How horny can humans get before it's too horny

Question

Trying to create horns which are both ornamental and defensive, I've read somewhere that beards evolved in humans because we punch each other so much that even just a minuscule amount of hair cushion can make the difference between you dying with a broken jaw or surviving with a few broken teeth but no internal bleeding. With these in mind, one would think that human males are min-maxed for violence.

I'm trying to push the meta even further beyond, by giving people horns; each horn is pointy, and these pointy horns also have sharp and pointy protuberances. In real life if you punch someone barehanded and hit their chin, unless you are considerably heavier than your opponent, you are more likely to crush your own fingers and break them against the sharp jawline of your adversary. Or at least it happens more often when both the victim and the aggressor weigh the same: that's kind of the point of why boxers use gloves.

Following this logic, the jaw horns follow the jawline and then bend down both to expose the pointy protuberances forward and to cover part of the neck.

The top horns exist to block attacks from predators. Historically predators used to pounce on people from behind and bite them in the top of the head.

The prototype also shows some smaller barbs on the neck, which I will remove and place with a 2D textured version but the concept still remains.

I want the horns to be made of either dentine or iron-enriched bone, like the teeth of beavers or scaly foot gastropods.

As of now, there are 8 big horns; can it get up to 16 before it becomes unliveable? What am I trying to achieve? Basically these situations:

• You hit this person with a sword in the head; your sword gets stuck between the horns and then she proceeds to beat you with your own weapon.

• You punch her face; your fist bleeds and breaks.

• You kick her face; you don't walk any more.

• You watched too much Twilight and want to bite her neck; her neck bites back.

Also, the rest of the body will be covered in external bony round/flat plates, of the same materials as the horns; it will cover mostly the thighs, back, belly, shins, forearms and chest

Answer 1

You have the wrong horns for your stated goal of defense.

Long pointed horns a bad for defense, and even worse on the head of a biped. There is a reason humans only ever put horns on ceremonial helmets, they make the head more vulnerable to blows. The horns you have would make weapon attacks against the head MORE likely to injure the head and neck. They provide leverage to the blows and make them more likely to hit the head; there is little chance of getting your weapon caught. Worse, your horns are attached to the weakest part of the skull, so simply cracking the skull wide open is very likely, making them more vulnerable, not less. The lower horns are just as bad - they are attached to the zygomatic arch (literally can't be attached to anything else in that area) which is fairly weak, so a blow will simply rip them off the head along with bone and jaw muscle. This is doubly dangerous as it will prevent them from being able to chew properly.

Even worse, the horns would provide leverage to grab the head, which is a huge liability to a creature with hands - why punch someone when I can just grab their horns and wrench them sideways, twisting the whole head and neck. Some minor cuts on the hand are nothing if I can literally snap their neck or even just knock them off their feet. The last thing you want on an upright biped with a thin neck is easy-to-grab leverage on the head.

The small horns on the neck are fine and may help with defense; something like that has evolved more than once even in mammals. Small widely spaced scales are the best you can get in order to keep neck flexibility. But if your goal is to protect the head, you want broad flat horns - like those of a musk-ox or mouflon. Or you can have lots of tiny interlocking spikes, similar to those of a horny toad. Either would make grabbing or biting the head difficult, and provide a helmet-like extra layer of protection.

The YouTube Unnatural History Channel created a great video about how horns function, titled Spec evo short : the practical uses of horns and antlers. According to their terminology, you seem to have put jousting horns on something that can't use them, so they can only be pure ornamentation. So which is more important to you? If you want the shape, they are pure ornamentation and a huge disadvantage in a fight. If you want the function, you need a drastically different shape and layout.

Also just FYI small horn covered bones covering the body are called either scutes or scales, depending on which layer of the skin they originate from. Horn, scales, and even hair and feathers are all made of the exact same material, Keratin.

Answer 2

You can cover the whole body with sharp, pointy horns if you want... but before you do that, you may need to justify yourself.

How did these horns get there? Did they evolve? If they evolved, what evolutionary pressures led to their evolution? Did the ancestor species have horns that could have evolved into these horns? Maybe they were bioengineered...

However, you need to consider the cost. Babies can't be born with horns, otherwise they and their mothers will die in childbirth, so they have to grow later. Growing horns has a cost, the most basic cost being a higher protein intake required to feed the growth of the horns. However, that's not the only cost. Humans engage in body contact a lot for social bonding, and lots of horns are going to make a person literally too prickly to hug or kiss... so you're going to have to change fundamental social bonding rituals.

Also, if these horns evolved, the environment would have to be so hostile that any negative pressures from looking different and feeling prickly to the individuals' mates would be outweighed by the increased survivability of the individuals.

Then, don't forget that evolution is slow. It might take millions of years for horns such as these to evolve... has there been time? Are these 'horny hominids' even human any more, and would they need to be? It's far more likely that, given that no hominids, apes or primates have horns, some other mechanism of defence or avoidance of injury might evolve than horns.

This puts the question of horned hominids into the realm of traits that have appeared as the result of bioengineering or magic. If that's the case, then the limits of how many horns the hominid can bear comes down to practicalities of their protein intake and how social bonding rituals have been modified to allow for this spiky defence.

Your horned humans may be genetically human, but with all those horns and armour, they're going to become a separate species pretty quickly, since regular humans and these people are going to see the others as being pretty different and unapproachable.

Then don't forget that all this horn has weight. Your horned hominids are going to need either more muscle to carry it all, or they are going to need lower muscle-joint lever ratios to allow them to be stronger for a given mass of muscle... which will make them slower. Either way, it's a trade-off... more muscle, needing a higher protein and energy intake... or slower than normal humans, or something in between. You don't get something for nothing.

Further, humans have evolved to have the best cooling system and greatest physical endurance of all terrestrial animals, due to their ability to sweat in order to lose body heat. However, covering the body with horn and adding all that mass would reduce the cooling capacity and increase the body mass, thus reducing endurance. Horned hominids would not be as good at persistence hunting as humans.

Horns are sexual signals for many species, and are in effect saying to potential mates, 'Look at me, I can afford to carry these huge, otherwise useless things around and still be healthy, so I must be good breeding material!' As a rule of thumb, any time a biologist sees a huge, expensive, flamboyant and otherwise useless structure on an animal, sexual selection is probably involved.

TL;DR

So, how horny can humans become? As horny as they can be before less horny humans aren't horny for them any more... at which point, the horny hominids aren't human any more.

Answer 3

Anything more than a handful is too much.

Humans have something no horned animal has: prehensile hands. Any horns large enough to be grabbed will be a massive disadvantage in a fight, giving the opponent an easy way to grab and control the head, and thus the whole body.

It's doubtful any horns small enough not to produce this problem would be much use, but they could evolve as sexual markers.

Answer 4

The dangers and advantages of exoskeletons

There is something important you've glossed over at the start. You've mentioned that a beard cushions the blow. A horn will be more Newtons cradle. Those balls on wires that show how a force is moved through other balls to the outer ones. It shows why a hard surface in itself is not necessarily a good protection, as any force can as easily be passed through. Check out wounds of people shot while having a bullet proof vest. It's not pretty, despite them being alive. A fist against a horn will definitely dissuade pummelling your opponent, so it will be better in the long run. But a single strike against the neck will be better bearded than horned for the receiver.

That being said, that is only when all else is equal. Evolution will likely step into cushion the blow. It is advantageous to catch a blow with a larger surface area as well as over distance. That means you can have the horn move to force of the blow to skin beneath it, which has evolved a clever layer to cushion blows. A larger surface area thanks to the horn means it can be a thinner layer, giving the explanation why it's better than just having such layer on top. The horn is also better suited against sharp things, which might be more important in a world where sharp horn edges can frequently come close.

Unfortunately horns provide one really bad property. Weight. They can make people top heavy, requiring much more muscles to stay upright. With a thicker neck it can also make it more difficult to turn a head. Having horns is a costly business in not just growing, but even without it growing after maturity it has a large cost on the body and movement as well.

Finally there's the plates on the rest of the body. These have the same problems as the horns with transferring energy and being heavy. Humans only have an 'exoskeleton' around the brain and a layer to cushion blows. This is because at a certain size, an exoskeleton for the rest of the body is simply too heavy. Your proposition of plates is even worse. Not only does it transfer the energy and is heavy, but it's also not used as an exoskeleton. So now you have in essence two skeletons to maintain, of which the outer one would be too heavy even without the inner skeleton.

That being said, I would always choose story over reality. For a good story people will ignore or not think about such trifling things.

Answer 5

I'd be interested to see the evidence that a beard provides any significant cushioning to being punched in the face. A beard would have to be VERY thick for this to work. I find the theory that a beard helps keep your face warm in cold weather much more plausible. On the other hand I don't notice feeling any colder when I go outside in winter since I shaved off my beard. I always found that the main advantage of a beard was that it helped to hide my face so women didn't notice how unattractive I am. :-)

That said ... As others have noted, a long horn can be a disadvantage in combat: an opponent can grab it and use it to control your head (or whatever part of the body).

If you had a hundred horns all over your body, these would likely get in the way of performing routine tasks. Likewise large horns could be heavy and weigh you down. There's probably a reason why no real animal has a hundred horns.

Yes, a horn could get in the way of some other creature trying to attack you. But a better defense would probably be a thick skull. Which in fact people already have. One could always say it would be better if it was thicker still, but then again you have trade offs. At some point it becomes so heavy that it takes a lot of muscles just to move your head.

It suddenly occurs to me that when people make defensive armor, they do NOT put horns on it. (Viking helmets with horns were a product of fiction, a Wagner opera, and were never used in real life.) If horns were a good defense, surely armor with horns would have proven effective and become popular.