Abstract
Scientists have been unable to reach a consensus on why organisms age and why they live as long as they do. Here, a multidisciplinary approach was taken in an attempt to understand the root causes of aging. Nonequilibrium thermodynamics may play a previously unappreciated role in determining longevity by governing the dynamics of degradation and renewal within biomolecular ensembles and dictating the inevitability of fidelity loss. The proposed model offers explanations for species longevity trends that have been previously unexplained and for aging-related observations that are considered paradoxical within current paradigms—for example, the elevated damage levels found even in youth within many long-lived species, such as the naked mole-rat. This framework questions whether declining selective pressure is the primary driver of aging, and challenges major tenets of the disposable soma theory. Unifying pertinent principles from diverse disciplines leads to a theoretical framework of biological aging with fewer anomalies, and may be useful in predicting outcomes of experimental attempts to modulate the aging phenotype.