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Rank-order selection is capable of maintaining all genetic polymorphisms
1Dept. of Biology, University of California at San Diego, La Jolla, California 92093.
Genetics
|June 1, 1978
Summary
Organism fitness is linked to heterozygosity ranking. Strong selection can maintain genetic variation in populations around 100,000 individuals, influencing polymorphism behavior differently than neutral models.
Area of Science:
- Population genetics
- Evolutionary biology
- Molecular evolution
Background:
- Organism fitness is influenced by genetic factors.
- Heterozygosity plays a role in genetic variation within populations.
- Understanding the mechanisms maintaining genetic polymorphisms is crucial.
Purpose of the Study:
- To investigate the relationship between organism fitness and heterozygosity.
- To determine the population size required to maintain observed genetic variation through selection.
- To explore how selection affects the behavior of polymorphisms compared to neutral evolution.
Main Methods:
- Modeling the impact of a fitness curve based on heterozygosity ranking.
- Calculating the number of polymorphisms retained at selective equilibrium.
- Estimating the population size necessary for maintaining genetic variation.
Main Results:
- The number of polymorphisms retained increases with the square of population size.
- A population size of approximately 10^5 individuals can maintain observed genetic variation.
- Selected polymorphisms exhibit distinct behavior compared to neutral polymorphisms.
Conclusions:
- Fitness curves related to heterozygosity are a primary driver of organism fitness.
- Selection is sufficiently strong in large populations to maintain substantial genetic variation.
- The dynamics of selected polymorphisms differ significantly from neutral alleles, impacting evolutionary trajectories.
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