ABSTRACT
Many homeostatic systems (living and non-living) respond to a disturbance in such a way as to lessen its impact. This is the chemical principle of Le Chatelier [12]. It is a basic property of equilibrium dynamics. When a system is in equilibrium and you push it left, it comes back part-way to the right. It settles in a position further left than originally, but not as far left as you had pushed it. In a homeostatic chemical or physical system that includes a component C, when some of C is removed, the equilibrium shifts in such a way that C is partially restored. The amount of C will still be less than the system had originally, but more than there was after the system was disturbed by removing some C. Conversely, if some C is added, the equilibrium shifts the other way, so that some of the additional C is used up. For example, a buffered solution may have a pH of 7. If you add acid with a pH of 2, it will become only slightly more acidic, perhaps 6.5.
