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Evolutionary dynamics of pathogen resistance and tolerance.
Journal article

Evolutionary dynamics of pathogen resistance and tolerance.

  • Roy BA Geobotanical Institute, Swiss Federal Institute of Technology (ETH), Zürich, Switzerland. roy@geobot.umnw.ethz.ch
  • Kirchner JW
  • 2000-08-11
Published in:
  • Evolution; international journal of organic evolution. - 2000
Animals
Biological Evolution
Communicable Diseases
Fungi
Genetics, Population
Humans
Models, Biological
Parasitic Diseases
Plant Diseases
English Host organisms can respond to the threat of disease either through resistance defenses (which inhibit or limit infection) or through tolerance strategies (which do not limit infection, but reduce or offset its fitness consequences). Here we show that resistance and tolerance can have fundamentally different evolutionary outcomes, even when they have equivalent short-term benefit for the host. As a gene conferring disease resistance spreads through a population, the incidence of infection declines, reducing the fitness advantage of carrying the resistance gene. Thus genes conferring complete resistance cannot become fixed (i.e., universal) by selection in a host population, and diseases cannot be eliminated solely by natural selection for host resistance. By contrast, as a gene conferring disease tolerance spreads through a population, disease incidence rises, increasing the evolutionary advantage of carrying the tolerance gene. Therefore, any tolerance gene that can invade a host population will tend to be driven to fixation by selection. As predicted, field studies of diverse plant species infected by rust fungi confirm that resistance traits tend to be polymorphic and tolerance traits tend to be fixed. These observations suggest a new mechanism for the evolution of mutualism from parasitism, and they help to explain the ubiquity of disease.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/228136
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