Question

Following is the digrammatic representation of the operation of natural selection on different traits. Which of the following options correctly identifies all the three graphs A,B and C?

A. `{:(A,B,C),("Directional","Stabilising","Disruptive"):}`
B. `{:(A,B,C),("Stabilising","Directional","Disruptive"):}`
C. `{:(A,B,C),("Distruptive","Statbilising","Directional"):}`
D. `{:(A,B,C),("Directional","Disruptive","Stabilising"):}`

Answer 1

Correct Answer - B
Stabilising selection favours average sized individuals whereas eliminates small sized individuals. It reduces variation and thus does not promote evolutionary change. But, it maintains the mean value form generation of generation. In directional selection, the population changes towards one particular direction. It favours small or large sized individuals and more the mean size of the population changes. Disruptive in eliminates most of members with mean expression, so may lead to developemnt of two different individuals. it is important in bringing about evolutionary change.