What advantages did curly hair give to our early human ancestors?

Straight hair is all the rage among women today – and many who were not born with it will try anything to make their locks look ironed. But if they were early humans living in Africa, they probably would suffer even more.
Curly hair does more than simply look good to devotees – it may explain how early humans stayed cool while conserving water, according to Pennsylvania State University researchers who studied the role human hair textures play in regulating body temperature. The findings can shed light on an evolutionary adaptation that enabled the human brain to grow to modern-day sizes.
“Humans are unique among mammals in having a functionally naked body with a hair-covered scalp. They evolved in equatorial Africa, where the sun is overhead for much of the day, year in and year out,” said anthropology Prof. Nina Jablonski. “Here the scalp and top of the head receive far more constant levels of intense solar radiation as heat. We wanted to understand how that affected the evolution of our hair. We found that tightly curled hair allowed humans to stay cool and actually conserve water.”
What advantages did curly hair give to our early human ancestors?