The Nature of Stability in Replicating Systems

Nathaniel Wagner,Addy Pross

doi:10.3390/e13020518

Abstract

We review the concept of dynamic kinetic stability, a type of stability associated specifically with replicating entities, and show how it differs from the well-known and established (static) kinetic and thermodynamic stabilities associated with regular chemical systems. In the process we demonstrate how the concept can help bridge the conceptual chasm that continues to separate the physical and biological sciences by relating the nature of stability in the animate and inanimate worlds, and by providing additional insights into the physicochemical nature of abiogenesis.

Highlights

We tend to imagine that all systems converge towards equilibrium as embodied in the theory of equilibrium statistical thermodynamics [1], the notion of non-equilibrium steady-state (NESS) behavior is widely recognized [2,3]
In this review we describe how living organisms, and replicators in general, can display non-equilibrium characteristics, thereby manifesting low stability in a thermodynamic sense, yet exhibit high stability of a different type, a stability that derives from their underlying dynamic
In this review we have attempted to describe the concept of dynamic kinetic stability and how it relates to the traditional and well-established concepts of kinetic stability and thermodynamic stability

Summary

Introduction

We tend to imagine that all systems converge towards equilibrium as embodied in the theory of equilibrium statistical thermodynamics [1], the notion of non-equilibrium steady-state (NESS) behavior is widely recognized [2,3]. The second law of thermodynamics teaches us that closed systems tend to converge towards their equilibrium state and that the irreversible processes that lead to the equilibrium state result in an increase in global entropy. In chemistry, this is often expressed in terms of the minimization of the system’s Gibbs energy, G. H2-O2 mixture (under appropriate conditions) to be kinetically stable due to the high kinetic barrier separating reactants from products This well-known kinetic-thermodynamic dichotomy leads to the concepts of kinetic and thermodynamic control, whereby a substance A can react by two competing pathways—a kinetically preferred lower free energy pathway that leads to a thermodynamically less stable product, X, or a higher free energy pathway that leads to a thermodynamically more stable product, Y (Figure 1). A dynamic stability, is based on change, as opposed to lack of change

Dynamic Kinetic Stability of Replicating Systems

Interplay between Dynamic Kinetic Stability and Thermodynamic Stability

Summary