Figure 4
From: The maintenance of sex: Ronald Fisher meets the Red Queen
Adaptation profiles for sexual and clonal host populations at fixed parasite-mutation rates. (a) N = 3000; μ p = 10-4 bits/allele/generation; μ h = 10-7-10-2 bits/allele/ generation; number of loci, L = 10. Black curve = sexual population; red curve = clonal population, under the same steady-state conditions. For a parasite mutation rate, μ p , that is fixed, hosts have optimal adaptation scores when their own mutation rates are similar to or faster than that of the parasite. Curves of relative fitness (green curve) (= adaptation scores adjusted for fecundity) show that cloning displaces sex as the populations optimize. (b) N = 3000; μ p = 10-3 bits/allele/generation; μ h = 10-6-10-1 bits/allele/ generation; number of loci, L = 10. Black curve = sexual population; red curve = clonal population, under the same steady-state conditions. Differences in adaptation scores between clone and sex increase when compared with data in (a) above, an effect attributable to the effect of increased host mutation rates on levels of host polymorphism and polyclonality. The increase in polyclonality disproportionately and adversely affects the adaptation of the clonal population. (c) N = 3000; μ p = 10-4 bits/allele/generation; μ h = 10-6-10-2 bits/allele/ generation; number of loci, L = 20. Black curve = sexual population; red curve = clonal population, under the same steady-state conditions. (d) N = 3000; μ = 10-3 bits/allele/generation; μ p = 10-6-10-1 bits/allele/ generation; number of loci, L = 20. Black curve = sexual population; red curve = clonal population, under the same steady-state conditions. The data are similar to those in (a-c) above but the combination of a larger number of loci and higher parasite mutation rate markedly suppresses the adaptation of the clonal population. Standard Errors of the Mean are approximately the width of the line connecting the data points.