The fields of community ecology and evolution are theoretically tightly linked, but in general, community ecologists discount evolution in describing the dynamics of present-day community patterns. Yet, evolution in response to strong selection pressure might affect species interactions and alter ecological patterns on a relatively short time scale. Conversely, evolutionary studies are typically limited to examining the evolution of traits in response to, at most, one other species. In more complex communities, higher-order indirect effects emerge that might have significant effects on how species evolve. Evolution in a community context provides more insight into how species evole in natural communities. This dissertation focuses on the evolution of a ciliated protozoan, Colpoda sp. that lives within the water-filled leaves of the purple pitcher plant (Sarracenia purpurea). The evolution of several traits was measured in response to the direct effects of predators (specialist mosquito larvae that live in the same inquilines community), competitors (another co-occuring ciliated protozoan) and indirect effects that emerge when both predators and competitors are present. Two traits (cell size and population growth rate) evolved in response to predation, resulting in predator avoidance and tolerance, respectively. The evolution of these traits resulted in a significant decrease of the ecological effect of predators in only 12 days (approximately 40 prey generations), but less than one predator generation. These same two traits, as well as cyst production, evolved in response to competition. However, evolution in response to the indirect effects that occurred when both predators and competitors were present was stronger and in the opposite direction of direct effects. The result was little net evolution in response to the sum of direct and indirect effects. The importance of these indirect effects suggests that evolution in a community context may proceed much differently from that predicted by the simple additive effects of multiple species. To fully understand how species evolve in natural communities, complex interactions between multiple species must be fully understood. Similarly, to explain ecological patterns, it is imperative to account for the constant evolution of species in response to the suite of other species in their environment. / A Dissertation Submitted to the Department of Biological Science in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy. / Summer Semester, 2010. / April 28, 2010. / Effect Size, Tolerance, Resistance, Prey, Colpidium, Mosquito Larvae, Rapid Evolution, Selection Colpoda, Competition, Predation, Indirect Interactions, 18S rRNA, Character Displacement, Convergence, Divergence / Includes bibliographical references. / Thomas E. Miller, Professor Co-Directing Dissertation; Don R. Levitan, Professor Co-Directing Dissertation; J. Anthony Stallins, University Representative; David Houle, Committee Member; Jeanette L. Wulff, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_176125 |
| Contributors | TerHorst, Casey P. (authoraut), Miller, Thomas E. (professor co-directing dissertation), Levitan, Don R. (professor co-directing dissertation), Stallins, J. Anthony (university representative), Houle, David (committee member), Wulff, Jeanette L. (committee member), Department of Biological Science (degree granting department), Florida State University (degree granting institution) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource, computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
Page generated in 0.0016 seconds