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Synonymous and Nonsynonymous Rates

  1. Soojin Yi

Published Online: 21 DEC 2007

DOI: 10.1002/9780470015902.a0005110.pub2



How to Cite

Yi, S. 2007. Synonymous and Nonsynonymous Rates. eLS. .

Author Information

  1. University of Chicago, Chicago, Illinois, USA

Publication History

  1. Published Online: 21 DEC 2007


When comparing protein-coding DNA sequences between species, it is useful to distinguish between synonymous (silent) substitutions and nonsynonymous (amino-acid changing) substitutions. Because the two types of change are under different intensities of selective constraints, comparing their rates provides insights into the mechanisms of evolution of the gene under study.


  • coding regions;
  • nucleotide substitution;
  • degenerate code;
  • functional constraints;
  • positive selection