Generalized norms of reaction for ecological developmental biology

Abstract

A standard norm of reaction (NoR) is a graphical depiction of the phenotypic value of some trait of an individual genotype in a population as a function an environmental parameter. NoRs thus depict the phenotypic plasticity of a trait. The topological properties of NoRs for sets of different genotypes can be used to infer the presence of (non-linear) genotype-environment interactions. While it is clear that many NoRs are adaptive, it is not yet settled whether their evolutionary etiology should be explained by selection on the mean phenotypic trait values in different environments or whether there are specific genes conferring plasticity. If the second alternative is true the NoR is itself an object of selection. Generalized NoRs depict plasticity at the level of populations or subspecies within a species, species within a genus, or taxa at higher levels. Historically, generalized NoRs have routinely been drawn though rarely explicitly recognized as such. Such generalized NoRs can be used to make evolutionary inferences at higher taxonomic levels in a way analogous to how standard NoRs are used for microevolutionary inferences.

Plasticity in latitudinal patterns of leaf N and P of Oryza rufipogon in China

“…The clearest evidence for locally adapted genotypic diversity in O. rufipogon comes from the reaction norms of plant nutrients in the transplantation experiment, which yielded significant genotype × environment interactions (Sarkar & Fuller ). For all leaf nutrient traits, considerable co‐gradient and counter‐gradient variations in norms of reaction were found in the transplantation experiment.…”

The impact of fishing‐induced mortality on the evolution of alternative life‐history tactics in brook charr

“…To account for such plasticity in the process of migration, we adopted a reaction norm approach. Reaction norms in the narrow sense describe how a single genotype is translated into different phenotypes depending on environmental conditions (Stearns 1992), while estimations of reaction norms in field studies must typically rely on the broader notion of population‐level reaction norms (Sarkar and Fuller 2003; Hutchings 2004). Alternative tactics in salmonids have previously been described by reaction norms, based on the idea that the adoption of a particular tactic is governed by thresholds in growth rate (Myers and Hutchings 1986; Thorpe 1986; Bohlin et al.…”

Plasticity, stability, and yield: The origins of Anthony David Bradshaw's model of adaptive phenotypic plasticity

“…In the 1940s, Russian geneticist Theodosius Dobzhansky argued that the evolutionary process leading to higher cognitive function in humans likely involved selection for plasticity in brain development (Dobzhansky & Montagu, 1947). Some Russian biologists did develop theoretical accounts of adaptive phenotypic plasticity in the 1930s and 1940s, but focused mostly on how phenotypic plasticity could alter evolutionary processes, rather than interrogating plasticity in specific traits as products of natural selection (Blacher, 1982;Gause, 1947;Kirpichnikov, 1947;Sarkar & Fuller, 2003;Schmalhausen, 1949).…”