> This is almost certainly the wrong metaphor, since there aren't really any instances of animals that are always awake, which seems like an obvious competitive

> This is almost certainly the wrong metaphor, since there aren't really any instances of animals that are always awake, which seems like an obvious competitive advantage. Except that there are. For example dolphins and other sea based mammals who cannot breath underwater. They do so via sleeping half their brain then flipping over and sleeping the other half. This prevents them from drowning. Going back to the computer analogy, I always thought it sleep more like a disk defrag rather than GC pause. However as other commenters have pointed out, the brain is so different to any computer we've built that any comparison to a computer methodology would quickly fall apart under even the slightest bit of scrutiny.