Fig. 1

The evolution of the mutation rate under scenarios of directional environmental change, probability of recombination pR, and percentage of beneficial mutations bm. Each data point corresponds to the mean mutation rate present in the population at the end of each simulation run (200 generations). The number of data points per box is shown in parenthesis (selection parameter γ = 2.2). A weaker selection regime (γ = 3.2) showed a similar pattern (data not shown). Stable env: stable environment (no directional environmental change)