Evolutionary GEM: Coevolution of Yuccas and Yucca Moths

Abstract

The relationship between yucca moths and yucca plants is an example of obligate mutualism. Many species of yucca plant can be pollinated by only one species of yucca moth, while those yucca moths use the yucca flowers as a safe space to lay their eggs. The traits found in yucca plants and yucca moths that enabled them to cooperate were originally suspected to have arisen due to coevolution. However, the majority of these traits appear to have been present before yuccas became the host plant. In addition, there is a delay in speciation of yucca moth lineages when compared with the phylogenies of yucca plants, suggesting that coevolution was not the main driving force of the mutualistic relationship between the two species. Yucca moths may have acquired adaptations as selection drove the populations to complement the unique template already established by yucca plants.