Competition as a source of constraint on life history evolution in natural populations

Abstract

Competition among individuals is central to our understanding of ecology and population dynamics. However, it could also have major implications for the evolution of resource-dependent life history traits (for example, growth, fecundity) that are important determinants of fitness in natural populations. This is because when competition occurs, the phenotype of each individual will be causally influenced by the phenotypes, and so the genotypes, of competitors. Theory tells us that indirect genetic effects arising from competitive interactions will give rise to the phenomenon of 'evolutionary environmental deterioration', and act as a source of evolutionary constraint on resource-dependent traits under natural selection. However, just how important this constraint is remains an unanswered question. This article seeks to stimulate empirical research in this area, first highlighting some patterns emerging from life history studies that are consistent with a competition-based model of evolutionary constraint, before describing several quantitative modelling strategies that could be usefully applied. A recurrent theme is that rigorous quantification of a competition's impact on life history evolution will require an understanding of the causal pathways and behavioural processes by which genetic (co)variance structures arise. Knowledge of the G-matrix among life history traits is not, in and of itself, sufficient to identify the constraints caused by competition.

Differentiation of ovarian development and the evolution of fecundity in rapidly diverging exotic beetle populations

“…Competition for resources, such as food or nesting sites, plays a critical role in shaping the ecology, population dynamics, and life histories of natural populations (Fisher, ; Mueller et al, ; Agnew et al, ; Wolf, ; Hadfield et al, ; Wilson, ). In the presence of competition, the expression of a resource‐dependent phenotype in any given individual depends upon the degree to which resource acquisition is limited by competitors (Wilson, ).…”

“…Competition for resources, such as food or nesting sites, plays a critical role in shaping the ecology, population dynamics, and life histories of natural populations (Fisher, ; Mueller et al, ; Agnew et al, ; Wolf, ; Hadfield et al, ; Wilson, ). In the presence of competition, the expression of a resource‐dependent phenotype in any given individual depends upon the degree to which resource acquisition is limited by competitors (Wilson, ). As a resource‐dependent life history trait, fecundity is expected to be heavily influenced by the degree of competition that natural populations experience in the field, and much evidence exists that reproductive output can vary substantially depending on the competitive environment individuals experience either as juveniles (e.g., Credland et al, ) or adults (e.g., Beckers et al, ).…”

Heritability and social brood effects on personality in juvenile and adult life‐history stages in a wild passerine

“…Evidence for social effects on personality is mounting (Carter et al ., ; Courtene‐Jones & Briffa, ; Mahr et al ., ). Niemelä & Santostefano () argue that social interactions can change personality over short and long timescales, and the latter could lead to indirect genetic effects of one individual on those that it interacts with (Bijma, ; Wilson, ). Indirect genetic effects can speed up or slow down the response to selection (Wilson, ; Niemelä & Santostefano, ).…”

“…Niemelä & Santostefano () argue that social interactions can change personality over short and long timescales, and the latter could lead to indirect genetic effects of one individual on those that it interacts with (Bijma, ; Wilson, ). Indirect genetic effects can speed up or slow down the response to selection (Wilson, ; Niemelä & Santostefano, ). Clearly, both an individual's behavioural traits and the selection on these traits can be altered within and by social contexts, complicating the measures of both trait and selection.…”

Green beards in the light of indirect genetic effects

“…The utility of the IGE models has been highlighted numerous times (Bijma & Aanen, 2010;Bijma, Muir, Ellen, et al, 2007a;Bijma, Muir, & Van Arendonk, 2007b;Hadfield & Thomson, 2017;McGlothlin et al, 2010McGlothlin et al, , 2014Nonacs & Hager, 2010;Wilson, 2013).…”