Genotype to Phenotype: Insights from Evo-Devo

All models of evolution make assumptions about how genotypic variation influences phenotypic variation. As such, they make assumptions about development. The simplest such assumption is that genes contribute additively to phenotype. While this is sometimes a reasonable approximation, there are many cases in which it is not. This article discusses a number of these cases in which development cannot be ignored. These include the quantitative genetics of highly correlated traits, questions about the presence or absence of phenotypic traits in large phylogenetic groups, and questions about the evolution of specific loci that interact epistatically in development.