Say “hair,” and most people think of the fluffy stuff covering the scalp. But those fibers make up only about 100,000 of the 5 million or so hairs we have overall. In fact, each of us has about the same number of hairs as an ape!
Hair is often treated as an adornment. Yet hair serves a more serious purpose. It cushions minor blows, keeps the sun off, and provides warmth. Hair can alert us to a touch or temperature change. And eyebrows, eyelashes, and nose hairs keep dirt and foreign objects out of places where they shouldn’t be.
Fingernails are survival tools as well. Try getting a pin or a coin off the floor without using them, or try to scratch that itch on your scalp.
