Discuss the role of different patterns of selection in evolution.

Natural Selection is mainly of three types namely:
a) Stabilising selection
b) Directional Selection
c) Disruptive selection

a) Stabilising selection:

• This selection operates in a stable environment.
• The organisms with average phenotype are selected and organisms with extreme phenotypes are removed.

b) Directional Selection:

• This selection operates in gradually changing environment.
• It removes the individuals from one end of the phenotype and selecting the individuals towards the other end of the phenotype.

c) Disruptive selection:

• This selection operates in rapidly changing environment.
• The organisms with extremes of the phenotype are selected and organisms with average of the phenotype are removed.