The Cellular State Filter: Prebiotic Origins of the Regulatory "Dark Zone" Between Membrane Physics and Biochemistry

This conceptual essay introduces the notion of a cellular state filter as a missing regulatory layer between membrane physics and intracellular biochemistry. Drawing on prebiotic systems composed of simple amphiphilic membranes, the text argues that regulation initially emerged as a physical, state-based phenomenon rather than a biochemical, process-driven one. In early protocellular systems, membrane properties such as fluidity, permeability, and stability acted as the sole regulators, determining which chemical processes could occur within enclosed compartments. Modern cells retain this state-based regulation, although it is largely obscured by complex biochemical signaling networks, creating the impression of a conceptual ‘dark zone’ between membrane behavior and intracellular processes. Recognizing this layer provides a coherent evolutionary and physical framework for understanding cellular regulation beyond receptor-centric and pathway-based models.