linucs

I'm referring to the human race evolving in the African continent and then migrating to the rest of the world.

Evolving in Europe made people light skinned to account for the reduction in sunlight exposure, are there any other traits which other ethnicities developed to adapt to their new environment? Or are the diifferent traits in different ethnicities just stuff that developed by chance and got somehow reinforced because of the isolation between populations?

This question came to my mind first thinking about "Asian eyes", do they serve any "purpose"?

Alternative title: Dinosaurs wouldn't be that big if they weren't that big

Any topic, just explain what it is please

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?

The birth (or death) of a relative, the release of a new program, game, series, movie, the date you were dreaming about, could be anything

What I mean is: some boolean flags are perfect for the real world phenomenon they are representing e.g. is_light_on makes you understand perfectly that when it is true the light is on and when it is false the light is off.

There are other cases in which if you didn't write the code and you don't read any additional documentation, everything is not clear just by looking at the variable name e.g. is_person_standing, when true it's clear what that means but when false, is the person sitting? Lying? Kneeling?

I'm obviously not talking about cases in which there are more states, boolean would of course not be a good solution in those cases. I'm talking about programs in which there are only two states but it's not obvious, without external knowledge, which ones they are.