Figure 2. Distributions of evolutionary rate (σ2) estimates comparing traditional character coding with new methods. Each plot shows the distribution of σ2 values estimated from 100 simulated datasets with a true σ2 = 0. Simulations were run with 6-, 50-, 100-, and 490-taxon trees generated using a birth-death model and simulated species with either cool (24-28°C) or warm niches (25-29°C). Horizontal axes are plotted on a logarithmic scale.