Punctuated chirality

Marcelo Gleiser, Joel Thorarinson, Sara Imari Walker

Research output: Contribution to journalReview articlepeer-review

28 Scopus citations


Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively L-amino acids, while only D-sugars appear in RNA and DNA. The mechanism behind this fundamental asymmetry of life remains an open problem. Coupling the spatiotemporal evolution of a general autocatalytic polymerization reaction network to external environmental effects, we show through a detailed statistical analysis that high intensity and long duration events may drive achiral initial conditions towards chirality. We argue that life's homochirality resulted from sequential chiral symmetry breaking triggered by environmental events, thus extending the theory of punctuated equilibrium to the prebiotic realm. Applying our arguments to other potentially life-bearing planetary platforms, we predict that a statistically representative sampling will be racemic on average.

Original languageEnglish (US)
Pages (from-to)499-508
Number of pages10
JournalOrigins of Life and Evolution of Biospheres
Issue number6
StatePublished - Dec 2008
Externally publishedYes


  • Early planetary environments
  • Homochirality
  • Origin of life
  • Prebiotic chemistry

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Space and Planetary Science


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