Answer:
It's controlled by the Brain
The study of human populations is called Demography. Sorry it’s late.
I think it's the first one: the red fox that inhabits farmlands and forests has a red coat, but it's relative, the kit fox, lives in a desert has a sandy-colored coat
The tilt of the earth changing would affect the distance to the sun. This, the radiation from the sun, and resulting temperatures, would change as well.
