The data table below illustrates the change that occurred in the frequency of phenotypes in an insect population over five years. What is the most probable explanation for this change over time?

Phenotype (genotype) Year 1 | Year 5
Dark Brown (BB and Bb) 2500 | 900
Light Brown (bb) 300 | 3100

A) The adaptive value of allele b increased.
B) The adaptive value of allele b decreased.
C) The population of this insect species increased.
D) The population of this insect species decreased.

Question

The data table below illustrates the change that occurred in the frequency of phenotypes in an insect population over five years. What is the most probable explanation for this change over time? 

Phenotype (genotype)       Year 1 | Year 5 
Dark Brown (BB and Bb)     2500 | 900 
Light Brown (bb)                   300 | 3100 

A) The adaptive value of allele b increased. 
B) The adaptive value of allele b decreased. 
C) The population of this insect species increased. 
D) The population of this insect species decreased.

anonymous · Answer

@Abhisar

anonymous · Answer

@ParthKohli

anonymous · Answer

@Luigi0210 @dan815 please help

anonymous · Answer

I think the answer is A) The adaptive allele B is increased

abhisar · Answer

What do you think it should be?

anonymous · Answer

I think it is A

abhisar · Answer

Yes, that's correct. This is a perfect case when population of dark moths increased after industrial revolution because darker moths were able to adapt much better than lighter ones in pretext of polluted darker background.

anonymous · Answer

Alright, thank you so much for all your help!! @Abhisar