Dissecting correlated characters: adaptive aspects of phenotypic covariation in melanization pattern of Pieris butterflies.

Abstract

Quantifies and analyses variation in the wing-melanization pattern within species for a series of Pieris populations from relatively cool environments in North America and compares results with predictions based on an adaptive hypothesis. The hypothesis correctly predicts many of the qualitative features of covariation in melanization among major regions of the wings, at the level of biogeographic variation among populations, for both male and female Pieris occidentalis. When within-population variation is considered, agreement with the adaptive predictions varies considerably in different populations for both P. occidentalis and P. napi males and females. In both species, there is a consistent difference in melanization pattern between alpine and arctic sites; this difference is discussed in relation to the differences in the radiative environment between these 2 types of 'cold' habitats.-from Authors