Student research in the Biological Sciences Department

Biology majors at Chapman University are engaged in a variety of research activities that prepare them for graduate school, medical school or other careers in science, medicine, pharmacology or for careers with government agencies. Here are some examples of what some current biology major students are doing (in alphabetical order):

Ali Ansary (biology major) has been working in Dr. de Gouvenain’s lab and can confirm that some hills in San Diego County, where Tecate cypress grows, are steep. His research involves demographic census, tree coring, dendrochronology (tree core analysis) and population modeling to find out whether these trees are on the decline (as other researchers have suggested in the past). He is collecting field data on Forest Service, BLM and California Department of Fish & Game public lands in San Diego and Riverside Counties.

Nohea Arkus and Nicole Johnson, two sophomore biology majors presented their work entitled "The Use of Irradiation for Pathogen Elimination on Fresh-Cut Produce" at the Graduate Women In Science conference held in March at Cal State University Fullerton. They are continuing their work with Dr. Denise Foley in the hopes of being able to present at a National Meeting next year.

Erika Koltavary, with able assistance of a recent graduate of Colorado State University, Brian Hoover, has performed a different kind of experiment with Aplysia in Dr. Wright’s lab. In collaboration with mariculture scientists at the University of Miami they carefully controlled the food that sea hares eat as they are growing up. One kind of food promotes the production of ‘ink’, an anti-predator substance that Aplysia releases when it is under attack. Another kind of food is completely lacking the critical chemicals for ink production, and such animals, normal in all other respects, cannot defend themselves with ink when attacked. They predicted that inkless Aplysia would compensate by showing more sensitization when attacked. This time we were right! Sensitization was more robust and longer lasting in animals with compromised ink glands.

Kimberly Takagi has developed a powerful assay of sea-slug palatability: she simply freeze-dries the slugs (in the Food Sciences freeze dryer!), and mixes the fine powder into small food pellets. Using hermit crabs, she has clearly shown that some slugs are much more palatable than others. Our original hypothesis was that slugs like Dolabrifera and Phyllaplysia, which show minimal learning compared to Aplysia, should compensate by increasing their chemical defenses. To our surprise we found that Phyllaplysia does not compensate for its lack of cognitive defense by increasing its chemical defenses. In fact, careful experiments by Kimberly Takagi clearly demonstrated that just the opposite is true. Hermit crabs ate Phyllaplysia more readily than they did Aplysia. Clearly our “trade-off” hypothesis is due for an overhaul! Kimberly‘s research will be branching out in many directions. She will investigate whether Dolabrifera, another slow learner, will make the trade-off and concentrate more anti-predator chemicals.

Several other biology majors have started research in various labs in the Spring of 2004. Stay tuned to this website for news on their research.