Polymerization and replication of primordial RNA induced by clay-water interface dynamics

TL;DR

This paper presents a theoretical and computational model demonstrating that primordial RNA could have polymerized and replicated at clay-water interfaces under oscillating environmental conditions, supporting RNA's role in life's origins.

Contribution

It introduces a novel framework modeling RNA polymerization and replication driven by environmental oscillations, highlighting the importance of tidal-like dynamics and genetic alphabet composition.

Findings

RNA polymerization and replication feasible at clay-water interfaces.

Oscillating environments enhance RNA replication efficiency.

Four-letter genetic alphabet optimizes replication speed and diversity.

Abstract

In the study of life's origins, a key challenge is understanding how RNA could have polymerized and subsequently replicated in early Earth. We present a theoretical and computational framework to model the non-enzymatic polymerization of ribonucleotides and the template-dependent replication of primordial RNA molecules, at the interfaces between the aqueous solution and a clay mineral. Our results demonstrate that systematic polymerization and replication of single-stranded RNA polymers, sufficiently long to fold and acquire basic functions ($>$15 nt), were feasible under these conditions. Crucially, this process required a physico-chemical environment characterized by large-amplitude oscillations with periodicity compatible with spring tide dynamics, suggesting that large moons may have played a role in the emergence of RNA-based life on planetary bodies. Interestingly, the theoretical analysis presents rigorous evidence that RNA replication efficiency increases in oscillating environments compared to constant ones. Moreover, the versatility of our framework enables comparisons between different genetic alphabets, showing that a four-letter alphabet -- particularly when allowing non-canonical base pairs, as in current RNA -- represents an optimal balance of replication speed and sequence diversity in the pathway to life.