Figure 5

Mutational statistics for the reference strict phylogeny. Quantitative and statistical analysis of tree properties not only offers useful information about the evolutionary processes under study, but is also a very powerful means of detecting discordances at all stages of the reconstruction. Strict trees are particularly amenable to this treatment. (a) The histogram of point mutations per branch highlights typical patterns of evolution and identifies unusual and possibly error-prone generation points. Red dots represent outliers; and blue dots mark standard ranges and legitimate exceptions within the outlier range, with the green dot signaling the frequency of empty clades. (b) The histogram of individual mutation frequencies (i.e., the number of generation points for each mutation or group of related mutations) aims at the identification of especially important and recurrent mutations and the subsequent study of their patterns of generation.