Introduction: a curious disconnect
Chapter 1 begins with a synopsis of the central argument concerning models of evolution (and theories of causation) that incorporate a mutational introduction process, using a study of laboratory adaptation that shows proportional effects of a 50-fold range of rates for different mutations. The exploration of the role of variation in this book covers mutation and randomness, the neo-Darwinian dichotomy of selection and variation, the shifting-gene-frequencies theory of the Modern Synthesis (and its relation to population-genetic “forces“), developmental bias, self-organization, the emergence of evolvability as a major topic, and the causes of parallel adaptation. This chapter provides a guide to the remainder of the book, and explains how the main arguments relate to more familiar topics such as evo-devo, the distinctiveness of molecular evolution, the “directed mutations“ controversy, and debates about the adequacy of a “Modern Synthesis.”