“…Here are what one might call the "canonical complex systems", the particular systems, natural, artificial and fictional, which complex systems science has traditionally and habitually sought to understand. Here we find networks (Wuchty, Ravasz and Barabási, this volume), turbulence [13], physio-chemical pattern formation and biological morphogenesis [14,15], genetic algorithms [16,17], evolutionary dynamics [18,19], spin glasses [20,21], neuronal networks (see Part III, 4, this book), the immune system (see Part III, 5, this book), social insects, ant-like robotic systems, the evolution of cooperation, evolutionary economics, etc. 1 These topics all fall within our initial definition of "complexity", though whether they are studied together because of deep connections, or because of historical accidents and tradition, is a difficult question.…”