Ancestral plasticity may have played an important role in guiding the repeated, parallel evolution of benthic and limnetic ecotypes. In shallow, relatively eutrophic lakes, stickleback forage for large invertebrates on the lake bottom and are characterized by deep bodies, large mouths, and relatively small eyes. Stickleback populations in deeper, more oligotrophic lakes spend their lives eating plankton in the water column, and have more fusiform bodies, small, upturned mouths, and relatively large eyes. As ancestral stickleback repeatedly encountered either of these two environments, ancestral developmental plasticity may have differentially shaped their morphology, initiating the evolution of parallel patterns of divergence- an inference compatible with our research findings. Ancestral patterns of plasticity have also evolved in derived, freshwater populations demonstrating evolutionary transitions (genetic accommodation) in the patterns of plasticity (reaction norms). Morphological research has been conducted primarily in collaboration with Matthew Wund. In contrast there is little evidence for armor plasticity in response to selection by invasive northern pike. In response to this voracious invasive predator rapid contemporary evolution of morphology (and behavior) has occurred.