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Experimental coevolution: rapid local adaptation by parasites depends on host mating system
Levi T Morran1, Raymond C Parrish, Ian A Gelarden
1Department of Biology, Indiana University, Bloomington, Indiana 47405.
The American Naturalist
|July 26, 2014
Summary
Host mating systems significantly impact coevolutionary dynamics. Obligate outcrossing accelerates host-parasite adaptation and divergence compared to mixed mating systems.
Area of Science:
- Evolutionary Biology
- Genetics
- Ecology
Background:
- Host-parasite interactions drive reciprocal genetic changes (coevolution).
- Host mating systems can influence the rate of coevolutionary change.
- High heritability for resistance and infectivity are key for rapid coevolution.
Purpose of the Study:
- To investigate the effect of host mating systems on coevolutionary rates.
- To compare obligate outcrossing versus mixed mating in Caenorhabditis elegans and Serratia marcescens.
- To determine how host mating systems shape evolutionary trajectories.
Main Methods:
- Experimental coevolution between nematode hosts (Caenorhabditis elegans) and bacterial parasites (Serratia marcescens).
- Manipulation of host mating systems (obligate outcrossing vs. mixed mating).
- Measurement of host adaptation to parasites and parasite adaptation to local hosts.
Main Results:
- Obligately outcrossing hosts showed more rapid adaptation to parasites than mixed-mating hosts.
- Parasites from obligately outcrossing hosts exhibited a greater level of local adaptation.
- Host and parasite populations diverged more significantly under obligate outcrossing.
Conclusions:
- Host mating systems critically shape the pace and pattern of coevolution.
- Obligate outcrossing promotes faster and more divergent coevolutionary trajectories.
- The host's mating system influences the evolutionary paths of both host and parasite populations.
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