Negative feedback



Negative feedback is a process in a cybernetic system where a change in some property of a system triggers a change in one or more other properties which, in turn, push the first property back toward its original state. It is therefore the most common way to maintain homeostasis.

The simplest example of negative feedback is a common thermostat, a human-built system consisting of a thermometer, heating and/or cooling devices, and a control system to set the desired temperature. If a heating device is part of the system, then when the thermometer reading gets more than a short distance below the set temperature value, the thermostat turns on the heating device, leaving it running until the temperature is once again very close to the desired value.

Negative feedbacks in Gaia are different in that there is no control system per se. Life determines the "desired" value organically by changing the system until it is no longer adaptive to change it further.