Skip to main content
  • Get access
    Check if you have access via personal or institutional login
  • Cited by 5
  • Cited by
    This chapter has been cited by the following publications. This list is generated based on data provided by CrossRef.

    Baquero, Fernando 2017. Transmission as a basic process in microbial biology. Lwoff Award Prize Lecture. FEMS Microbiology Reviews, Vol. 41, Issue. 6, p. 816.

    Zhou, Fengyan and Yao, Hongxing 2014. Dynamics and Biocontrol: The Indirect Effects of a Predator Population on a Host-Vector Disease Model. Abstract and Applied Analysis, Vol. 2014, Issue. , p. 1.

    Thieme, Horst R. and Smith, Hal L. 2013. Chemostats and epidemics: Competition for nutrients/hosts. Mathematical Biosciences and Engineering, Vol. 10, Issue. 5/6, p. 1635.

    Brown, Charles R. Moore, Amy T. and O'Brien, Valerie A. 2012. Prevalence of Buggy Creek Virus (Togaviridae:Alphavirus) in Insect Vectors Increases Over Time in the Presence of an Invasive Avian Host. Vector-Borne and Zoonotic Diseases, Vol. 12, Issue. 1, p. 34.

    Gandon, Sylvain 2004. EVOLUTION OF MULTIHOST PARASITES. Evolution, Vol. 58, Issue. 3, p. 455.

  • Print publication year: 2002
  • Online publication date: January 2010

2 - Alternative Transmission Modes and the Evolution of Virulence


Introduction: Historical Background

For most of the 20th century, medical scientists writing about the evolution of infectious diseases generally concluded that parasites are expected to evolve toward states of benign coexistence with their hosts (reviewed in Ewald 1994a). According to this line of reasoning, parasites that harm their hosts are harming their own long-term chances of survival, and are therefore at a disadvantage over evolutionary time. Theory developed since the 1980s emphasizes that this traditional viewpoint is based on faulty assumptions about the level at which natural selection acts. Specifically, natural selection is a process by which organismal variants that contribute more of their genetic instructions into future generations become increasingly represented in the gene pool of future generations. When applied to parasite virulence, the appropriate focus is therefore on the short-term competitive processes among parasite variants rather than on the characteristics that would allow a particular parasite species to persist most stably over the long term. According to this reasoning, by the time any variants reap such long-term benefits, they would already have been displaced by the variants that held the short-term advantage. Any increases in long-term survival of the parasite species associated with benignity are therefore of little if any relevance to the evolution of virulence if benign strains lose the short-term competition.

Recommend this book

Email your librarian or administrator to recommend adding this book to your organisation's collection.

Adaptive Dynamics of Infectious Diseases
  • Online ISBN: 9780511525728
  • Book DOI:
Please enter your name
Please enter a valid email address
Who would you like to send this to *