Calow (1983) realized that differences between parasites and their free-living
relatives can be explained by the differences in nutrient richness. I
propose a model that is based on Calow's idea which identifies the relative
position of different trophic strategies (e.g. predation, grazing, parasitism and
others) based on (1) the differences by which consumers arrive at their intrinsic
rate of growth, and (2) the ecological impact they inflict on their hosts. I
hypothesize that trophic interactions can be clarified if a parameter is included
that takes into account the host's/prey's fate in the interaction. Moreover, this
model suggests specific trophic evolutionary pathways (TEPs) between each
strategy, and suggests that some pathways are more likely than others. In
particular, parasitoidism is believed to be a highly derived strategy, and the
TEPs presented in the model suggest parasitoidism could have arisen from
either a predator-like or a typical-parasitic ancestor. Though the trophic
categories determined by the model seem intuitive, this approach does
provide, apparently for the first time, an objective, mathematically and
ecologically useful basis for classifying animal trophic relationships. / Graduation date: 1998
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/33848 |
| Date | 30 May 1997 |
| Creators | Morris, A. Kimo |
| Contributors | Rossignol, Philippe A. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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