Related Experiment Video
Updated: Jun 22, 2026
08:39
Shifting Zebrafish Lethal Skeletal Mutant Penetrance by Progeny Testing
Published on: September 1, 2017
Is inbreeding depression lower in maladapted populations? A quantitative genetics model
Ophélie Ronce1, Frank H Shaw, François Rousset
1Université Montpellier 2, Place Eugène Bataillon, 34095 Montpellier cedex 5, France. ophelie.ronce@univ-montp2.fr
Summary
Inbreeding depression, the reduced fitness of offspring from related parents, is influenced by environmental and genetic factors. Our model shows inbreeding depression is minimal in maladapted populations, challenging previous assumptions.
Area of Science:
- Evolutionary Biology
- Quantitative Genetics
- Ecology
Background:
- Inbreeding depression, a reduction in fitness due to mating between related individuals, is known to vary with environmental and genetic contexts.
- Theoretical predictions explaining this variation remain limited, hindering a comprehensive understanding of its ecological and evolutionary implications.
Purpose of the Study:
- To develop a quantitative genetics model predicting inbreeding depression under Gaussian stabilizing selection.
- To link inbreeding depression levels to population maladaptation and environmental shifts.
Main Methods:
- Utilized a quantitative genetics model with additive genetic effects on a single phenotypic trait under stabilizing selection.
- Employed simulations to test analytical predictions in populations with varying degrees of adaptation and environmental conditions.
Main Results:
- Inbreeding depression is predicted to vary with genetic variance and the difference between the breeding value and the optimal phenotype.
- Minimal inbreeding depression is expected in severely maladapted populations.
- The model successfully relates inbreeding depression to population maladaptation and environmental change history.
Conclusions:
- Population history of adaptation, not just environmental harshness, influences inbreeding depression.
- The model offers a novel framework for interpreting experimental results on inbreeding depression across diverse environments.
Related Concept Videos
02:04Conservation of Small Populations
Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less likely to...
01:21Frequency-dependent Selection
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.Positive Frequency-Dependent SelectionIn positive...
01:43Incomplete Dominance
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.
01:23Mechanistic Models: Compartment Models in Individual and Population Analysis
Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least squares (OLS)...
01:49Hardy-Weinberg Principle
Diploid organisms have two alleles of each gene, one from each parent, in their somatic cells. Therefore, each individual contributes two alleles to the gene pool of the population. The gene pool of a population is the sum of every allele of all genes within that population and has some degree of variation. Genetic variation is typically expressed as a relative frequency, which is the percentage of the total population that has a given allele, genotype or phenotype.In the early 20th century,...
02:46Chi-square Analysis
The chi-square test is a statistical hypothesis test. It is used to check whether there is a significant difference between an expected value and an observed value. In the context of genetics, it enables us to either accept or reject a hypothesis, based on how much the observed values deviate from the expected values.
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...