Meeting Abstract
The tight fits between form and function in organisms suggests the influence of adaptive evolution in biomechanics; however, the prevalence of adaptive traits, the mechanisms by which they arise and the corresponding responses to selection are subjects of extensive debate. Recent work is demonstrating that an integrative approach, combining the study of genetics and development with a more thorough approach to phenotypic variation, has the potential to render insight into adaptive divergence more tractable. Because organisms are integrated to function as a whole, associations between quantitative traits of evolutionary interest are predicted to arise from correlated selection or for genetic reasons. Adaptive changes in trophic morphology in fishes are particularly relevant from this perspective, as trophic specializations are often a key component of rapid diversification within lineages. The threespine stickleback (G. aculeatus) provides an intriguing natural framework in which to examine adaptive diversification in the trophic apparatus using an integrative approach: this organism has undergone rapid, repeated evolution from marine to transitional and freshwater habitats, and during the course of these transitions has adapted to occupy different trophic niches within the water column. We characterized phenotypic covariation structure within the stickleback trophic apparatus and its supporting structures in wild and controlled crosses of fish, revealing a key role for development in facilitating rapid evolutionary change. Further, integrating covariation structure and quantitative trait locus analysis holds tremendous promise for establishing new links between genes, development, biomechanics and the environment.
