Amino acid dating

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The amino acid dating (also Aminosäureracemisierung , amino acid method , Aminosäureuhr , Eiweißuhr or Racematmethode is called) a chemical dating method of geologically young fossilized bone material. It is based on the fact that after the death of an organism, the quantitative ratio between the L - and the D form of enantiomeric amino acids shifts: the significant excess of the L form in the living organism is slowly broken down after death ( racemization ).

By knowing the speed of this process, conclusions can be drawn about the age of the sample from the ratio of L - to D - amino acids measured in a sample of fossil material . Since the racemization is highly temperature-dependent, reliable dating is only possible if the fossil has been exposed to stable temperatures. Because the entire surplus of L forms is broken down after a certain time , the upper limit of the determinable age is around 100,000 years, in cold regions it is a little over 1 million years.

See also

swell

  • Amino acid method. In: Spectrum Online Lexicon Biology.
  • Mebus A. Geyh, Helmut Schleicher: Absolute Age Determination - Physical and Chemical Dating Methods and Their Application. Springer-Verlag, Berlin · Heidelberg 1990, ISBN 978-3-540-51276-9 , pp. 345-371.

Individual evidence

  1. ↑ PM Masters, JL Bada, JS Zigler: Aspartic acid racemization in heavy molecular weight crystallins and water insoluble protein from normal human lenses and cataracts. In: Proceedings of the National Academy of Sciences . Volume 75, Number 3, March 1978, pp. 1204-1208, PMID 274711 , PMC 411438 (free full text).