The Shape of the Dissipation Trajectory as a Determinant of Aging: A Hypothesis and a Proposed Test in Drosophila

Thermodynamic accounts of aging generally treat the level of an organism’s energy dissipation as the quantity of interest — whether framed as metabolic rate, entropy production, or heat output. This article proposes a different variable: the shape of the dissipation trajectory over life. During growth, dissipation rises continuously; after growth ends it plateaus. The hypothesis is that a rising dissipation trajectory is protective, and that aging follows once that rise flattens — so that, for a given cumulative or average level of dissipation, a trajectory that continues to rise should be associated with slower functional aging than one held constant. This is a claim about form, not amount, and it is distinct from the classical rate-of-living view (which concerns level) and from mechanistic accounts in which specific interventions extend life through defined pathways. The central difficulty is that no available manipulation raises dissipation cleanly: chemical uncouplers also lower reactive oxygen species (ROS), temperature also engages thermosensory signaling, and exercise also drives mitochondrial adaptation. The proposed test turns this difficulty into a design principle. Three mechanistically independent levers — a mitochondrial uncoupler, ambient temperature, and enforced exercise — are each delivered to adult Drosophila in a rising trajectory versus a matched-average constant trajectory. Because the three levers carry different confounds but share only the elevation of dissipation, convergence of their effects on aging would be difficult to attribute to any single side-pathway, whereas divergence would argue against dissipation per se. Explicit confirmation and falsification criteria are stated, including the requirement that any trajectory effect survive at matched ROS. The hypothesis is presented as falsifiable and, at present, unproven.