Is human facial hair like a cat's whiskers?
Do cat whiskers and human facial hair have anything in common as of their uses?
We put this question to Nick Crompton, a Zoologist in the Mammal Evolution and Morphology group in Cambridge University... Nick - To a certain point, the whiskers on your cat's face and stubble on mine look pretty similar. After all, they're both part of our Pelage - our insulating furry coat. But whiskers are a type of specialised hair called vibrissae. Now among other places, they're found in the maxillary - that's the upper lip region, and they come in both macro and micro forms, and in the same way as normal hairs, they're keratinous structures growing out of the skin - the epidermis. But whiskers tend to be far thicker and as we know, they act as mechanoreception organs.
Now obviously, when someone pulls a hair out of my head it hurts, and to some extent, all hairs act as mechanoreceptors for very light touch. So, I can feel if something brushes very lightly up against the hairs on my arm. But vibrissae sport a suite of tactile sensitive organs at their base, so any tiny displacement results in a far more complicated signal being transduced to the animal's brain wherein a large portion of its somatosensory cortex is concerned with interpreting signals as spatial information.
Beardy chaps don't have this sort of specialisation within our brains and in fact, humans are almost unique in being one of only two mammals known not to sport any vibrissae at all, along with the anteater. But it's recently been reported that the muscles used to move whiskers around are present in the human lip, but has very degenerate vestigial structures. Now our beards are more than likely the result of sexual selection like the mutton chops and moustaches on some old world monkeys, and they just help their owners look dashing, if maybe, a little bit scruffy.