Genetic variation in a population arises due to

Explain the example of insect resistance to pesticides as an instance of natural selection.

By performing the replica plating experiment,Lederberg supported the

Given below are two statements regarding evolution.
$Statement-I$: Isolation is the separation of a population of a particular species into smaller units, which prevents interbreeding between them.
$Statement-II$: Due to isolating mechanisms, divergence and speciation do not occur.
In the light of the above statements, choose the most appropriate answer from the options given below.

Which of the following concepts is attributed to Charles Darwin?

Who coined the phrase 'Survival of the Fittest'?