Models of compensatory molecular evolution: effects of back mutation

Area of Science:

• Molecular evolution
• Population genetics
• Bioinformatics

Background:

• Compensatory mutations arise when individually deleterious mutations become harmless in specific combinations.
• Understanding the evolutionary dynamics of these mutations is crucial for predicting molecular evolution.
• Back mutations can potentially influence the trajectory of compensatory evolution.

Purpose of the Study:

• To investigate the impact of back mutations on the rate of compensatory molecular evolution.
• To estimate selection parameters for deleterious single mutants in models with and without back mutation.
• To compare these estimates with existing data from folded RNA sequences.

Main Methods:

• Modeling compensatory molecular evolution under different back mutation scenarios.
• Estimating selection coefficients for deleterious mutants using sequence data.
• Analyzing sequence data from folded RNA molecules.

Main Results:

• The rate of compensatory molecular evolution is shown to be weakly affected by back mutations.
• Selection parameters for deleterious single mutants were estimated for models with and without back mutation.
• Estimated values were compared, providing insights into the robustness of evolutionary models.

Conclusions:

• Back mutations play a minor role in the overall rate of compensatory molecular evolution.
• The study provides quantitative estimates of selection parameters, refining our understanding of molecular evolution.
• Findings contribute to the accurate modeling of evolutionary processes in biological systems.