There’s a great article on Nina G. Jablonski in the International Herald Tribune. She’s written a book called Skin: A Natural History…

But when you really start thinking about it, it’s a factory that produces vitamin D, sweat, hormones, oils, wax, pigments — substances we need. Skin is a raincoat in that it protects us from water, bugs and noxious chemicals. It’s also a billboard which we adorn with powder, tattoos, piercing and scars to give off instant messages about our history, health, values and availability for mating.