Climate, Geography, and Traits as Biodiversity Drivers in Ecological and Evolutionary Timescales

Abstract

I examined the role of traits in driving patterns of species richness in ecological and evolutionary timescales. First, three chapters discuss the role of traits on explaining patterns of species richness across space and taxonomic groups. Finally, a fourth chapter discusses contemporaneous climate-related changes in species richness over space. Overall, Chapter 1 identifies congruent differential effects of alternative geographical locations on the diversification patterns of unrelated groups. Chapter 2 indicates the existence of two contrasting scale-dependent patterns in animals. First, it suggests that diversification patterns at lower taxonomic levels, where diversification is generally associated with diet, do not necessarily scale up to the level of phyla. Second, although diet seems to be especially labile at lower taxonomic scales, our results across phyla in Chapter 2 suggest that diet is rather conserved across the animal Tree of Life. Chapter 3 provides insights on the climatic drivers of species extinctions during the 1900s. Specifically, in this Chapter we discuss the positive association between increases in maximum temperatures and the occurrence of extinctions at local scales. We also discuss the primary role of niche shift in potentially allowing species to avoid climate-related extinctions by the end of the current century. Chapter 4 summarizes a comprehensive panorama on habitat-associated (freshwater, terrestrial, and marine) diversity for plants and animals. This final chapter also indicates richness differences among habitats to be primarily explained by differences in times of first colonization. In sum, this thesis exposes multiple examples where the instances driving ecological and evolutionary processes and patterns vary across space (Chapter 1), taxonomic scales (Chapter 2), climatic conditions (Chapter 3) and temporal context (Chapter 4).