Meeting Abstract
Signal diversity is driven by a variety of selective pressures such as predation and mate recognition. In butterflies, the ventral and dorsal wing surfaces are generally under separate and sometimes opposing selective pressures. We collected reflectance spectra for color patches on the dorsal and ventral wings of individuals in the lepidopteran group Lycaena. We then plotted these colors within a trichromatic and tetrachromatic color space to model the relative stimulation of cones in conspecific and heterospecific (avian) predator visual systems, respectively. We estimated the volume of occupied color space, the average hue disparity, and the color richness to obtain measures of colorfulness and, using phylogenetic comparative methods, we compared the rates of color and contrast evolution for both wing types. We tested the best fit model of evolution for each wing type, considering Brownian motion, Ornstein-Uhlenbeck, diversifying selection and white noise. By comparing the results between color spaces and wing types, we can infer the relative strength of natural and sexual selection on wing surfaces as well as the role of sensory systems in the evolution of signals.
