Fig. A4.

Scaled substitution trajectories $\tilde{S}$ for different values of initial beneficial mutation rates ${\mu }_{b0}$ on different fitness landscapes (left panel: diminishing returns model with $\alpha (F)=20F^5$ and ${\mu }_b={\mu }_{b0}$, middle panel: House-of-Cards/uncorrelated landscape with $\alpha (F)=100F$ and ${\mu }_b={\mu }_{b0}{e}^{-(F-1)}$, right panel: a mutation-releasing landscape with $\alpha (F)=50e^{F-1},\hspace{0.17em}{\mu }_b={\mu }_{b0}{e}^{F-1}$) [Other parameters: $N={10}^6$, β = 1]. The solid lines are obtained from solving Equation (A27), while the lighter, shaded regions represent the 95%-confidence interval around the mean obtained from the average of 10 simulation replicates. The rescaled time $\tilde{t}$ is the same as that for the fitness trajectories in Fig. A2. The average number of accumulated mutations S is not scaled for the case where ${\mu }_{b0}=1\times {10}^{-8}$, and for the other values of ${\mu }_{b0}$, S is rescaled such that the initial gradient $\frac{d\tilde{S}}{d\tilde{t}}{|}_{t=0}$ is the same as when ${\mu }_{b0}=1\times {10}^{-8}$.