On the methods for predicting the effective size of populations under selection

Area of Science:

• Population genetics
• Evolutionary biology
• Quantitative genetics

Background:

• Effective population size (Ne) is crucial for understanding genetic drift and inbreeding.
• Existing models for Ne under selection show apparent inconsistencies.
• Two primary methods exist: neutral allele drift and inbreeding rate.

Purpose of the Study:

• To reconcile differing equations for effective population size under selection.
• To clarify the relationship between drift and inbreeding-based approaches.
• To identify the conditions under which these methods yield consistent results.

Main Methods:

• Analysis of population genetics models.
• Derivation of equations for effective population size.
• Comparison of predictions from drift and inbreeding approaches.
• Incorporation of selective advantage accumulation over generations.

Main Results:

• Inconsistencies between the two approaches are explained by accounting for selective advantage.
• The long-term genetic contribution method, when correctly accounting for mating effects, yields identical results to the drift approach.
• This unification clarifies Ne calculations in populations with selection.

Conclusions:

• The long-term genetic contribution and neutral allele drift methods for effective population size are fundamentally consistent.
• Accurate accounting for mating effects is critical for the validity of the inbreeding approach.
• This work provides a unified framework for effective population size under selection.