In this short review, we put forward the idea that randomly fluctuating, or stochastic, molecular events can and do play a role in the emergence of complex biological phenomena at longer length scales. There is a growing body of evidence of this occurring in natural systems, and we survey the computational and experimental attempts of researchers to demonstrate this challenging idea.

Abstract

Random molecular fluctuations, or stochasticity, are intrinsic to all biological systems, influencing processes from molecular interactions to cellular biochemistry. These fluctuations, often labelled as “noise,” are not always disruptive but can serve as a source of adaptability and functionality. Evolution has taken place in the presence of these molecular fluctuations over billions of years, yielding mechanisms that enable versatile and enhanced activity of a range of biochemical processes. This review explores how stochastic variations, from Brownian motion to higher-order system dynamics, can drive complex biological functions. First, we summarize landmark examples of the role of stochasticity in biological processes, emphasizing its capacity to yield beneficial outcomes. Computational modeling and model experimental systems are highlighted as tools to investigate stochasticity in a quantitative manner. In addition, the review comments on how deliberate incorporation of stochasticity into synthetic experimental systems provides novel avenues for controlling and designing life-like processes. By understanding and utilizing stochastic variation, new principles for engineering robust and adaptable synthetic systems are uncovered.