The generation and maintenance of genetic variation by frequency-dependent selection: constructing polymorphisms...

Area of Science:

• Evolutionary genetics
• Population genetics
• Theoretical biology

Background:

• Genetic variation is crucial for evolution.
• Frequency-dependent selection is a key hypothesis for maintaining genetic variation.
• Previous models often simplify the complex dynamics of allele generation and maintenance.

Purpose of the Study:

• To model frequency-dependent selection with mutation using a construction approach.
• To investigate the pairwise interaction model for generating and maintaining genetic polymorphism.
• To explore the conditions under which genetic variation persists in populations.

Main Methods:

• Utilized a construction approach to model frequency-dependent selection and mutation.
• Applied the pairwise interaction model at the genotypic level.
• Analyzed constructed fitness sets to identify selection signatures.

Main Results:

• Frequency-dependent selection can generate a large number of alleles at a single locus.
• The model produces multiallelic polymorphisms with diverse allele frequencies and fitness relationships.
• Polymorphism levels and mean fitness are uncoupled, leading to persistent invasibility by new mutants and no equilibrium state.
• Identified signatures of heterozygote advantage and positive frequency dependence.

Conclusions:

• Frequency-dependent selection with mutation provides a robust mechanism for generating and maintaining substantial genetic variation.
• The pairwise interaction model demonstrates that populations can avoid equilibrium, facilitating continuous evolutionary dynamics.
• The findings support frequency-dependent selection as a significant driver of evolutionary novelty and polymorphism.