Chapter 23: The Evolution of Populations This chapter begins with the idea that we focused on as we closed the last chapter: Individuals do not evolve! Populations evolve. The Overview looks at the work of Peter and Rosemary Grant with Gal?pagos finches to illustrate this point, and the rest of the chapter examines the change in populations over time. As in the last chapter, first read each concept to get the big picture and then go back to work on the details presented by our questions. Don?t lose sight of the conceptual understanding by getting lost in the details! Overview The Smallest Unit of Evolution ?One misconception is that organisms evolve, in the Darwinian sense, during their lifetimes