Figure 4.

Illustrations of emergence of (A,B) complete phenotypic sex‐specific dominance reversal (SSDR) or (C,D) an absence of SSDR, given a threshold trait with sexual dimorphism in mean baseline liability and a large‐effect locus with purely additive allelic effects on liability. Specifications are as for Figure 3, where blue and gray denote the alternative homozygotes (aa and AA) and red denotes the heterozygote (Aa). (A,B) Same scenario as Figure 3 except with smaller variances in liability. Liability distributions for the heterozygotes therefore fall almost entirely on opposite sides of the threshold in (A) females versus (B) males, resulting in almost complete SSDR (inset panels). (C,D) Same scenario as Figure 3 except with higher mean baseline liabilities in both (C) females and (D) males. Liability distributions for the heterozygotes therefore fall predominantly on the same side of the threshold in both sexes, resulting in no SSDR (inset panels: red points lie above the dotted lines in both sexes). Parameter values are in Supporting Information S2. Plotted y‐axis scales differ between panels A and B versus C and D.