Why is hair under the arm-pit of both human males and females? What is the function of this hair?

The presence of hair is a mammalian character.Homo sapiens has lost most of the body hair.But still why do we have this uncomfortable arm-pit and pubic hair?

Why is hair under the arm-pit of both human males and females? What is the function of this hair?

As always, to understand things that humans have in their anatomies but that

have no apparent use [e.g., arm pit hairs] one needs to think about

evolutionary forebears and look to closely related species for clues. Two

levels to the response: the nature of those particular hairs and how they

serve to help advertize your basic adult [post-pubertal] human condition,

however masked by contemporary perfumes %26amp; deodorants. Hair is akin to fur

but without the insulative properties, and comes in generally coarse %26amp; fine

varieties. The particular coarse hairs which develop in the pubic area and

in the armpits arise at puberty [clue #1]. Hair follicles in these areas

have a type of sweat gland associated with them, called an apocrine gland,

that begins to function at puberty and is widely associated with

scent-communication via chemicals known as pheromones [clue #2]. Apocrine

glands produce an otherwise non-offensive secretion that now appears to be

homologous with animal sex-specific scents. Unfortunately its components are

broken down by bacteria to form odors associated with dirty locker room

smells. The arm pit hairs serve as extended surface from which these

volitile chemicals can be more efficiently broadcast. Scientific data

supporting the presence %26amp; effect of human pheromones have become more

substantial in the last couple of years. Interestingly, perfume companies

have recently begun playing up the nature of human pheromones!

Dr. Dinsmore