Relative reproductive rate at a neutral marker locus induced by two selection regimes. In the absence of migration, overdominant selection (α0 = β2 = 0.8, α2 = β0 = 0.7, α1 = β1 = 1) with segregation distortion (d1 = 0.55, d2 = 0.45) maintains stable polymorphisms in the two demes separately. The blue line shows relative reproductive rate ω1 (27) near this joint overdominant polymorphism for m = 0.01. The red line depicts ω1 under purifying selection (α0 = β2 = 1, α1 = β1 = 0.8, α2 = β0 = 0.2) and segregation distortion (d1 = 0.2, d2 = 0.8) for m = 0.001. The black line represents the Bengtsson (1985) expectation (12) with (1 − s) = 0.8.