Abstract
Understanding why some clades contain more species than others is a major challenge in evolutionary biology, and variation in dispersal ability and its connection to diversification rate may be part of the explanation. Several studies have suggested a negative relationship between dispersal capacity and diversification rate among living mammals. However, this pattern may differ when also considering extinct species, given known extinction biases. The colonization of new areas by various lineages may be associated with both diversity increases in those colonising lineages and declines in the lineages already present. Past diversity declines are, however, effectively impossible to infer based on phylogenies of extant taxa, and the underlying process may, therefore, be difficult to determine. Here we produce a novel species-level phylogeny of all known extant and extinct species of the order Carnivora and related extinct groups (1,723 species in total) to show that there is instead a positive relationship between dispersal rate and diversification rate when all extinct species are included. Species that disperse between continents leave more descendant species than non-dispersers, and dispersing species belong to lineages that at the time of dispersal were diversifying faster than the average non-disperser. Our study showcases the importance of combining fossils and phylogenies to better understand evolutionary and biogeographic patterns.
