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EyeSprout t1_iyom6dr wrote

Absolutely stability is difficult since the world is constantly changing, but the change is slow enough that evolution does tend to produce approximately stable systems. That's a straightforward result of the math; less stable states change quickly and therefore your system spends less time in them.

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[deleted] t1_iyomgr2 wrote

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EyeSprout t1_iyon8r9 wrote

The oxygen catastrophe is possibly the worst possible counterexample you could pick here. The oxygen catastrophe happened slowly enough for all forms of life to settle in niches, enough for game theory to direct evolution, and for a stability condition to apply. Those niches were approximately stable while they existed.

That's all that the stability condition needs to be applied. It's not some complicated concept.

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[deleted] t1_iyonzdu wrote

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EyeSprout t1_iyopym1 wrote

For example, in iterated prisoner's dilemma "always cooperate with your opponent" is not stable, because your opponent's optimal strategy against that is to defect every turn. The simulation I linked in my original comment shows a ton of strategies that are not stable and shows quite directly how they would quickly get eliminated by evolution.

For a simple example in evolution, most mutations harm the organism and are unstable. If most organism in a population had a very harmful mutation and a small population didn't, that small population would quickly take over the larger population. Hence, that mutation is unstable.

A slightly nontrivial example would be blind altruism in a situation where your species is severely starved of resources. If most animals were blindly altruistic and a small number of animals were not and would take advantage of the altruistic animals, then again, that small number would outcompete the larger population. So blind altruism isn't stable.

Of course we can't find many real-life examples; that is because they tend to be quickly eliminated by evolution. If they exist, it's usually only temporary.

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EyeSprout t1_iyos2ps wrote

Ah, wait, just in case... when I say "stability" it has nothing to do with stability of government and things like that. I meant it in more of the physics sense, that small perturbations wouldn't cause a large effect.

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