Introduction to Part B

“How fast, as a matter of fact, do animals evolve in nature?” was asked by George Gaylord Simpson (1944) in his renowned book Tempo and Mode in Evolution. Ecological and evolutionary processes are often thought to occur on different time scales, so much so that it is common to hear biologists talk about ecological time in contrast to evolutionary time. However, several decades of study in evolutionary ecology and evolutionary genetics have revealed that the time scales of ecological and evolutionary processes can overlap for many crucial questions posed by ecologists. A number of recent studies have reported on the rapid evolution of morphological, physiological, behavioral, and demographic traits over time scales of a few decades, or tens of generations, which coincides with the time horizon of many conservation schemes. How robust is the evidence that leads to the conclusion of commensurate time scales? What do we know about the ecological and genetic conditions under which fast evolutionary change is likely to occur? How relevant are these conditions from the vantage point of conservation biology? The purpose of Part B is to address these important questions.

One of the classic examples of rapid adaptation in response to environmental change is the celebrated case of the peppered moth (Biston betularia).