What was the purpose in evolution for curly hair?

Why did some people evolve with curly hair and other straight? What's the purpose biologically for curly or straight hair?What was the purpose in evolution for curly hair?
It was probably due to genetic drift rather than natural selection, though perhaps sexual selection may have played a part.





The tight curls of the Africans, on the other hand, may have been the result of natural selection because of the environment.What was the purpose in evolution for curly hair?
It depends on the 'pore' the hair grows out of. If it is oval shaped the hair tends to curl due to the small space. If the pore is circle shaped the grows straight. Wavy is in between. Actually curly hair is a dominant trait and straight is recessive. Straight hair shows someone lived in a cooler region as it lays flat and holds oils easier, locking in heat. A person living in a hotter area will have curly hair as it holds in moisture more easily and disperses more efficiently. The amount of eumelanin someones hair has depends on the color. The more you have the darker it will be, it also becomes more dense.
If something doesn't affect the likelihood of reproduction then it won't be acted on by natural selection. So, there was no evolutionary pressure to either stop the spread of curly hair or to increase it.
';Not all traits evolve'; is correct. It is passed on genetically but it was possibly just a mutated gene from whatever humans originally had. There is no real explanation for the evolution of curly or straight hair.
Not all traits are evolutionary.
hydrogen bonding!