Unicorns really too much of stretch?

[Maze1125]

As long as the mutation isn't directly harmful to the organism, it might still get passed on, and might become useful to the organism later, or become vestigial.

That's not really true at all.
Yes, a single mutation can get passed on by chance, but a horn isn't a single mutation, to grow a horn on a species takes more than thousands of generations of mutations and that does not just happen by chance.

Further, a unnecessary horn is harmful. Horns are usually made of bone and so require the resources that bones require. That means that, in an environment of limited resources, an animal with a horn has brittler bones than one without the horn, which means an increased chance of injury and death.

Mutations are random, but that doesn't mean the evolution of species is. "Vestigial" doesn't refer to organs that never had a purpose, it refers to organs that once had a purpose but that purpose has since been lost.

 

[Quaxar]

From an evolutionary stand point, what would be the point of the horn?

Not used for hunting prey.
Not used to fend off predators (cause what preys on horses that a horse could stab with his head?)

Maybe for mating like a peacock's feathers?

... The same as a rhino would?

Why would a rhino have a horn and a horse wouldn't?

Last I checked, Rhinos didn't eat meat.

So horns can be used for defense. Charging and stabbing would have the same effect as a bayonet charge. Get em in the ribs and you would likely hit a vital organ.

I would wager a unicorn horn would probably be the best weapon a fast animal could have.

Rhino's are like walking battle tanks though... Plus the placement of their horn makes sense as an offensive weapon against predators.

I don't think horses are built to charge at things with their head down.

Bulls charge, and they seem pretty nasty in a fight. Any rodeo shows horned herbivores are far from defenseless.

Horses can be build to stab at things with a horn, it just needs to be a sturdy horn.

I disagree. Horns are almost always pointed away from the direction of movement because they are used as either natural helmets or a sexual characteristic. Stabbing is stupid since you just get yourself stuck to the enemy, screwing up your own freedom of movement, blocking your main defense and making yourself vulnerable especially against pack hunters.
Also, horse anatomy doesn't really support ramming into something headfirst with speed whereas rhinos and bulls are short-necked thick-skulled tanks.

Herbivores are of course not defenseless, the strongest and biggest land animals are herbivores, but they are generally more about ramming into things which is as effective as stabbing minus possible side-effects like breaking or getting stuck.

 

[shrekfan246]

I, for one, am glad that unicorns don't exist.

They're bastards, you know. They give away the location of peoples' gold.

Spoiler

 

[Heronblade]

A "horse with a horn" doesn't cut it. A horse does not have the right musculature to use such a weapon properly, and its skull cannot support it without fracturing. Furthermore, changing to allow for a horn would seriously inhibit a horse's ability to use its main survival tactic. (running away really fast)

Now, granted, the existence of a horse like creature with the necessary modifications for a horn is not out of the question, but given no evidence of its current or prior existence, it gets lumped in with all of the other fantastical though technically possible creatures, such as living dirigibles and centaurs.

 

[EHKOS]

From an evolutionary stand point, what would be the point of the horn?

Not used for hunting prey.
Not used to fend off predators (cause what preys on horses that a horse could stab with his head?)

Maybe for mating like a peacock's feathers?

Impaling things and then having those things hang down to its mouth to eat it? That's the best I can think of.

OT: Yes, I can see this being real at some point, after all, there is a such a thing as a Narwhal.

 

[Yopaz]

From an evolutionary stand point, what would be the point of the horn?

Not used for hunting prey.
Not used to fend off predators (cause what preys on horses that a horse could stab with his head?)

Maybe for mating like a peacock's feathers?

The thing about evolution is that not everything has to have a point. We have an appendix, a horse could hypothetically have a horn on it's head as long as it's not severely reducing its survival rate.

But the most likely reason would be attracting a mate.

So yeah, I see no biological reason that they couldn't exist, if evolution had randomly gone that way.

Actually the appendix is a part of what made us able to digest cellulose before we became omnivore so it has actually had a very important function. As of right now the appendix is important to maintain a healthy level of bacteria in the large intestine. Most "useless" structures or functions that we may think are there have been useful before or are still useful.

Useless structures as a horn on a unicorn might exist or have existed at some point, but unless they were common or served any use they would rank low on natural selection thus not be advantageous in the evolutionary process. Even the feathers of the peacock is important for more than show, the feathers got a pattern that looks like an eye so when they strut their feathers predators think they are outnumbered by several big animals. That's why the peacock with the nicest feathers get to reproduce, they're more likely to fend of predators.

 

[Schadrach]

It's not that it's impossible. It's that it doesn't exist.

Occasionally people are wrong about that, sometimes the cryptozoologists win, just not very often. For example, the Kellas cat was discovered in 1984, and is believed to be the origin of the mythological cait sidhe.

I'd be very surprised if that were the case with unicorns, but it does occasionally happen. we haven't completely catlogged every life form on the planet.

 

[Owyn_Merrilin]

Ok hear me out please. Excluding magical powers I don't see how a unicorn is so unbelievable. From a biological standpoint whats so crazy about a horse with a horn? I mean rhinos have horns, there are wasps that look like flowers, and have you seen some of the creatures in the deep ocean? A horse with a horn doesn't seem that wild to me. I know little or no evidence exists about unicorns but I think they just might have existed or could have existed with the right conditions.

if you think of a horse with a horn, you will have a very hard time to find anything.

but if you think of a goat with one horn that could had been easily mistaken for a horse, you might find something....

The unicorn is a legendary animal from European folklore that resembles a white horse with a large, pointed, spiraling horn projecting from its forehead, and sometimes a goat's beard and cloven hooves. First mentioned by the ancient Greeks, it became the most important imaginary animal of the Middle Ages and Renaissance when it was commonly described as an extremely wild woodland creature, a symbol of purity and grace, which could only be captured by a virgin. In the encyclopedias its horn was said to have the power to render poisoned water potable and to heal sickness.

also:

I'm not saying it's impossible, but they would certainly not look like any of the fossils we have found so far.

damn, why cant we have eohippi instead of cats

Now that's interesting. Especially because during the ice age one of the larger predators was a relative of the modern goat, so that even ties in with the "carnivorous unicorns" thing: http://walkingwithdinos.wikia.com/wiki/Andrewsarchus

Edit: Except I had the time period wrong. Less ice age, more 45 million years ago.

 

[Panorama]

I think the problem here is that most people associate unicorns with magic.

This is exactly what i was thinking, might be possible without the magic idea, but otherwise they are not a unicorn, they are a horney horse otherwise or some other name.

 

[BrotherRool]

Okay I get that Moose horns are clearly more practical than a unicorn horn would be, but what about springbok horns or goat horns? (Incidentally I'm not arguing unicorns existed because, people imaging a horse with a horn on it's head is simpler but I don't know if in an alternate universe it's that ridiculous of an idea. Maybe a big horn would be silly, but I'm thinking 30cm tops)

Also someone can take the opportunity to explain something to me, can't animals develop strange 'useless' characteristics for mating purposes? Special calls, inflatable throats, brightly coloured coats, red breasts, funny bottoms etc I never really understood how that worked (humans are normally put off by other people who aren't like they are) but couldn't a horn fall into this category?

EDIT: Also wikipedia adds that along with the other ones already discussed, horns can be used to root in the soil or strip bark from trees, courtship and cooling (apparently true horns work as radiators)

 

[Imp_Emissary]

From an evolutionary stand point, what would be the point of the horn?

Not used for hunting prey.
Not used to fend off predators (cause what preys on horses that a horse could stab with his head?)

Maybe for mating like a peacock's feathers?

Sane, Unicorns used their horns the same way narwhals use theirs today.

Spoiler: :D Like this.

 

[Substitute Troll]

It's not that it's completely unbelievable, it's that we deny it because of MLP.

Think about it, let's say they found evidence of unicorns tomorrow. The MLP fanbase would go fucking bananas. I don't think I can handle another 2011 on this forum, never again.

Please keep unicorns in fiction and out of real life, it's better for the children.

 

[AeroZeppelinSevenfold]

I think people don't believe in unicorns because they want to believe that they may someday own a Pegasus instead. A horse that can fly? Farmers would own the sky.

 

[Crazy]

I don't know about you, but I've come to know that unicorns are quite stretchy. And flexible, too! Scientifically speaking, of course.

 

[Haukur Isleifsson]

They could theoretically exist or have existed. But there are no evidence I have seen.

 

[lacktheknack]

From an evolutionary stand point, what would be the point of the horn?

Not used for hunting prey.
Not used to fend off predators (cause what preys on horses that a horse could stab with his head?)

Maybe for mating like a peacock's feathers?

It would be used for shit puns from regular horses.

The could shout out "OI, YOU LOOK HORNY".

I'm trying to punch you through the screen for that pun, but it's not working. ;__;

OT: No, there's no reason it COULDN'T exist, but lack of evidence of any kind lends to the idea that it SHOULDN'T exist.