Figure 1.—

Evolution of stochastic switching rates in symmetric fitness landscapes, i.e., s = s₀ = s₁. The log₁₀ evolutionarily stable switching rate on the y-axis depends both on the fitness cost of being maladapted in both environments (s) and on the variance of the distribution of waiting times. The mean waiting time is fixed at n = 20 and the variance ranges from zero, which corresponds to a periodic environment where the environment changes exactly every 20 generations, to 400, which corresponds to an exponential distribution (a = 1, b = 20) where the environment changes with probability 0.05 at each generation. Different values of s are plotted using the colored open and solid circles. The expectation that switching rates evolve to be in tune with the rate of environmental change (1/n) is given by the dashed line.