Abstracts (first author)
Visual adaptation of threespine stickleback (Gasterosteus aculeatus) to divergent spectral regimes
Vision is a sensory modality of fundamental importance for many animal species, aiding in foraging, the detection of predators and colour based mate choice. Consequently, adaptation to divergent spectral environments is often essential and can influence reproductive isolation. This study collected opsin gene expression data from 11 populations of threespine stickleback (Gasterosteus aculeatus) in order to model the spectral sensitivity of stickleback inhabiting divergent spectral environments. We found that the spectral sensitivity of freshwater stickleback populations was significantly shifted toward longer wavelengths relative to their marine ancestors. The observed divergence in spectral sensitivity was repeated for multiple independently derived populations inhabiting similar spectral habitats, suggesting parallel evolution of the visual system and the action of natural selection. This shift in sensitivity has important implications for prey detection and mate choice. Correspondingly, divergence in the visual system of threespine stickleback could have important implications for speciation in this system and requires further attention. Additionally, the observed shifts in visual sensitivity after freshwater colonization from marine environments could be extremely widespread.