The Impact of Environmental Fluctuations on Evolutionary Fitness Functions

TL;DR

This paper explores how environmental fluctuations affect evolutionary fitness, revealing that reduced sensitivity to environmental changes can be more advantageous than higher reproduction rates, and that environmental noise influences fixation times and population dynamics.

Contribution

It demonstrates that environmental variability impacts fitness and fixation times, highlighting the importance of sensitivity reduction as an evolutionary strategy under fluctuating conditions.

Findings

Reduced sensitivity to environmental fluctuations increases fitness.

Environmental noise shortens fixation times for species.

Variability in growth rates influences neutral evolution dynamics.

Abstract

The concept of fitness as a measure for a species's success in natural selection is central to the theory of evolution. We here investigate how reproduction rates which are not constant but vary in response to environmental fluctuations, influence a species' prosperity and thereby its fitness. Interestingly, we find that not only larger growth rates but also reduced sensitivities to environmental changes substantially increase the fitness. Thereby, depending on the noise level of the environment, it might be an evolutionary successful strategy to minimize this sensitivity rather than to optimize the reproduction speed. Also for neutral evolution, where species with exactly the same properties compete, variability in the growth rates plays a crucial role. The time for one species to fixate is strongly reduced in the presence of environmental noise. Hence, environmental fluctuations constitute a possible explanation for effective population sizes inferred from genetic data that often are much smaller than the census population size.