 |
| |
|
Current
| |
Jazlen Samboy, '08, Honors Thesis Research: "An Examination of Incipient Speciation in the Form of Behavioral Isolation between Pairs of Populations Experiencing Strong Selection in Different Directions in Drosophila melanogaster." Jazlen is examining four pairs of populations in which one population of each pair has been under strong selection for DDT resistance, while the other has been maintained as an unselected control. The members of each pair have been separated (no gene flow between them) for 50 or more years, which is equivalent to 860-1300 generations in fly time. Evolutionary genetic theory proposes that such pairs of populations should experience changes in combinations of alleles at a variety of genes that cause them to diverge in numerous traits. When brought back together, adults may preferentially mate with members of their own population because of subtle changes in courtship behaviors. Such nonrandom mating is characteristic of the behavioral isolation that is commonly found between species.
Faculty Advisor: Phil Barnes
|
| |
Adam Campos, '08, Honors Thesis Research: "Changes in Brackish Marsh Vegetation and Macrofaunal Communities Following Phragmites australis Control". Adam participated in summer field work on tidal marshes with a team of faculty and students. For his thesis, he is comparing data on vegetation and populations of invertebrates and fish in control marshes and marshes that have been restored by eradication of an invasive plant (Phragmites). The results should show whether marsh restoration projects sponsored by The Nature Conservancy and the Connecticut Department of Environmental Protection have been effective at restoring the biological diversity and productivity of marshes.
Faculty Advisors: Scott Warren and Robert Askins
|
| |
Adrian Idrizi '08, Honors Thesis Research: "Characterization of Denitrifier Diversity in Salt Marshes by Determining Terminal Restriction Fragment Length Polymorphisms of nirS Genes." Adrian is using DNA fingerprinting methods to characterize the denitrifier community based on the gene for dissimilatory nitrite reductase (nirS). Denitrifying bacteria play an important role in the global nitrogen cycle by converting oxidized forms of nitrogen back to atmospheric nitrogen gas. Nitrogen plays a tremendously important role in the biogeochemistry of coastal systems where inputs of nitrogen can stimulate primary production and create eutrophic conditions. Despite the broadly accepted role that microbes play in nitrogen cycling in coastal habitats, little is known about direct and indirect controls on the microbial communities responsible for nitrogen cycling.
Faculty Advisor: Anne Bernhard
|
| |
Rachel Zwick '08, Honors Thesis Research: "Diversity of Denitrifying Bacteria in Salt Marsh Sediments Based on Sequence Analysis of the nirS Gene." Rachel's main focus is identifying how diversity of denitrifiers changes with sediment depth. Denitrifying bacteria convert oxidized forms of nitrogen back to atmospheric nitrogen gas and mediate the loss of nitrogen from coastal ecosystems where nitrogen plays an important role in regulating productivity. Rachel is using DNA sequences of the dissimilatory nitrite reductase gene (nirS) to characterize the denitrifying communities. These genes serve as functional markers, and are responsible for generating the enzymes necessary to reduce nitrite to nitrous oxide and then to elemental nitrogen.
Faculty Advisor: Anne Bernhard
|
| |
David Marshall '09, Independent Study: "Bacterial Diversity Patterns along Latitudinal Gradients." David is studying whether bacterial diversity decreases along increasing latitudinal gradients, a well-known ecological pattern of biodiversity observed among many macroorganisms. David is compiling data from the literature to determine whether there is evidence to support this common ecological pattern among bacteria. He is using the ribosomal RNA gene as a diversity marker.
Faculty Advisor: Anne Bernhard
|
| |
Alex McCorkle '10, is working on the effects of natural ice nucleating bacteria on the freezing tolerance in the ribbed mussel Geukensia Demissa. To do this he has characterized and is identifying ice nucleating bacteria isolated from the mantel fluid from the mussels. He is determining if the bacteria influence overall survival and if tissues have less damage when frozen in the presence of the bacteria. Cell death is being assayed using two fluorescent markers. One emits red light when inside a dead cell. The other emits green light when inside a live cell.
Faculty Advisor: Steve Loomis
|
 | |
Stephen Rossiter '09, William Karis '09, (top photo left to right) and Corrine Folsom, M.A. candidate, Visna Ngov '07, (bottom photo left to right) completed standardized surveys of birds along powerline corridors. They also monitored nest success of prairie warblers and field sparrows on along a powerline. They set up laser-triggered cameras at nests to identify predators that take eggs and nestlings. Their goal is to assess the importance of the low vegetation along powerlines as nesting habitat for several declining species of birds. The results of this study will be directly applicable to improving conservation along powerline corridors, providing data on what types of vegetation management are likely to enhance biological diversity. These same management recommendations also would apply to nature preserves and other conservation lands that are being restored for grassland and shrubland species.
Faculty Advisor: Robert Askins
|
|
|
