title: Postindustrial melanism in the peppered moth.
abstract: New data show the geographical pattern of frequency of the melanic morph carbonaria of the peppered moth, Biston betularia, in 1983-84. These frequencies are compared with data from 1952 to 1970. After 20 years of smoke control, the area of high melanic frequency has contracted to the northeast. The change indicates a disadvantage to carbonaria of about 12 percent compared with 20 years ago. Computer simulations, which do not include the assumption of heterozygote advantage, provide a good match to the surface for the period 1952 to 1970, and also the 1983-84 surface. Experiments on visual predation have been criticized as giving unrepresentative estimates of selection but they permit satisfactory simulations to be made.
authors.forename: L M
authors.initials: LM
authors.lastname: Cook
authors.forename: G S
authors.initials: GS
authors.lastname: Mani
authors.forename: M E
authors.initials: ME
authors.lastname: Varley