Ecological and spatial overlap indicate interspecific competition during North American canid radiation

Understanding biodiversity patterns and the processes that generate them are key goals in macroevolution. Diversity-dependent models of diversification have been used to indirectly infer the relevance of interspecific competition on diversification dynamics. Here, we develop a new approach that more explicitly incorporates spatial and ecomorphological overlap among species to test how interspecific competition may affect diversification dynamics. We build different metrics that capture temporal and spatial coexistence, and ecological overlap to test the hypothesis that an increase in the intensity of competition would result in a decrease in speciation and an increase in extinction rate. We test our predictions using the fossil record of North American canids, a group that has been well characterized both ecologically and from a paleontological point of view. We find that interspecific competition only resulted in the suppression of speciation rate at the time the clade was expanding in diversity. We find no association with extinction dynamics, nor an association between changes in diversification dynamics and changes in temperature. We discuss how evaluating the role of interspecific competition using different metrics that better capture the intensity of competition might be a way forward to investigate the role of biotic interactions at deep time..