The cellular switch that explains why humans aren’t nocturnal
9h 37m ago by lemmus.org/u/Beep in science from www.cam.ac.uk
Differences in cellular pathway activity flip the switch from nocturnality to diurnality and explain a major evolutionary change humans have undergone.
Early mammals were nocturnal, sleeping during the day while large predators were active. However, after the extinction of dinosaurs, several different lineages of mammals independently transitioned to become active during the day. Exactly how this dramatic change occurred has proved elusive. A new study, published in the journal Science, has revealed a cellular switch which holds the answer.
Not nocturnal? Speak for yourself, maybe... :p
I'd say it still counts as diurnal, unless you're actually sitting completely in the dark (and yes, the screen counts as a light source) Ü
Also, as someone who also is awake most nights, I get the impression that it's not particular healthy, i.e. is in conflict with our biology.
Tool use and being nocturnal are kind of a bad fit, so it's hard to believe that humans would have evolved in a recognizable form if they had been nocturnal.
How so? I use tools at night all the time. Fire enabled a lot of going to dark places with tools. If we were nocturnal we would probably have large eyes and so our vision would be better. I can see it making written communication less dense but thats a bit down the tool use path
All other things being equal, eyes specialized on daylight activity will just be better at the kinds of intricacies needed for shaping the tools, collecting the right materials etc., mostly because night vision is pretty much greyscale for mammals. And would humans even be as likely to start using fire if they could see in the dark? It's obviously still useful for preparing food, but IDK that I'd choose to place a beacon of light and smoke (smell) in the night if I could see without it.
I'd assume that humans used tools long before they started using fire, because making fire is far more involved than using simple tools. Though this might actually be worth looking up.