RECONSTRUCTING THE EVOLUTION OF SEXUAL DICHROMATISM: CURRENT COLOR DIVERSITY DOES NOT REFLECT PAST RATES OF MALE AND FEMALE CHANGE
Article first published online: 6 MAY 2014
© 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
Volume 68, Issue 7, pages 2026–2037, July 2014
How to Cite
Price, J. J. and Eaton, M. D. (2014), RECONSTRUCTING THE EVOLUTION OF SEXUAL DICHROMATISM: CURRENT COLOR DIVERSITY DOES NOT REFLECT PAST RATES OF MALE AND FEMALE CHANGE. Evolution, 68: 2026–2037. doi: 10.1111/evo.12417
- Issue published online: 1 JUL 2014
- Article first published online: 6 MAY 2014
- Accepted manuscript online: 1 APR 2014 02:23PM EST
- Manuscript Accepted: 20 MAR 2014
- Manuscript Received: 8 DEC 2013
- plumage evolution;
- sexual dimorphism;
- sexual selection;
Males of sexually dimorphic species often appear more divergent among taxa than do females, so it is often assumed that evolutionary changes have occurred primarily in males. Yet, sexual dimorphisms can result from historical changes in either or both of the sexes, and few previous studies have investigated such patterns using phylogenetic methods. Here, we describe the evolution of male and female plumage colors in the grackles and allies (Icteridae), a songbird clade with a broad range in levels of sexual dichromatism. Using a model of avian perceptual color space, we calculated color distances within and among taxa on a molecular phylogeny. Our results show that female plumage colors have changed more dramatically than male colors in the evolutionary past, yet male colors are significantly more divergent among species today. Historical increases in dichromatism have involved changes in both sexes, whereas decreases in dichromatism have nearly always involved females evolving rapidly to look like males. Dichromatism is also associated with mating system in this group, with monogamous taxa tending to exhibit relatively low levels of sexual dichromatism. Our findings suggest that, despite appearances, female plumage evolution plays a more prominent role in sexual dichromatism than is generally assumed.