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> Why doesn't evolution get stuck in local maxima Is there any compelling reason to believe evolution _doesn't_ get stuck in local optima? It's not my field, s
by stordoff 11y ago
> Why doesn't evolution get stuck in local maxima
Is there any compelling reason to believe evolution _doesn't_ get stuck in local optima? It's not my field, so may be missing something obvious, but I see no reason that evolution requires complete avoidance of local optima. Different species could be the result of being "pulled" towards to different local optima. Local optima could disrupt evolution but, over time, a single large enough mutation or large enough change in external environment will either push you out of that optima, or stop it from being an optima.
- adevine 11y agoEvolution most certainly DOES get stuck in local maxima: http://m.youtube.com/watch?v=cO1a1Ek-HD0 http://m.youtube.com/watch?v=cO1a1Ek-HD0 . Also, it's quite easy for me to imagine an animal like an angel, with arms and wings. Tetrapods only have 4 limbs to work with though. For bats to gain wings they had to lose their front legs.
- GFK_of_xmaspast 11y agoOne obvious local sticking point is mammalian cervical vertebrae (a couple critters have more or fewer, but basically you're stuck at 7 whether you're a rat or giraffe)
- roywiggins 11y agoCephalopod eyes are better than mammalian ones. They evolved independently, but cephalopods ended up with an arguably "better" solution, and mammals aren't about to swap their eyes around entirely given that their eyes work just fine, even with a blindspot. https://en.wikipedia.org/wiki/Cephalopod_eye https://en.wikipedia.org/wiki/Cephalopod_eye > In vertebrate eyes, the nerve fibers route before the retina, blocking some light and creating a blind spot where the fibers pass through the retina. In cephalopod eyes, the nerve fibers route behind the retina, and do not block light or disrupt the retina.