Why are we awake during the day and sleep during the night, and generally not the opposite?


Why are we awake during the day and sleep during the night, and generally not the opposite?

In: Biology

Multiple reasons but one is just social conventions.

People can be up at night but why bother when the rest of the world is sleeping. As to why it developed that way, before the advent of electric light it should be obvious what one reason is. It’s simply smart to be awake when you can actually see stuff.

The other big factor is biological, sunlight stops the production of chemicals that make us sleepy.
This is a big reason BTW why smartphones and laptops screw with our sleep cycle. Get a night screen app folks!

Our vision isn’t that good so we can live in the dark, cats and other felines have a great eye sight so they can walk and see in the dark, and we as humans need to do our stuff during the day cause, we need the sun like our body needs the sun so we can absorve vitamins, minerals. We also produce hormones that makes us sleepy when the sun goes down, that’s why you can’t sleep properly when you stay in the computer too much. If suddenly everything changed and we had to live in the dark things would get pretty fucked up for us humans

Circadian rhythm

A circadian rhythm is a roughly 24 hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria.

In a strict sense, circadian rhythms are endogenously generated, although they can be modulated by external cues such as sunlight and temperature.

Circadian rhythms are important in determining the sleeping and feeding patterns of all animals, including human beings.
There are clear patterns of brain wave activity, hormone production, cell regeneration and other biological activities linked to this daily cycle.

From: https://www.sciencedaily.com/terms/circadian_rhythm.htm

Natural selection.

Probably the trait where you walk around at night and sleep through the day got weeded out as an inferior trait. They must of gotten eaten by predators or other dangers that they couldn’t see and for whatever reason, our bodies better adapted to sleep at night as opposed to gaining night vision (just one example).

Basing owls, apparently eyes have a hard time both being large enough to see at night but at the same time, able to get small enough to block enough light to see during the day. Owls can see at night, but during the day their pupils can’t get small enough to account for the daylight. They have to resort to keeping their eyelids half way closed to block out all the extra light during the day. And so natural selection probably just favored having eyes better optimized to see during the day.

Frogs can also see at night, but to compensate for the lack of light, they basically get a vision delay. I think I heard somewhere that it could take up to 4 seconds for them to get an updated vision of their environment and is why they target really slow, sluggish pray. That would be disastrous for us, and so evolution favored to just sleep at night.

Insects also much much more active at night. I also believe they are drawn to heat. When you sleep, your body temperature goes down. Maybe that helps? Also related, the reason insects can see at night is because they actually just see in much much worse resolution. For us, a high resolution is also probably an advantage. And so instead of adapting all that at night, just sleep instead.

Tarsiers see at night because of their abnormally large eyes which is an evolutionary advantage because it is horrifying and terrifies their predators into submission.

Tarsiers also eat insects, bats, etc. Their diet basically consists of night animals and so giving them those nightmare inducing eyes to see at night makes more sense to them. Because their eyes are so large compared to their bodies, they had to sacrifice their ability to move them to gain that night vision – instead they have to resort to moving their entire head to look around.

Night vision is just really hard thing to achieve, it comes with too many draw backs. You need have a very good reason to be FORCED to adapt to it. We didn’t have all those reasons and so we just adapted for the day time.