Descriptive statistics of estimated rate variation for 8-taxon equal-branch-length trees.

Overall rate variation, rate variation between depths, and rate variation between clades, were calculated from rates estimated in Bayesian and Maximum Likelihood (ML) frameworks for 100 simulated datasets for trees with branch lengths of 0.01 – 1.4 substitutions/site. Estimated rate variation expected due to the Poisson process was calculated as (μ+2σ)/(μ−2σ). Each dataset was tested for rejection of the molecular clock using Bayes factor comparisons for Bayesian analyses with and without the clock enforced, and a likelihood ratio test for ML analyses.