The basic idea of dominant and recessive genes is that:
- Variants compete;
- When two different versions are present at once, sometimes one consistently overshadows the other in terms of its effects.
For example, reef knots dominate granny knots. For another example most words in English dominate those in Esperanto.
Homozygousity is not a terribly useful concept in cultural evolution - but most of the rest of the associated concepts apply about equally well to both realms.