On the evolution of homochirality - 20/04/11
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Abstract |
This work reconsiders recent ideas on the origin of biological homochirality by formally invoking the standard groupoid approach to stereochemistry in a thermodynamic context that generalizes Landau’s spontaneous symmetry breaking arguments. On Earth, limited metabolic free energy density may have served as a low temperature-analog to ‘freeze’ the system in the lowest energy state, i.e., the set of simplest homochiral transitive groupoids representing reproductive chemistries. These engaged in Darwinian competition until a single configuration survived. Subsequent path-dependent evolutionary process locked-in this initial condition. Astrobiological outcomes, in the presence of higher initial metabolic free energy densities, could well be considerably richer, for example, of mixed chirality. One result would be a complicated distribution of biological chirality across a statistically large sample of extraterrestrial stereochemistry, in marked contrast with recent published analyses predicting a racemic average.
Le texte complet de cet article est disponible en PDF.Keywords : Evolution, Groupoid, Homochirality, Information theory, Morse Theory, Prebiotic, Punctuated equilibrium
Plan
Vol 334 - N° 4
P. 263-268 - avril 2011 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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