The Endocrine-Chronobiological Axis: Hormones, Lifespan Transitions, and Biological Operating Range

How do major lifespan transitions unmask hidden genetic vulnerabilities? This paper introduces the Endocrine-Chronobiological Axis, establishing hormone profiles as time-varying, internal modifiers of an organism's biological operating range. It reframes hormones from static cross-sectional values into highly timed, dynamic signals that alter tissue mechanics, chromatin accessibility, and regenerative reserve. Evaluating puberty, pregnancy, and menopause as non-linear state transitions, the model utilizes cutting-edge 2026 data on tissue remodeling to map how moving endocrine conditions trigger temporal handoff failure and terrain carryover.