Statistical Mechanics of Living Systems

Statistical mechanics of living systems applies the methods of equilibrium and non-equilibrium statistical physics to biological matter — treating cells, tissues, and ecosystems as assemblies of many interacting degrees of freedom whose collective behavior emerges from local rules.

The field departs from traditional statistical mechanics in a crucial respect: biological systems are not at equilibrium. They consume free energy to maintain themselves far from thermal equilibrium, which means the Boltzmann distribution — the foundation of classical statistical mechanics — does not apply. Instead, researchers use tools from stochastic thermodynamics and non-equilibrium statistical mechanics to describe how living systems harvest energy from their environment to perform work, compute, and replicate.

A central puzzle is whether living matter occupies a distinct region of statistical mechanical phase space — whether there are universal constraints on the organization of biological systems that can be derived from first principles, independent of evolutionary history. If such constraints exist, they would constitute a physics