Figure 5
From: How does epistasis influence the response to selection?
Evolution of the additive variance under stabilising selection in the presence of epistasis. Top: variance components are plotted against the mutation rate, μ, for the epistatic model (solid lines show the mean, and grey areas the s.d.). The upper line shows the total genotypic variance, VG, that is the sum of additive and nonadditive components (middle, lower lines). This is compared with the variance, V*A, under the corresponding additive model, starting from the same allele frequencies and the same additive effects; this is indistinguishable from VG (upper line). The (small) s.d. among 10 replicates is indicated. Bottom: the variance of additive effects at the beginning and end; this is proportional to the mutational variance V*m. Fitness is 1−z2/(2Vs), Vs=5. The trait, z, is the sum of exponentially distributed main effects plus random pairwise interactions. There are M=1000 biallelic loci, but otherwise parameters are as in Figures 1 and 2. A single realisation of the genetic architecture is used with 10 replicates for each mutation rate starting from allele frequencies drawn from a β-distribution with mean=0.2 and variance 0.2. Simulations are deterministic and run for 50 000 generations. Linkage equilibrium is imposed, so that only allele frequencies are followed.
