Phenotypic Variation from Single Genotypes: A Primer

Abstract

Abstract A plant senses competitors for light and elongates its stem, accepting and elevating the challenge. A zooplankter senses diurnal predators and alters its daily vertical movements. A great breadth of ideas fall under the rubric of phenotypic plasticity, and this book is designed to express that breadth as a broad historical and conceptual review, bringing together a variety of (sometimes conflicting) viewpoints. In this chapter, we set the stage for the rest of the book by reviewing these diverse ideas under an intentionally broad definition of plasticity: environment-dependent phenotype expression. We emphasize the value of combining proximate, ultimate, and historical views. We hope to convey the need to understand how trait values are influenced by the environment, how individuals vary in this ability, and what such variations imply for how organisms live and reproduce.