There's a lot of sound reasonings here. the only thing I can really add is that
<youtube=e-lKImWtmSU> Or does it?!!
If Zebras' Stripes Aren't For Camouflage, What Are They For?
- Thread starter PatrickJS
- Start date
I always thought it was so it was hard to pick one 'cos it's hard to tell where one ends and another begins.
Black and white stripes on a brown back drop is just stupid, which is why lions, tigers, hyenas are all kind of the same colour (ok tigers are more orange and have stripes but it's not like they are flymango pink).
It's like wearing snow camo in spec ops the line.
I don't want to seem like some know it all smart arse ('cos quite frankly I'm an idiot! especially when you guys start talking math!) but even as a kid I knew that zebras didn't have stripes to be camo in their environment but more like camo with each other.
Black and white stripes on a brown back drop is just stupid, which is why lions, tigers, hyenas are all kind of the same colour (ok tigers are more orange and have stripes but it's not like they are flymango pink).
It's like wearing snow camo in spec ops the line.
I don't want to seem like some know it all smart arse ('cos quite frankly I'm an idiot! especially when you guys start talking math!) but even as a kid I knew that zebras didn't have stripes to be camo in their environment but more like camo with each other.
Can Hyena's see in colour? Cuz they don't seem to have problems murder zebras for food.Dragonbums said:
This right here. There is a pretty good rule of thumb among evolutionary biologists: If a trait has no recognizable adaptive function derived through natural selection, it is very likely that it has been derived through sexual selection.BiH-Kira said:
Does it have to serve a purpose?
Evolution doesn't mean any and all traits a living organism has are somehow beneficial and selected for. Evolution means any and all traits a living organism has are traits that, usually, don't kill it before it manages to reproduce. That's it really. They don't have to be beneficial, they can be harmful. As long as they're not harmful enough.
As the saying goes. It's not the bear you have to outrun, it's your fellow men. Evolution isn't selecting for ultimate organisms, it's just selecting for not horrible enough to get oneself killed before reproduction.
Evolution doesn't mean any and all traits a living organism has are somehow beneficial and selected for. Evolution means any and all traits a living organism has are traits that, usually, don't kill it before it manages to reproduce. That's it really. They don't have to be beneficial, they can be harmful. As long as they're not harmful enough.
As the saying goes. It's not the bear you have to outrun, it's your fellow men. Evolution isn't selecting for ultimate organisms, it's just selecting for not horrible enough to get oneself killed before reproduction.
I'll second this. There are a lot of inherited traits which serve no real function. They just persist because they didn't have too negative an effect on a species' ability to survive and procreate.Hagi said:
The sex hypothesis is quite good, but doesn't explain why both males AND females exhibit the same pattern.
In other species, only males ou females wear a different wardrobe, to standout from their challengers.
IMO, it's probably a movement thing: while running and dodging, stripes make it harder for lions to estimate the real distance between their claws and their target (see the first volumes of Ruroni Kenshin). Yet, lions adapted themselves recently, and are now able to shrug it off, leaving zebras with a useless visual artifice.
Maybe in 10 000 years, we'll see full-gray zebras... or plasma-farting zebras.
In other species, only males ou females wear a different wardrobe, to standout from their challengers.
IMO, it's probably a movement thing: while running and dodging, stripes make it harder for lions to estimate the real distance between their claws and their target (see the first volumes of Ruroni Kenshin). Yet, lions adapted themselves recently, and are now able to shrug it off, leaving zebras with a useless visual artifice.
Maybe in 10 000 years, we'll see full-gray zebras... or plasma-farting zebras.
Nononono...It's sole purpose is to be a metaphor (or simile, whatever) for all our racial harmony songs.
Wait, no one remembers the actual study establishing biting flies as a quantifiable reason for the stripes?
EDIT: http://motherboard.vice.com/read/the-reason-zebras-have-stripes-isnt-what-you-think
Apparently they are a deterrent for tsetse flies and a few other fly species. In fact, the only equine species with stripes live in areas with very high concentrations of those flies. As the concentration of these flies increase in the region, the concentration of striped equine species (Zebras and their like) are found there too whereas non-striped species goes down. Studies have shown that these flies land on striped surfaces far less than non-stripped surfaces. That's interesting.
So there is a direct correlation between those flies and zebras. The only question remaining is why other species don't present more heavily in those regions too since they are also vulnerable to flies. But this particular mutation could be rare or the ancestor of this species may have been more vulnerable to the flies than other kinds of animals.
It's also possible that these stripes serve additional purposes, but it is clear this is at least one advantage it is for.
EDIT: http://motherboard.vice.com/read/the-reason-zebras-have-stripes-isnt-what-you-think
Apparently they are a deterrent for tsetse flies and a few other fly species. In fact, the only equine species with stripes live in areas with very high concentrations of those flies. As the concentration of these flies increase in the region, the concentration of striped equine species (Zebras and their like) are found there too whereas non-striped species goes down. Studies have shown that these flies land on striped surfaces far less than non-stripped surfaces. That's interesting.
So there is a direct correlation between those flies and zebras. The only question remaining is why other species don't present more heavily in those regions too since they are also vulnerable to flies. But this particular mutation could be rare or the ancestor of this species may have been more vulnerable to the flies than other kinds of animals.
It's also possible that these stripes serve additional purposes, but it is clear this is at least one advantage it is for.
To put it a little more accurately - In WW1 warships were painted with strange, confusing designs, that were intended to make them seem as if they were moving in different directions than they actually were. There's very little evidence to suggest it actually worked. It's also worth bearing in mind that there's not even much agreement on whether that was actually the intention at all - various people both at the time and later have made conflicting claims about whether it was supposed to obscure the heading (so that a submarine would end up in the wrong position when trying to set up an attack), make range-finding difficult for actually targeting weapons, or simply to make identification trickier.PatrickJS said:
Hyena's also have the benefit of having some monstrously strong jaws to boot. I'm not saying it's 100% failsafe (since Lions have successfully hunted and killed Zebras.)The White Hunter said:
But comparing our feline friends to hyenas are a bit unfair. The little laughers are somewhere around 70% successful in all their hunts while Lions are a poor 30%. So failure to catch zebras are the least of their worries.
Hyenas kill the most shit on the African continent, they're by far the most successful chase predator, Lions tend to scavenge their kills a lot. They have also been recorded having actually killed a Hippo, which is fucking scary tbh.Dragonbums said:
It's possible for them to kill hippos if they manage to get one alone by itself on the land. But otherwise it seems that their relatively thick hides and preferences to being near water (which means quick getaway.) usually make them way too much the effort to even bother most of the time. Plus one nasty bite from it's jaws and it's game over.The White Hunter said:
At least that's what I think of it when I see any lions interacting with hippos on documentaries. It's usually just one or two lionesses getting a half assed bite in here and there and then they just fuck off.
It's one recorded incident in a national park involving a lone Hippo and 4 Hyenas. It's not a common occurence by any means but I found it impressive, give Hippos are monstrous things.Dragonbums said:
There's some stuff floating around about their camoflauge being adapted to confuse and deter tsetse flies; key vectors of sleeping sickness in both humans and many grazing animals.
"In World War 1, for example, warships were painted with strange, confusing designs, that made them seem as if they were moving in different directions than they actually were, frustrating torpedo operators.
Possibly, zebras' stripes fulfil the same function - when they run, a predator's eyes have a hard time tracking them. No one can say for sure just yet."
Gonna geek out just slightly here and mention that the stripes on ships was not just to obfuscate direction, which is easily sussed out by an observant captain, but to make it more difficult to find the water line in a periscope which was one of the primary ways that you used to verify distance to target. Even a small deviation would be enough to throw off a torpedo calculation.
As for the rest, I thought this was understood about the stripes for a while now. Adding further to the mix is when you have the animals herding together they can be hard to tell apart with the striping and since zebras are herd animals whose primary safety is sticking to the pack that can make the difference.
Possibly, zebras' stripes fulfil the same function - when they run, a predator's eyes have a hard time tracking them. No one can say for sure just yet."
Gonna geek out just slightly here and mention that the stripes on ships was not just to obfuscate direction, which is easily sussed out by an observant captain, but to make it more difficult to find the water line in a periscope which was one of the primary ways that you used to verify distance to target. Even a small deviation would be enough to throw off a torpedo calculation.
As for the rest, I thought this was understood about the stripes for a while now. Adding further to the mix is when you have the animals herding together they can be hard to tell apart with the striping and since zebras are herd animals whose primary safety is sticking to the pack that can make the difference.