Journal of Molecular Evolution

, Volume 59, Issue 5, pp 598–605 | Cite as

A New Classification Scheme of the Genetic Code

  • Thomas WilhelmEmail author
  • Svetlana Nikolajewa


Since the early days of the discovery of the genetic code nonrandom patterns have been searched for in the code in the hope of providing information about its origin and early evolution. Here we present a new classification scheme of the genetic code that is based on a binary representation of the purines and pyrimidines. This scheme reveals known patterns more clearly than the common one, for instance, the classification of strong, mixed, and weak codons as well as the ordering of codon families. Furthermore, new patterns have been found that have not been described before: Nearly all quantitative amino acid properties, such as Woese’s polarity and the specific volume, show a perfect correlation to Lagerkvist’s codon–anticodon binding strength. Our new scheme leads to new ideas about the evolution of the genetic code. It is hypothesized that it started with a binary doublet code and developed via a quaternary doublet code into the contemporary triplet code. Furthermore, arguments are presented against suggestions that a “simpler” code, where only the midbase was informational, was at the origin of the genetic code.


Genetic code Origin of life Doublet code Pattern Amino acid properties 



We thank two anonymous reviewers for many valuable comments and for referring us to relevant literature and A. Beyer, F. Grosse, M. Friedel, and M.-L. Merten for critical reading of the manuscript. This work was supported by Grant 0312704E from the Bundesministerium für Bildung und Forschung.


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Copyright information

© Springer Science + Business Media Inc. 2004

Authors and Affiliations

  1. 1.Institute of Molecular BiotechnologyJenaGermany

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