The biological process of evolution—descent with modification—generates and structures the remarkable diversity of life on Earth today and in the geological past. Take a moment to consider the vast number of different kinds of living things: mushrooms, koalas, sunflowers, whales, mosquitoes, kelp, bacteria, tapeworms, lichens, clams, redwoods,…the list could go on and on, seemingly forever. Without some understanding of how the diversity of life was generated, the scope of the diversity may seem overwhelming, perhaps even unknowable. Fortunately the structure of this extraordinary diversity, generated by the process of evolution, can be discovered using the methods of systematics. Evolution can be thought of as “an axiom from which systematic methods and concepts are deduced” (de Queiroz, 1988). Systematics, therefore, provides a way to organize the diversity surrounding us, and make sense of it in an evolutionary framework. Patterns of similarity and difference in morphology, genetics, and development—the evidence of evolution—can only be explained in an evolutionary context by means of systematics. No other method seeks to identify patterns that are evolutionary in origin, generated by the process of common descent.