The Chirality Of Life: From Phase Transitions To Astrobiology

TL;DR

This paper explores the origin of biological homochirality on Earth, proposing a mechanism called punctuated chirality, and discusses its implications for detecting extraterrestrial life through stereochemistry analysis.

Contribution

It introduces the concept of punctuated chirality as a mechanism for life's homochirality and applies it to astrobiology, offering predictions about extraterrestrial stereochemistry.

Findings

Life's homochirality may result from environmental triggers causing chiral symmetry breaking.

Extraterrestrial life is predicted to have racemic stereochemistry on average.

The mechanism has implications for the search for life beyond Earth.

Abstract

The search for life elsewhere in the universe is a pivotal question in modern science. However, to address whether life is common in the universe we must first understand the likelihood of abiogenesis by studying the origin of life on Earth. A key missing piece is the origin of biomolecular homochirality: permeating almost every life-form on Earth is the presence of exclusively levorotary amino acids and dextrorotary sugars. In this work we discuss recent results suggesting that life's homochirality resulted from sequential chiral symmetry breaking triggered by environmental events in a mechanism referred to as punctuated chirality. Applying these arguments to other potentially life-bearing platforms has significant implications for the search for extraterrestrial life: we predict that a statistically representative sampling of extraterrestrial stereochemistry will be racemic on average.