Phenotypic variation is necessary for evolution, but despite this central role we currently lack a general understanding of how phenotypic variation is generated. This limits our ability to predict and understand evolution. Here, we treat a specific problem regarding the generation of variation, and its evolutionary consequences: the relationship between the phenotypic effects of genetic and environmental perturbations. Using results from dynamical systems theory, we obtained theoretical conditions for when we should expect an alignment between the phenotypic effects of perturbations with different origins. This alignment occurs because, regardless of their source, the perturbations are affecting the same developmental process that generates the phenotypes. We illustrate using in silico experiments of gene regulatory networks that these conditions for alignment allow us to predict a system’s ability to respond to genetic change –its evolvability– based on how it responds to environmental changes –its plasticity– and vice versa. Alignment can further be used to accelerate or slow down evolution in a desired direction. This insight could hold significance in various fields related to the phenotype, such as environmental interventions and disease management.
Development bridges plasticity and evolvability