Many hypotheses have already been proposed for the enormous biodiversity emergence observed in neotropical regions, and the refuge theory is one of the most discussed to date. South America is an interesting region for these studies, as it is composed of two large dense forest biomes (Amazon and Atlantic Forest) currently separated by a strip of open vegetation. Geomorphological and paleopalinological studies suggest that the two biomes have already been united, and were separated as a result of climate change in the Pleistocene. Recently, studies involving phylogeography have corroborated this hypothesis, although these studies are still scarce in Brazil and few taxa have been investigated to date. Spiders (Arachnida: Araneae) have been the focus of these studies in various regions of the world, but never in the neotropics. Araneus venatrix (Araneidae) is a good study model, as its distribution is restricted to the Amazon and Atlantic Forest, with no specimens in central Brazil. This work proposes the study of phylogeographic patterns and population structure of A. venatrix by sequencing the mtDNA cytochrome oxidase I (COI) gene region and microsatellite amplification. The objectives of the study are to relate the variability and structure to species and environmental characteristics, and to discuss the probable evolutionary processes responsible for the geographical distribution of these spiders, discussing the effects of Pleistocene climate change on the populations of this species.
News published in Agência FAPESP Newsletter about the scholarship: