From Bad to Good: Fitness Reversals and the Ascent of Deleterious Mutations
Figure 4
Mutation Accumulation and Mean Fitness of Evolving Populations
The top pane shows the accumulation of beneficial and deleterious mutations in the lineage leading to the MRCA, while the bottom pane shows the mean fitness of the populations over time. In both panes, the thicker lines represent the mean value, and the thin, dotted lines represent bounds for 95% confidence intervals. In the top pane, the dark lines represent beneficial mutations and the light lines represent deleterious mutations (see text for definition). The jaggedness in the lines is the result of averaging over all simulations, which frequently differ in the length of their MRCA lineages. Within any single run the number of mutations monotonically increases. In the lower pane, the dark lines correspond to U = 0.32 and the light lines correspond to U = 0.08.