The peppered moth provides a well-known example of natural selection. the light-colored form of the moth was predominant in england before the industrial revolution. in the mid-19th century, a dark-colored form appeared. the difference is produced by a dominant allele of one gene. by about 1900, approximately 90% of the moths around industrial areas were dark colored, whereas light-colored moths were still abundant elsewhere. apparently, birds could readily find the light moths against the soot-darkened background in industrial areas and, therefore, were eating more light moths. recently, use of cleaner fuels has greatly reduced soot in the landscape, and the dark-colored moths have been disappearing. should the two forms of moths be considered separate species?