Abstract
All living organisms are gravitationally bound to earth's surface and spun through three major gravitational potentials at nearly Mach 88. Along this pathway, organisms are subjected to non-isotropic strains that are repetitive in their geometry and their periodicity. Because of the relative smallness of this bias and the slow rate at which such strain accumulates, it typically goes undetected or treated stochastically as a variance from 'best-fit' models and woven into our empirical data. Far from being purely isotropic, equilibrium in systems co-moving with the earth possesses a dynamic component with bias defined by our orbital motion. Interestingly, biologists identify a similar bias in living organisms expressed in the chiral nature of key metabolic molecules and the periodicities of their metabolic cycles. Biologists have also identified a mean mass-specific metabolic rate that correlates well with the daily change in gravitational potential energy experienced by an organism. The evidence is only correlative, but it raises the intriguing question of whether 3 billion years of exposure to gravitational strain cycles might have led to a metabolic strategy that coupled to them. Because the subject of gravity has been omitted from most biology textbooks and, with only a few notable exceptions, relegated to the far corners of biology conferences, this paper is written with two goals in mind. The first goal is to summarize the extensive experimental record produced by biologists, botanists, and zoologists, identifying the strong correlation between metabolic processes and orbital periodicities. The second goal is to suggest experiments that might provide insight into how metabolic processes and gravitation might be so coupled.