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Updated: Aug 6, 2026
04:52
Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
Effect of population structure and stabilizing selection on quantitative genetic variation
Juan Li1, Joachim Hermisson1,2, Himani Sachdeva1,3
1Faculty of Mathematics, University of Vienna, Oskar-Morgenstern-Platz 1, 1090 Vienna, Austria.
Genetics
|July 21, 2026
Summary
Population structure significantly increases genetic variation in subdivided populations, especially below a critical migration rate. This impacts the portability of Genome-Wide Association Studies (GWAS) across different subpopulations.
Area of Science:
- Population Genetics
- Quantitative Genetics
- Evolutionary Biology
Background:
- Polygenic traits are influenced by multiple genes.
- Understanding genetic variation in subdivided populations is crucial for evolutionary studies.
- Stabilizing selection favors intermediate trait values.
Purpose of the Study:
- To investigate genetic variation maintenance in a simple polygenic selection model.
- To analyze variation within and among subpopulations at mutation-selection-migration-drift equilibrium.
- To assess the impact of population structure on trait variation and GWAS portability.
Main Methods:
- Analytical approximations for variance components and statistics (FST, QST).
- Individual-based simulations under the infinite-island model.
- Mean-field approach using single-locus diffusion approximation.
Main Results:
- Population structure inflates genic variance above panmictic levels below a critical migration threshold.
- Subpopulation variation is maximized near this critical migration rate.
- Genetic basis similarity across subpopulations decreases with higher migration rates, affecting GWAS portability.
Conclusions:
- A critical migration threshold governs genetic variation and trait structure in polygenic models.
- Migration rates significantly influence the genetic architecture of traits and GWAS efficacy.
- Analytical models accurately predict population genetic quantities under specific assumptions.
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