TY - JOUR
T1 - Is inbreeding depression lower in maladapted populations? a quantitative genetics model
AU - Ronce, Ophélie
AU - Shaw, Frank H.
AU - Rousset, François
AU - Shaw, Ruth G.
PY - 2009/7/1
Y1 - 2009/7/1
N2 - Despite abundant empirical evidence that inbreeding depression varies with both the environment and the genotypic context, theoretical predictions about such effects are still rare. Using a quantitative genetics model, we predict amounts of inbreeding depression for fitness emerging from Gaussian stabilizing selection on some phenotypic trait, on which, for simplicity, genetic effects are strictly additive. Given the strength of stabilizing selection, inbreeding depression then varies simply with the genetic variance for the trait under selection and the distance between the mean breeding value and the optimal phenotype. This allows us to relate the expected inbreeding depression to the degree of maladaptation of the population to its environment. We confront analytical predictions with simulations, in well-adapted populations at equilibrium, as well as in maladapted populations undergoing either a transient environmental shift, or gene swamping in heterogeneous habitats. We predict minimal inbreeding depression in situations of extreme maladaptation. Our model provides a new basis for interpreting experiments that measure inbreeding depression for the same set of genotypes in different environments, by demonstrating that the history of adaptation, in addition to environmental harshness per se, may account for differences in inbreeding depression.
AB - Despite abundant empirical evidence that inbreeding depression varies with both the environment and the genotypic context, theoretical predictions about such effects are still rare. Using a quantitative genetics model, we predict amounts of inbreeding depression for fitness emerging from Gaussian stabilizing selection on some phenotypic trait, on which, for simplicity, genetic effects are strictly additive. Given the strength of stabilizing selection, inbreeding depression then varies simply with the genetic variance for the trait under selection and the distance between the mean breeding value and the optimal phenotype. This allows us to relate the expected inbreeding depression to the degree of maladaptation of the population to its environment. We confront analytical predictions with simulations, in well-adapted populations at equilibrium, as well as in maladapted populations undergoing either a transient environmental shift, or gene swamping in heterogeneous habitats. We predict minimal inbreeding depression in situations of extreme maladaptation. Our model provides a new basis for interpreting experiments that measure inbreeding depression for the same set of genotypes in different environments, by demonstrating that the history of adaptation, in addition to environmental harshness per se, may account for differences in inbreeding depression.
KW - Genetic variance
KW - Maladaptation
KW - Outbreeding depression
KW - Quantitative traits
KW - Source-sink dynamics
KW - Stabilizing selection
UR - http://www.scopus.com/inward/record.url?scp=67649443945&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67649443945&partnerID=8YFLogxK
U2 - 10.1111/j.1558-5646.2009.00678.x
DO - 10.1111/j.1558-5646.2009.00678.x
M3 - Article
C2 - 19473406
AN - SCOPUS:67649443945
SN - 0014-3820
VL - 63
SP - 1807
EP - 1819
JO - Evolution
JF - Evolution
IS - 7
ER -