Biology and nonequilibrium: remarks on a paper by J.L. England

This note analyzes the physical basis of J.R. England's paper "Statistical physics of self-replication." [J. Chem. Phys. {\bf 139}, 121923(2013)]. We follow England's use of time-reversal symmetry but replace stochastic by deterministic dynamics, and introduce a definition of metastable states based on equilibrium statistical mechanics. We rederive England's detailed balance relation and obtain another similar relation which appears more natural and remains valid for quantum systems. The detailed balance relations are based on serious physical ideas, and either of them can be used for England's biological discussion. This biological discussion does of course deserve further scrutiny.