A local survey of the distribution of industrial melanic forms in the moth Biston betularia and estimates of the selective values of these in an industrial environment

Clarke, C. A.; Sheppard, Philip Macdonald

doi:10.1098/rspb.1966.0075

A local survey of the distribution of industrial melanic forms in the moth Biston betularia and estimates of the selective values of these in an industrial environment

The survey shows that there is a rapid decline in the frequency of the industrial melanic carbonaria of the moth Biston betularia from a value of about 97 % in Liverpool to less than 10 % 50 miles to the west in North Wales. The decline in the frequency of the intermediate phenotype insularia in …