How biodiversity gradients are made: speciation, extinction, and colonization
How were hotspots of biodiversity formed? I take a macroevolutionary approach to understand which processes generated present-day biodiversity gradients and how long these processes have operated over deep time scales. In my talk I will focus on three global-scale biodiversity patterns: the peak in marine richness at the Central Indo-Pacific region, the latitudinal biodiversity gradient on land, and the difference between terrestrial and marine richness. Species can be added to a region through in-situ speciation or colonization from elsewhere, and removed through local or global extinction. To understand the relative roles of these processes, I reconstructed past biogeography on time-calibrated molecular phylogenies of vertebrates. A common link between these three biodiversity patterns is that species-rich regions have provided stable habitats for their occupants for much longer than species-poor regions.