Why do adaptations occur?

How do predators identify moths in the context of industrial melanism?

The most likely reason for the development of resistance against pesticides in insects damaging a crop is

What is the variation of traits among the members of a species called?

'$A$ brief reduction in size of a population,due to natural calamities,usually leads to random genetic drift'. For this statement,identify the correct example from the following.

Select the incorrect statements:
$I.$ Natural selection is essential for evolution.
$II.$ Natural selection does not include variations.
$III.$ The concept of natural selection was given by Hugo de Vries.
$IV.$ Mutation is a sudden inheritable change.
$V.$ The synthetic theory is also called the Neo-Darwinism theory of evolution.