Records of industrial melanism in British moths

Naturalists in the polluted industrial Britain of the 19th century discovered melanic forms in many species of moths and noted their increasing commonness. This increase came to be studied as a case of rapid adaptive response to a changing environment. More recently, the high frequencies of such forms have reversed as polluting agents have declined. There has been a radical fall in allele frequency in the best studied species, Biston betularia (L.). Frequencies have declined in other species, with differing responses. Study of the dynamics has always depended on sample data, which are dispersed in the literature and not always easy to locate. Sources of earlier information are given and data from the later period are brought together as a resource for further analysis.