A major goal in biology is to understand the biological basis of traits that mediate an organism's interactions with its environment. Color mediates organismal success in diverse ways, including camouflage and signaling to other organisms. While pigments such as melanin are one familiar source of coloration, many organisms also employ structural coloration. Structural color is caused by interference of light as it interacts with nanometer-sized physical structures near the surface of an organism. Organisms use structural mechanisms to display colors for which they lack pigments (frequently blue) or to create optical effects like iridescence. Structural coloration is a pervasive and adaptive phenomenon, and is highly relevant for the bio-inspired synthesis of optical materials and devices. This project investigates the biological basis of structural color (e.g. how genes and developmental processes sculpt the underlying nanostructures, as well as how the shapes of nanostructures evolve). The researchers are also involved in outreach to K-12 teachers in rural Nevada.
This study will focus on a single species, the Buckeye butterfly, to explore the biological basis of blue structural color. Although wild buckeyes are predominantly brown, a population that was artificially selected to be a pronounced blue, through structural mechanisms, is recently available. In this study, blue and brown buckeyes will be interbred to generate variably colored offspring. These progeny will be statistically analyzed to correlate extent of blueness with the genetic information carried by each individual, thus identifying genetic loci that regulate structural color. This study will also analyze the nanostructures of six related species to track the evolution of structural color within a phylogenetic context.
