Phenotypic Plasticity

by

Nick Levis, David W. Pfennig

• LAST REVIEWED: 24 November 2021
• LAST MODIFIED: 25 October 2017
• DOI: 10.1093/obo/9780199941728-0093

Introduction

Phenotypic plasticity (often termed “plasticity”) is generally defined as the capacity of an individual organism to alter its behavior, physiology/gene expression, and/or morphology (i.e., some aspect of its phenotype) in direct response to changing environmental conditions. Plasticity is ubiquitous and many have suggested that it can have important ecological and evolutionary implications. Among other things, plasticity may allow organisms to persist in otherwise unfavorable environments, produce novel, complex traits, and experience altered interactions with other members of their community. In recent decades, the evolutionary power of plasticity has received renewed interest. In particular, the process of genetic accommodation has dominated the literature because of its potential relevance to all aspects of biology. However, there is some skepticism regarding the importance of phenotypic plasticity generally, and genetic accommodation specifically, in evolution. Indeed, despite plasticity being acknowledged for over 100 years, its importance to evolutionary biology has evolved from being a relevant source of phenotypic variation, to being considered just developmental noise, to possibly forming the basis of an extended evolutionary synthesis. While phenotypic plasticity may be viewed as a primarily ecological/evolutionary phenomenon, it touches on such diverse fields as behavior, learning, conservation biology, and human health. Because of its pervasiveness, appreciation for and understanding of phenotypic plasticity would be beneficial to all biologists.

General Overview

Although interest in phenotypic plasticity has increased since the 1980s (Forsman 2014), the resulting proliferation of the literature can make it difficult to keep concepts organized. As a starting point, Whitman and Agrawal 2009 should be the first piece read in this entire bibliography because of its accessibility. A common problem when sifting through literature on phenotypic plasticity is the terminology. The authors of Fusco and Minelli 2010 do a good job of defining and clarifying terms in their review. Stearns 1989 provides a historical perspective in terms of the writing, but also provides a brief history of the field (to that point). While a lot of plasticity research focuses on “higher-order” phenotypes, Callahan, et al. 1997 sets the stage for current work on phenotypic plasticity at the molecular level, which is complemented by Piersma and Drent 2003, which emphasizes how physiological processes are phenotypically plastic. Wund 2012 and Forsman 2014 are particularly useful as introductions to the types of questions being asked by plasticity researchers and how one can test hypotheses relating to plasticity. Finally, Nijhout 1990 provides an excellent introduction to the thinking that drives much of the current research being done on plasticity and evolution—particularly that development is completed by genes alone.

• Callahan, H. S., M. Pigliucci, and C. D. Schlichting. 1997. Developmental phenotypic plasticity: Where ecology and evolution meet molecular biology. BioEssays 19:519–525.

  DOI: 10.1002/bies.950190611

  This review highlights how evolutionary and molecular biology can successfully be married to investigate questions of developmental plasticity. It uses the phytochrome-mediated shade-avoidance and light-seeking responses of flowering plants as a model for this approach.

• Forsman, A. 2014. Rethinking phenotypic plasticity and its consequences for individuals, populations, and species. Heredity 115:276–284.

  DOI: 10.1038/hdy.2014.92

  The major strength of this review is its emphasis on how to study and test hypotheses relating to phenotypic plasticity. It provides a “whole-organism” rather than “single-trait” perspective for understanding plasticity.

• Fusco, G., and A. Minelli. 2010. Phenotypic plasticity in development and evolution: Facts and concepts. In Special issue: From polyphenism to complex metazoan life cycles. Edited by G. Fusco and A. Minelli. Philosophical Transactions of the Royal Society B 365:547–556.

  DOI: 10.1098/rstb.2009.0267

  As an introduction to a special volume in the Philosophical Transactions of the Royal Society, this article provides one of the more succinct overviews of phenotypic plasticity, how it evolves, and its role in evolution. It is useful in trying to sort out the myriad of terminology associated with phenotypic plasticity.

• Nijhout, H. F. 1990. Problems and paradigms: Metaphors and the role of genes in development. BioEssays 12:441–446.

  DOI: 10.1002/bies.950120908

  An excellent review of how a gene-driven view of development is flawed. Although it gets a bit technical in places, this generally accessible essay should be read by anyone interested in genetics, development, and/or evolution.

• Piersma, T., and J. Drent. 2003. Phenotypic flexibility and the evolution of organismal design. Trends in Ecology and Evolution 18:228–233.

  DOI: 10.1016/S0169-5347(03)00036-3

  By focusing on reversible forms of phenotypic plasticity (termed phenotypic flexibility), Piersma and Drent offer a perspective that highlights the ubiquity of phenotypic plasticity. They utilize less frequently noted examples of plasticity, pay particular attention to diet-induced changes in body and organ size and life-cycle staging, and emphasize the role of intra-individual variation.

• Stearns, S. C. 1989. The evolutionary significance of phenotypic plasticity. BioScience 39:436–445.

  DOI: 10.2307/1311135

  As an introductory article to a special issue of BioScience, this work sets the stage for the rest of its volume, but also introduces readers to terms and concepts used throughout plasticity literature. Among other things, it gives a short, informative history of the reaction norm concept in evolutionary biology.

• Whitman, D. W., and A. A. Agrawal. 2009. What is phenotypic plasticity and why is it important? In Phenotypic plasticity of insects: Mechanisms and consequences. Edited by D. W. Whitman and T. N. Ananthakrishna, 1–63. Boca Raton, FL: CRC.

  This book chapter should be the first piece read by anyone interested in phenotypic plasticity. Although this chapter is in a book on insects, it provides one of the most accessible, comprehensive overviews of phenotypic plasticity available.

• Wund, M. A. 2012. Assessing the impacts of phenotypic plasticity on evolution. Integrative and Comparative Biology 52:5–15.

  DOI: 10.1093/icb/ics050

  This review (in particular Table 1) is a vital resource for those interested in testing hypotheses related to phenotypic plasticity. Almost acting as a “how-to” guide, it outlines approaches and empirical examples for testing eight key hypotheses of plasticity’s role in evolution.