Manipulative Approaches to Testing Adaptive Plasticity: Phytochrome-Mediated Shade-Avoidance Responses in Plants.

Phenotypic plasticity is often assumed to be adaptive, but this hypothesis has rarely been tested. To support the hypothesis, it is necessary to demonstrate that the phenotype induced in each relevant environment confers high fitness in that environment, relative to alternative phenotypes. Unfortunately, such tests are difficult to perform because plasticity prevents the expression of "inappropriate" phenotypes within each environment. Genetic …