Group selection, individual selection, and the evolution of genetic drift

Area of Science:

• Evolutionary biology
• Population genetics
• Behavioral ecology

Background:

• Genetic drift, the random fluctuation of allele frequencies, significantly impacts evolution in subdivided populations.
• Population member behavior influences the rate of genetic drift, a key factor in evolutionary outcomes.
• Understanding the interplay between behavior, genetic drift, and selection is crucial for evolutionary theory.

Purpose of the Study:

• To investigate the coevolution of behavioral traits affecting genetic drift with traits under group and individual selection.
• To model how behavioral traits that modify genetic drift rates can change in frequency within populations.
• To determine the conditions under which behaviors that enhance genetic drift become prevalent.

Main Methods:

• Development of three mathematical models.
• Simulation of coevolutionary dynamics between behavioral traits and selection pressures.
• Analysis of trait frequencies under varying strengths of group versus individual selection.

Main Results:

• Behavioral traits that increase the rate of genetic drift tend to increase in frequency when group selection is strong relative to individual selection.
• The colonization of vacant sites by population members influences the strength of this evolutionary effect.
• Coevolutionary dynamics reveal a significant role for behavior in modulating genetic drift's impact on evolution.

Conclusions:

• Behavioral traits can evolve to influence genetic drift, particularly under strong group selection.
• The colonization strategy of a population is a critical factor in the evolution of drift-enhancing behaviors.
• This research highlights the complex interactions between behavior, genetic drift, and multilevel selection in shaping evolutionary trajectories.