Which factors contribute to the success of organisms with variations?

Who proposed the mutation theory of evolution? Explain it.

For a mutation to be successful in evolution,it must occur in which of the following?

Identify $P, Q,$ and $R$ in the following descriptions of natural selection types:
$P -$ More individuals acquire peripheral character values at both ends of the distribution curve.
$Q -$ More individuals acquire mean character value.
$R -$ More individuals acquire value other than the mean character value.
$\quad\quad P \quad\quad\quad Q\quad\quad\quad R$

In a small population,the frequency of alleles changes due to which of the following?

The phrase 'Survival of the Fittest' was used by