Evolutionary trajectories for fitness and mutation rate on a complex fitness landscape.

<p>(A) Evolution of average log-fitness±1 s.e.m. for treatments with the mutation rate fixed at <i>U_opt</i> = 4.641 (black) and for treatments with variable mutation rates starting at either 10 (red) or 10⁻³ (blue). (B) Evolution of average log genomic mutation rate±1 s.e.m. for treatments with variable mutation rates starting at either 10 (red) or 10⁻³ (blue). The black line indicates the mutation rate that had produced the highest average fitness for that time point.