In some contexts, nonlinearity simply means non-straight-line change. As used here, nonlinearity will mean behavior or structure that looks random or complex but which really isn’t, and can be recognized as deterministic when examined in the proper way. Nonlinear systems give rise to this kind of behavior, called chaos, and its signature is a fractal structure. Further, I will show that thinking in a nonlinear way can potentially lead to solutions to problems not otherwise solvable. Throughout the talk I omitted almost all mathematical detail to help foster an intuitive feeling for the power and significance of nonlinearity in biology.