Mapping phenotypes: canalization, plasticity and developmental stability

The relationship between genotype and phenotype is not one to one. This statement is central to our understanding of how natural selection shapes phenotypic evolution. Here, we clarify the links between canalization, plasticity and developmental stability, the three major processes involved in the control of phenotypic variability. We present a short historical review, including the original definitions of these concepts, and then summarize their current meaning and use, highlighting possible sources of confusion. Some of the perspectives allowed by a more synthetic conceptual framework are presented, in the light of the recent advances in molecular and developmental genetics.