Evolution and intraspecific exploitative competition. II. A two-locus model for additive gene effects.

Area of Science:

• Population genetics
• Theoretical biology
• Quantitative genetics

Background:

• The Christiansen and Loeschcke (1980) model examines genetic variation at two loci influencing resource utilization.
• Understanding the interplay of selection and linkage is crucial for predicting evolutionary trajectories.

Purpose of the Study:

• To analyze a two-locus genetic model with two alleles per locus.
• To investigate the impact of allele contributions and linkage on genetic disequilibrium.
• To explore the balance between optimizing and disruptive selection.

Main Methods:

• Analysis of a two-locus model.
• Numerical iterations of recurrence equations.
• Exploration of allele contributions and linkage effects.

Main Results:

• High linkage disequilibrium confirmed for small allele contributions and close linkage.
• Results approach those of symmetric viabilities models for larger allele contributions.
• Model degeneracy observed when allele contributions are equal.

Conclusions:

• Genetic disequilibrium is influenced by allele contributions and linkage.
• Selection operates as a balance between optimizing and disruptive forces.
• Small allele contributions lead to results largely independent of specific optimizing genotypes.