Fig. 2.

Diverse evolutionary paths lead to the origin of Dobzhansky–Muller incompatibilities in plants. (A) Two substitutions within a single lineage illustrated by Cf-2 and RCR3 loci in Solanum species. (B) Divergent resolution of an ancestral gene duplication as illustrated by the HPA1 and HPA2 loci in Arabidopsis thaliana populations. (C) Divergent resolution of an ancestral polymorphism at one locus and lineage-specific substitution at a second tightly linked locus as illustrated by the SaF and SaM loci in domesticated Oryza sativa subspecies.