The two strategies remain in equilibrium because, if one became rarer compared with the other, its practitioners would enjoy more individual success, passing their genes on preferentially and thus restoring the balance.

ECONOMIST: Males can take many routes to reproductive success

That is at model time folks seem to forget that they are dealing with a complex system that has specifically evolved to maintain equilibrium in the face of exogenous shocks.

FORBES: Could Long Commutes Be Making Us Fat?

Eventually the patent database becomes rich enough with prior art to reach an equilibrium, but the errors in the interim produce a batch of legacy patents that never should have issued.

FORBES: The Problems With Software Patents (Part 1 of 3)

Those who worked with what was alive in an infinity of yesterdays complained that even though they had no good explanation of why punctuated-equilibrium theory worked, you couldn't argue with the evidence in the rocks, maths or no maths.

ECONOMIST: Stephen Jay Gould