The book includes Kettlewell's original papers in the journal Heredity on his classic predation experiments on the peppered moth.
The book is centered on the authors research of evolution of industrial melanism in peppered moths.
These included two-spot ladybirds (Adalia bipuncta) in the U.K. (Creed, 1970) and some Lepidoptera from North America (Owen, 1961).
He has altered many figures and tables slightly compered to the originals which were mostly published in the journal Heredity.
The entomologist and geneticist Michael Majerus reviewed this in his 1998 book Melanism: Evolution in Action, and compared it with more recent studies which did not support some of Kettlewell's conclusions.
Majerus concluded his research in 2007, with results which he described as a complete vindication of the natural selection theory of peppered moth evolution, answering the various questions which had been raised.