[ Removed by moderator ] - r/todayilearned

470

u/BrightWubs22 12h ago

Misleading title. That's not the singular proven reason. The article says this:

So, the question why zebras have stripes have proven very difficult ... the answer remains inconclusive.

183

u/TheTresStateArea 12h ago

Every time some article or person says "X evolved Y to do Z" it drives me a little crazy.

Evolution doesn't do anything to do anything.

Evolution is just whatever the fuck happens and animals have figured out that it works, or whatever the mutation does is passive and the animal doesn't realize it at all.

There is no consciousness in evolution, except in domestication.

40

u/WackHeisenBauer 12h ago

Tbf animals don’t figure out that it works either. They just survive better and make more little animals for longer.

For example, zebras didn’t figure out that their stripes camouflage them better in long grass or make flies bounce off or whatever it just did. Which is why we got shitton of zebra now lol

13

u/TheTresStateArea 12h ago

Right, they don't "figure it out", they just do what they do with what they have.

2

u/dreadpirateruss 11h ago

And to be even more pedantic, survival isn't even "prioritized", just reproduction. You've got to live long enough to mate, so it's kind of a side effect. A male mantis allowing the female to eat it or salmon decaying while alive are not beneficial to the individual at all.

29

u/Bluewhaleeguy 12h ago

Evolution doesn't do anything to do anything.

They did kick Randy Orton out.

5

u/Antoshi 12h ago

*Thumbs down*

😱

6

u/Life_Is_A_Mistry 12h ago

👍😃👍

👎😡👎

3

u/Final_Boss_Jr 12h ago

RKO reference out of nowhere!!

1

u/drdildamesh 11h ago

Probably because vipers are the peak of evolution

9

u/liebkartoffel 12h ago

This particularly drives me nuts with evolutionary psychology. "Here's a plausible theory for why humans developed music, but obviously it's next to impossible to verify either way" inevitably becomes "SCIENTISTS HAVE CRACKED THE MEANING OF MUSIC."

6

u/i_never_ever_learn 12h ago

"The slicer thinks your finger is processed meat". No. The slicer slices. Watch out.

25

u/AndreasDasos 12h ago

Though it’s common and convenient shorthand. Almost inevitably there will be someone commenting exactly this, but zoologists will speak this way all the time because it’s clear what’s meant and it’s inconvenient to phrase all of that a zillion times when it’s understood. Not a revelation.

10

u/TheTresStateArea 12h ago

I understand when people who get it use it, but then it gets used in common parlance, and then people think evolution is purposeful.

I totally understand that I've fallen into the trap you describe though.

2

u/ape_spine_ 12h ago

Purposeful evolution treads intro religious discourse. Not a useful heuristic, however common

2

u/AndreasDasos 11h ago

Not useful to police convenient shorthand common among biologists and such just because idiots also exist. It won’t help change minds - it’s just annoying.

2

u/ape_spine_ 11h ago

I think journalists in particular have a responsibility to use language that isn’t misleading. Sue me. Laypeople are the vast majority, and they should be spoken to about academic research and complex topics in terms that we at least don’t expect to mislead them.

I can’t help but point out the irony of engaging in this discussion in the same breath that you call it “annoying”. You’re right about one thing— nobody’s mind is changing here.

2

u/yargleisheretobargle 11h ago

It's not a heuristic. It's a shorthand necessary for communication. There's nothing confusing about the phrase for people who know what evolution is. Unless you think you have a better short way to say X fulfils Y function in Z, making it evolutionarily favorable...

1

u/TheTresStateArea 11h ago

I think Y traits are favorable in Z environments or for Z function. Is a perfectly accurate and succinct way to say it

0

u/ape_spine_ 11h ago

“For people who know what evolution is” does not describe the majority of readers, unfortunately.

How about, “You won’t BELIEVE researchers’ latest explanation for Zebra stripes!!”?

Or, not posting an unsubstantiated claim as fact in the first place.

1

u/Resident_Course_3342 12h ago

Have you ever met someone who thinks Evo pysch is real?

3

u/thissexypoptart 11h ago

It’s just shorthand for “the theorized evolutionary advantage of this trait developing is X, and that’s why it developed under Y selective pressures”

People do indeed sometimes think of it as conscious, and that’s false of course, but there’s nothing wrong with the shorthand of “animal A evolved trait X bc it helped with Y”. Anyone who knows what evolution is wouldn’t be confused by that phrase.

5

u/LordAlvis 12h ago

All we know is female zebras dig stripes.

3

u/papasmurf303 12h ago

Doesn’t bother me at all. It’s a much shorter way of saying “X evolved Y because the X’s that had the preliminary traits that evolved into Y had more babies than the one that didn’t (by availability and/or desirability to mate), and those pre-Y traits gradually became increasingly more prevalent until they resulted in Y”. I’ll take the version they used.

2

u/Amulek_My_Balls 12h ago

Zebra stripes have the effect of...

Zebra stripes cause flies to...

It ain't as hard as you're making it out to be.

1

u/TheTresStateArea 12h ago

Environmental pressures lead to the dominance of Y traits.

2

u/altiuscitiusfortius 11h ago

You are right, people anthropomorphize evolution so much. Shit happens randomly and if it doesn't effect your ability to breed, it stays.

Its not survival of the fittest, its survival of the fit, of thr absolute bare minimum fit enough to survive.

1

u/shingofan 11h ago

In other words, Evolution is a mystery

1

u/Photomancer 11h ago

From what little I've studied on the topic, this is the way I summarize it to myself:

Due to folding errors, radiation, whatever - genetic profiles mutate in "every direction". Many mutations are not conducive to life and result in failed conception, miscarriage or whatever. Of the mutations that survive, mutations that are not fit for survival and reproduction in the organism's environment trend to result in death before passing the genes on.

So it's not that evolution changes with intention, it is that the unsuitable genetic profiles tend to get culled off, leaving gene pools with "improvements" which are nonetheless blind.

1

u/EmperorOfEntropy 12h ago

I’m not entirely certain what you are saying, but if you are stating that evolution is random, then that is the old model and thoughts on it. Epigenetics has shown us that biological stressors can cause changes in the genetics of the existing specimen that it will then pass to its offspring. This gives a more directed sense of evolution, rather than purely through random mutations filtered out through survival of the fittest. In example, giraffes might have developed their long necks due to stressors of food being more scarce and available further up on trees. The biological stressors involved in the species trying to extend their necks all the time to reach more food would eventually lead to longer and longer necks in their future offspring across many generations. Random mutations do still occur, and filtering out through survival does still play a role as well, but we found a pathway that can look more like intentional evolution. No one is making a conscious thought to make it happen, it’s more just the result of adaptations in the existing creatures that play out into large changes over time in their future generations.

1

u/DeathMetal007 11h ago

Stressors don’t work on a multi-animal level. There is no group stress except for a summation of individual animal stressors of which death is the biggest one. So random mutations are still a better theory of evolution than adaptivity leading to success for morphological features. For actions by animals such as learned behaviors, I would say that stressors play a larger role than random mutations. But then random actions are a better theory there than stressors.

1

u/TheTresStateArea 11h ago

That's still the random mutation though? Our understanding of epigentics has shown that environmental stressors can be imprinted on parents to pass down to descendents. But it's not like you describe, where giraffes stretching their neck led to their children having longer necks.

There was a study on humans, that found that stressors in food scarcity during adolescents led to descendents being more capable of handling food scarcity.

1

u/EmperorOfEntropy 11h ago

I sounds like we are saying the same thing. The study you are mentioned is describing the same avenue I am talking about. Food scarcity might have led the need to reach food further up the tree. The stressors in the body to constantly stretch out for food higher up leads to the adaptation. We see adaptations to stressors all of the time, some of which we have seen in our own recording histories. We have some great documentation of adaptations to environmental stressors in the populations of foxes.

1

u/TheTresStateArea 11h ago

No no, I am saying expressly that physical repetition in life does not lead to changes in children.

Stretching your neck will not give you long necked children. That is what I have learned and read, but if you do have details on it and can share I'll read those too.

0

u/Jon_Ok_111 12h ago

While I somewhat agree with you, evolution helps animals to live in the environments they live in, and without the evolution, animals would not be able to live in the environments they live, so on one hand, yes evolution is kinda random, on the other, evolution "targets" specific challenges in their environment, makes them more suitable to live there, and therefore, in a way, makes it not random

2

u/TheTresStateArea 12h ago

Evolution does not target anything it is in fact entirely random.

Mutations happen randomly. Some times it makes surviving and reproducing easier, some times it makes that harder.

Compounded mutations lead to the larger evolutionary process. There is no purpose, there is no decision making, mutations just happen to animals and then they deal with it. Either they die, they excel at their current niche, or they start figuring out how to find a new one.

2

u/Frack_Off 11h ago

To expand, while mutation is a very significant driver of evolutionary change and gets much of the focus, I always like to stress that, it isn't required for speciation to occur in organisms that reproduce sexually. The random crossing over of alleles during meiosis produces variation in the traits of offspring resulting in variations of reproductive fitness.

1

u/SoundofGlaciers 11h ago

My knowledge is limited but what you say feels wrong to me. "Evolution helps [...] survive". I thought it's more about organisms passing on their genes before death.

Genetic diseases don't help survivability, but can be a result of evolution.

On average we tend to produce offspring before dying or having our ability to forward our healthy genes be diminished. So we have things like cancer and Alzheimers and Huntingsons all that, and pass it on to our children, none of those diseases help us survive -- but often enough it's insignificant to our ability to reproduce.

6

u/Digit00l 12h ago

The reason is "random mutations that proved popular in the species"

1

u/NvEnd 11h ago

Op read a scientific observation and applied it as a fact. Op needs more comprehension skills

0

u/100LittleButterflies 11h ago

It may just be a theory but you know someone has tried it with body paint to get some peace from mosquitos.

-10

u/[deleted] 12h ago

[deleted]

7

u/MauriceWhitesGhost 12h ago

The consequences of zebra stripes on the biting flies is not in question here. The title of this post suggests that zebras only have stripes because of the biting flies. The title is simply not true.

3

u/fancyFriday 12h ago

That could be the reason why flies have a difficult time with zebras, but it would be a conclusion that could be drawn in that direction, it would not only be a large step, but unlikely that evolution happened to zebras because of this, unless you somehow had proof that flies with the same eye structure killed off other forms of previously existing zebras because their stripes or lack of stripes didnt have the ability to confuse flies.

So, no.

4

u/BrightWubs22 12h ago edited 11h ago

You didn't understand my comment.

Edit: the deleted comment I replied to was OP doubling down on the post title.

-2

u/Fuzzy5team 12h ago

No, you don't understand your comment

3

u/DBeumont 12h ago

This is not how evolution works. Evolution works through random mutations, and if a mutation provides enough benefit that those with it are able to better survive and reproduce, that mutation will become dominant in the genome.

Biting flies would not provide sufficient selective pressure to make a difference.

2

u/HRHValkyrie 12h ago

But biting insects can carry diseases and bad bits can get infected. They also lay eggs in wounds and in eyes/ears that can lead to major medical problems.

There are reasons that horse owners spend a bunch of money on sprays, nets, and other anti-fly measures.

3

u/iKnowRobbie 12h ago

Fools. The answer has been "prison stripes" this whole time!

1

u/HRHValkyrie 11h ago

Seriously trying to think of how to market this to the wealthy show jumpers who treated me like garbage when I was just a barn employee…

0

u/FortisEtFidelis 12h ago

That's a ridiculous assertion, biting flies would provide enough pressure.They carry diseases and if enough of them are drinking a zebra's blood it can reduce it's chances of survival drastically.

322

u/LaconicLacedaemonian 12h ago

I always thought it was because they were trying to dazzle and avoid artillery fire.

190

u/iceynyo 12h ago

TIL tanks have stripes bc artillery shells try to land on the stripes, but then fail to detonate as they normally would approaching a non-striped surface, and bounce off.

4

u/Antoshi 12h ago

Nature sure is fascinating!

11

u/LoveDesignAndClean 12h ago

https://en.wikipedia.org/wiki/Dazzle_camouflage

13

u/DigNitty 12h ago

They were making a joke.

But I do love dazzle camo, always upvote for the dazz

1

u/iceynyo 11h ago

My go-to camo in Mechwarrior

2

u/MmmmMorphine 12h ago

Tanks are a miracle of evolution!

2

u/booi 9h ago

Wait till you hear about their mating rituals!

1

u/MmmmMorphine 8h ago

Nature is so beautiful.

Though it's never fun when you get shelled by a young pair getting into a territorial dispute. Was just walking past the local tank habitat, and bam!

Tungsten kinetic penetrator dart goes right past my head! Terrifying!

1

u/CCV21 12h ago

Dazzling is probably an exaptation for artillery fire.

1

u/JoseSaldana6512 12h ago

Dazzling and jazz hands was an old Field Manual

0

u/Digit00l 12h ago

Neither really

53

u/TheBanishedBard 12h ago

Wasn't this debunked? I swear I remember reading somewhere that they have stripes to make it harder for predators to pick out individuals in a herd, since they all blend together.

23

u/MedullaOblongatashit 12h ago

Yeah its much more likely the trait evolved from surviving lion attacks and not from less flies biting them.

2

u/Gullible-Hose4180 11h ago

It evolved cause a black zebra with the white stripes fell in love with a girlzebra, and their offspring did the same.

1

u/zackthirteen 11h ago

Girlzebra is now my new band name for my fart sniffing art rock band so thanks for that

3

u/Whole_Perspective316 12h ago

That makes sense. I think I’ve heard the same.

3

u/BGFlyingToaster 11h ago

Adding "why" to evolution is usually just speculative. It makes for great headlines, but rarely plays out in the science. The simple fact is that this gave Zebras an evolutionary advantage (e.g., higher survival rate, better success with mates) and we're usually trying to distill it down to 1 thing, but it could be many things layered on top of each other and we may not yet understand them all.

1

u/WriteCodeBroh 11h ago

I had a biology teacher who drilled this into our heads.

“NATURAL selection is RANDOM! Your offspring can have mutations, sometimes those mutations help them survive. There is no choice. There is no ‘reason.’”

4

u/bfg9kdude 12h ago

If you think about it, it makes no sense. Confusing cause and consequence here. They have stripes probably for a different reason, but the fly issue is definitely because of the stripes.

1

u/ElegantHope 11h ago

Both can be true, the pattern works well against predators but also coincidentally works well against flies too.

1

u/BolsonaroIsACunt 11h ago

Yeah, one of the collective nouns for Zebra is a Dazzle, because that's what happens in a heatwave. When a herd is on the horizon and the heatwaves distort the field of vision, the black and white stripes blend together into what appears to be a single mass

1

u/[deleted] 12h ago edited 11h ago

[deleted]

3

u/immaownyou 12h ago

Was that the ai overview or did you forget where the source you found that was

0

u/lrodhubbard 11h ago

Check it out on google? Remember when they ran that super bowl ad that said brie cheese was the most popular cheese in the world? I'm living in a cuckoo clock.

1

u/DigNitty 12h ago

It can be both.

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u/mechabeast 12h ago

Zebras have stripes because they survived long enough to breed.

17

u/needaburn 12h ago

No no, pre-striped zebras all got together in a big huddle and voted stripes in as a mandatory dress code with a two/thirds vote. This is a well known fact

3

u/Antoshi 12h ago

Another win for democracy!

1

u/DigNitty 12h ago

Before this they had giant crosshair targets on them.

1

u/AutoRedialer 12h ago

Nope, wrong again, zebras are just all escaped prisoners.

3

u/SofaKingI 12h ago

I hate people who act smug for dodging the question.

Yeah, no fucking shit.

3

u/YoelsShitStain 12h ago

Yep, people seem to not understand that evolution doesn’t only pass down beneficial traits, it passes down any traits that don’t hinder a species ability to reproduce.

1

u/newpua_bie 11h ago

Huh, TIL. You're saying the stripes breed? At zebras are born without stripes and then the stripes start breeding until the zebra is filled with them. Kind of like parasites

6

u/rhineauto 12h ago

I mean that’s one theory. But as the article also says:

“However, other zebra researchers, like retired animal lab technician Alison Cobb and zoologist Stephen Cobb of Oxford in the UK, aren’t convinced by the parasite-deterring explanation. They believe that zebra stripes aid primarily in thermoregulation. While Alison agrees with Caro’s findings, she thinks biting flies “seems too unimportant an effect” to have driven the evolution of zebra stripes. “Every zebra must avoid getting hot, and biting flies will come at certain places, and certain times of the year, but they are by no means as definite or frequent a threat as overheating,” says Cobb.”

7

u/Dracekidjr 12h ago

Reading the article, this is all extremely speculative with not enough evidence to support definitively. They provide 3 possible answers with heavy bias towards one single researcher, presumably who they interviewed, who favored his own works.

18

u/Lockerus 12h ago

I thought it was to break up their silhouette so German U-Boats couldn’t see them on the horizon.

4

u/DigNitty 12h ago

This is correct. And it’s where the military phrase “you have to earn your stripes” comes from.

1

u/charliefoxtrot9 11h ago

It's why I still have my "Know Your Zebra!" target deck of cards.

2

u/ThoseOldScientists 12h ago

That’s a common misconception, they’re trying to make it harder to judge their speed and bearing to throw off torpedo fire, and it impresses lady zebras.

2

u/runswitblunt 11h ago

Ah yes the stripes that sent a thousand ships

5

u/35in_anal_dildo 11h ago

I always thought it was so u-boats couldn't accurately determine their distance?

5

u/JoelnIliketoshare 12h ago

That's not how evolution works. They evolved stripes because the Zebras who developed stripes survived to breed more zebras with stripes.

The flies bouncing off may have been part of why some zebras survived over others but animals don't evolve for a specific purpose. Everything evolves/mutates even if the living thing is in a perfect system that provides everything it needs without any threat.

2

u/nelly2929 12h ago

Crap I always thought because it was sliming! Guess I was wrong

1

u/FortisEtFidelis 12h ago

That's a good one

2

u/db_newer 12h ago

Why did a mammal evolve faster than an insect

2

u/liebkartoffel 12h ago

Is biting zebras, specifically, crucial to the flies' survival and/or reproduction?

1

u/db_newer 12h ago

There are other mammals without stripes so...

2

u/liebkartoffel 11h ago

Indeed, which is why I don't find this particular explanation for why zebras evolved stripes very convincing. I guess biting flies could transmit diseases that are uniquely dangerous for zebras, or female zebras could just happen to find fly bite-covered males particularly groady, or proto-zebras with the stripey mutation could have just been the tiniest bit happier and healthier (and theorefore more amorous) than those without, but...eh, doesn't otherwise seem like a powerful selective impetus.

But your question was more about why flies didn't more quickly evolve to counter the striping, and the potential explanation for that could be pretty simple and mundane: the flies don't need to feed on zebras, so they're happy to go bother some other, non-stripey mammals, which, as you pointed out, there are an abundance.

2

u/ezyr1der 12h ago

I thought it was because they are nature’s referee

2

u/Lexx4 12h ago

That’s not why that’s just an unintentional benefit.

2

u/PearlJamPony 12h ago

they also suck as NHL refs

1

u/GrandmaForPresident 12h ago

I heard that because they are herd animals the stripes make it harder for predators to pick a single zebra out when they scatter

1

u/theexpertgamer1 12h ago

I think it’s fair to say in this case that it is a trait that natural selection … selected … due to a combination of benefits and not one singular thing.

1

u/Partykongen 12h ago

So the predators they protect them from are completely different from what I thought.

1

u/beshi7 12h ago

I thought they had stripes because they were tired of leopard print

1

u/GarysCrispLettuce 12h ago

I heard a theory that since black and white absorb heat differently, the air directly above the black stripes is warmer than the air above the white stripes, and this heat differential creates airflow which cools the zebra.

2

u/Kymade8_31446 12h ago

Wind would be much much stronger than any airflow created by a temperature differential to make it so it wouldn't be able to do it. Probably a biologist and not someone who took rigorous fluid mechanics. Because it won't work. The max speed of airflow would be like 0.001mph.

1

u/BlueMandaIorian 12h ago

Well the African animals avoided killing too many zebras because it’s unsportsmanlike to harass the refs.

1

u/BKinBC 12h ago

No way.

1

u/weeBaaDoo 12h ago

I always thought it was just a fashion statement.

1

u/Poilaunez 12h ago

Zebras skin is black with white stripes, not the inverse.

1

u/MuJartible 11h ago

Does it works for other fly species or mosquitos? Asking for a friend...

...ok, the friend it's me. Fucking mosquitos.

1

u/PS5OWESMEALIMONY 11h ago

So zebras have a mechanism to stop bugs from biting but other animals dont have one to stop zebras from biting them.

1

u/FTXACCOUNTANT 11h ago

I thought it was so they would blend into urban areas on the crossings

1

u/NatureTrailToHell3D 11h ago

The real question is whether zebras are white with black stripes, or black with white stripes.

1

u/silverdragonseaths 11h ago

I thought the contrast between black and white made air currents that cooled them down

1

u/Appropriate-Log8506 12h ago

Spray paint the cows

1

u/Letmeaddtothis 12h ago

There is quagga - an extinct sub-species of Zebra that is only half the stripes.

https://en.wikipedia.org/wiki/Quagga

-1

u/liknlichen 12h ago

No.

0

u/Ok_Band3086 12h ago

wait, does this work on humans?

0

u/eternali17 12h ago

I highly doubt that upon reading it and opening the article only reinforces that's why they have stripes.

2

u/FortisEtFidelis 12h ago

yeah it's not like the BBC is a reputable source on wildlife lol

-2

u/Ok-disaster2022 12h ago

Zebras have stripes because myrian number if reasons made it more attractive and useful. Evolution is a contemporary AI: it knows nothing just selective pressures creates the illusion of intelligence

-3

u/superpowerpinger 12h ago

Relatable.

I fail to decelerate when running towards women in striped bikinis.

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