Large-scale phylogenetic analyses reveal the causes of high tropical amphibian diversity.

摘要: Many groups show higher species richness in tropical regions but the underlying causes remain unclear. Despite many competing hypotheses to explain latitudinal diversity gradients, only three processes can directly change across regions: speciation, extinction and dispersal. These be addressed most powerfully using large-scale phylogenetic approaches, previous studies have focused on small recent time scales, or did not separate speciation rates. We investigate origins of high amphibians, applying new comparative methods a tree 2871 species. Our results that is explained by tropics, temperate limited dispersal out tropics compared with colonization from regions. patterns are strongly associated climate-related variables such as temperature, precipitation ecosystem energy. Results models dependence rate suggest clades may lower carrying capacities more saturated (closer capacity) than clades. Furthermore, we estimate strikingly low rates over geological stark contrast dramatic losses occurring presently.