A population is exhibiting genetic equilibrium answer the

A population is exhibiting genetic equilibrium answer the following with regard to this statement.
(i) Explain the above statement.
(ii) Name the underlying principle.
(iii) Name any two factors which could upset the genetic equilibrium (i.e. allele frequency) of the population.

(i) The relative frequency of alleles of sexually reproducing organisms in a given population remains constant from generation to generation.
(ii) Hardy-Weinberg equilibrium.
(iii) Gene mutation, recombination, gene flow, genetic drift and natural selection (any two).