ENTROPY AND AGING IN BIOLOGICAL SYSTEMS

The Second Law of Thermodynamics (which is often referred to as “times arrow” because it dictates the direction of increasing chronological time), should have a direct bearing on the aging process in biological systems. Basic aging related phenomena are discussed from the point of view of an entropy rate balance, and the known effects of body temperature, metabolic rate and food consumption rate on lifespan are considered. The problems of quantifying the rate of internal entropy production of complex systems is investigated using the fundamentals of non-equilibrium thermodynamics. Entropy rate balance data over the lifespan of the annual fish Nothobranchius guentheri are used to illustrate basic aging phenomena.