Testing macro-evolutionary models using incomplete molecular phylogenies

Phylogenies reconstructed from gene sequences can be used to investigate th e tempo and mode of species diversification. Here we develop and use new st atistical methods to infer past patterns of speciation and extinction from molecular phylogenies. Specifically, we test the null hypothesis that per-l ineage speciation and extinction rates have remained constant through time. Rejection of this hypothesis may provide evidence for evolutionary events such as adaptive radiations or key adaptations. In contrast to previous app roaches, our methods are robust to incomplete taxon sampling and are conser vative with respect to extinction. Using simulation we investigate, first, the adverse effects of failing to take incomplete sampling into account and , second, the power and reliability of our tests. When applied to published phylogenies our tests suggest that, in some cases, speciation rates have d ecreased through time.