Reducing the extinction risk of stochastic populations via non-demographic noise

TL;DR

This paper investigates how non-demographic noise, specifically uncertainty in reaction step size, can significantly decrease the extinction risk of stochastic populations, with implications for evolutionary strategies.

Contribution

It introduces a model incorporating reaction step size variability and demonstrates its impact on population stability, supported by simulations and empirical data analysis.

Findings

Non-demographic noise can reduce extinction risk.

Certain reaction step size distributions are more beneficial.

Model validated with numerical simulations and empirical data.

Abstract

We consider non-demographic noise in the form of uncertainty in the reaction step size, and reveal a dramatic effect this noise may have on the stability of self-regulating populations. Employing the reaction scheme mA->kA, but allowing, e.g., the product number k to be a-priori unknown and sampled from a given distribution, we show that such non-demographic noise can greatly reduce the population's extinction risk compared to the fixed k case. Our analysis is tested against numerical simulations, and by using empirical data of different species, we argue that certain distributions may be more evolutionary beneficial than others.