Answer :
The answer is natural selection. It is the procedure whereby life forms better adjusted to their condition have a tendency to survive and create all the more posterity. The hypothesis of its activity was first completely clarified by Charles Darwin and is currently accepted to be the principle procedure that achieves development.
Through the process of natural selection, the insects become resistant to the insecticides. If a small population of the insect is able to survive i the presence of an insecticide, they will gorw, populate and emerge as a completely resistant species, with all the organisms being resistnat, throug natural selection.
