Review

Heredity (2015) 115, 335–348; doi:10.1038/hdy.2015.66; published online 5 August 2015

Iterative development and the scope for plasticity: contrasts among trait categories in an adaptive radiation

S A Foster1, M A Wund2, M A Graham1, R L Earley3, R Gardiner2, T Kearns2 and J A Baker1

  1. 1Department of Biology, Clark University, Worcester, MA, USA
  2. 2Department of Biology, The College of New Jersey, Ewing, NJ, USA
  3. 3Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA

Correspondence: Professor SA Foster, Department of Biology, Clark University, 950 Main St, Worcester, MA 01610, USA. E-mail: sfoster@clarku.edu

Received 5 December 2014; Revised 2 June 2015; Accepted 4 June 2015
Advance online publication 5 August 2015

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Abstract

Phenotypic plasticity can influence evolutionary change in a lineage, ranging from facilitation of population persistence in a novel environment to directing the patterns of evolutionary change. As the specific nature of plasticity can impact evolutionary consequences, it is essential to consider how plasticity is manifested if we are to understand the contribution of plasticity to phenotypic evolution. Most morphological traits are developmentally plastic, irreversible, and generally considered to be costly, at least when the resultant phenotype is mis-matched to the environment. At the other extreme, behavioral phenotypes are typically activational (modifiable on very short time scales), and not immediately costly as they are produced by constitutive neural networks. Although patterns of morphological and behavioral plasticity are often compared, patterns of plasticity of life history phenotypes are rarely considered. Here we review patterns of plasticity in these trait categories within and among populations, comprising the adaptive radiation of the threespine stickleback fish Gasterosteus aculeatus. We immediately found it necessary to consider the possibility of iterated development, the concept that behavioral and life history trajectories can be repeatedly reset on activational (usually behavior) or developmental (usually life history) time frames, offering fine tuning of the response to environmental context. Morphology in stickleback is primarily reset only in that developmental trajectories can be altered as environments change over the course of development. As anticipated, the boundaries between the trait categories are not clear and are likely to be linked by shared, underlying physiological and genetic systems.