Natural selection operates at

In the case of the peppered moth $(Biston \text{ } betularia)$, the black-coloured form became dominant over the light-coloured form in England during the industrial revolution. This is an example of:

Given below are two statements.
Statement-$I$: Elimination of particular alleles from a population due to natural disasters is called genetic drift.
Statement-$II$: Sudden temporary heritable change in the gene is called point mutation.
In the light of above statements,choose the most appropriate answer from the options given below:

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

Which is the basis of evolution?

If changes in a population occur by chance,it is called .....