Evolutionary dynamics from fluctuating environments with deterministic and stochastic noises

Uncertainty is ubiquitous and has a significant impact on individuals' actions. Inspired by the reality, this paper considers a population affected by changing evolutionary environments with both payoff noise and demographic noise. Meanwhile, we discuss two different types of changing environments, one with deterministic fluctuations and the other with stochastic fluctuations. To explore how changing environments influence the dynamics of cooperation, we first build a theoretical model, which introduces a geometric mean instead of an arithmetic mean of growth rate to present a time-dependent performance of cooperation. Through simulation results, we find that a fluctuating environment with the two noises is beneficial for promoting cooperation, and a deterministic environment is better at promoting cooperation than a stochastic environment. Besides, both deterministic and stochastic fluctuations can make the cooperative species get a higher payoff than the defective species, which is the cause of cooperation promotion. Moreover, in an environment with stochastic noises, the type of time-dependent noise distribution has little impact on evolutionary dynamics. In addition, a high noise variance is beneficial for promoting cooperation, but not for maintaining cooperation.

Automated summary

This paper examines a population affected by changing evolutionary environments with both payoff noise and demographic noise. Two types of changing environments are discussed, one with deterministic fluctuations and the other with stochastic fluctuations. The results show that a fluctuating environment with the two noises promotes cooperation, and a deterministic environment is better at promoting cooperation than a stochastic environment.