Graduate Student Bios
BS Biology College of William and Mary 2007
Very broadly, I am interested in applying molecular techniques and evolutionary-based studies to questions of conservation concern. My current research is focused on freshwater crayfish in the upper Midwest. The rusty crayfish (Orconectes rusticus) is an aggressive and successful invasive species that has been introduced into the upper Midwest fairly recently. In many freshwater lakes, its introduction has resulted in declines in native crayfish populations as well as a variety of fish and snail species. O. rusticus also hybridizes with the species O. propinquus, producing highly competitive offspring. I am investigating how long O. propinquus genes remain in populations after an invasion has occurred. I also plan on looking at the distribution of rusty crayfish genotypes to try to determine past routes of invasion.
My research interests lie in the field of the evolutionary ecology of insect-plant interactions. I received my M.S. in Population and Conservation Biology at Texas State University addressing ecological dynamics and complex life histories of a gall forming insect under the mentorship of Dr. James Ott. My current focus is on the origin of incipient insect parasitoid species that attacks flies of the Rhagoletis pomonella species complex, a model system for studying sympatric speciation. Previous research by Forbes et al. (Science, 2009) has shown that sequential radiation of R. pomonella from its host-plants (hawthorn to introduced, domesticated apple) has triggered a reciprocal radiation event in a species of parasitoid wasp (Diachasma alloeum) that attacks the R. pomonella complex. I am currently using population genetics techniques with several other species of parasitoids that attack the R. pomonella sibling species complex (Diachasmamorpha mellea and Utetes cancliculatus, and more) to test for sequential radiation in these species among their variety of host (hawthorn, apple, blueberry, and snowberry, etc. infesting flies). Lab and field techniques such as fruit volatile odor testing and eclosion phenology experiments will also allow me to better understand the possible ecological drivers of this phenomenon.
I am also addressing several questions regarding parasitoid co-occurance and/or competition on individual host, local and regional levels to gain insight into how competitive interactions might be driving potential host race formation.
BS Biology Shepherd College 2005
I focus my work on understanding speciation in an ecological context. I am interested in how variation at the molecular genetic level interacts with both abiotic and biotic ecological factors to promote population divergence. My primary study system is Rhagoletis pomonella in unglaciated N. America, where it infests several members of the extremely diverse genus Crataegus as well as Cornus florida. I’m using laboratory and field experiments to look for evidence of host plant adaptation along two key phenotypic axes: eclosion timing and fruit volatile recognition. I’m investigating the genetic architecture of these traits, as well as their effect on overall population genetic structure in this species. I hope to understand the role of southern populations as potential reservoirs for diapause and odor response variation in the classic hawthorn-apple shift and speak to the broader question of the prevalence of sympatric speciation via host-shifts as a general mechanism for adaptive radiation.
I am also involved in a few other projects outside my dissertation work, including population genetics and host plant adaptation of R. pomonella in Pacific Northwest, host plant adaptation in the blueberry maggot fly, R. mendax, hybridization in invasive Tilapia species in Zambia, and understanding the role of top-down control in the demographic release of invasive species.
Gilbert Saint Jean
BS Biology Florida International University 2005
A graduate student in the Feder lab and a GLOBES fellow, I work in partnership with Thomas Streit, CSC, PhD, director of the University of Notre Dame Haiti Program, to apply genetic principles for understanding the co-structure of Culex quinquefasciatus and Wuchereria bancrofti, the vector and causative agent respectively, of Lymphatic Filariasis (LF) in the Caribbean island country of Haiti and in LF elimination efforts worldwide.
BS Ecology and Evolutionary Biological Sciences University of California 2006
A graduate student in the Feder lab and a fellow in the GLOBES program, I conducted undergrad research on the ecological genetics of Brassica rapa and its rapid evolution in the face of climatic shifts under the advisement of Dr. Arthur Weis. After graduating, I participated in a post-baccalaureate fellowship funded by an NSF Frontiers in Integrative Biological Research (FIBR) grant where I studied the quantitative genetics of Arabidopsis thaliana, mapping genes associated with photoperiod sensitivity and gathering data to elucidate differences in biochemical pathways involved with flowering time under the advisement of Dr. Johanna Schmitt. Currently, with Prof. Feder, I am investigating the genetics of incipient sympatric speciation using Rhagoletis pomonella as a model species. Using molecular markers, it is our current goal to determine differences between host races and geographic populations, as well as mapping genes associated with differences in diapause breaking times.