In the evolution of industrial melanism in Biston betularia, the allele resultin
ID: 216258 • Letter: I
Question
In the evolution of industrial melanism in Biston betularia, the allele resulting in black body coloration may be considered a favored dominant. In this species, the frequency of melanic moths increased from a value of 1% in 1848 to a value of 95% in 1898. The species has one generation per year.
A. Estimate the approximate value of the selection coefficient s against nonmelanics that would be necessary to account for the change in frequency of the melanic forms.
B. How many generations would be required for the same change in frequency of melanic forms in a hypothetical case in which the allele for melanism is recessive, assuming the same value of s against nonmelanics?
Explanation / Answer
The evolution of the peppered moth is an evolutionary instance of colour change in the moth population as a concequences of air pollution during the industries. the dark coloured of the melanic moth was not known before 1811. after field collection 1848 from Manchester , city in england, the frequency of the variety was to be found. the light coloured type with a record of 98% in 1895. data are presented for the recent change in frequency of melanic morph and peppered moth. the frequency has fallen from 90% in 1983 to below 10% at present. the changes observed agree with a migration selection model, change in atmospheric sulphur dioxide concentration and frequency dependent protection of rare forms, there is a negative relation between atmospheric pollution.
Increasing frequency of typical form of peppered moth in manchester in 1970.
Industrial melanism continues to provide an opportunity to analyse a pattern of selection and change in gene frequency.change in moth populations are broadly correlated with environmental modifications brought about human activity , and experimental work points to differential predation on the moths by birds.The darkest melanic named carbonaria, is solid black, the carbonaria allele shows complete dominance. from the 1950 generations to 1970 indicate the major frequency change in melanic forms. the peppered moth biston and its melanic mutant will be familiar to readers of heredity example of evolutionary change. there are over 200 species of british moths with naturally occuring melanic forms. changes in the environment resulting from increased pollution favored these dark forms and their frequencies increased.