Figure 1.

The potential influence of different mating/sexual systems on hybridization patterns. The different sections follow the main text: (1) self‐incompatible (SI) systems and the SI × SC rule, (2) self‐compatible systems (selfers, outcrossers and mixed‐maters, SC‐O in the figure is equivalent to SC‐OC in the main text) and (3) sexual systems (dioecy with or without sex chromosomes). On the left‐hand side of each panel, hybridization scenarios are depicted. For each scenario, the two coloured circles represent the mating/sexual system of each taxon, which can affect hybrid zone mode (rectangle) and the level and direction of gene flow (arrows). Possible underlying processes are shown on the middle panel (migration) and on the right‐hand side (selection and recombination). BDMIs, Bateson–Dobzhansky–Muller incompatibilities; S alleles, self‐incompatibility alleles; NFDS, negative frequency dependent selection; t _m, outcrossing rate.