Probability tables for the average branch length of trees that are allowed to evolve for three time steps.

The entries in this table correspond to the different tree structures obtained at t = 3, as shown in Figure 2B. The first row lists the probability to obtain a certain tree, the second enumerates the length of mature branches contained in this tree and the last row displays the average branching length of these mature branches. Note that the entries 4 and 5 correspond to trees that have identical lists and averages. In particular, these trees contain an early mature branch that has generated two sub-branches. One of these sub-branches has branched again, while the other one is still evolving.