For each region, the posterior probability for a tree that supports (1) reciprocal monophyly of chimpanzees and bonobos (2) and monophyletic grouping of bonobos (3) chimpanzees as a whole (3–6) each population of chimpanzee separately.

To compute this posterior probability, we counted in how many trees from the posterior distribution was a given population monophyletic, and in how many trees were both bonobos and chimpanzees monophyletic. For the text, we arbitrarily defined a tree as showing support for monophyly if the posterior probability >95% and as showing support for paraphyly if the posterior probability <5%.