Spontaneous Chiral Symmetry Breaking in a Random Driven Chemical System

TL;DR

This paper demonstrates that energy-driven chemical networks can spontaneously break chiral symmetry, leading to homochirality, through intrinsic fluctuations and environmental matching, revealing a generic pathway for chiral emergence.

Contribution

It introduces a model showing that external energy sources can induce chiral symmetry breaking in random chemical networks, a novel mechanism beyond autocatalysis.

Findings

Chiral symmetry breaking occurs spontaneously in energy-driven chemical networks.

Achiral-to-chiral fluctuations and environmental matching amplify enantiomer divergence.

States cluster as highly-dissipating, energetically favorable configurations.

Abstract

Living systems have evolved to efficiently consume available energy sources using an elaborate circuitry of chemical reactions which, puzzlingly, bear a strict restriction to asymmetric chiral configurations. While autocatalysis is known to promote such chiral symmetry breaking, whether a similar phenomenon may also be induced in a more general class of configurable chemical systems -- via energy exploitation -- is a sensible yet underappreciated possibility. This work examines this question within a model of randomly generated complex chemical networks. We show that chiral symmetry breaking may occur spontaneously and generically by harnessing energy sources from external environmental drives. Key to this transition are intrinsic fluctuations of achiral-to-chiral reactions and tight matching of system configurations to the environmental drives, which together amplify and sustain diverged enantiomer distributions. These asymmetric states emerge through steep energetic transitions from the corresponding symmetric states and sharply cluster as highly-dissipating states. The results thus demonstrate a generic mechanism in which energetic drives may give rise to homochirality in an otherwise totally symmetrical environment, and from an early-life perspective, might emerge as a competitive, energy-harvesting advantage.