Date of Submission

Spring 2012

Academic Program

Biology

Project Advisor 1

John Ferguson

Abstract/Artist's Statement

The trade-off hypothesis of virulence evolution suggests that the morbidity and mortality associated with infection is a consequence of host exploitation by parasites and that evolution of virulence is closely tied to the conditions under which the pathogen is transmitted. According to this model, the trade-off that pathogens make is between the potential fitness benefits conferred by greater exploitation of the host and the potential fitness costs in terms of reduced transmission possibilities if the host dies or alters its behavior. In this project I sought to test this hypothesis using Drosophila melanogaster and Vibrio cholerae. I found that mortality of flies exposed to this pathogen was highly variable and did not follow patterns described by previous research. Although survival of flies fed with V. cholerae was significantly less than flies fed with LB, the curves were not sharp enough to find significant differences in median survival, and sample sizes were not large enough for 100-hour cumulative death rate to be useful as a parameter for estimating virulence. With some changes in experimental design, this model could be improved, but very large sample sizes will be required in order to proceed with testing the original hypothesis.

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Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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