TY - JOUR

T1 - Variation in reaction norms

T2 - Statistical considerations and biological interpretation

AU - Morrissey, Michael B.

AU - Liefting, Maartje

PY - 2016/9/1

Y1 - 2016/9/1

N2 - Analysis of reaction norms, the functions by which the phenotype produced by a given genotype depends on the environment, is critical to studying many aspects of phenotypic evolution. Different techniques are available for quantifying different aspects of reaction norm variation. We examine what biological inferences can be drawn from some of the more readily applicable analyses for studying reaction norms. We adopt a strongly biologically motivated view, but draw on statistical theory to highlight strengths and drawbacks of different techniques. In particular, consideration of some formal statistical theory leads to revision of some recently, and forcefully, advocated opinions on reaction norm analysis. We clarify what simple analysis of the slope between mean phenotype in two environments can tell us about reaction norms, explore the conditions under which polynomial regression can provide robust inferences about reaction norm shape, and explore how different existing approaches may be used to draw inferences about variation in reaction norm shape. We show how mixed model-based approaches can provide more robust inferences than more commonly used multistep statistical approaches, and derive new metrics of the relative importance of variation in reaction norm intercepts, slopes, and curvatures.

AB - Analysis of reaction norms, the functions by which the phenotype produced by a given genotype depends on the environment, is critical to studying many aspects of phenotypic evolution. Different techniques are available for quantifying different aspects of reaction norm variation. We examine what biological inferences can be drawn from some of the more readily applicable analyses for studying reaction norms. We adopt a strongly biologically motivated view, but draw on statistical theory to highlight strengths and drawbacks of different techniques. In particular, consideration of some formal statistical theory leads to revision of some recently, and forcefully, advocated opinions on reaction norm analysis. We clarify what simple analysis of the slope between mean phenotype in two environments can tell us about reaction norms, explore the conditions under which polynomial regression can provide robust inferences about reaction norm shape, and explore how different existing approaches may be used to draw inferences about variation in reaction norm shape. We show how mixed model-based approaches can provide more robust inferences than more commonly used multistep statistical approaches, and derive new metrics of the relative importance of variation in reaction norm intercepts, slopes, and curvatures.

KW - Phenotypic plasticity

KW - reaction norm

KW - statistics

UR - http://www.scopus.com/inward/record.url?scp=84985906474&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84985906474&partnerID=8YFLogxK

U2 - 10.1111/evo.13003

DO - 10.1111/evo.13003

M3 - Article

C2 - 27431762

AN - SCOPUS:84985906474

SN - 0014-3820

VL - 70

SP - 1944

EP - 1959

JO - Evolution

JF - Evolution

IS - 9

ER -