The central homeorhetic principle: Lipid-organized boundary systems as constraints on cellular state realization

Sequence information can specify molecular components, but specification is not equivalent to cellular state realization. A gene product contributes to living function only when gradients persist, compartments remain intact, diffusion and phase organization remain compatible with execution, and perturbations can be recovered without loss of viability. This gap defines a state-realization problem: what physical architecture constrains the feasible state space within which molecular programs are executed, stabilized, reversed, or transformed? I derive substrate requirements for such architecture: self-bounded aqueous interfaces, selective permeability, electrochemical asymmetry, tunable continuous physical variables, cross-scale coupling, recursive interaction with protein-metabolic execution and information-memory systems, and measurable recovery dynamics. Lipid-organized boundary systems satisfy these requirements in an integrated way in modern aqueous cellular life. I therefore propose the Central Homeorhetic Principle (CHP): cellular identity, robustness, and fate transitions are constrained by a distributed homeorhetic state architecture in which lipid-organized boundary systems occupy a privileged but non-exclusive substrate position. CHP is not a rejection of the Central Dogma or a lipid-determinist theory of phenotype. It is a complementary constraint framework addressing how molecular information becomes physically executable and dynamically sustainable. Mechanistically, boundary-state variables are sensed, thresholded, converted into regulatory responses, and recursively remodeled by execution and memory systems. CHP yields testable predictions concerning temporal precedence of boundary-state shifts, threshold-like fate transitions, recovery kinetics, state degeneracy, protocell persistence, and state-trajectory restoration, and is falsifiable if boundary-state variables do not precede, predict, or perturb state transitions beyond molecular profiles.