Many toxic animals have bright warning colors to deter predators such as birds and lizards. Often a group of unrelated species mimic one another by sharing a single defensive pattern. For insects such as butterflies that use wing patterns to recognize their own species, especially when they are choosing mates, mimics of different species might be confusing. This group has recently found that the color vision of toxic passion vine or Heliconius butterflies of South and Central America is able to distinguish the Heliconius yellow wing pigments from those of their mimics, whereas the two types of yellow pigment produce colors that are indistinguishable for bird color vision. This project will investigate the differences in color vision between species and sexes of Heliconius butterflies, using molecular, anatomical, biochemical, electrophysiological and next-generation sequencing methods. The resulting data and models of color vision will provide evidence on how color is used for both choosing mates and finding leaves on which to lay eggs and flowers to feed. This study will make predictions about Heliconius color vision that can be tested behaviorally. This research will reveal in unprecedented detail the evolution of color vision within a group of closely-related animals in relation to the signals they encounter in their daily lives. Whereas much is know about sexual differences in animal coloration, virtually nothing is known about sexual differences in color vision. This is a major gap that can now be addressed. Spectral data resulting from this project will be deposited in the Dryad Data Repository http://datadryad.org/ and made freely available to the public. There will be training of a postdoc, graduate and undergraduate students in intracellular recording and anatomical methods, as well as in the analysis of next-generation sequencing data. This research group will recruit undergraduate math and chemistry majors to analyze color reflectance spectra.
