Species spanning the animal kingdom have evolved extravagant and costly ornaments to attract mating partners. Zahavi's handicap principle offers an elegant explanation for this: ornaments signal individual quality, and must be costly to ensure honest signalling, making mate selection more efficient. Here, we incorporate the assumptions of the handicap principle into a mathematical model and show that they are sufficient to explain the heretofore puzzling observation of bimodally distributed ornament sizes in a variety of species.
Electronic supplementary material is available online at https://dx.doi.org/10.6084/m9.figshare.c.3575198.
- Received September 6, 2016.
- Accepted November 1, 2016.
- © 2016 The Author(s)
Published by the Royal Society. All rights reserved.