Figure 5.
Critical behavior caused by selection noise. (A) Uniformly distributed white noise was added to the target function. Each point represents an independent evolution history under strong selection (M = 1, R = 2, 1,000 elements/organism), showing the (negative of) fitness at the end of 105 generations. Above the critical noise amplitude, no adaptive evolution takes place. (B) Fitness as a function of selection-noise amplitude for the two-genotype analytical model used to derive Eq. 1, with μ21 = 0.47.