Boundary Shedding as Basin Maintenance: A Control-Theoretic Extension of Life as a Phase Transition

Living systems persist by maintaining regulated states within bounded regions of state space under continuous perturbation. While prior work has defined life as a phase transition in regulation, less attention has been paid to the mechanisms required for such regulated basins to remain viable over time in open, dissipative environments. This paper argues that boundary shedding—the export of accumulated disorder, damage, or constraint—is a necessary control strategy for maintaining basin viability under sustained flow. Using a control-theoretic perspective, we show that if internal repair capacity is finite and boundary load production is non-zero, long-term persistence requires active export at the boundary. Shedding is therefore not an adaptive embellishment but a structural necessity imposed by regulation itself. The framework is scale-invariant and pre-genetic. Shedding arises wherever regulated boundaries exist, independent of genes, signalling, or multicellularity. Familiar biological processes such as vesicle release, cellular turnover, apoptosis, and sacrificial loss are reinterpreted as manifestations of basin maintenance rather than communication or failure. By situating shedding as a foundational requirement of regulated life, this work provides a mechanistic bridge between early chemical regulation and later biological complexity, and establishes a basis for understanding persistence, robustness, and controlled loss across scales. This paper is Companion Paper 3 in a series developing a regulation-first, boundary-centric framework for biological identity. Foundational Paper: Life as a Phase Transition: https://doi.org/10.5281/zenodo.18176157 Companion Paper 2: The Basin of Identity: microRNA as a Kinetic Anchor in Multicellular Dynamics https://doi.org/10.5281/zenodo.18181118 Companion Paper 3: Boundary Shedding as Basin Maintenance A Control-Theoretic Extension of Life as a Phase Transition https://doi.org/10.5281/zenodo.18215113 Companion Paper 4: Cohesive Membranes and the Emergence of Multicellular Basin Identity When Many Compartments Become One Organism https://doi.org/10.5281/zenodo.18215283 Companion Paper 5: From Control to Replay: Archives, Development, and Sexual Reproduction in Boundary-Defined Life https://doi.org/10.5281/zenodo.18215367