Figure 5. Relationship between the intensity of the optimum fluctuation and the fitness effect of various types of mutations during evolution.

Points represent the results of a population that evolved under various conditions of random-walk optimum shift. Horizontal axes indicate the time-averaged fitness of a population. Panels in each column indicate the effect of different types of mutations (same as Figure 4). Nt indicates the total number of mutations that arose during the evolution for each types of mutations. P indicates the proportions of mutations that have beneficial (red), neutral (blue), and deleterious (black) effects, respectively.