Question

Name and define the three types of natural selection.

Answer 1

The three types of natural selection are:
(1) Stabilizing or Balancing Selection: It leads to the elimination of organisms having extreme expression. It maintains the homogenous population which is constant. It favors the normal phenotypes
(2) Directional or Progressive Selection: In this, the population changes towards one particular direction as there is a change in environment. As the environment is undergoing continuous change, the organisms having acquired new characters survive, and rests are eliminated
(3) Disruptive or diversifying Selection: It is a type of natural selection that favours the expression of certain traits to increase that variance in a population. It breaks a homogenous population into many different forms and results in balanced polymorphism