On the statistical mechanics of life: Schr\"odinger revisited

TL;DR

This paper revisits the thermodynamics of life, proposing that structure and complexity can increase in closed systems through thermodynamic channels, challenging traditional views and highlighting implications for biological evolution and future prospects.

Contribution

It introduces a novel perspective on the thermodynamics of life, emphasizing the role of structure in facilitating entropy growth and explaining stepwise and catastrophic changes in biological systems.

Findings

Entropy can increase alongside order in closed systems.

Structure and complexity are entropically favored as they enable entropy growth.

Metastable states and phase space channels explain stepwise and collapse phenomena.

Abstract

We study the statistical underpinnings of life. We question some common assumptions about the thermodynamics of life and illustrate how, contrary to widespread belief, even in a closed system entropy growth can accompany an increase in macroscopic order. We consider viewing metabolism in living things as microscopic variables directly driven by the second law of thermodynamics, while viewing the macroscopic variables of structure, complexity and homeostasis as mechanisms that are entropically favored because they open channels for entropy to grow via metabolism. This perspective reverses the conventional relation between structure and metabolism, by emphasizing the role of structure for metabolism rather than the other way around. Structure extends in time, preserving information along generations, particularly in the genetic code, but also in human culture. We also consider why the increase in order/complexity over time is often stepwise and sometimes collapses catastrophically. We point out the relevance of the notions of metastable states and channels between these, which are discovered by random motion of the system and lead it into ever-larger regions of the phase space, driven by thermodynamics. We note that such changes in state can lead to either increase or decrease in order; and sometimes to complete collapse, as in biological extinction. Finally, we comment on the implications of these dynamics for the future of humanity.