I know evolution is governed by chance and it is random but does it make sense to “ruin” sleep if there’s light? I mean normally, outside, you never have pure darkness, there are the moon and stars even at night. In certain zones of the Earth we also have long periods of no sunshine and long periods of only sunshine.
I don’t know if my question is clear enough but I hope so.
Bonus question: are animals subject to the same contribution of light or lack of it to the quality of sleep?
Hmm. Are we talking a high canopy, and fairly level ground? I feel like I’d definitely break an ankle if I tried sprinting otherwise.
I never had too much trouble, but sometimes things hiding in tall grass would surprise me, and in heavily treed patches I’d occasionally hit a low branch I didn’t notice.
I also have to account for the fact that there was some light pollution, and I could always see skyglow from towns in the distance. I doubt land ever gets close, prehistoric or not, but in the darkest conditions that happen at sea apparently you can’t see your own hands.