Fig. 4.

Scaled rates of substitution at the two sites relative to the neutral expectation as a function of N_A (the population size at the A/a locus), for the case of free recombination and asymmetry in the strength of selection (s₂ ≠ s₃), with various combinations of effective population sizes and mutation rates between sites. In all cases, u_A = 10⁻⁹. Solid and dashed lines, derived from theory, denote results for the A and B loci, respectively. Parameters in the four panels are set as: (A) $N_A=100N_B$, $u_A=u_B$; (B) $N_A=N_B$, $u_B=100u_A$; and (C) $N_A=100N_B$, $u_B=100u_A$.