4. Industrial melanism refers to the dark pigmentation that evolved in some inse

ID: 18041 • Letter: 4

Question

4. Industrial melanism refers to the dark pigmentation that evolved in some

insects giving them protective coloration on vegetation darkened by soot in

heavily industrialized areas prior to the requirement for smokestack

filtration. In one heavily polluted area near Birmingham, England in 1956,

87% of the moths of the species

Biston betularia had black bodies due to

the presence of a dominant gene for melanism. Estimate the frequency of

the dominant allele in this population, and the frequency of melanics that

are heterozygous.

5. A group of Parisians were assayed for CCR5-del32 deletion polymorphism.

223 were +/+, 64 were +/del32, and 6 were del32/del32. Are the observed

data significantly different from HWE

Explanation / Answer

Square root method

P---------DOMINANT ALLELE,Q--------RECESSIVE

p^2 + 2pq + q^2 = 1

q^2 = 13/100

Q =SQUARE ROOT OF 13/100=0.36

P+Q=1

P=1-0.36=0.64

phenotype

genotype

Frequency of genotype

black

p^2

0.64 X0.64

0.64 X0.64 X100

41%

black

2pq

2X0.64X0.36

2X0.64X0.36 X100

46.08%

ANSWER

LIGHT

q^2

0.36X0.36

0.36X0.36 X100

12.96%