Popular science writing has received increasing interest, especially in its relation to professional science. I extend the current scholarly focus from the nineteenth to the twentieth century by providing a microhistory of the early popular writings of evolutionary biologist John Maynard Smith. Linking them to the state of evolutionary biology as a professional science as well as Maynard Smith’s own professional standing, I examine the interplay between author, text and audiences. In particular, I focus on Maynard Smith’s book The Theory (...) of Evolution and show how he used it to both promote neo-Darwinism and advocate the utility of mathematics in biology. Following in the footsteps of Charles Darwin and David Lack, Maynard Smith was a science communicator blurring the lines between genres and audiences while contributing to ongoing discussions within and on the profession of evolutionary biology around the Darwin-Wallace centenary. (shrink)