 Any variation at a specific genomic locus is referred to as an ‘allele’. If there are two different versions of a specific gene that can be found in a population at a specific locus on a chromosome, then that means that there are two different alleles of that gene present in that  population.[15]  If one of these single nucleotide alleles is found in more than 1% of a specific population it is treated as a ‘common’ variant and researchers speak of a ‘polymorphism’ or, more precisely, a ‘single nucleotide polymorphism’ (abbreviated ‘SNP’; pronounced ‘snip’). If a variation is found in less than 1% of the population researchers simply call it a ‘mutation’ (or also a ‘point  mutation’).[16]  On average there are about 3 million SNPs found in each individual and there is a pool of more than 10 million SNPs present in the human population as a whole (HapMap 2005).