2026/07/10 by Joséphine Ledamoisel, Vincent Debat, Violaine Llaurens · 1 voice
Agricultural and Biological Sciences · Neuroscience · #Animal Behavior and Reproduction #Plant and animal studies #Neurobiology and Insect Physiology Research
paper · doi:10.1093/evlett/qrag028
Abstract The evolution of visual traits in closely related species living in sympatry is highly influenced by their ecological interactions: while sexual selection tends to promote the divergence of visual cues involved in mate choice, natural selection via predation may promote the convergence of dissuasive signals between prey species, especially in unpalatable or evasive prey. Here, we investigate the impact of sympatry on the evolution of the blue structural coloration in the wings of two closely related Morpho butterfly species across several localities throughout Central and South America. Dorsal iridescence might affect mate choice and species recognition, which should promote its local divergence among species. However, the bright flashes and dynamic color patterns produced by iridescence during flight might also increase survival by confusing predators and favoring escape. Such an effect might in turn lead to convergence in wing iridescence between evasive species occurring in sympatry, a phenomenon dubbed evasive mimicry. To test the effect of these putative antagonistic selective forces on visual cues evolution, we quantified the variation of the structural blue color displayed at 13 different combinations of illumination/observation angles, on the wings of 2 closely related Morpho species. We contrasted 10 sympatric and 11 allopatric locations and specifically compared the phenotypic distances between individuals from different species. Phenotypic distances between heterospecific pairs of individuals were significantly smaller in sympatry, suggesting local convergences of iridescence consistent with the expected pattern assuming evasive mimicry. Interestingly, sexual dimorphism was found between males and females, suggesting that the trade-off between natural and sexual selection on the evolution of iridescence might differ between sexes. Our results suggest that local predation pressures may promote repeated evolutionary convergence of structural coloration between evasive prey species living in sympatry.