Ecological stability in the context of "Wolves and moose on Isle Royale"

An evolutionarily stable strategy (ESS) is a strategy (or set of strategies) that is impermeable when adopted by a population in adaptation to a specific environment, that is to say it cannot be displaced by an alternative strategy (or set of strategies) which may be novel or initially rare. Introduced by John Maynard Smith and George R. Price in 1972/3, it is an important concept in behavioural ecology, evolutionary psychology, mathematical game theory and economics, with applications in other fields such as anthropology, philosophy and political science.

In game-theoretical terms, an ESS is an equilibrium refinement of the Nash equilibrium, being a Nash equilibrium that is also "evolutionarily stable." Thus, once fixed in a population, natural selection alone is sufficient to prevent alternative (mutant) strategies from replacing it (although this does not preclude the possibility that a better strategy, or set of strategies, will emerge in response to selective pressures resulting from environmental change).

The term Golden Age comes from Greek mythology, particularly the Works and Days of Hesiod, and is part of the description of temporal decline of the state of peoples through five Ages, Gold being the first and the one during which the Golden Race of humanity (Greek: χρύσεον γένος chrýseon génos) lived. After the end of the first age was the Silver, then the Bronze, after this the Heroic age, with the fifth and current age being Iron.

By extension, "Golden Age" denotes a period of primordial peace, harmony, stability, and prosperity. During this age, peace and harmony prevailed in that people did not have to work to feed themselves for the earth provided food in abundance. They lived to a very old age with a youthful appearance, eventually dying peacefully, with spirits living on as "guardians". Plato in Cratylus (397 e) recounts the golden race of humans who came first. He clarifies that Hesiod did not mean literally made of gold, but good and noble.

In the context of ecological stability, resistance is the property of communities or populations to remain "essentially unchanged" when subject to disturbance. The inverse of resistance is sensitivity.