Anomalously slow attrition times for asymmetric populations with internal group dynamics

TL;DR

This paper reveals that in populations with internal group dynamics, minority groups tend to survive longer than expected, with attrition times influenced by asymmetry and group structure, contrasting traditional theories.

Contribution

It introduces an analytical and numerical framework showing how internal group dynamics cause nonlinear attrition times, especially favoring minority populations, which is a novel insight.

Findings

Minority populations have longer survival times than symmetric ones.

Internal group dynamics significantly alter attrition duration dependence on population asymmetry.

Adding a third population allows tailoring of attrition times based on group sizes.

Abstract

The many-body dynamics exhibited by living objects include group formation within a population, and the non-equilibrium process of attrition between two opposing populations due to competition or conflict. We show analytically and numerically that the combination of these two dynamical processes generates an attrition duration T whose nonlinear dependence on population asymmetry x is in stark contrast to standard mass-action theories. A minority population experiences a longer survival time than two equally balanced populations, irrespective of whether the majority population adopts such internal grouping or not. Adding a third population with pre-defined group sizes allows T(x) to be tailored. Our findings compare favorably to real-world observations.