Project Director
Becca Price, PhD bprice@uwb.edu
Student Researchers
Anthony Hughes (IAS: STE)
Andrew Jerome (CUSP)
Kelsey Nebeck (CUSP)
Meredith Sibley (CUSP)
Description
Over the last 500 million years, snail shells adapted to different ecological conditions. The shells are compromises, evolutionary solutions to conflicting selective pressures, but surprisingly little is known about those pressures. My research aims to elucidate the role of environmental factors that affect the shells of a marine snail called Nucella lamellosa. During spring 2007, the students in my lab studied how Nucella repairs damage to its shell.
We had 36 specimens of Nucella in the lab, and the students drilled small holes into the shells. In one treatment, the hole was 90 degrees back from the aperture (Figure 1), and in the other treatment, the hole was one revolution-plus-90 degrees back from the aperture. Other specimens formed a control group. To assess how the snails repair the hole, we weighed the specimens every week and took photographs. At the end of the experiment, we found that the weights of the shells in all three treatments were indistinguishable (P> 0.09 in all comparisons, Mann Whitney U Test; Figure 2).
The students also wrote instructions for the methods they mastered, streamlining the experiments that I conducted the following summer. They combed the literature to describe the method used to dye shells at particular times during the experiment, and they also mastered the method for weighing snails.
Work in the lab extended beyond the research centered on snails. We also studied how scientists do research. In weekly lab meetings, students led discussions about papers that they chose from the primary literature. We read the papers in conjunction with chapters from Booth et al.'s Craft of Research (2003), focusing on what hypotheses the authors tested, how they employed evidence in making their claims, and how they acknowledged and responded to weaknesses in their arguments. Because none of the students had taken intro biology, we also spent a lot of time discussing the basics of evolutionary biology.
Anthony Hughes graduate from UW Bothell at the end of Spring Quarter, and he accompanied me as a field assistant at Friday Harbor Laboratories this summer (see inset above). By the end of the summer, Anthony formulated his own project to explore how the density of snails affects the rate at which they grow.
Over the summer, we completed a series of experiments based on the ones we had performed at UW Bothell in the spring. The last bit of data we need to collect for this project is to take thin sections of the shells to determine where and how new shell material was deposited. This requires embedding shells in epoxy and then using a rock saw (at the Burke Museum of Natural History and Culture) to section them. I plan for students to help me make and analyze the thin sections this fall and then to collaboratively write a paper on our results to submit next summer. I hope that we'll be able to attend the Western Society of Naturalists meeting in Fall 2008 where the students can present our results.
Figure 1. At the end of the quarter, the weights of specimens in the three treatments were statistically indistinguishable.
Figure 2. Nucella lamellosa in the process of repairing a hole that we drilled into the shell.
