Frequency-dependent selection: the high potential for permanent genetic variation in the diallelic, pairwise...

Area of Science:

• Evolutionary genetics
• Population genetics
• Theoretical biology

Background:

• Frequency-dependent selection is a key mechanism driving genetic diversity.
• Understanding genotype interactions is crucial for predicting evolutionary trajectories.

Purpose of the Study:

• To analyze the potential for permanent genetic variation in frequency-dependent models with pairwise genotype interactions.
• To investigate the equilibrium structure and gene-frequency dynamics of these models.
• To determine how different genotypic interactions affect the maintenance of genetic diversity.

Main Methods:

• Detailed analytical derivations for the symmetric pairwise interaction model.
• Extensive numerical simulations for general and special cases of the model.
• Analysis of equilibrium patterns and domains of attraction for polymorphic equilibria.

Main Results:

• The pairwise interaction model demonstrates a high potential for permanent genetic diversity.
• Various genotypic interactions were shown to enhance or reduce this potential.
• While two stable polymorphic equilibria are possible, a greater variety of single stable polymorphic equilibria and larger domains of attraction for internal equilibria increase the likelihood of maintaining both alleles.

Conclusions:

• Pairwise genotype interactions in frequency-dependent models strongly influence the maintenance of genetic variation.
• The study highlights the complexity of evolutionary dynamics and the limitations of simple measures like protected polymorphism conditions.
• These findings offer insights into the conditions favoring stable genetic diversity in natural populations.