COSTS AND CONSTRAINTS CONSPIRE TO PRODUCE HONEST SIGNALING: INSIGHTS FROM AN ANT QUEEN PHEROMONE
Article first published online: 9 APR 2012
© 2012 The Author(s).
Volume 66, Issue 7, pages 2094–2105, July 2012
How to Cite
Holman, L. (2012), COSTS AND CONSTRAINTS CONSPIRE TO PRODUCE HONEST SIGNALING: INSIGHTS FROM AN ANT QUEEN PHEROMONE. Evolution, 66: 2094–2105. doi: 10.1111/j.1558-5646.2012.01603.x
- Issue published online: 3 JUL 2012
- Article first published online: 9 APR 2012
- Accepted manuscript online: 21 FEB 2012 02:38PM EST
- Received April 19, 2011 Accepted February 3, 2012 Data Archived: Dryad: doi:10.5061/dryad.222q601n
- Cuticular hydrocarbons;
- fertility signal;
- Lasius niger
Signal costs and evolutionary constraints have both been proposed as ultimate explanations for the ubiquity of honest signaling, but the interface between these two factors is unclear. Here, I propose a pluralistic interpretation, and use game theory to demonstrate that evolutionary constraints determine whether signals evolve to be costly or cheap. Specifically, when the costs or benefits of signaling are strongly influenced by the sender's quality, low-cost signals evolve. The model reaffirms that cheap and costly signals can both be honest, and predicts that expensive signals should have more positive allometric slopes than cheap ones. The new framework is applied to an experimental study of an ant queen pheromone that honestly signals fecundity. Juvenile hormone was found to have opposing, dose-dependent effects on pheromone production and fecundity and was fatal at high doses, indicating that endocrine-mediated trade-offs preclude dishonesty. Several lines of evidence suggest that the realized cost of pheromone production may be nontrivial, and the antagonistic effects of juvenile hormone indicate the presence of significant evolutionary constraints. I conclude that the honesty of queen pheromones and other signals is likely enforced by both the cost of dishonesty and a suite of evolutionary constraints.