Explain how the 5 factors:- Gene flow, Genetic drift, Mutation, Genetic recombinatin and Natural selection affect the Hardy-Weinberg principle?

Hardy-Weinberg equilibrium is affected by

1. gene flow or gene migration
2. genetic drift (changes occurring by chance)
3. mutation
4. genetic recombination
5. natural selection

1. Gene flow is the transfer of alleles of genes from one population to another. It results in increase in frequency of that allele in the second population. In this way,  Hardy weinberg equlibrium is not maintained. 
2. Genetic drift refers to the fact that variations in gene frequencies within populations can occur by chance rather than by natural selection. Random genetic drift may be an important mechanism in evolutionary change in small or isolated populations. Thus. it also results in the change in allelic frequency. 
3. Mutations are the sudden changes that takes place in the DNA sequence of an organism. These are the permanent changes that can be either induced or occur naturally leading to the variation in the populations.
4. Genetic recombination is the formation of new combinations of alleles in offspring as a result of exchange of DNA sequences between molecules. It occurs naturally, as in sexual reproduction during meiosis or artificially, as a result of experiments on genetic engineering.
5. Natural selection is the mechanism by which new species arise from pre existing ones. The theory of Natural selection states that there is "struggle for existence" within a population and variation exists within all population. The continuous competition between individuals for environmental resources creates a 'struggle for existence' and this struggle makes sure that certain organisms would fail to survive or reproduce. This would eliminate less suited organisms and better adapted organisms would survive and pass on their traits to next generation leading to evolution.