Every student of evolution will be familiar with the peppered moth, Biston betularia. It is right up there with the Galápagos finches as an example of evolution happening right under our noses. The story of the rapid spread of dark moths in response to the soot deposition that accompanied the Industrial Revolution, and the reversal of this pattern when air pollution abated, is iconic. Yet, as Emeritus Professor of biology Bruce S. Grant shows, there are a lot more subtleties to it than my one-liner suggests. Observing Evolution details research by himself and many others, and along the way addresses criticism – legitimate and otherwise – levelled at some of the earlier research. Eminently readable, this is a personal story of the rise, fall, and ultimate redemption of one of the most famous textbook examples of evolution in action.