Figure 4.—

Cumulative fixation of mutators and concomitant fitness decrease. Results for N = 500, = 0.1, U₀ = 0.025, and t_mut = 0.01 are shown. (A) f = 1.1, t_let = 0; (B) f = 1.3, t_let = 0; (C) f = 1.5, t_let = 0.1. The left y-scale and red crosses show the mutation rate from 30 replicate simulations vs. its fixation time; the gray region shows the variation in fixation time in the replicate runs. The blue curves and the right y-scale show the corresponding fitness decline for each replicate. The mean time to reach fitness 0.01 is listed in Table 1.