Figure 7.

Hill–Robertson interference explains part of the difference in equilibrium $U_{\mathrm{d}}$ between sexual (red) and asexual (black) populations. Shown are equilibrium values of the genome-wide deleterious mutation rate $U_{\mathrm{d}}$ vs. census population size N (open circles, replotted from Figure 1) and vs. effective population size $N_{\mathrm{e}}$ (solid circles). Lines are best fit linear models obtained separately using N (dashed lines) or $N_{\mathrm{e}}$ (solid lines) as a dependent variable together with reproductive mode. The total difference in $U_{\mathrm{d}}$ exhibited by sexual and asexual populations of census size $N={10}^4$ (gray line a) is attributable to differences in both the strength and the efficiency of selection acting on genetic architecture. The difference in $U_{\mathrm{d}}$ exhibited by sexual and asexual populations of effective size $N_{\mathrm{e}}=510$ (gray line b) is the proportion of the total difference that remained after controlling for differences in the efficiency of selection that arise through Hill–Robertson interference.