Journal of Evolutionary Biology · 1993 · 321 citations · 37 references
Life SciencesEvolutionary BiologyGeneticsEvolutionary TheoryPopulation GeneticsQuantitative GeneticsDevelopmental ConstraintsDevelopmental PlasticityEvolutionNatural SelectionPhenotypic PlasticityReaction NormsConstraintsExperimental StudiesGenetic ConstraintsLinear Reaction Norm ModelsNonlinear Reaction Norm ModelsPhenotypic Plasticity GeneticsQuantitative Trait Reaction NormsReaction Norm Slope
Earlier models are special cases of our general model, which incorporates two macroenvironments, linear, and quadratic reaction norms. We present a general quantitative genetic model for the evolution of reaction norms and discuss its limitations, noting the need for more realistic gametic models and additional data on the genetic and developmental bases of plasticity. The model permits any shaped reaction norm and imposes genetic constraints, extending previous models. The model predicts that in temporally varying environments a population converges on the genotype with maximum mean geometric fitness, a linear reaction norm whose slope matches the covariance between developmental and selection environments, and even a linear reaction norm when nonlinear options exist; experimental studies provide limited support.
Abstract We present a general quantitative genetic model for the evolution of reaction norms. This model goes beyond previous models by simultaneously permitting any shaped reaction norm and allowing for the imposition of genetic constraints. Earlier models are shown to be special cases of our general model; we discuss in detail models involving just two macroenvironments, linear reaction norms, and quadratic reaction norms. The model predicts that, for the case of a temporally varying environment, a population will converge on (1) the genotype with the maximum mean geometric fitness over all environments, (2) a linear reaction norm whose slope is proportional to the covariance between the environment of development and the environment of selection, and (3) a linear reaction norm even if nonlinear reaction norms are possible. An examination of experimental studies finds some limited support for these predictions. We discuss the limitations of our model and the need for more realistic gametic models and additional data on the genetic and developmental bases of plasticity.
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