TEMPORAL DYNAMICS OF OUTCROSSING AND HOST MORTALITY RATES IN HOST–PATHOGEN EXPERIMENTAL COEVOLUTION
Article first published online: 20 DEC 2012
© 2012 The Author(s). Evolution © 2012 The Society for the Study of Evolution.
Volume 67, Issue 7, pages 1860–1868, July 2013
How to Cite
Morran, L. T., Parrish, R. C., Gelarden, I. A. and Lively, C. M. (2013), TEMPORAL DYNAMICS OF OUTCROSSING AND HOST MORTALITY RATES IN HOST–PATHOGEN EXPERIMENTAL COEVOLUTION. Evolution, 67: 1860–1868. doi: 10.1111/evo.12007
- Issue published online: 1 JUL 2013
- Article first published online: 20 DEC 2012
- Accepted manuscript online: 21 NOV 2012 08:47AM EST
- Manuscript Accepted: 23 OCT 2012
- Manuscript Received: 21 MAY 2012
- National Science Foundation. Grant Number: DEB-0640639
- National Institutes of Health. Grant Number: 1F32GM096482-01
- experimental selection;
- mating systems;
Cross-fertilization is predicted to facilitate the short-term response and the long-term persistence of host populations engaged in antagonistic coevolutionary interactions. Consistent with this idea, our previous work has shown that coevolving bacterial pathogens (Serratia marcescens) can drive obligately selfing hosts (Caenorhabditis elegans) to extinction, whereas the obligately outcrossing and partially outcrossing populations persisted. We focused the present study on the partially outcrossing (mixed mating) and obligately outcrossing hosts, and analyzed the changes in the host resistance/avoidance (and pathogen infectivity) over time. We found that host mortality rates increased in the mixed mating populations over the first 10 generations of coevolution when outcrossing rates were initially low. However, mortality rates decreased after elevated outcrossing rates evolved during the experiment. In contrast, host mortality rates decreased in the obligately outcrossing populations during the first 10 generations of coevolution, and remained low throughout the experiment. Therefore, predominant selfing reduced the ability of the hosts to respond to coevolving pathogens compared to outcrossing hosts. Thus, we found that host–pathogen coevolution can generate rapid evolutionary change, and that host mating system can influence the outcome of coevolution at a fine temporal scale.