Effect of changes in population size on the correlation between mutation rate and heterozygosity

Area of Science:

• Population Genetics
• Evolutionary Biology

Background:

• The relationship between mutation rate and heterozygosity is a key concept in population genetics.
• Understanding how population size fluctuations affect this correlation is crucial for evolutionary studies.

Purpose of the Study:

• To investigate the effect of population size changes on the correlation between mutation rate and heterozygosity.
• To compare the outcomes of sudden versus gradual population size changes.

Main Methods:

• Utilized two population genetics models: sudden and gradual changes in population size.
• Performed numerical computations to analyze the correlation under different demographic scenarios.

Main Results:

• Results from sudden and gradual change models are comparable, except for extremely slow gradual changes.
• Expanding populations exhibit a stronger mutation rate-heterozygosity correlation than equilibrium populations.
• Decreasing populations show a weaker correlation compared to equilibrium populations.

Conclusions:

• The simpler sudden population size change model can often approximate gradual changes.
• Population history significantly influences the mutation rate-heterozygosity correlation.
• Molecular weight variation has a minor impact on heterozygosity, especially at low mean heterozygosity.