Evolutionary potential and constraints in an aposematic species: Genetic correlations between warning coloration and fitness components in wood tiger moths.

Abstract

Variability in warning signals is common but remains puzzling since deviations from the most common form should result in a higher number of predator attacks. One explanation may lie in constraints due to genetic correlations between warning colour and other traits under selection. To explore the relationship between variation in warning colour and different life-history traits, we used an extensive data set comprising 64,741 individuals from a Finnish and an Estonian population of the wood tiger moths, Arctia plantaginis, that have been maintained in captivity over 25 generations. This species exhibits variable warning coloration in larval and adult stages. Measuring these traits alongside several fitness components allowed us to set colour variation into context and obtain a better understanding of selection and constraints. Complete pedigree information enabled us to estimate genetic variances and covariances, which revealed several complex interplays between fitness components: Selection for faster development led to a significantly reduced fecundity. Fecundity was also constrained by negative correlations between direct genetic and maternal effects. However, we found no evidence that genetic associations with life-history traits constrain efficiency of warning colours.