Public goods games in populations with fluctuating size

Area of Science:

• Evolutionary Game Theory
• Population Dynamics
• Mathematical Biology

Background:

• Traditional evolutionary game dynamics models assume constant population size and focus on strategy frequency.
• Variable population size introduces the possibility of population extinction, impacting evolutionary outcomes.

Purpose of the Study:

• To investigate evolutionary game dynamics within a variable population size framework using an extended Wright-Fisher process.
• To explore how strategy dynamics influence population survival and extinction, particularly in cooperative dilemmas.

Main Methods:

• Utilized an extended Wright-Fisher process to model evolutionary game dynamics with variable population size.
• Incorporated a mutation-selection model to analyze the interplay between strategy, selection, and population viability.
• Examined cooperative dilemmas where cooperators promote survival and defectors drive extinction.

Main Results:

• A continuous influx of cooperators can ensure long-term population survival if selection pressure is sufficiently strong.
• Selection can increase the absolute number of cooperators but may decrease their relative frequency within the population.
• The success of a strategy is multifaceted, depending on both its abundance and its impact on population viability.

Conclusions:

• Evolutionary game dynamics in variable populations redefine the concept of long-term trait success.
• Cooperative strategies are crucial for population persistence in models with extinction risk.
• Selection's role is complex, influencing both strategy abundance and overall population survival.