Patterns and processes in the origin and diversification of terrestrial vertebrate diversity in the Brazilian Atlantic Forest

Abstract

The Atlantic Forest (AF) is a global conservation hotspot due to the large number of highly threatened endemic species. Several models have been proposed to explain the underlying causes of the high biodiversity in this biome. For example, the refuge theory poses that areas richer in species today are so because they were more climatically stable during the Plio-Pleistocene. This theory has been supported by data on several groups of vertebrates and invertebrates. Conversely, other studies have found that dispersion barriers and allopatric speciation were the key factors determining species genetic diversity. However, there is still no consensus on the relative importance of these two models or how they vary across space and organisms with different dispersal abilities and thermal tolerance. Therefore, integrative research using not only theories but also methods from disparate areas like ecology, macroevolution, and phenotypic evolution may contribute to form a comprehensive scenario of key processes involved in the origin and maintenance of FA's biota today. Here, I will explore how the functional diversity (as a measure of multivariate niche space) of non-flying mammals, amphibians, and birds varies spatially and its underlying causes. I will use databases already available in the literature and compile the same data for about 564 amphibian species. In addition, I will use comparative phylogenetic methods to investigate how these traits evolved along the phylogeny of species occurring in AF separately for each group of organisms. Finally, I will investigate how the climatic niche influenced the rate of trait evolution. By analyzing functional diversity, I could infer ecological and evolutionary mechanisms involved in the distribution of complementary facets of biodiversity. (AU)