This chapter provides a conceptual foundation for understanding change through the lens of evolutionary theory. It challenges the notion of universal behavioral models in economics and instead emphasizes context-dependent adaptation shaped by both biological and cultural evolutions. The discussion draws on key thinkers including Darwin, Veblen, Schumpeter, and Georgescu-Roegen to build a theoretical framework for evolutionary economics. Through a classification of different types of societal change, the chapter highlights how innovations, human-caused transformations, and worldviews interact to shape economic systems. It further explores how key concepts from biology—such as selection, drift, speciation, and inclusive fitness—can be mapped to economic behavior, offering a more dynamic and empirically grounded approach to theory development and policy analysis. This chapter serves as a bridge between foundational ideas and the applied modeling strategies developed in later parts of the book.