slable and is constant from generation to generation, i.e., the gene pool (total genes and their alleles) in a population remains constant. This is called genetic equilibrium. The sum
total of all the allelic frequencies is

Five factors that influence these values are

(i) Gene Migration or Gene Flow When migration of a section of population to another
place occurs, gene frequencies change in the original as well as in the new population.
New genes/alleles are added to the new population and these are lost from the old
population. There would be gene flow if this gene migration, happens multiple times

(ii) Genetic Drift It refers to the elimination of the genes of certain traits when a section of
population migrates or dies of natural calamity. It is an evolutionary force operating in small populations whereby gene frequency changes by chance leadings to loss of some genes or gain of others irrespective of their selective advantages or disadvantages.

(iii) Mutation The sudden heritable change which is ditectionless in gene is called mutation
It alters the genetic frequency or genetic make up of an individual.

(iv) Genetic Recombination This phenomenon occurs during gamete formation when
chromosomes pass from parents to offsprings which show new combination of
characteristics.

(v) Natural Selection It is a phenomenon by which some members of population having
traits that enable them to grow and reproduce at higher rater are favoured. Hence, they
leave more surviving offspring in the next generation than others.