Evolution of a finite population under gene conversion

Area of Science:

• Evolutionary genetics
• Population genetics
• Molecular evolution

Background:

• Evolutionary processes like mutation, selection, and genetic drift shape genetic diversity.
• Gene conversion, a non-reciprocal DNA recombination process, also plays a role in evolution.
• Understanding the interplay of these forces is crucial for evolutionary biology.

Purpose of the Study:

• To investigate the evolutionary dynamics at a multiallelic locus under the combined action of gene conversion, mutation, selection, and genetic drift.
• To develop a diffusion approximation model for gene frequency dynamics with these forces.
• To analyze the impact of gene conversion on fixation probabilities and fixation times.

Main Methods:

• Developed a diffusion approximation model for gene frequency dynamics.
• Assumed weak evolutionary forces (gene conversion, mutation, selection, drift).
• Analyzed the model for a two-allele system, extending classical diffusion processes.

Main Results:

• Gene conversion modifies selection parameters in the diffusion model.
• Small gene conversion disparities significantly alter fixation probabilities and reduce fixation times.
• The model demonstrates applicability to biologically general scenarios.

Conclusions:

• Gene conversion is a critical factor influencing the rate of gene substitution.
• Biased gene conversion can lead to the loss of genetic variability within populations.
• Gene conversion can be a key driver of genetic divergence between isolated populations.