| We assume that the relative fitnesses of these genotypes remain constant. |
| The differential fitnesses are weighted averages of phenotype fitnesses. |
| But more importantly, it demonstrated that cultural evolution cannot be predicted purely on the basis of genetic fitnesses. |
| We predict the relative fitnesses of hybrid genotypes by calculating the expected numbers of each type of incompatibility. |
| We ignore environmental variation and deal directly with the fitnesses of genotypic values. |
