Figure 4.

(a) Fixation probability and (b) absorption time versus initial vertex of mutant (cooperator) for a death–birth process on the Frucht graph. In both figures, the game is a Snowdrift Game whose pay-offs are described by pay-off matrix (3.4), and the selection intensity is β = 1. Unlike the Moran process, this process is frequency-dependent, and it is evident that both fixation probabilities and absorption times (measured in number of updates) depend on the initial placement of the mutant. See appendix C for details. Notably, the three vertices (7, 11 and 12) for which both fixation probability and absorption time are highest are the only vertices in the Frucht graph not appearing in a three-cycle. (Online version in colour.)