Origins of Life and Evolution of Biospheres

, Volume 42, Issue 4, pp 333–346

Chiral Polymerization in Open Systems From Chiral-Selective Reaction Rates

  • Marcelo Gleiser
  • Bradley J. Nelson
  • Sara Imari Walker
Models for Homochirality

DOI: 10.1007/s11084-012-9274-5

Cite this article as:
Gleiser, M., Nelson, B.J. & Walker, S.I. Orig Life Evol Biosph (2012) 42: 333. doi:10.1007/s11084-012-9274-5

Abstract

We investigate the possibility that prebiotic homochirality can be achieved exclusively through chiral-selective reaction rate parameters without any other explicit mechanism for chiral bias. Specifically, we examine an open network of polymerization reactions, where the reaction rates can have chiral-selective values. The reactions are neither autocatalytic nor do they contain explicit enantiomeric cross-inhibition terms. We are thus investigating how rare a set of chiral-selective reaction rates needs to be in order to generate a reasonable amount of chiral bias. We quantify our results adopting a statistical approach: varying both the mean value and the rms dispersion of the relevant reaction rates, we show that moderate to high levels of chiral excess can be achieved with fairly small chiral bias, below 10%. Considering the various unknowns related to prebiotic chemical networks in early Earth and the dependence of reaction rates to environmental properties such as temperature and pressure variations, we argue that homochirality could have been achieved from moderate amounts of chiral selectivity in the reaction rates.

Keywords

Prebiotic chemistry Chirality Exoplanets 

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Marcelo Gleiser
    • 1
  • Bradley J. Nelson
    • 1
  • Sara Imari Walker
    • 2
    • 3
  1. 1.Department of Physics and AstronomyDartmouth CollegeHanoverUSA
  2. 2.NASA Astrobiology InstituteMountain ViewUSA
  3. 3.BEYOND: Center for Fundamental Concepts in ScienceArizona State UniversityTempeUSA

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