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Coevolution between parasite virulence and host life-history traits
Sylvain Gandon1, Philip Agnew, Yannis Michalakis
1Centre d'Etudes sur le Polymorphisme des Microorganismes, Unité Mixte de Recherche, Centre National de la Recherche Scientifique-IRD 9926, IRD, 911, avenue Agropolis, BP 5045, 34032 Montpellier Cedex 1, France.
The American Naturalist
|August 19, 2008
Summary
Parasitism drives host reproduction, but coevolution with parasites, especially superinfections, complicates this relationship. This study models host-parasite coevolution, revealing complex interactions affecting life-history traits.
Area of Science:
- Evolutionary Biology
- Epidemiology
- Theoretical Ecology
Background:
- Epidemiological models typically examine parasite evolution (virulence, transmission) with static host traits.
- Host trait evolution in response to parasitism is known, but host-parasite coevolution is understudied.
- Resource allocation theory provides a framework for understanding life-history trait evolution.
Purpose of the Study:
- To analyze the coevolution of host reproductive effort and parasite virulence using an epidemiological model.
- To incorporate fixed (genetic) and conditional (plastic) host responses to parasitism.
- To investigate the impact of superinfections on host-parasite coevolutionary dynamics.
Main Methods:
- Development of an epidemiological model based on resource allocation theory.
- Analysis of host-parasite coevolutionary dynamics considering superinfections.
- Modeling of both fixed and phenotypically plastic host responses to parasitism.
Main Results:
- Parasitism consistently favors increased host reproductive effort.
- Epidemiological feedbacks can decouple host reproductive effort from parasite virulence.
- Superinfections drive parasite virulence evolution and generally increase host reproductive effort.
- Coevolution can generate correlations between host and parasite traits across environmental gradients.
Conclusions:
- The study provides a theoretical framework for host-parasite coevolution, integrating resource allocation and epidemiology.
- Coevolutionary dynamics, particularly with superinfections, lead to complex interactions between host and parasite life-history traits.
- Results offer a basis for interpreting experimental and field observations of host-parasite interactions.
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