Figure 1. Branch size and cumulative branch size examples. The values of the branch size (A) and of the cumulative branch size (C) are shown (in brackets, as (A,C)) at each node of three small example trees. A: a completely balanced tree of 15 nodes; B: a completely imbalanced tree of 15 nodes; C: a subtree of 15 nodes of a real phylogenetic tree, the intraspecific Vibrio vulnificus phylogeny presented in full in Fig. S2A. Note that the value of C at the root is maximum for the fully imbalanced tree, and minimum for the balanced one.