Weak neutral currents and the origin of biomolecular chirality

It has long been known that Earth’s biochemistry is overwhelmingly dissymmetric or chiral.1–4 In model chemical systems5–7 that spontaneously evolve to a state dominated by either the L or the D emantiomer parity violation in β‐decay and that attributable to weak neutral currents (WNC) in molecules8,9 is thought to be too small to have any significant influence on the emergent chirality.10,11 Other conceivable systematic chiral influences are generally even weaker.12–14 We show here that there is a simple and extremely sensitive mechanism by which a minute but systematic chiral interaction, no stronger than the WNC interaction is amino acids, can, over a period of ∼15,000 yr, determine which emantiomer will dominate. Such a mechanism is especially interesting when considering the origins of terrestrial biochemistry, particularly in view of the work by Mason and Tranter,15 who found that it is the terrestrially dominant L amino acids that are favoured by the WNC interaction.