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.基于贝叶斯法（Bayesian）与最大似然法（Maximum Likelihood，ML）框架下估算的演化速率，针对100个模拟数据集计算了整体速率变异、不同分支深度间的速率变异以及不同进化支（clade）间的速率变异；所用进化树的分支长度范围为0.01～1.4 替换/位点。由泊松过程预期得到的估算速率变异，通过公式(μ+2σ)/(μ−2σ)计算得出。针对每个数据集，均采用两种方法检验其是否违背分子钟假设：一是对强制实施与未强制实施分子钟的贝叶斯分析结果开展贝叶斯因子比较，二是对最大似然分析实施似然比检验。