Emergence, Cavity Reorganization, and Open-Water Persistence of Membrane-Rich Organization under Coupled Field Dynamics.

How protocell-like organization can arise before cells, division programs, and genetic templates remains unresolved. We developed a three-dimensional field model in which resource, lipid, hydrothermal, waste, membrane-density, membrane-thickness, and history-retaining fields interact locally in confined aqueous environments and after release into open water. No cell was initialized. Across 168 confined runs, membrane-like components emerged and expanded to domain-spanning states. Matched counterfactual simulations showed that explicit temporal delay was not required for membrane expansion or lumen formation, but delayed their development, whereas removing direct coupling from the history-retaining field to membrane fields reduced lumen formation and overlap-defined splitting. Lumen births and splits occurred predominantly after domain spanning, indicating cavity reorganization within spatially extensive membrane-rich states rather than division of localized protocells. Signed and spatially structured field states persisted across lumen reorganization but also under instantaneous updating. Shape-field helicity exceeded a shared-geometry permutation null. After release, replicated open-water simulations showed resource-dependent persistence or regeneration of detectable membrane-rich organization, including lumens, membrane-associated field state, and displacement. These results separate delay, field coupling, boundedness, state continuity, and structural persistence as distinct components of protocell-like organization.