Séminaire reporté : Ignacio Quintero de l’Institut de Biologie de l’École Normale Supérieure

Through geological time, variation in biodiversity has been observed along three main axes: time, space and taxa, and disentangling deterministic drivers of such variation from contingency has been problematic. Yet, any hypothesis attempting to explain differences in biodiversity is bound to link to the only three evolutionary processes that underlie changes in species richness: speciation, extinction and dispersal. Here, we develop and employ probabilistic modeling approaches to gain understanding in these processes in a multifaceted approach across different evolutionary timescales. We investigate the effect of recent diversification rates on shaping current spatial patterns of species richness and find that climatically stable regions undergo less extinction and enable the build-up of species richness. Then we explore the effect of environmental fluctuations through geological time on the spatial diversification of lineages, exploring the hypotheses that biome area might enhance rates of origination or lessen extinction rates. Thirdly, we incorporate biotic interaction dynamics when reconstructing biogeographic and trait evolutionary history jointly and investigate the radiation of the Darwin’s Finches and find that negative biotic interactions acting on beak size have been key in shaping biogeographic and phenotypic patterns. Finally, we use a novel and flexible modeling approach were we consider niche space as a multivariate domain rather that as dimensionless coordinates in climatic space. We find that rates of climatic evolution have remained constant throughout the evolutionary history, seemingly independent of the number of species. However, at any given moment, there is wide rate variability among lineages, with some undergoing dramatic high rates of evolution while others presenting overall niche stability. Together, these results further our understanding on the fundamental processes that generate diversity in richness and disparity, and encourage further model enhancements and empirical applications.