Modeling microevolution in a changing environment: The evolving quasispecies and the Diluted Champion Process

TL;DR

This paper introduces a simplified model of viral evolution that captures the paradoxical low variability within populations despite high overall variability, highlighting how feedback mechanisms can induce punctuated evolution.

Contribution

It presents a novel simplified model that links host immunity feedback to viral population dynamics, explaining the evolving quasispecies phenomenon.

Findings

Model exhibits evolving quasispecies behavior under certain parameters.

Feedback mechanism can induce punctuated evolution.

Provides insights into pathogen survival strategies.

Abstract

Several pathogens use evolvability as a survival strategy against acquired immunity of the host. Despite their high variability in time, some of them exhibit quite low variability within the population at any given time, a somehow paradoxical behavior often called the evolving quasispecies. In this paper we introduce a simplified model of an evolving viral population in which the effects of the acquired immunity of the host are represented by the decrease of the fitness of the corresponding viral strains, depending on the frequency of the strain in the viral population. The model exhibits evolving quasispecies behavior in a certain range of its parameters, ans suggests how punctuated evolution can be induced by a simple feedback mechanism.