Inferring Branch-Specific Rates of Lineage Diversification Under the Birth–Death-Shift Process

Inferring how rates of speciation and extinction vary across lineages has proven to be a difficult statistical problem. Here, we describe a stochastic-diversification model-called the birth-death-shift (BDS) process-in which diversification rates may vary across both extant and extinct and unsampled lineages. We estimate the parameters of this model in a Bayesian statistical framework from phylogenies of exclusively extant lineages. We perform simulation studies to validate the implementation of our method and to characterize its statistical behavior. We also perform analyses of an empirical primates data set, which reveal that estimates of branch-specific diversification rates are robust to the assumed prior distribution on the number of diversification-rate shifts. Our implementation of the BDS model in RevBayes provides biologists with a flexible approach for estimating branch-specific diversification rates under a statistically coherent model.