does curly hair has anything to do with the climate of a place?

I don't think climate has anything to do with having cury hair, but your genes in your body. My four children all have the same father and only my little girl has cury hair, the rest of us, that is hubby, me, big daughter, big son and litle son all ahve straight hair, while little girls is so cury we keep i tied up in plaits as it gets so knotty. I don't know what other peoples views are on this matter