Few observations in biology arouse as much curiosity as those on the shape, function, and mechanics of morphological structures. Evolutionary morphology embraces the “how” of morphology, such as the mechanics of how an animal can bite into a hard object with extraordinary force without knocking out its own teeth or shattering them. It also embraces the “why” of morphology, retracing the patterns of evolution in features to understand how a few basic morphological patterns gave rise to the stunning diversity we see in groups from molluscs to mammals to plants. The “how” and the “why” combine to reveal the ways in which organismal evolution has transformed structures and promoted novel functions as well as patterns of association between morphological features and either geographic area or habitat.