Chirality and Cosmic Origin of Life

TL;DR

This paper discusses the role of chirality in the universe and its implications for the cosmic origin of life, emphasizing the dual process of extraterrestrial ingredient transport and terrestrial chemical evolution, supported by recent observations of amino acid chirality.

Contribution

It proposes a dual origin theory for life involving extraterrestrial delivery of chiral molecules and terrestrial chemical processes, highlighting the significance of chirality in life's emergence.

Findings

Meteorites contain lefthanded amino acids similar to terrestrial life.

Laboratory experiments produce racemic mixtures of amino acids.

Chirality is linked to life's ability to harness solar energy.

Abstract

Chirality or the property that distinguishes lefthandedness from righthandedness is an important aspect of the universe, starting from neutrinos, which are lefthanded. Fifteen years ago the author had proposed that life on the earth was formed through a dual process -- several key ingredients being transported from outer space to the earth by comets or meteorites and these in turn interacting with compounds already cooked up in the earth's seas. Several recent observations point to the fact that the amino acids brought out to the earth by meteorites are lefthanded, as in terrestrial life forms. Experiments in the laboratory however throw up equal numbers of lefthanded and righthanded amino acids, what are called racemic mixtures. Not only would the latest observations endorse this dual mode theory of the origin of life, but on the other hand it would point to the key trigger for life processes itself. This is because racemic mixtures are not optically active, unlike the handed or chiral constituents. It is this activity of harnessing solar radiation and converting it into chemical energy, and storing this in the sugar bonds, as in photosynthesis, that characterizes life.