In this study, we are using the Single nucleotide polymorphisms, or SNPs as a molecular tool. SNPs are Single nucleotide changes on the nuclear DNA resulting from replication errors and DNA damage – It is in fact a new term for polymorphic alleles, so it is not a new concept.
	For SNP identification, alignment and comparison of multiple sequences from the same genome region is necessary
	Many SNPs occur in 3rd   codon position of protein coding genes and may or may not cause amino acid changes. If it does not cause an amino acid change, then it is called a synonomous ( or silent) substitution. If it does cause an amino acid change , it is called a non-synonomous substitution. In fact some SNPS may occur at sites when any of the 4 bases will code for the same amino acid. These 4-fold degenerate sites, in particular, may be highly variable.