Evolutionary features in a minimal physical system: diversity, selection, growth, inheritance, and adaptation

TL;DR

This paper introduces a minimal physical model demonstrating key features of biological evolution, such as diversity, selection, inheritance, and adaptation, based solely on thermally-driven processes without biological mechanisms.

Contribution

The model shows that life-like evolutionary properties can emerge from simple physical principles, challenging traditional views on the requirements for biological evolution.

Findings

Samples a diverse range of non-equilibrium steady states

Displays directionality and increasing quantities over time

Exhibits inheritance and environment-dependent adaptation

Abstract

We present a simple physical model that recapitulates several features of biological evolution, while being based only on thermally-driven attachment and detachment of elementary building blocks. Through its dynamics, this model samples a large and diverse array of non-equilibrium steady states, both within and between independent trajectories. These dynamics exhibit directionality with a quantity that increases in time, selection and preferential spatial expansion of particular states, as well as inheritance in the form of correlated compositions between successive states, and environment-dependent adaptation. The model challenges common conceptions regarding the requirements for life-like properties: it does not involve separate mechanisms for metabolism, replication and compartmentalization, stores and transmits digital information without template replication or assembly of large molecules, exhibits selection both without and with reproduction, and undergoes growth without autocatalysis. As the model is based on generic physical principles, it is amenable to various experimental implementations.