This Is AuburnElectronic Theses and Dissertations

Characterizing the Chemical and Structural Basis of Animal Coloration from an Evolutionary Perspective




Justyn, Nicholas

Type of Degree

PhD Dissertation


Biological Sciences


Many questions regarding how animals produce their striking range of colors remain unanswered, particularly when pigments and structures are combined. In this dissertation, I completed four studies centered around questions involving the mechanisms of color production in different groups of animals. For each of these studies, I present evidence detailing unique color production mechanisms that have been previously unstudied. Chapter 1 examines five birds in the Manacus genus to examine color variation in the genus and describes how this new knowledge can inform long standing hypotheses on speciation within their hybrid zones, and the genes involved in feather coloration. Chapter 2 investigates the peculiar case of the persistence of red coloration in the eyespots of Tigriopus californicus copepods on carotenoid-restricted diets, and thoroughly details how carotenoids and nanostructures can be combined in a novel manner. Chapter 3 describes the mechanisms that underlie the wide variety of colors present in the Painted Bunting (Passerina ciris), including the unique lime green back and pink rump feathers. Painted buntings are one of the most colorful birds in North America, yet surprisingly the mechanisms responsible for their coloration were previously largely unexplored. Chapter 4 examines how vultures produce their black and red head coloration and hypothesizes the potential consequences of each mechanism. I hope that by detailing the mechanisms of color production in these groups of animals, that it will also help inform future research involving signaling and the genetic mechanisms responsible for producing the variation in coloration described.