Figure 4.—

Range of epistasis values under which a modifier increasing recombination increases in frequency, under gametophytic selfing, and under the fitness matrix given in Table 2. (A) Increased recombination is selected between the two vertical planes when α = 10⁻⁵ and between the two other planes when α = 10⁻¹. (B–D) Regions of e_a×a, e_a×d, and e_d×d, where increased recombination is selected, when α = 10⁻⁵ (dotted lines), α = 10⁻² (dashed-dotted lines), and α = 10⁻¹ (dashed-double-dotted lines). Each time, a modifier increasing recombination is predicted to increase in frequency between the two lines (obtained from Equations 29 and 30). Circles correspond to simulation results for α = 10⁻² and 10⁻¹: solid circle, the modifier increases in frequency when rare; open circle, it decreases in frequency. Parameter values are: (B) s = −0.1, h = 0.1, r_ij = 0.2, r_ik = 0.2, e_a×d = 0.01; (C) e_d×d = 0.01; and (D) e_a×a = 0.01. In the simulations, dr = 0.01, h_M = ¹/₂, and u = 10⁻⁵.