A model shows that individuals imprint on a genetically transmitted trait during early ontogeny and choosy females later use those parental images as a basis of mate choice.
A study on guppies, Poecilia reticulata, revealed that the female preference was sufficient to tightly maintain polymorphism in male traits.
The best-known example of disassortative mating in humans is preference for genes in the major histocompatibility complex (MHC) region on chromosome 6.
Specifically, odor profiles in mice are strongly linked to genotypes at the MHC loci controlling changes in the immune response.
[11] Thus, the mice tend to prefer providing "good genes" to their offspring so they will mate with individuals with differences at the MHC loci.
In the seaweed fly, Coelopa frigida, heterozygotes at the locus alcohol dehydrogenase (Adh) have been shown to express better fitness by having higher larval density and relative viability.
White-throated sparrows, Zonotrichia albicollis, prefer strong disassortative mating behaviors regarding the color of their head stripe.
Additionally, the heterozygote arrangement of chromosome 2 from disassortative mating produced offspring of high aggression which is shown to be a social behavior that allows them to dominate their opponents.