Understanding how the evolutionary processes expounded by Darwin and Wallace have shaped current patterns of biodiversity is a profound challenge to modern Evolutionary Biogeography. We live in a time of accelerating global change due to human impacts on the biosphere, leading many to refer to an anthropogenic extinction crisis. Yet our knowledge of the distribution of biodiversity remains woefully incomplete. This limits the effectiveness of conservation efforts, especially those within recognized global hotspots. Here then, is the challenge to the new generation of evolutionary biogeographers – to be able to predict the current distribution of diversity, at multiple scales, by harnessing our knowledge of evolutionary processes and past environmental change. From this point, we can forecast better the inevitable impacts future global change and identify strategies that will protect both the products of past evolution and the processes that ensure ongoing viability of natural systems. In this talk, I will describe how key biogeographic insights of Darwin and Wallace have been supported and extended by modern (especially molecular) biogeography, with particular reference to island radiations and tropical rainforests. Drawing on this, I will outline a predictive approach to biogeographic analysis. Though incomplete, such a framework should enhance both the fundamental science and the effectiveness of conservation in a rapidly changing world.