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A population genetics model for multiple quantitative traits exhibiting pleiotropy and epistasis
1School of Biological Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, U.K.
Journal of Theoretical Biology
|March 29, 2000
Summary
Population genetics models reveal how genomes shape quantitative traits. Stabilizing selection allows populations to drift through sequence space, influenced by mutation, selection, and recombination rates.
Area of Science:
- Population genetics
- Quantitative genetics
- Evolutionary biology
Background:
- Organisms possess genomes with loci influencing quantitative traits.
- Stabilizing selection maintains trait values near optima, considering pleiotropy and epistasis.
- Understanding genotype distribution in sequence space is key to evolutionary dynamics.
Purpose of the Study:
- To model population genetics dynamics under stabilizing selection on quantitative traits.
- To investigate genotype distribution and accessibility in sequence space.
- To analyze the impact of genetic and environmental factors on evolutionary drift.
Main Methods:
- Adaptive walk simulations to identify high-fitness genotypes.
- Simulations of haploid and diploid population evolution on fitness landscapes.
- Analysis of mutation rate, selection strength, population size, and recombination effects.
Main Results:
- Populations exhibit genotype drift in sequence space despite stabilizing selection.
- Three distinct evolutionary regimes identified based on genome complexity (LT vs. L(tot)).
- Neutral evolution on high-fitness plateaux, confined exploration, or wide exploration with compensatory mutations observed.
Conclusions:
- Genotype drift is a significant factor in evolution under stabilizing selection.
- The interplay between genome architecture and evolutionary parameters shapes accessible sequence space.
- Compensatory neutral mutations play a crucial role in population dynamics in specific regimes.
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