Research in my laboratory combines molecular and genomics techniques with field studies to address central issues in ecology, evolution, behavior and conservation. Major questions under investigation include:

1) Determining the role host-plant shifts play in sympatric speciation for phytophagous insects.

2.) Accessing threats to biodiversity posed by hybridization and introgression following species invasions.

3.) Discerning the adaptive significance of bioluminescent color.

Former graduate students in the lab include:
Joe Roethele (research scientist at Lexicon Genetics, Houston, Texas), Bill Perry (assist. professor at Illinois State University), Kristin Lewis (instructor, Univ. of Notre Dame), Uwe Stolz (staff scientist, Environmental Protection Agency, Cincinnati, Ohio), Ken Filchak (instructor, Univ., of Notre Dame). Current students include: Hatti Dambroski, Frank Xie, Sebastian Velez, Andrew Forbes.

Dr. Feder's departmental webpage

A second ongoing area of Rhagoletis research involves field studies testing the synthetic odor blends of apple, hawthorn and dogwood fruits for their attractiveness to flies in nature. The combination of lab and field research will help us resolve how ecology influences the formation of new races and incipient species.

2.) Accessing threats to biodiversity posed by hybridization and introgression following species invasions. In collaboration with Dr. David Lodge (Univ. Notre Dame), my laboratory has been investigating the role hybridization plays in facilitating species invasions for North American crayfish. Most studies of invasions emphasize the ecological impacts of nonidigenous taxa on natives (e.g., effects related to predation, parasitism, and competition). But hybridization can also pose a serious threat to endemic gene pools. Crayfish are an important study system in this regard because they are keystone species in freshwater communities, controlling the structure and flow of energy in lake and river ecosystems. Moreover, the biodiversity of N. American crayfishes is the greatest in the world (390 taxa comprising 75% of the worlds described species), with many closely related endemics confined to one or a few catchments. Our objective here is to use molecular markers and field surveys to assess the extent to which hybridization is a general threat to crayfish taxa.

3.) Discerning the adaptive significance of bioluminescent color. The Jamaican click beetle, Pyrophorous plagiophthalamus (abbr. P. pl.), provides a rare opportunity to investigate the entire adaptive recursion from enzyme structure and function to phenotype to gene frequency change in natural populations. The beetle bioluminesces from a ventral light organ in the abdominal cleft and a pair of dorsal organs on the pronotum. P. pl. uses the light organs for mate recognition in a similar, but not identical, fashion as fireflies. Males fly at night and continuously display from their ventral organs, while females respond intermittently from the bush using their dorsal organs. What is unique about P. pl. is that different individuals bioluminesce different colors. For example, ventral organs can emit either green, yellow / green, yellow, yellow / orange or orange colored light. As such, P. pl. represents the only known instance of a color polymorphism for any bioluminescent organism. Moreover, the genetic basis for the color polymorphism is known and involves specific amino acid substitutions in the protein.

Uwe Stolz (a Ph. D. student), Keith Wood (Promega Corp.) and I have completed a population / genomics / phylogenetic analysis of cloned ventral luciferase genes from P. pl. and related taxa. The results support an evolutionary progression (positive Darwinian selection) from shorter (green) to longer (orange) wavelength ventral emission occurring on the Jamaican beetle lineage.

On going research involves testing a biogeographic model that the most recently evolved orange arose in an isolated subpopulation before rapidly spreading through Jamaica.

Studies are also being planned to test the visual sensitivity of beetles to different wavelengths of light (leading to the cloning of opsin genes) and to elucidate the ecological basis for the color polymorphism (e.g., sexual selection, predation, character displacement from fireflies), which will let us to complete the adaptive recursion from gene to phenotype to evolutionary change.