4 ms·

coliveira, you have obviously given this some thought. Any further nuances?

• coliveira 5y ago
  I'm not a biologist, so I consider this just my pet theory. But the idea is that one key element of evolution was the appearance of an alert state, which we now call wakefulness. The normal for all organisms was what we now call sleep. Organisms that developed this awake state were obviously able to better adapt to the environment. Like in many other cases, we can take clues from embryonic development. We know for example that fetuses spend at least 95% of their time sleeping. So we know from pretty early stage that sleeping seems to be the norm. Sleeping is also the most efficient, energy-wise, state for an organism. Even nowadays certain animals are able to hibernate for months. Humans can do this too in extreme situations, it is called comma. So, when we go to sleep we're not just "recharging". We're going to our normal state, and while it is possible to stay that way for long periods, I never heard of anyone staying awake for more than a few days.