The biology hidden inside residual within‐individual phenotypic variation

Abstract

Phenotypes vary hierarchically among taxa and populations, among genotypes within 2 populations, among individuals within genotypes, and also within individuals for repeatedly 3 expressed labile phenotypic traits. This hierarchy produces some fundamental challenges to 4 clearly defining biological phenomena and constructing a consistent explanatory framework. We

Circadian Rhythms of Urinary Cortisol Levels Vary Between Individuals in Wild Male Chimpanzees: A Reaction Norm Approach

“…Individual variation in a trait represents the raw material for natural selection and the stability of differences between individuals impacts the efficiency of adaptive responses to selection (Roche et al, 2016). Between individual variation in a trait is generated by differential exposure to relatively stable environmental factors, such as mothering styles (see for instance Liu et al, 1997;Francis and Meaney, 1999;Caldji et al, 2000), or by heritable differences between individuals (Dingemanse et al, 2010b;Forsman, 2015;Westneat et al, 2015). Individual trait repeatability, defined as the proportion of phenotypic variance explained by consistent between individual differences, indicates whether a trait can evolve through selection in principle (Dingemanse and Dochtermann, 2013;Baugh et al, 2014): traits with high repeatability-that is high relative between individual variation-can potentially be selected for if between individual variation is generated by genetic differences.…”

“…Reaction norm repeatability-that is how stable individuals are in their responses to environmental change over time-is expected only when individual attributes related to the costs and benefits of plasticity are stable over time. In the past years, research on average reaction norms and plasticity revealed that both can be subject to sexual and natural selection, and thus have important implications for environmental processes and trait evolution (Piersma and Drent, 2003;Nussey et al, 2005Nussey et al, , 2007Brommer, 2013;Dingemanse and Dochtermann, 2013;Westneat et al, 2015;Martin et al, 2017;Villegas-Ríos et al, 2017).…”

“…Currently, a strand of research in the field of evolutionary ecology focuses on examining levels of repeatability of labile traits, such as behavior or hormonal profiles (Nussey et al, 2007;Baugh et al, 2014;Westneat et al, 2015;Villegas-Ríos et al, 2017) as this is a promising avenue to tackle ultimate questions on selection pressures, adaptation, and fitness implications of traits that are affected by ever changing environmental conditions (Brommer, 2013). A fair share of scientific effort in this line of research has focused on individual repeatability of glucocorticoid levels (e.g., Hruschka et al, 2005;Bonier et al, 2009;Thomas et al, 2009;Dingemanse et al, 2010a;Flinn et al, 2011;Ouyang et al, 2011a;Brommer, 2013;Cockrem, 2013;Narayan and Hero, 2013;Baugh et al, 2014;Hau et al, 2016).…”

Individual quality and personality: bolder males are less fecund in the hermit crabPagurus bernhardus

“…Similarly, Briffa et al [3] described six categories of behavioural variation but again arrived at residual variation within individuals as the finest level of behavioural organization. This fine scale residual variation [4] has also been described as consistency [5], stability [6,7] and recently as predictability and intraindividual variation (hereafter IIV) [3,[8][9][10][11]. Although such hierarchies represent a useful framework for discussing the structure of behavioural variation, the levels are not isolated from one another.…”

Experimental manipulation of brood size affects several levels of phenotypic variance in offspring and parent pied flycatchers

“…In summary, hierarchical analysis of variance allow detection of patterns in the residual variance 560 that then provide new insights into behavioral strategies (Westneat et al 2015 Table 2. Effects of begging in previous visits on parental IVI and load mass.…”