According to $Darwin$,fitness refers to .........

$A$: Due to the bottleneck effect,among the survivors,certain alleles may be overrepresented,some may be underrepresented,and some alleles may be totally eliminated.
$R$: The path of extinction of a species cannot be reversed due to the bottleneck effect.

Give scientific reasons: Genetic drift is much more likely to change allele frequencies in a small population rather than a large population.

Which scientist introduced the initial concept of 'Survival of the Fittest'?

Darwin's theory of evolution was primarily based on which of the following concepts?

What is the primary force of evolution?