Natural selection in which more individuals acquire peripheral character value at both the ends of the distribution curve is

In Hardy-Weinberg principle expression of allele frequency is represented by

In Hardy­Weinberg equation, the frequency of heterozygous individual is represented by

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

According to Hardy-Weinberg principle, allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences. It makes several assumptions which were given below.

$i.$  Random Mating

$ii.$  Sexual Reproduction

$iii.$  Non-overlapping Generations

$iv.$  Occurrence of Natural Selection

$v.$  Small size of population

Identify two assumptions which do not meet for a population to reach Hardy-Weinberg Equilibrium?

Which is the most common mechanism of genetic variation in the population of a sexually reproducing organism ?