One fundamental characteristic is reproductive isolation, or the inability of organisms from two closely related species to effectively reproduce with one another. When two closely related species can interbreed, their hybrid offspring often do not develop properly into viable or fertile adults. Over the past year, Sarah Cavanaugh, a Trumbull, Connecticut resident, has been conducting research on this topic through UBRP.

Cavanaugh, a fourth year general biology major, has been working under Dr. Carlos Machado, Assistant Professor of Ecology and Evolutionary Biology. The Machado lab studies the mechanisms of speciation (or process by which new biological species arise) in fruit flies. Cavanaugh aims to determine and characterize which gene copies are being expressed in the hybrid offspring of two common American Drosophila species: D. pseudoobscura and D. persimilis. The male hybrids of these crosses are sterile. This work hopefully will lead to an understanding of which genes may be linked to the cause of this sterility. Ultimately, the identification of these "speciation" genes will enable this research group to ask if reproductive isolation is due to the same set of genes across different species of fruit flies and other organisms.

Sarah's work is funded in part by a grant from the Howard Hughes Medical Institute (52003749).