Convergence and Divergence of Eye Morphology in Mimetic Butterflies


Meeting Abstract

105.4  Sunday, Jan. 6  Convergence and Divergence of Eye Morphology in Mimetic Butterflies SEYMOURE, B. M.*; MCMILLAN, W. O.; RUTOWSKI, R. L. ; Arizona State University; Smithsonian Tropical Research Institute; Arizona State University brett.seymoure@gmail.com

Within the animal kingdom there are many groups of mimetic organisms that have converged on phenotypes. Within the tropical butterfly genus of Heliconius, the amounts of mimetic groups are astounding. In the former canal zone of Panama, there are at least five different mimetic groups of Heliconius that have converged on the same wing color and shape, flight pattern, and ecological niches. Previous research has shown that these different mimetic groups occupy different microhabitats within the forest and that these microhabitats differ in light environment. We asked whether co-mimics have converged on eye morphology. We hypothesized that eye morphology has converged within co-mimics because certain eye morphologies are more adaptive in certain light environments. In darker light environments, compound eyes should be structured to heighten sensitivity while in brighter environments, compound eyes should be structured to heighten acuity. We performed three separate studies to test the hypothesis. We measured interommatidial angles, eye size, and facet diameters for two different mimetic groups: postman and blue-white. The postman group consisted of H. erato and H. melpomene, the blue-white consisted of H. cydno and H. sapho. We predicted that the three parameters: eye size, interommatidial angle, and facet diameters will be similar within the mimetic groups but different between mimetic groups. We show similarities and differences in eye morphology for the different mimetic groups and conclude that convergence and divergence has occurred in eye morphology within this mimicry complex.

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