We\’re a pretty resourceful species, but when it comes to body parts, humans definitely have a couple that seem like a waste of space. After all, we could do perfectly well without the appendix, male nipples, and our wisdom teeth, and scientists think these could simply be a hangover from our evolutionary past. But what\’s the point of all that hair on our bodies, and why do we have eyebrows anyway? The
of the University of New South Wales\’ (UNSW) How Did We Get Here explains. For starters, even though we might consider ourselves pretty hairless, humans are actually covered in around five million hair follicles – tiny organs on our skin\’s surface that produce hair. In fact, after our heads, the area with the highest concentration of hair is our nostrils. But why aren\’t we as hairy as our ape cousins? As evolutionary biologist Darren Curnoe, it\’s believed that our ancestor\’s body hair got a lot shorter as they evolved from walking on all fours to standing, and this allowed them to keep cool while walking and running long distances in pursuit of food.
And our hair still plays a very important role in regulating our body temperature. When it\’s cold outside, tiny muscles surrounding the hair follicle cause the hairs to stand up, to trap more heat near the body. This is what happens when you get goosebumps. So those tiny hairs all over our bodies make sense. As do nostril hairs and eyelashes, which keep dirt out of our bodies. But what about things like chest hair, pubic hair, and eyebrows? Why do they grow so much longer than the hair on our arms, and what\’s the point of them? Scientists still aren\’t entirely sure, and we\’ll let you to find out why. But one thing\’s for sure, our hair definitely isn\’t useless. В Don\’t forget to to see new episodes of How Did We Get Here? as they\’re released, and find out more about the research happening at Beards exist for attracting mates and for male vs. male competition.
Beards make males look bigger and more intimidating, and they also cushion blows and hide scars from past altercations. A beard s color and texture are known to influence womens perceptions of a man s age, social status, and general health. They have nothing to do with keeping the head/face warm or almost any aspect of natural selection. Beards also have nothing to do with keeping pathogens out of your mouth/nose either, we have nose hair and saliva to protect those orifices. As for why there is no hair on our forehead, well, facial hair growth patterns simply weren t selected to cover our entire face. Probably because hair in those areas would not make the profile of an individuals face/head appear larger and would not be very visible, so there is less benefit to a male when it comes to sexual competition vs. hair running along and around the jawline, which is more striking to potential mates and competitors.
And also long hair around your eyes usually isn t very helpful. A lot of answers on this thread don t fully understand evolution and how traits develop and are passed on. In evolution, sexual selection is much more powerful and impactful on physical form than natural selection. Evolution is more accurately summed up as reproduction of the fittest, rather than survival of the fittest. A creature who can yield 100 offspring but only live a week is considered more successful than a creature of the same species that yields 1 offspring but lives a hundred years. Critters are trying to fuck, not to simply exist. Chances are when examining any traits in nature that are highly visible and affect the appearance of an organism they are more influenced by sexual selection than natural selection, and beards are a perfect example of this in humans. Sources: