Genealogical tree and skyline plots of coalescent statistics for sequences simulated under purifying selection. There were 10,000 individuals in the simulation, and a mutation rate μ of 10-5 per site per individual per generation with each mutation having a 99% probability of being deleterious with a selective disadvantage of 0.01. The tree shown represents the maximum posterior tree sampled over the course of the MCMC analysis of the simulated data. Colors move from red to purple as fitness decreases. For coalescent statistics, TMRCA, diversity and N
τ, solid lines represent mean values and gray outlines represent 95% credible intervals across MCMC replicates. TMRCA, diversity and N
τ are measured in units of generations.