Mean and standard deviation of the RF distances with different levels of incongruence. The results of the true and reconstructed gene trees are computed from the distribution of mean distances of all simulations. Note that θ does not increase linearly but the last step is a doubling. The detailed results for θ = 0 and θ = 0:005 are shown in Figure 4 and Figure 9, respectively. Different numbers of simulation replicates were used: 500 for θ = 0 and θ = 0:005 and 200 for the remaining settings.