Fig. 2

Evolution of the aging rate in prey \({k}_{d}\) in the absence of predators when there is no cost of aging (\(x=0\), a, b), a very low cost (\(x=0.001\), c, d) or a higher cost (\(x=0.01\), e, f). The left panels (a, c, e) show one replicate of the temporal course of evolution for three different initial mean values of \({k}_{d}\); mean \({k}_{d}\) over the prey population is shown. Various replicates look very similar so we do not plot them here. The right panels (b, d, f) are the respective pairwise invasibility plots: while bright colors correspond to low proportions of mutants in the population and hence indicate mutant extinction, dark colors correspond to high proportions of mutants in the population and hence indicate that mutants would eventually replace residents. Other parameters are as in Table 1