A single mode of canalization

The evolution of mechanisms underlying the buffering of the phenotype against genetic and environmental influences has received much theoretical and experimental attention, yet many issues remain unresolved. Here, we consider the kinds of biological process that are likely to promote this buffering, or canalization, and the circumstances under which the evolution of these mechanisms will be favored. We conclude that evolution should produce a single mode of canalization that will buffer the phenotype against all kinds of perturbation, and that the major fitness benefit driving the fixation of canalizing alleles derives from a reduction in environmental influences on phenotypic variation.