Have you ever woken up in the middle of the night from a sound sleep and not been able to drift back off to dreamland? In our current daytime 9 to 5 society this is seen as a problem and is often treated with pharmaceuticals or recommendations of more exercise and proper eating habits. But it may be an evolved trait, A leftover of our biphasicc sleep patterns. Simply put, our circadian rhythms aren’t set to sleep in eight hour chunks. This older article from Live Science has a great overview of how our sleep patterns have changed over the centuries and what caused the transition. And if you find yourself awake in the middle of the night, don’t fret, enjoy the quiet, read a comic and have a laugh.