Which one of the following is $NOT$ the main postulate of Darwinism?

In a gene pool,along with beneficial mutations,those mutations also exist which are damaging to an individual. It has been found that these mutations are often not eliminated from the population because:
$I.$ They have survival value.
$II.$ They are acquired.
$III.$ They are recessive and carried by heterozygous individuals.
$IV.$ They show genetic drift.
Choose the incorrect option$(s)$ regarding why these mutations persist in the gene pool.

The theory proposed by Hugo de Vries is called .......

In recent years,$mt-DNA$ and $Y$-chromosome $DNA$ sequences have been used for the study of human evolution because:

The scientist who proposed the theory of natural selection is $......$.

Which of the following is the most accurate reason for the development of resistance to pesticides in insect populations that damage crops?