Observing Evolution

The extraordinary tale of the humble peppered moth is at the very foundation of our acceptance of Darwinian evolution. When scientists in the early twentieth century discovered that a British population of the small Biston betularia had rapidly changed in its appearance as a result of the industrial revolution-becoming black in response to its newly sooty environment over the course of mere decades-the revelation cemented Darwin's theory of natural selection. This story was the staple example of "natural selection in action" until the turn of the millennium, when proponents of Creationism fomented doubts about the experimental methods employed. In the midst of this upheaval, scientist Bruce S. Grant was busy collaborating with respected contemporaries to build a dataset that would ultimately vindicate the theory of industrial melanism in the peppered moth and, by extension, the theory of natural selection itself. Observing Evolution tells the remarkable story of his work. Focusing on the little-known but enormously important research of biologists who tested the theory of natural selection after Darwin, Grant describes the historical foundations of research on the peppered moth, then explains how he and his collaborators were able to push this famous study forward. He details how his experiments were designed and conducted, painting a picture of the personalities, events, and adventures around the world that shaped his successes-and struggles. The story culminates with his discovery that peppered moth populations separated by the Atlantic mirrored each other strikingly in terms of the "rise and fall" of melanism, settling a major scientific controversy by documenting nature's repeat experiment. Observing Evolution is a crash course in natural selection and the history of evolutionary biology for anyone interested in Darwin's legacy. It's also a fascinating read for scientists interested in the bridge between the first efforts to count moths and the sophisticated DNA sequencing and statistical modeling that continue to reveal how these tiny organisms can carry such enormous implications.