Life as a Phase Transition in Chemical Dynamics - Basin-Dependent Chemistry, Boundary Constraints, and the Origin of Biological Lineages

Life is commonly approached as a problem of molecular ingredients—genes, membranes, or metabolic pathways—yet such approaches struggle to explain how chemical systems persist under continuous energetic disruption. Here we propose that life can be defined as a phase transition in chemical dynamics, characterised by the coupling of energy flow, spatial boundaries, and persistent internal memory such that collapse no longer erases organisation but instead enables reconstruction, giving rise to life-like behaviour. We distinguish three regimes: (i) dead chemistry, in which collapse destroys all structure; (ii) systems with persistent memory but no regulation, which fail to stabilise under energy flux; and (iii) a life-like regime in which memory actively constrains energy dissipation, producing repeated re-entry into the same organisational state. Within this framework, iron–sulphur redox chemistry represents a minimal mechanism for controlled electron flow, membranes provide spatial constraint, and DNA-like polymers function as durable reconstruction constraints that bias system reassembly after disruption. Boundary inheritance emerges only downstream of the phase transition, once memory-coupled regulation is established. This perspective reframes life not as a specific molecular composition, but as a dynamical state in which collapse becomes non-terminal. Version 1.1 refines the phase-transition framework by formalising recovery-capable basins in state space, clarifying the geometric role of the existing order parameter, and introducing an explicit resilience criterion for collapse and reconstruction. The core thesis and control variables remain unchanged from v1.0; this revision strengthens falsifiability and conceptual coherence without altering scope. This paper is The Foundational Paper in a series developing a regulation-first, boundary-centric framework for biological identity. Update (v1.11):Section 2.6 has been expanded with clarifying paragraphs that make the phase-transition criterion explicit, defining the transition into biology in terms of recoverable organisation following collapse. These additions do not alter the framework or conclusions of the paper, but clarify the discriminant between chemical reset and biological persistence. An accompanying explanatory essay on heredity and DNA has been added as supplementary material. Life as a Phase Transition — Series Overview Foundational framework A. An Architectural Origin of Organismal UnityFoundational Paperhttps://doi.org/10.5281/zenodo.18305134 B. Life as a Phase TransitionFoundational Paperhttps://doi.org/10.5281/zenodo.18176157→ Defines life as a maintained, non-equilibrium basin governed by regulation and boundary constraints. Heredity constraint and theory closure C. The Analogue Heredity Ceiling and the Basin Digitisation TransitionHeredity constraint frameworkhttps://doi.org/10.5281/zenodo.18250555→ Formalises the limit of compositional (analogue) heredity and explains why replayable archives (digitisation) become unavoidable within the life-as-a-phase-transition framework. Companion papers — Mechanisms and consequences 2. The Basin of Identity: microRNA as a Kinetic Anchor in Multicellular Dynamics https://doi.org/10.5281/zenodo.18181118 → Explores how kinetic anchoring mechanisms stabilise basin identity in multicellular systems, now interpretable as local management of identity dimensionality and heritability stress. 3.Boundary Shedding as Basin MaintenanceA Control-Theoretic Extension of Life as a Phase Transitionhttps://doi.org/10.5281/zenodo.18215113→ Describes boundary shedding as a regulatory strategy for maintaining basin coherence under stress. 4.Cohesive Membranes and the Emergence of Multicellular Basin IdentityWhen Many Compartments Become One Organismhttps://doi.org/10.5281/zenodo.18215283→ Examines how multicellular organisation emerges from coupled boundary systems and shared basin identity. 5. From Control to ReplayArchives, Development, and Sexual Reproduction in Boundary-Defined Lifehttps://doi.org/10.5281/zenodo.18215367→ Investigates replay, development, and sexual reproduction as stabilising mechanisms, now unified by the Basin Digitisation Transition. 6. Boundary Architecture and Failure in Living SystemsA regulation-first classification of biological formhttps://doi.org/10.5281/zenodo.18226987→ Classifies biological form and failure modes through boundary architecture and regulatory breakdown. 7.The Boundary Renewal Principle:An Architectural Account of Heredity and Evolutionhttps://doi.org/10.5281/zenodo.18335521