http://en.wikipedia.org/wiki/Levinthals_paradox http://en.wikipedia.org/wiki/Levinthals_paradox pretty interesting, but it sounds more like the protein folding

http://en.wikipedia.org/wiki/Levinthals_paradox http://en.wikipedia.org/wiki/Levinthals_paradox pretty interesting, but it sounds more like the protein folding nature does isn't NP-complete. Like, Scott Aaronson says, nature may just have selected a subset of proteins that it happens to have figured out how to fold well: http://www.scottaaronson.com/papers/npcomplete.pdf http://www.scottaaronson.com/papers/npcomplete.pdf (also discusses other instances of nature seeming to solve NP-complete problems)