Abbreviation: Ks values
A synonymous mutation is a change in the DNA sequence that codes for amino acids in a protein sequence, but does not change the encoded amino acid. Due to the redundancy of the genetic code (multiple codons code for the same amino acid), these changes usually occur in the third position of a codon. For example, GGT, GGA, GGC, and GGG all code for glycine. Any change in the third position of the codon (e.g. A->G), will result in the same amino acid being incorporated in the protein sequence at that position.