Fig. 4.

Abundance of beneficial multimutation combinations depending on the mutation rate. Abundance of beneficial multimutation combinations, $\phi \left(L\mu \right)$, given by Eq. 24, relative to $r_2$. (A) $r_h\left(h\right)=r_2{\left(h-1\right)}^{-\alpha }$ with $\alpha =0$ (blue), $\alpha =0.5$ (orange), $\alpha =1$ (green), and $\alpha =2$ (red). (B) $r_h\left(h\right)=r_2{\xi }^{h-2}$ de with $\xi =1$ (blue), $\xi =0.9$ (orange), $\xi =0.5$ (green), and $\xi =0.25$ (red).