This document discusses single nucleotide polymorphisms (SNPs) and methods for identifying and analyzing them. It defines SNPs as variations in a single nucleotide that can differ between members of a species. Several methods are described for identifying known and new SNPs, including gel electrophoresis, mass spectrometry, and DNA sequencing. SNPs can serve as biological markers and help locate genes associated with diseases. While they provide useful information, SNPs have less informative power than other genetic markers due to fewer alleles.