FIGURE 3.

Illustration of local perturbations, using the phylogeny introduced in Figure 1. Pairs of successive panels show the process (left) and the product (right) of the perturbation. a, b) The root is being repositioned elsewhere on the tree. c, d) The length of one branch is being scaled by a factor of α∈[0,∞]. As drawn in panel (d), α = 3. e, f) The subtree defined by Ateles and Galago is being regrafted elsewhere on the branch (shadowed in gray) connecting Macaca to the Homo/Pongo clade. The new graft site is parameterized by λ∈[0,1] in terms of distance from the Homo/Pongo clade as a fraction of total branch length (here 0.77). As drawn in panel (f), λ = 55/77.