Why are some traits constitutive and others inducible? The term costs often appears in work
addressing this issue but may be ambiguously defined. This review distinguishes two …

The size and shape of morphological characters are rarely constant within a species.
Although some characters typically exhibit low levels of phenotypic variation, others vary …

Phenotypic characteristics of animals can change independently from changes in the
genetic code. These plastic phenotypic responses are important for population persistence …

A research agenda for the next phase of plasticity studies calls for contributions from a
diverse group of biologists, working both independently and collaboratively, to pursue four …

Theoretical and empirical work has described a range of scenarios in which plasticity may
shape adaptation to a novel environment. For example, recent studies have implicated a …

Phenotypic plasticity is traditionally defined as the capacity of a given genotype to render
alternative phenotypes under different environmental conditions. Some studies focus on the …

Is behavior special? This question has often had a dual meaning in evolutionary biology.
Not only does it ask whether behavioral expression is different from other traits, but it also …

Exposure to environmental variation is a characteristic feature of normal development, one
that organisms can respond to during their lifetimes by actively adjusting or maintaining their …

The generation of variation is paramount for the action of natural selection. Although
biologists are now moving beyond the idea that random mutation provides the sole source of …

Abstract Development in many organisms appears to show evidence of sensitive windows—
periods or stages in ontogeny in which individual experience has a particularly strong …