Selection in a subdivided population with dominance or local frequency dependence

Area of Science:

• Evolutionary biology
• Population genetics
• Mathematical modeling

Background:

• Population structure influences the effects of natural selection on allele frequencies.
• Subdivision can alter fixation probabilities, particularly under complex selection regimes like dominance or frequency dependence.
• Previous models often simplify population structures, limiting understanding of selection in real-world scenarios.

Purpose of the Study:

• To analytically relate subdivided populations under a finite island model to equivalent panmictic populations.
• To quantify how population subdivision modifies selection parameters, including dominance and frequency dependence.
• To provide a framework for understanding the interplay between population structure and natural selection.

Main Methods:

• Development of analytic results connecting finite island models to panmictic populations.
• Mathematical formulation of equivalent population size and selection parameters.
• Analysis of fixation probabilities under various selection scenarios, including dominance and polynomial frequency dependence.

Main Results:

• Subdivision can significantly alter fixation probabilities, contrary to frequency-independent selection.
• A subdivided population can be represented by an equivalent panmictic population that is larger than the actual population size.
• Selection parameters, such as the degree of dominance, are modified in the equivalent panmictic population.

Conclusions:

• Population subdivision plays a crucial role in shaping evolutionary trajectories under natural selection.
• The finite island model can be effectively approximated by an equivalent panmictic population with adjusted parameters.
• These findings offer insights into the evolutionary dynamics of populations with complex structures and selection patterns.