Casey terHorst

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Assistant Professor
Office location:
Chaparral Hall 5316



Ph.D. Florida State University

Research Specialties

As a community ecologist, I am interested in the factors that allow species to coexist. I am interested in how evolution on contemporary time scales alters the outcome of species interactions and affects species and genetic diversity in communities. However, species in natural communities interact with many other species, so evolutionary outcomes are the result of multiple direct and indirect species interactions. Consequently, I also examine the evolutionary importance of indirect species interactions to better understand how species evolve in a community context.

My research combines theoretical and experimental approaches that bridge the gap between evolutionary biology and community ecology. I have explored these questions in various natural systems, including plant-herbivore interactions in California grasslands, microbial communities that live inside pitcher plants, coral-algal symbioses, and communities of epifaunal marine invertebrates.

For more information, visit my current website at

Selected Publications

terHorst, C. P. and J. A. Lau. 2012. Direct and indirect transgenerational effects alter plant- herbivore interactions. Evolutionary Ecology 26:1469-1480.

Miller, T. E. and C. P. terHorst. 2012. Testing successional hypotheses of stability, heterogeneity, and diversity in pitcher-plant inquiline communities. Oecologia 170: 243-251.

terHorst, C. P. 2012. Context-dependent orientation cues in an intertidal amphipod. Marine and Freshwater Behaviour and Physiology 45: 45-50.

Miller, T.E. and C.P. terHorst. 2012. Indirect effects in communities and ecosystems. Oxford Bibliographies in Ecology. Ed. David Gibson. New York: Oxford University Press.

terHorst, C. P. 2011. Experimental evolution of protozoan traits in response to interspecific competition. Journal of Evolutionary Biology 24: 36-46.

terHorst, C.P., T.E. Miller, and E. Powell. 2010. When can competition for resources lead to ecological equivalence? Evolutionary Ecology Research 12: 843-854.

terHorst, C. P. 2010. Evolution in response to direct and indirect effects in pitcher plant inquline communities. The American Naturalist 176: 675-685.

terHorst, C.P., T.E. Miller and D.R. Levitan. 2010. Discrepancies in evolutionary rates change ecological effect size of predators on prey. Ecology 91: 629-636.

Miller, T. E., C.P. terHorst, and J. H. Burns. 2009. The ghost of competition present. The American Naturalist 173: 347-353.

terHorst, C.P. and S.R. Dudgeon. 2009. Beyond the patch: disturbance affects species abundances in the surrounding matrix community. Journal of Experimental Marine Biology and Ecology 370: 120-126.

Burns, J.H., P. Munguia, B. Nomann, S. Braun, C.P. terHorst, and T.E. Miller. 2008. Vegetative morphology and trait correlations in 54 species of Commelinaceae. Botanical Journal of the Linnean Society 158: 257-268.

terHorst, C.P. and P. Munguia. 2008. Measuring ecosystem function: consequences arising from variation in the biomass-productivity relationship. Community Ecology 9: 36-41.

Levitan, D.R., C.P. terHorst and N.D. Fogarty. 2007. The risk of polyspermy in three congeneric sea urchins and its implications for gametic incompatibility and reproductive isolation. Evolution 61: 2009-2016.

Hoekman, D., C.P. terHorst, A. Bauer, S. Braun, P. Gignac, R. Hopkins, S. Joshi, K. Laskis, N. Sanscrainte, J. Travis, and T. E. Miller. 2007. Oviposition decreased in response to enriched water: a field study of the pitcher-plant mosquito, Wyeomyia smithii. Ecological Entymology 32: 92-96.

Fierst, J.L., C.P. terHorst, J.E. Kubler, and S. R. Dudgeon. 2005. Fertilization success can drive patterns of phase dominance in complex life histories. Journal of Phycology 41:238-249.