Proud to be curly

As we head into winter, which the climatologists say will be colder and wetter than usual, I wondered about why we have so little bodily hair to keep us warm.. We wear clothes, layers of it during winter, while my dogs have thick curly fur that trap the air and therefore keep their bodily heat to themselves for longer, much like the ozone layer traps the earth’s heat.

Hair does not fossilise easily. It is very difficult therefore to establish from the fossil record when and how we lost our bodily hair. Our closest living relative the Chimpanzee may provide some clues. About 6.2 million years ago we shared a common ancestor with the Chimp and went our separate ways since.

Cousin Chimp has straight black hair covering a pink skin. This is likely our original state. Nina Jablonski in her book titled SKIN reckons that as we increased in body mass while emerging as hunters in equatorial Africa we required some means of getting rid of bodily heat more quickly (Berkeley, 2007). We develop the ability to sweat and hair loss helped along the way.

The pink skin underneath did not do very well in the equatorial sun. Judging from fair-skinned individuals living in hot ecologies today, for those living long enough skin cancer was likely the common malady. Nature’s sun screen melanin saved those who happen to own the genes and the survivors developed darker skins in the course of time.

And our hair? If you look well enough you will see that the entire human body is covered with hair, most of it almost invisibly fine. Head hair is for heat regulation, protecting the brain case from heat stroke during summer and cold during winter. Armpit and pubic hair are survivors of the ascent towards the naked and hairless third chimpanzee, which is what we are.

There is evidence that straight hair act as fibre optic tubes which allow a certain band of good ultra-violet light, which we require for all manner of biochemical effects like synthesising Vitamin D, to pass into the skin. Much as we need the UV rays though, too much of it can destroy folate stores and damage the skin itself.

As we may expect, the shift towards a darker skin necessitating by loss of hair prompted by the millions of sweat glands we required to dissipate heat, made straight hair a liability. More than enough UV rays reached and penetrated the skin. What would be beneficial was a texture of hair that prevented the passage of UV rays.

The upright walking two legged hominid – and it was likely Homo erectus, we are not quite sure – who happen to have the hair texture mutation that made for tightly coiled hair was the one. Curly hair was just a normal variation of the theme and it was this range that spread in populations that require more protection against harmful sunlight.

What is curly hair? How did it arise? First, we should say that there are three types of hair (1) Lanugo hair, fine hair that covers nearly the entire body of fetuses (2) Vellus hair, the short, fine and fuzzy hair found in most places of the body and (3) Terminal hair, the fully develop type, which is longer, coarser, thicker and darker than Vellus hair.

Then, hair texture can be fine, medium, coarse or wiry. It can be straight, curly, tightly curled or ‘kinky’ or wavy. Finally, as every hairdresser knows, hair can be healthy, normal, oily, dry or damaged. Biologically, curly or ‘kink’ hair is determined by the shape of the hair follicle, the direction of its growth, the cross section of the shaft and a higher level of dryness.

In racist societies like South Africa, curly or ‘kinky’ have negative aesthetic connotations, which the Black Consciousness Movement tried to reverse and with some success. However, the weight of the straight-hair-is-beautiful legacy have many individuals still spending an unusual amount of money on grooming experts called hairdresser to straighten their normally curly hair.

As every blow-dried or metal-ironed woman knows, hair whether curly or straight, is affected by the amount of humidity in the air. It is a restorative process where water is forced back into the hair fibre bringing it back into its original shape. And so kroeshare (Afrikaans for ‘kinky’) comes, goes and comes again. There is something pathetically hilarious and very human about all this, isn't there?