Figure 5.

Corrections to the substitution rate for an exponential distribution of beneficial fitness effects. Symbols denote the results of forward-time simulations for N = 10⁵ (triangles) and N = 10⁷ (circles), with the remaining parameters the same as in Figure 4. Once again, Δr_b and Δr_d are calculated using the simulated value of v₀, with x_c estimated from Equation 16 and $s_{\text{b}}^{\ast }$ and $U_{\text{b}}^{\ast }$ estimated from Equation 25. For comparison, the solid red lines show the first-order predictions from Equation 27, using the same estimated values of v₀, x_c, and $s_{\text{b}}^{\ast }.$