Here Sir Terry Farrell, who has built an international career as an architect-planner, encourages other planners and architects to follow the biologists—look at, learn from, and, indeed, admire the nature of the forces that drive the change, and then with humility and respect work with them to nudge, anticipate and prepare for where it takes us. Searching for patterns within the apparent turbulence and complexity, he analyses the notions of urban design and urban evolution and examines whether or not they need necessarily be seen as opposing one another. The first two chapters discuss emergence as an idea in a biological and architectural context, as well as the distinction between urban design and planning in both education and practice, and the impact of other fields such as landscape design. Seven further chapters examine a range of themes embracing the importance of chain reactions in the progress of urban engineering; the character of habitation; layering; taste and context; adaptation and conversion; the advocacy of the architect-planner; and the effects of digital technology on city evolution. Farrell brings his considerable experience in practice to bear, elucidating his thoughts with examples from cities across the world, including Beijing, Hong Kong, London, New York, and Paris.