Understanding patterns of biodiversity and the processes that produce them is a key goal of research in ecology and evolution. This symposium aims to link biogeographic patterns observed in nature with evolutionary and ecological processes. In particular, we compare the relative role of geological and evolutionary history vs. contemporary species distributions and interactions in explaining broad patterns of diversity. We first introduce two studies exploring the evolution of morphological divergence in isolated radiations. Then, we examine macroecological patterns of species distributions and propose novel theoretical models to explain them. We also explore the role of historical evolutionary processes in driving diversification on continents and islands. Lastly, we stimulate scholarly debate among our participants in an attempt to derive a research agenda for future biodiversity studies.