John J Wiens - WEES seminar Februari 2010

John J Wiens (Stony Brook University NY, USA)

A major challenge in the 21^{st century is the rapid loss of the planet’s biodiversity. But we still have only a limited understanding of that biodiversity, including the actual number of extant species and what explains spatial variation in biodiversity across the globe. Much work on global biodiversity patterns has focused on correlations between species richness with climate. But even if these correlations were perfect, climate can only offer a partial picture of what causes spatial variation in biodiversity. In fact, climate does not directly change the number of species in a region, but instead must act through the evolutionary and biogeographic processes of speciation, extinction, and/or dispersal. How these processes drive large-scale diversity patterns remains uncertain. I will review recent research from my lab that attempts to explain biodiversity patterns by considering both evolutionary and ecological processes. I will discuss our analyses of the causes of high tropical diversity in amphibians using large-scale phylogenies and temporal, distributional, and climatic data. I will also discuss our ongoing studies of patterns of elevational and local diversity, and the roles of trait evolution and divergent speciation processes in driving biodiversity patterns.}