionary studies. We will compare the patterns of variability and structure of the species and of the habitats, and discuss possible evolutionary processes acting on the historical geographic distribution of these spiders. It is intended to do phylogeographic studies of different species to contribute for the understanding of general processes that shaped the current distribution of species and communities in Brazil. (AU)