My primary interest lies in the mechanisms driving the diversification of tropical organisms. In the past my research has focused on amphibians of the Neotropics though my work has expanded to Madagascar and now includes numerous groups of arthropods. The fauna of the South American continent has been subjected to extreme environmental changes in the past such as the separation of the continent from Africa and Antartica, intermittent contact with North America, the rise (The Andes) and fall (Guianan highlands) of great mountain ranges, and significant climactic fluctuations. All of these factors and many more have resulted in the largest diversity of amphibians on the planet and in some cases a great deal of variation within these species. The presence of species such as Dendrobates tinctorius, which exhibit a great deal of interpopulational variation across their range indicate that the environment is still changing and that these animals are adapting to this dynamic environment. It is my goal to increase our understanding of the evolutionary history of the fauna (of the Guianan region in particular) by examining patterns of genetic variation within and among species in this area utilizing current population genetic and phylogreographic techniques. In order to investigate this and other interesting aspects of Neotropical biodiversity I have conducted extensive fieldwork in the Guianas over the past eight years and am collaborating with a number of researchers in these countries.