Are biological systems poised at criticality?

TL;DR

This paper reviews evidence that various biological systems, from proteins to bird flocks, operate near critical points, suggesting a possible universal principle underlying their collective behavior.

Contribution

It highlights the success of data-driven statistical mechanics models in revealing that biological systems are often poised at criticality, indicating a potential fundamental principle.

Findings

Models of proteins, neurons, and bird flocks are at critical points.

Data-driven models successfully capture collective biological behaviors.

Criticality may be a universal feature of biological systems.

Abstract

Many of life's most fascinating phenomena emerge from interactions among many elements--many amino acids determine the structure of a single protein, many genes determine the fate of a cell, many neurons are involved in shaping our thoughts and memories. Physicists have long hoped that these collective behaviors could be described using the ideas and methods of statistical mechanics. In the past few years, new, larger scale experiments have made it possible to construct statistical mechanics models of biological systems directly from real data. We review the surprising successes of this "inverse" approach, using examples form families of proteins, networks of neurons, and flocks of birds. Remarkably, in all these cases the models that emerge from the data are poised at a very special point in their parameter space--a critical point. This suggests there may be some deeper theoretical principle behind the behavior of these diverse systems.