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  • Open Access

Evolution of mutating pathogens in networked populations

Aviel Ivry*

Reuven Cohen†

Amikam Patron‡

  • *Contact author: aviel9363@gmail.com
  • †Contact author: reuven@math.biu.ac.il
  • ‡Contact author: patron@g.jct.ac.il
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Phys. Rev. Research 8, 043061 – Published 16 October, 2026

DOI: https://doi.org/10.1103/c9vq-tclt

Abstract

Epidemic spreading over population networks has been an important subject of research for several decades, especially during the Covid-19 pandemic. Most epidemic outbreaks are likely to create multiple mutations during their spreading over the population. In this paper, we study the evolution of a pathogen that can mutate continuously during the epidemic spreading. We consider pathogens whose mutating parameter is the mortality mean time and study the evolution of this parameter over the spreading process. We use analytical methods to compute the dynamic equation of the epidemic and the conditions for it to spread. We also use numerical simulations to study the pathogen flow in this case and to understand the mutation phenomena. We show that the natural selection leads to less violent pathogens becoming predominant in the population. We discuss a wide range of network structures and show how different effects are manifested in each case. We also applied our theory in the context of the Covid-19 pandemic, using relevant epidemiological data collected for this outbreak. We provided insights for the variants spreading processes observed throughout this pandemic.

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Outline

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Phys. Rev. Research 8, 043061– Published 16 October, 2026
  • Received 21 October 2022
  • Accepted 5 September 2026
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