Competition plays a fundamental role in structuring ecological communities, and is a particularly important interaction for sessile organisms such as plants (Goldberg & Fleetwood 1987; Tilman 1994). To mitigate the negative effects of competition on fitness, plants can alter their phenotypes and reproductive traits through plastic responses. For example, decreases in the red to far-red ratio of light signal the presence of competitors, inducing a suite of responses known as shade avoidance syndrome (Franklin 2008).
My thesis examines the impact of the competitive environment on reproductive output, the phenotypes Impatiens capensis produce and natural selection acting on shade avoidance responses. I found that heterospecific competitors affect both the phenotypes of I. capensis, and selection on shade avoidance traits. I also found evidence of population differentiation in hypocotyl lengths and flowering time. My thesis elucidates the influence of competition on the evolution of phenotypic plasticity in Impatiens capensis.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/18912 |
| Date | 15 February 2010 |
| Creators | McGoey, Brechann |
| Contributors | Stinchcombe, John |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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