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How does the strength of selection influence genetic correlations?
Stéphane Chantepie1, Luis-Miguel Chevin2
1Centre d'Ecologie et des Sciences de la Conservation (CESCO), Muséum national d'Histoire naturelle, Centre National de la Recherche Scientifique Sorbonne Université Paris France.
Evolution Letters
|December 14, 2020
Summary
Genetic correlations are shaped by mutation and selection. In large populations, selection strength doesn't alter these correlations, but in finite populations, it shifts the balance between drift and selection, impacting evolutionary adaptation.
Area of Science:
- Evolutionary biology
- Quantitative genetics
- Population genetics
Background:
- Genetic correlations between traits influence evolutionary trajectories and adaptation.
- Equilibrium genetic correlations arise from pleiotropic mutation effects and correlational selection.
- The impact of stabilizing selection strength on genetic correlations remains unclear.
Purpose of the Study:
- To investigate how the strength of stabilizing selection affects genetic correlations.
- To determine the role of population size and genetic drift in mediating this relationship.
Main Methods:
- Theoretical modeling of genetic correlations under varying selection strengths and population sizes.
- Analysis of evolutionary dynamics in both Gaussian (small-effect mutations) and House-of-Cards (large-effect mutations) genetic architectures.
- Examination of the interplay between mutation, selection, and genetic drift.
Main Results:
- In large populations, genetic correlations are independent of selection strength, irrespective of mutation effect size.
- In finite populations, selection strength modulates genetic correlations by altering the balance between drift and selection.
- The transition from drift-dominated to selection-dominated dynamics is influenced by mutation parameters.
Conclusions:
- Population size is a critical factor determining the influence of selection strength on genetic correlations.
- Understanding these dynamics is crucial for explaining senescence patterns and adaptation constraints in new environments.
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