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- เผยแพร่เมื่อ 22 พ.ค. 2024
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In the race to survive, both predators and prey use visual tricks to get ahead. One nearly universal trick is countershading, a color pattern that helps animals erase their own shadows or blend into different backgrounds. It’s worked well enough that nature has produced this pattern over and over again, all over Earth, for at least tens of millions of years.
0:00 Why does every animal look like this?
0:52 A painter's big idea
1:49 Disappearing shadows
2:22 Testing the idea
3:48 Countershading everywhere!
6:10 What about water?
7:22 Making light to hide shadows
8:19 Outro
References: sites.google.com/view/counter...
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This episode of Be Smart is licensed exclusively to TH-cam.
Adds a whole different meaning to throwing shade, eh?
pretty sure the darkening is due to the sun's harmful rays. having more pigment or darkness prevents harmful rays from preventing the body preventing DNA deconstruction and mutation!
Is it that though or is it just a physiological reaction producing more melanin on the side that receives more UV?
Audio in this video is undercooked. Got a bit of cracklin' goin' on.
you should watch that latest Vsauce short on contrast illusion and combine efforts. Just sayin. Yall coulda had something magical here with each other's research and like a couple hours over zoom.
Totally, but any idea why Humans didn't also evolve with counter shading?
Looking only at the title of the video, I thought the question would be "Why do so many animals have a head, torso, and four appendages (with possibly a tail)?
Same, that’s what I was expecting and and then he throws the curveball of lighter underside. Now I’m more curious why 4 limbed animals (advanced/vertebrates) are by far the overwhelming majority. Like even the animals that seem to only have two useful limbs also have two vestigial limbs.
@@monhi64 All mammals, reptiles, amphibians, and birds evolved from a single tetrapod ancestor. The majority of the animal kingdom's species actually have more or less legs (e.g. insects), but the tetrapods are certainly the largest land animals so we're more familiar with them.
@@monhi64 having for 4 limbs (with specific orientation of knees and elbows) helps moving around your environment to escape predators or get food. Also explain why land mammals have a neck.
Me too.
I do feel like the title was way too broad.
You absolutely didn't have to make the example creature make little noises but you still did, and I appreciate it so much
If only all animals did that.
MWAH! Wah MwAh!!
Super auto pets sound
Me to
thisss, i even rewinded it just so i could watch it again 😭
0:42
I have a pet upside-down catfish which likes to spend its time upside-down as the name suggests, its got a dark belly and light back. So countershading obviously does something important because compared to its close relatives in the same genus that dont swim like weirdos its shading is reversed.
Gotta say that sounds like the most interesting pet fish EVER.
I love way the first half of this is written😭
@@Beryllahawk Actually it just feels wrong more than anything. It hides most of the time but comes out the instant it smells food, it is a ravenous and greedy little guy.
Synodontis nigriventris is the species name in Latin if you wanted to know. they are rather easy to care for and common in the pet trade since they breed readily. Just be carful since they can outcompete other fish for food.
aw i love those guys
@@Exquailibur Gotta admit most of the fish I handled growing up were tetras and mollies. The coolest fish we ever had, had to have a tank to himself because he would've eaten all the others. An Oscar, I think is what my stepfather said he was. But this was also a fish with Big Opinions and we could "play fetch" with him by dropping a d20 in the tank. He'd catch it and spit it out and 10 year old me thought that was the funniest thing...
I no longer have the means or fortitude to keep fish but they still interest me!
And TBH, ravenous and greedy fits right in with most catfish from what I've seen
Another potential function of countershading is to protect against sun damage on the most exposed parts of the body
This is actually what I assumed the answer would be!
Exactly! And this is also (supposedly) why humans have more hair in the top of the head, back, and specifically on the "top" of the lowerarms, etc
@@O.Genericobald humans be like: Wait WTF
@@O.Generico I believe it's more of an all-around protection(against heat, dirt, water, bacteria etc. etc.), because we also have hair in our nose, around our eyes, in our armpits(that in my opinion has zero purpose in any way), and in the crotch.
I would guess that was the initial reason for it happening with the nice side effect of going completely camou for other animals.
Counter shadowing definitely works. I have a dog and he is a Border Collie crossed with a Labrador and he has a gorgeous coat of mostly black fur with white paws and a white chest and belly. When he's in the garden at night, or lying in the hall at the top of the stairs with the light out you can only really see his paws because of that contrast and if he lies a certain way in the dark then it's literally impossible to see him at all and you wind up tripping up over him. So in conclusion it works for the domestic dog so they can confuse and trip up owners.
My parents dog is part black lab with some light grey on her belly and muzzle from the blue tick coonhound in her. When she lays down on the floor at night she's invisible with the lights off, such a tripping hazard. (I learned to walk slowly and without picking my feet up above the level of her body for both our protection)
Sometimes she's loud at night, and other times she will silently follow you and lay infront of the bathroom door so you trip on her as you leave. (Presumably unintentionally, she likes to be close to people)
Works for cats too.
@@FerreTrip it does 🤔
It may also help regulate an animal from the heat of the sun and protect their vulnerable spots.
we used to have a rottweiler which would lay underneath my dad's desk and due to the shadows and his dark coat the only thing you could see was his eyes. Every time I came home and would look around for him I would walk into my dad's office and peek beneath the desk to find him and just see a pair of eyes staring back at me.
In birds, it's thought that the counter-shading helps them remain hidden in flight. The darker top hides them from falcons or other birds of prey that would swoop down from above, blending them in with the ground, while the lighter belly hides them from their own prey that watches for them, blending them in with the sky.
similar to the point about fish
I thought this was about why every animal looked like a potato with ears
Not only you brother, not only you
Slightly different, but it blew me away how much my black cat can dissappear. That's a huge advantage to a shadow hiding pounce predator
My grey cat was impossible to see at night and in shadow. Even more so than my black one. Mind blowing.
Wow, I had no idea that countershading was so common in the animal kingdom! This video really opened my eyes to the amazing ways animals have adapted to their environments.
Does this means us humans have white underbellies?
@@wisesquirrel4986 As someone who rarely sees the sun, I'm pretty white all over.
@@wisesquirrel4986 i guess this works on animals who walk on 4 legs or like walk with horizontal bodies
I agree, now I will also look at it in a new way.
@@wisesquirrel4986
Maybe a little...it's most visible on black people when you see the hands and the legs (lighter below)
4:54 countershading definitely does keep animals from being spotted, in fact, it makes their topsides one colour and their middles and bottoms others! Those aren’t spots!
I approve of this wordplay
@@besmart I like it😊
interesting 🧐
Leopards are spotted. Theory incorrect 🤷♂️
@@lordhegamonster6931 too bad! They’re still counter shaded under their spots! 😉
And I said “keeps animals from” not “makes spots on amnimals impawssible”
Ever since I've learned kitefin sharks are the largest bioluminescent vertebrates, I've been fascinated by the concept of counterillumination. Was really neat to see it mentioned.
Is it just me, or is the audio really crunchy?
Thank you! I thought my airpods were blown out
"I promise there's two ducks in the photo."
Well, I guess people on the internet have told me worse lies.
Yeah, me thinks he's fibbing!
I ACTUALLY SEE IT , if you follow the wire on the right upwards, u can trace the shape. It is exactly the same duck and also looking to the right!!! no cap, try fullscreen on monitor perhaps?
@@xavierxrc I ACTUALLY SEE IT , if you follow the wire on the right upwards, u can trace the shape. It is exactly the same duck and also looking to the right!!! no cap, try fullscreen on monitor perhaps?
I think something is up with the audio? It is really popping and snapping for me. Every other video I have watched today hasn't had this issue.
I even cleaned up my headphones and it didnt help, other videos sound ok, defo somethings up with this one.
I think the audio is F'ed up
It got very distracting when I started noticing and got worried about my phone speaker being f'd up. Thsnk god it's just the video lol
Yeah it's super distracting I'm listening to it on my Samsung Galaxy pro earbuds and the popping and clicking is really pronounced. Something is definitely up with the audio in this particular video
I thought it was my computer speakers...
As someone who co-majors as an artist and scientist. THIS IS THE BEST VIDEO EVER THANK YOU
When i had to draw an underwater piece i actually realized how hard it is do paint noticeable fishes. I have searched online but most of the fishes are actually blend in with the ocean so well its merely different from painting sea with different reflections.
Interesting idea. I've noticed countershading in fish as it was more obvious that it helps blend in against any background but I've never thought about it in land animals. At the beginning I thought it would be the same explanation but surely animals on land don't have predators that look at them from below or above so that threw me for a loop.
While most land animals don't have predators looking up at them (not counting crocodiles lurking in the water), many have to deal with birds of prey or ambushes from cats in trees, so that means being watched from above. Although all of these prey species have to worry about conventional land predators who only view them from the side. (Assuming level ground and same head height)
In a lot of songbirds the female will blend in with the background, but the male will be brightly colored in order to draw away a predator.
As someone that has lived in a rural area most their life, and has Hunted quite a bit, I can understand how the color patterns do hide animals.
Great concept.
I can't help but think those cases probably commonly end up doubling as a mate selection display. Showing off just how brightly coloured you are and yet that you have survived suggests a degree of tenaciousness that could itself be an asset in a mate. It would suggest that not only are they well adapted to protect their mate and their offspring but also to live and return to continue to provide for them too. Those that were too slow or weak with such a colour scheme are likely to have already been weeded out before mating age so if the females were biologically prone to prefer the bright colours in a mate they would be more likely to select the males that also happened to be stronger, faster, and hardier too. After all this would be far from the only example in biology where a trait was adapted to pull double duty.
@@seraphina985 100% agree. The bright colors not only attract the female but pull away predators. Like I stated I live in a rural area, so I watch this dance Every Spring and it is beautiful to watch.
Dang, this reminds me, I need to get my hummingbird feeders up.
Thanks Smarter Everyday, and commenter I can't remember the name of as I wasn't even thinking about it till now.
@@seraphina985 seriously thank you, I love to watch my hummingbirds dance, and I wasn't even thinking about that yet.
Such dimorphism is reversed ang species where the females compete for mates.
You saying male birds are colorful to draw away predators sound silly. One reason, is they use that to attract mates. Some female birds are colorful too. So you're saying female birds are colorful to draw away predators too? What about colorful fish, reptitles, amphibians, bright yellow baby chickens or ducklings, or even humans like ones with orange hair?
The 5:58 « Eh, good enough » - Mediocrates haha
I need that on a shirt!
Fun fact, almost all of these designs were used in war to varying effects.
Counter shading is the most common, getting used on planes and ships (and similar concepts to the fish and birds, airplanes were often designed to blend in with the ground when seen from above, and sky from below). Virtually every variant of colours, whether just to eliminate shadows or to actually match colours with ground/sky were tried.
Counter illumination was used on some canadian warships, although it was used in ww2 in limited numbers. When it worked it could reduce the ships visibility by others up to 70%. Unfortunately it was expensive, complicated, and the lights were too fragile and often too slow to change. Allied victory in the battle of the atlantic lead to increased control over the atlantic, less risk for convoys (and hence less need for camoflauge), and she was already being obsoleted by sonar and aircraft carriers - all of those things combining to mean it wasn't worth the money to continue development.
America did briefly experiment with counter illumination of aircraft after the canadian project fell apart. And although it was promising, again radar meant that it was obsolete, and it was dropped.
Zebra esque ships were designed to make judging their size, speed, and direction more difficult to make hitting them more difficult. However, the efficacy was limited at best, and made them more visible and more likely to get destroyed at worst.
Hey Joe! Love your video as always! For some reason, this one as a static low level noise.
Other than that, great video and great topic!!!
yeah I can hear the clipping/peaking too. it's kinda cool, electric like a rock and roll song
edit Especially on the sibilants /s/ /"th"/ /"sh"/
Thank goodness, I thought my speaker was slightly broken
I was looking for this comment to make sure that my speakers weren't broken 😂
Oh, so it wasn't me.
I thought my headphones were broken.
WHERE IS THE DUCK? IT'S DRIVING ME CRAZY! You have to be joking that there's another duck in the photo... right?
I ACTUALLY SEE IT , if you follow the wire on the right upwards, u can trace the shape. It is exactly the same duck and also looking to the right!!! no cap try fullscreen on monitor perhaps?
Thank you! A thousand comments and this is the only one worth liking.
Oh my heck. Thanks! I Can kind of see it!
@@brunoballakI can't even see the damned wire
I just love the lil critter just being a lil gremlin
It fills my soul with joy
I do believe most animals are camouflaged by default unless the benefit of whatever reduces their camouflage outweighs the downside of no longer being camouflaged.
Really, why wouldn't they be unless it doesn't matter?
@@CAMSLAYER13 agreed. If you look at it objectively, without photo editing, tigers, an animal we'd consider quite striking, are incredibly well camouflaged in their natural habitats. Wild cats in general are hard to even spot a few hundred feet away if they're still. You'd never know they were there unless you subconsciously picked up on the fact you were being watched. They're incredibly well camouflaged despite the fact if you put them in a white room that they're striking in appearance.
I think it started as a reaction to the sun.
Just one of those things where if it gives you an even minor but clear advantage, you're gonna live longer, that trait will be passed on. Coloration of fur, skin, scales, etc, is something that can change in only a few generations so that adaptation taking over very rapidly makes sense
@@ZentaBonAdding to that, most mammals are essentially red-green colorblind. So orange fur against a green background actually works well.
I knew it! A painter figured it out! I remember learning about this in college in my painting class when studying the masters
Thanks for the great subtitles. As a second language English speaker this is really appreciated.
Ps could you do a video about the coats of cats? I've heard that the reason tuxedo cats exist is due to something that happens with pigment during meiosis.
meowosis
Subtitles are also useful for the parts of the video recorded with a broken microphone, I can just mute it and read instead.
veritasium did a good idea about it
There is a theory that white markings are somehow connected to domestification. Even fish get them, and on the other hand, it isn't present in wild nature
Counter shading was also used to camouflage military aircraft during WWII: the upper surfaces of an aircraft were painted to match the environment they were expected to fly over, while the lower surfaces were painted in much lighter colors to reduce their contrast against the much brighter sky
Love you guys! Big thanks to the whole Be Smart team for your work and dedication❣
I'm not convinced there is a second duck. :)
How did you comment 10 hours ago?
@@LordPhoenix9251 Special donater
@@Cat-yx7xcGood Good Good.
@@Cat-yx7xcGood Good Good.
I can’t find any evidence that there is a second duck, either. 🤔
Hey "Be Smart" please keep uploadin! You have grown my interest in science so much! And broadened it to all the sciences, not just physics! Keep it up!
grown my internet
@@genesises idk what ur talking about 😇
One of the fascinating things about camouflage I saw was last summer in August / September on Greenland. Around a rock we found lapland longspurs and northern wheatears. We could the birds fly in the air. But even when we watched them land on rocks or the ground, just around the time they landed they disappeared and it wasn't easy to spot them again.
I feel like this highlights the importance of viewing a problem from completely different perspectives. I love how it was an artist, not a scientist, who came up with the solution!
Something that might play into the abundance of countershading is the relative low energy intensiveness and simple way of evolving such a pattern. Since pigments are produced anyways (I assume) and there's no evolutionary pitfall on the way to the new coloration. (Meaning no disadvantage in the middle steps of getting the new pattern.)
I'm sure there are some energy cost differences between different pigments, but the real evolutionary cost of going between patterns is the pattern itself. (Being halfway between 2 camouflages may be worse than fully commiting to just one. Most of our domesticated pet's weird patterns are recessive genes that normally are selected against in nature but are selected for by humans because we find them cute, just as an example of how the patern itself has a cost.)
But in general i agree with you that adjusting coloration patterns is probably an evolutionarily cheap adjustment vs say development of flight.
At first before watching I assumed it had to do with animals using coloring for all kinds of purposes such as attracting mates, warning predators, etc. And that having coloring on the underside, for land animals at least, is somewhat useless since those sides aren't seen.
I stumbled upon countershading on my own while drawing. I was coloring a animal with a lighter belly and was getting frustrated that when I added the shadows, the belly and back were the same color.
So cool! Nature is awesome. I had heard a little bit about countershading but not to this extent, and I CERTAINLY didn't know counterillumination was a thing. That's wild!
i... had absolutely never thought about this. ever. this really is quite fascinating
Could the sun also cause melanin production to be higher on top and not needed as much on underbellies?
I always thought that was the case.
That doesn't work with fur
Seems a much simpler explanation
I always wondered about this as a kid, thanks!
2:55 I don't believe there are two ducks in that picture. Does the other imaginary duck not have the wire base like the other? Because that would be easily visible even if the other duck was camouflaged.
I thought the same thing. Kind of think that the man got carried away trying to make his point there.
Not really, because that's the whole point of good camouflage, I'm sure many have seen pictures of animals with camouflage and only finding it because of the eyes and not the shadows, plus this si a grainy image so it probably looked more noticeable irl
I thought for sure they were going to come back and reveal the trick, but… are there really two ducks??
I can't see no damn duck, paused and stared at it with high quality for like 20 min. Pssh
@@TheNextFiles288 IKR
The praying mantis at 8:19 totally got me.
Yup, me too
I think it was an Orchid mantis.
@@tomsko863 absolutely beautiful little creature
If you were an ant, then literally!! 😅
Cube is life
Sorry I couldnt finish the video, I just hear the noise from a badsignal or cable from microphone...
Obliterative shading sounds much cooler than counter shading
THANK YOU! have been asking this for years!
I remember studying this in zoology class in college, but we only focused on aquatic animals.
Edit: Brilliant really is awesome! (Totally recommend) I'm taking a math course on it right now. Skillshare is good too, I'm taking a drawing course on there.
Skillshare is a big big scam. Watch the YT about it
I was so sure there was going to be an highlight of the other duck on the end of the video... can't overstate my disappointment 😢
I ACTUALLY SEE IT , if you follow the wire on the right upwards, u can trace the shape. It is exactly the same duck and also looking to the right!!! no cap, try fullscreen on monitor perhaps?
Fantastic video. Great intro. Thanks
wow, didn't know your content yet. Really nice!! Thanks!!
This was an awesome video .Evolution is fascinating .
Absolutely kind of mind-blowing to realize the reason to such a common thing.
I once again received an answer to a question that I had not thought about but would like to know. I love it when it happens. Great job. I would like to say that evolution is truly an amazing thing. What tricks will she go to so that life on this planet continues. And continued in the most practical and beautiful way. To be honest, I don't really understand how it works, but I find this topic very interesting. I would like more videos on this.😏
Very illuminating!
Countershading is propably also quite helpful preventing sunburns.
Great video!
Great video again, Joe. I wish you would have emphasized that our eyes are NOT the default. Every species sees the world differently through their own eyes. Some see more infrared while others see ultraviolet. Please look into how different birds and fish look when put under an ultraviolet light. To our eyes, a male and female bird may look idential, but when you put them under ultraviolet light, you can see different patterns between them.
The programmers responsible for simulating the animals were lazy and just copy pasted the same code with a few random changes to some factors
Oh, do you make videos too?
Yo inheritance
doesn't make sense
LISTEN HERE
Wait, isn't Mozart dead?
My theory is that it's for belly rubs. Everyone wants them and having a different color there just shows where you wanna be rubed.
I like the way you think
@@hammysan2090 I used to have a hamster that changed its color every 3 years and he loved getting them.
@@gilgabro420 that is just adorable
I love your videos so much. This is my favorite channel ever!
Amazing video 🙏
The stand for the 2nd duck is visible. I'm guessing that camouflage went further than just gradient shading though 😜
Yeah I've been staring for so long but I can only maybe make out the stand
@@ryanwester2559 I tried unfocussing my gaze just a little bit and I THINK I might have seen the outline: it's very close to the visible one, on the close right. But I agree with OP: there's also some pattern at work there.
I ACTUALLY SEE IT , if you follow the wire on the right upwards, u can trace the shape. It is exactly the same duck and also looking to the right!!! no cap, try fullscreen on monitor perhaps?
counter-illumination is just countershading that's more than 100%
p.s only works in one direction, hard to get blacker than black
Love this channel ❤
This is a really good question. I've never noticed this before
I always also imagined it helped with UV protection from the sun.
I've stared at that picture way too long. Its only got one duck.
Thank you!
Omg my cats dog and snake have this shading thing going on - never really opened my brain to it. Wow ! Black backs white tummy red back white tummy. How fascinating.. will be noting it everywhere from now on
This colour pattern has a tag on e621 btw, it's called "countershading"
I actually learned about countershading when I joined the military.
I only learned about it being learned from animals because I had a really well-educated Drill Sergeant.
Learned something new, thnx man
I loooove alle the memes and jokes you placed in there. Great video!
You mentioned that countershading sort of “transforms” 3-d to 2-d. Is there a “countershading” equivalent that can transform 4-d to 3-d?
5:58 “mediocrates” 😂😂😂
Great Video.
Very underrated thumbnail & title. Took me hours to figure out what common trait that creature shares with the rest of the animal kingdom, felt kinda dumb when I realized afterwards that the arrows are pointing right to it 😅
1:42 Something wrong with the audio from here, there's a crackle.
Hey there Joe, this video's audio is pretty annoying, there is noise and clipping right from the first mic sounds.. could you look into it?
This is an example of convergent evolution, btw.
Just like how evolution keeps producing crabs like body plan, it also produces counter shaded colouring.
Thank you
2:48 where's the second duck!?
It's there on the right. We can't see it because not only it proved the theory.... It's also an old picture taken in 1917, with old camera. So the quality kind of "help" it to camouflage it even more.
There is no duck
Yeah i did some effects and flipped the image and the duck never showed up
What's up with crackling in the audio? I think you missed it there 😅
Amazing!
Nice video
Audio sounds bad like there's some static going on when he's speaking. Fix the audio!
4:00 the audio is broken, i can hear crackling noise while you speak
and no, it's not my speakers
great vid. don't know if anyone else noticed but there was a rattle in the mastering of sound for this vid i think don't really have the means to properly test it out.
This video blew my mind over and over again. Nature is indescribably fascinating 😭😭🤍
I love this channel.
Audio problems Joe!
Animals, science AND art? Love it
That's super interesting.
Thanks PBS for still being a trustworthy news network!
am I the only one that hears a crackling? the sound seems to be bad on this one (the content is super as usual)
It's his mouth and nose, he does quick breaths and snorts. Watch his annunciation in video portions where he says "Especially" "Seem". At the end of the word caterpillars. Maybe he has a lisp as a kid and had to do speech therepy.
@@aresjerry no, it's not that, it feels like radiation interference or frequency clipping
0:49 crowns : hold my beer
Are you talking about crows or cows?
Can you make a video about color schemes, emotions and\or organization? Thank you for your videos
I wish there was a Spotify podcast of all your works on TH-cam 🥰
Am I the only person who finds evolution's motto of "good enough" to be incredibly comforting
something seems to be wrong with the sound of this video..
Fantasic video, can I ask if you know why humans aren't countershaded?
very nice video