Dr. Karen Marchetti

Karen Marchetti received her Ph.D. from UC Davis and performed postdoctoral work at McMaster University, and is currently an Assistant Professor at UC San Diego. Dr. Marchetti’s laboratory investigates the mechanistic bases of signals and perceptual systems used by animals in communication.  To examine the evolution of species differences in the colors used in visual signaling her group is integrating studies of genetic and functional characterization of the genes that code for visual pigments (opsin genes) with studies of the visual behavior and ecology of natural populations.  Her work focuses primarily on two genera of passerine birds, the Old World warblers (genus Phylloscopus) and the New World warblers (genus Dendroica).  The different Phylloscopus species scarcely vary in color, whereas Dendroica species exhibit enormous variation in plumage coloration.  The Phylloscopus and Dendroica groups, which both use color patterns in visual communication, are useful for examining how variation in opsin genes underlies species differences in color patterns, color vision, and visually oriented behaviors.  The long-term goal of her research is to integrate genetic, behavioral, ecological and physiological data as a way to examine how properties of signaling behavior, signal reception and the physical environment interact to drive species divergence in signaling characters, specifically animal color patterns and animal color vision.