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Why Are Animals Symmetrical?
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- Опубликовано: 18 авг 2024
- Animals range in size shape and biology drastically but there is one thing that unifies more than 95% of animals, and every known land animal. Something that almost all animals inherited from an incredibly ancient common ancestor hundreds of millions of years ago. they have a left and a right side which are mirror images of each other. So why is this and why has this made them so successful?
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I wish all my bilaterally symmetrical relatives a very pleasant evening.
They aren’t symmetrical, they have matching general outer components, bilaterally. In detail the sides are not symmetrical, and their asymmetry have separate functions both in use and display.
No crib b by ki donc g finding je
Sorry i am not symmetrical
all my homies are bilaterally symmetrical
I appreciate you
It's also interesting that despite being primarily symmetrical we and other animals have organs that aren't. For example our hearts are only on our left side, our livers on the rights, and the digestive tract is kind of all over the place. It seems that the evolutionary pressure towards symmetry mostly applies to our outside structure and sensory organs.
yeah, there's no selective pressure for heart on left vs right, but there is if your left leg is bigger than your right: you'll get eaten.
Yup. Binocular vision helps with depth perception, two ears make it easier to get the directions sounds come from, two nostrils.... in case one get clogged?
@@pansepot1490 Two nostrils help to smell directionally for a bunch of animals. We just decided smelling is for suckers.
I think it is also because most compact organisation is preferred. If you think about it, there is no space left for nothing. Everything is occupied by organs, muscels, bones, blood vessles, and fat reservoirs. There isn't any space which is just filled by "flesh". And since some organs do not need to appear two times, like two hearts would be hindering each other, it seems like they were sorted in the most compact way.
Well I guess it would be weird if your stomach had an urge to schlop around the ground and find food. If you're only a part of an organism, you don't have the burden to survive and evolve by your own means esp by selective pressures from other niches.
I just want to show my appreciation for your video. I was baked and sitting on the couch and thought "why are animals symmetrical" and was delighted to find such a great answer so quickly. thank you
Hahaha I love your comment
Yo same
Same bro
I like to make insects unsymmetrical
Also watching this baked
The answer is simple, it allowed for weight balance, and movement is a lot easier when you aren’t having to counterbalance a large weight on one side while having far less on the other. You would just end up falling over repeatedly which isn’t good when you are trying to move in a singular direction.
That’s all I need to hear.
Yes, but what still really surprizes me is just how symetrical we are in detail. I find it hard to imagine that a left ear 5 centimeters below the right ear would be different enough from 2 ears at equal height to actually make a big enough difference in our (and other animals) chances of survival. Or that we dont have 2 left, or 2 right hands. Or 4 fingers on the right and 5 on the left, etc. I'd like to see an explanation for that.
Said the fiddler crab...
@@smilloww2095 just look up punnet squares
@@smilloww2095 Owls lmao
this is such a fundamental thing i never thought about.
Same
Tényleg igen
I took acid and now I can’t stop thinking about it
@@johnnyshanahan2185 it becomes so scary just staring at a creature staring back at you
@@ninanando I got a feeling that any matter has "sight" after meditation. Not like humans, it just registers everything like a CCTV. It was just an intuition, and gone
"Bilaterians have a clear direction of movement"
Crabs: "And I took that personally"
But crabs can walk forward and every other direction too
@@darkaliebaba99 not rarely
lol
@OG MXBC that's what I came to say lol
The ones wit one big claw, did not
I swear, I wrote a paper that basically turned into 'why bilateral symmetry works' for my 1st year college Astronomy class back in 1992, (when they foolishly let us pick from a term paper topic list that included "describe the hypothetical evolution of life on another planet" and I am so thrilled to watch this video, because I came to similar realizattions and understandings and this video feels SO VALIDATING for that paper. Thank you! 🙂
that's really cool. so I'm assuming you argued that alien animals would also be symmetrical?
@@fkhan2006 It was 30+ years ago, but as I recall it was more focused on sapient life evolution, so the various alternate symmetries and asymmetries were just touched on as what had advantages over the others in passing. Not all life on earth has a symmetry let alone bilateral symmetry. Life evolves to be successful at thriving in its niche, and not all niches have the same traits that provide an advantage. 🤷♀
Whenever I’m articulating a skeleton, this is always super helpful! If I have a bone that I can’t place, I check if it’s symmetrical; if it is, it’ll go somewhere in the middle, and if not, there will be a matching one somewhere!
can make it a nightmare to side the bones though if you don't have the corresponding match - fibia are such a pain!
Yes! I’m currently working on a buzzard and the ribs are a nightmare, considering i’m missing a few!
I thought you meant a real life skeleton and got a bit worried
@@kingpotato7183 I do, many! Not human though😅 Specifically working on articulating a Buzzard skeleton atm!
To be clear - there's tons and tons of organisms that grow in fractals nowadays. They just are all plants. (ex, broccoli and cauliflower)
Rangeomorphs are thought to be animals so I think it's implied that he meant there are no extant fractal animals.
Broccoli and cauliflower are the same plant, so perhaps more varied examples?
@@michaeljordan4457 Ferns and Cacti? Almost all plants seem to be fractals, repeating smaller versions of themselves to grow and reproduce
Edit; You could even argue the entire universe is a fractal and we live in a simulation that uses nothing but numbers to fool everyone, Matrix style?
@@_NEPO_ but the universe isn't alive. It's not an organism so it's irrelevant
@@cesarcueto1995 Ah, however these things you call alive are very certainly made of things that are not. Even the very chemical process that run these fleshy machines are structured in ways that, when placed in an optimal environment, can form crystals and structures akin to the most perfect of computer models.
I was wondering about starfish, but you fortunately addressed that.
still weird we’re more related to it than ants or snails
Seconded. "But what about starfish... Oh."
Star fish is still symmetrical
Same
Flounder
Every frustrated artist has asked themselves this once when drawing a face.
The red fish at 9:07 is like: who are you filming? Are you filming me? No? Ok let me just get out of your way then.
Imagine a jellyfish with a brain. Now, don't ever imagine that again.
@@Wikispedia wat
I mean jellyfish do have a ring composed of neurons that’s basically a brain. It’s just fairly simple and not that sophisticated.
@@Meejie I'm talking human brains.
an octopus ?
King jelly
Flatfish are still born symmetrical though, right?
Their right eye migrates through their body to the other side when they mature.
It's almost like a mini evolution at super speed.
yes, they are born symmetrical
That’s kinda gross and kinda cool at the same time 😶
maybe if ur thinking of pokemon evolution lol
More like development. It's the same idea with humans in that we are embryos which develop into a bipedal organ sack
@@powfoot4946 not to mention we lose our tails during embryonic development
I’m blown away by your production, it’s simple, VERY factual and elegantly presented. Can’t wait to watch more of this content. Subscriber earned 🎉😅
I study left-right symmetry breaking in the embryo for my PhD so this video is extra fascinating.
It’s weird that I never wondered this thanks for opening my mind I’m gonna be stuck on this topic for a while 😅🧐
Spacekid Productions same
Fr
My mind has refused to go back to work also. 😄
I'm stuck on Pineapple Rag. ♪♪
it's cause symmetry is so inherent in your thought process
Huh, I never knew echinoderms were bilatarians (which autocorrect wants to render as “BiL Atari and”). You learn something new every day.
Autocorrect is a curse when writing anything scientific or specialized.
@@pansepot1490 The horror of every german student in biology is autocorrect constantly changing DNA to 'DANN' (eng: 'then') when writing a protocol
Anyway isn't bilatEral?
Just wait till you try to talk about they multi purpose anus’s without autocorrect.
Only if you try.
Just a reminder, humans are a species of animal. Some people are shocked or in denial of this.
I know right? Like, just because we're able to do shit other animals can't or won't, doesn't mean we aren't animals ourselves
@@TyrannoKoenigsegg yeah you're right! lol. We have consciousness, and therefor know of our own mortality. This is what I think pushed people towards religion or other definitions of their existence for justification. Why do humans need a reason for existing?; Perhaps it is by random circumstance. We just happened to survive more efficiently through evolution by random mutation. Now we have big brains and don't know why, I believe in the sentiment that, "We are the universe experiencing itself".
@@basedheretic4616 I agree
I don’t even like science that much but I found this so interesting and enjoyable
That means you like science
Flounder in development
Symmetry: "Imma head out.."
Flounder halibut and fluke are bilateral free swimming fish when they're young.
Dave Glines didnt get it, but this was the first thing in my mind.
I still don't. Well maybe. Nah.
yeah thats what i thought
Exactly what I was thinking!
The picture of that crossbesk bird hurts my teeth
Last Christmas, I had an inflamation on my jaw joint. My mouth was all crooked like that bird and I couldn't eat anything without feeling a lot of pain.
My teeth are worse than that bird.
@@sohopedeco I guess you should've tried pinecones! Glad you got better =)
same, it makes my jaw feel awkward
7:36
Bless that little fish at 9:09 who didn’t want to get in the way of the shot. Such a gentleman.
I swear the first time I saw this title it said "why are squirrels symmetrical?" and a couple days later and it's "why are animals symmetrical?"
This is something that I would have never realized even though it's so obvious: that most animals are bilateral (and all the advantages that this brings along).
It's because of things like these that I love this channel.❤️
Interestingly while it wasn't mentioned there is actually a group of cnidarians the anthozoans which have convergently evolved a bilateral axis. In the early development of both bilaterian and Anthozoan embryos this occurs by using a second Hox gene cluster(which seems to in both cases arisen by duplication of the original Hox gene cluster inherited from the last common ancestor of bilaterians and cnidarians that granted them their preferential axis of radial organisms) and using that second copy of the body orienting HOX gene clusters to form a second body axis perpendicular to the first resulting in a bilateral organism
@@Dragrath1 amazing! Thanks!
Same! It never occurred to me that normal animals could be anything but bilateral. It was never explained this way to me before, and now I feel bad for thinking things like anemones weren't "real animals". They just have a spread-out nervous system!
This makes me think that most animal-like aliens will be bilateral as well. Gravity and centralised nervous systems aren't things exclusive to Earth, so we'd expect that any other planet, which can hold life, will hold bilateral life.
Baka
The problem with all this type of speculation is we simply have no idea how typical life and evolution on earth is. Life itself has only emerged once that we know of, and it’s entirely possibly that we are not at all normal in terms of other life forms in the universe.
@@HkFinn83 What we know for certain is that every planet has gravity. And as bilaterally is the most effective way of balancing an organism in gravity, we'd expect they'd also do the same. It's not blind speculation. Organisms exposed to the same conditions develop the same structures regardless of their relations - wings, for instance, developed in bugs, birds, and bats, all independently.
@@wachyfanning Bilateral definitely would be a common trait, but in theory, we could also see radial symmetry occur. Imagine for example, a circular creature with legs all around it, akin to a circular centipede. It genuinely could live and survive. Considering evolution isn't based on what's best and instead is on what works, if there was no pressure on that animal to change, it wouldn't. On Earth, radially symmetric animals never evolved far enough to develop traits that would've allowed them to survive on land (even if it's just breach and stay on the surface for a bit), but that doesn't mean the story is universal.
@@wachyfanning Wings also developed in pterodactyls, a group of extinct dinosaurs. Although modern birds also evolved from dinosaurs (and many scientists consider them to actually be dinosaurs), pterodactyls were not ancestors of birds.
3:57 Ancient australian seabed would be a great name for a band
I had this exact question on my mind earlier today and didn't look it up for some reason, and now I got this video recommended on the home page. RUclips scares me sometimes 😐
Nice video btw :3
Today I was thinking about watching "the rock" rap. I knew it existed months ago but forgot. Only today I thought I should watch it so open the app and what do you know the first video was "the rock" rap part 1 hour version. ☠️
Heres me with a crooked nose, lazy eye and one leg longer than the other 💪
@@voopsin8116 my doctor told me one of my thighs is longer than the other, i dont know about this person but for me its completely normal and it always has been, i didnt even know about it until my doc told me
We all have a limb that is longer than another, it's not completely the same, though the difference is very small for an average hunan
we humans have stop natural selection,
You should find a partner with similar traits and starts a new species
@@lancebianzon6034 no?
I envy them, I am an ugly asymmetrical freak.
Me too. Evolution is against us procreating, which I suppose is a good thing for the species in the long term.
@@JohnyG29 People say humans defeated natural selection... we are the living proof than they are wrong lol
How asymmetrical? My left jaw is slightly bigger than the right.
Bruh is u a Denisovan or a Neanderthal :0
@@JohnyG29 : Allahu Akbar! 10
The fact we exist for the tiniest blip in time is so crazy
Great video, thank you. Your delivery is very calm, there's no jumpy music, and the visuals are clear and interesting.
I just read that some types of snakes have lungs that aren't bilateral - to fit their body shape, they have one large lung and one very small one, located one in front of the other - thought that was pretty cool.
(editing - I see some other commenters pointed out the snake stuff)
Really glad that you're covering this, becuase I remember wanting to learn a short explanation of this, because the things that go that far back for life are usually not necessarily intuitive.
I'm really glad when I was told that nothing IS symmet.
This is shaping up to be a top quality channel on this subject
Always has been
@@quartzking3997 I know but it's cementing itself more and more as time goes on. I'd actually rank this higher than PBS Eons which is also a great channel.
edit: And Ben G Thomas
This and the Ben G. Thomas channel are my favorites, though I have to say this is one may be edging them out in terms of these in depth videos about niche topics
@@kevinwells9751 Yeah forgot Ben G Thomas, also a great channel my bad.
The term "fractal organism" is one of the coolest things I've heard.
I wish I was a fractal organism :(
I think our blood vessels are fractal
that was truly educating, loved it. Made me understand the way we look at the world on a deeper even philosophical level. I think the way how our bodies are build, with a front and back and a center of nerves (brains), must have had an influence on how we think and view the world, how we developed a philosophy of "right" and "wrong", of "forward" and "backward", of truth itself.
Curious about Octpi... They are partially radially symmetrical (in their arms) but also partially bilaterally symmetrical (in their head.) They are part of the bilateral group but it is interesting they evolved this way.
Damn i was thinking about that when i was watching this.
not really, the base is more like an octagon stretched along the x axis.
I'm betting it's something like the starfish: octopedes are bilatrians, but their lifestyle encouraged a more radially symmetrical appearance.
@@NitroNinja324 it is literally a calcium deficient, boneless spider you mouldy lasagna fire.
@@aidanmatthewgalea7761 I'm sorry, did I hurt you somehow? That was a bit rude.
i love your videos, they’re so good. they’re just much less “hand-wavey” than other science channels, you just let these interesting topics speak for themselves instead of trying to hype them up.
the narrator’s voice is so calming, it is a really relaxing video
Both of your videos I've just watched dropped my jaw. Thank you for some excitement in sharing them and whatever is ahead.
Can you do a video on starfish and how they evolved away from bilateral symmetry? That’s an interesting exception to the other bilateral animals.
most radial symmetric animals have something in common that I noticed, and it's that their mouth tends to be in the center of their body, such as starfish and octopus
@@dewinmoonl Another common point of similarity is that both echinoderms and cnidarians require a solid substrate to attach to during their embryonic development. There is also fossil evidence that early comb jellies similarly evolved from sessile organisms so it seems that radial symmetry is likely useful for a sessile or fixed in place organism.
Of course embryonic studies show that in the two lineages that have convergently evolved bilateral symmetry Bilaterians & Anthozoan cnidarians(i.e. anemones &corals which primarily exhibit bilateral symmetry in their extended larval planula stage though there is a slight preferential bias remaining in their adult forms) did so by duplicating the genes that encoded the original preferential axis radial organisms have.
@@dewinmoonl in order for them to be radially symmetrical, they would need their mouth to be central. Otherwise the mouth would throw off the symmetry.
@@dewinmoonl
Octopus are not radially symmetric. They’re still bilateral. I understand your point though
Now I have to wonder stuff like: do jellyfish ever get their tentacles knotted up with another jellyfish's tentacles?
When i was younger i thought jellyfish mated that way
Yes, I've actually seen that at the beach.
It's so interesting how you get a question in your head, solve it, and share it with others
I never really acknowledged the symmetry in organisms, now it's super interesting to me
It is videos like these make me so intrigued by what potential alien life forms could look like. Something as simple as their gravity being less powerful than ours could result in body structures we cant even fathom.
We are essentially just tubes of mouths and anuses :’)
Should be a tag line for a porno.
I believe that’s the premise of human centipede
@@ShadesOfGuitar 🤢
Cue* Vsauce's video of how many holes we have
What
This is one of the only channels that I wish I could give more than one like to on all the videos. The content is just so good I want to make the SEO to promote the videos more, so more people can discover this channel
Like all the comments
I never really thought about how symmetrical every animal is. Just something I’ve not thought about that’s just how they are.
Best channel on RUclips!!! You should get a documentary award from someone. Love your vids!!
6:17 showing the crab at this moment is interesting since they are very assymmetric around the direction of motion! Thanks for the video
8:16 Kingler is real
He wacc
the title is something I would ask when I’m stoned
When RUclips recommendations is roasting you by saying:
*All these animals with good symmetry but you gotta look like that*
So, low gravity environments could sustain land animals with radial symmetry? I imagine something as alien as a flying jellyfish.
Sounds cool, but might not be feasible, since it seems way harder to have non deliberate movement on air.
Wouldn't flying jellyfish require a very dense atmosphere in order to pull off that trick? At least it seems so to me, but in order to have ah dense atmosphere, the planet itself would have to have a very strong gravitational field as well, so i think your point is somewhat moot. Sorry to be such a partypooper. 😢
Check out Alex "Abionenisis" Ries' brilliant work "The Shadow of the Sun".
@@BertGrink yes, and they'd most likely live their entire lives without touching the ground
It should be noted that radial symmetry on Earth appears to have been a prerequisite for bilateral symmetry.
Specifically radial symmetry requires one body orienting axis, but bilateral symmetry requires two body axes the second axis being perpendicular to the first resulting in a defined top and bottom for organ development.
In both bilaterians and Anthozoan cnidarians, bilateral symmetry was evolved thanks to gene duplication copying the original HOX gene cluster that made their first body axis possible. Anthozoan cnidarians bilateral symmetry is harder to observe as it's mainly expressed in their larval planula stage but they do apparently retain a degree of a preferential direction even as mature polyps not unlike Echinoderms
@@BertGrink -- Venus is somewhat smaller than the Earth yet has a vastly denser atmosphere, the pressure is about 90 times as high as at sea level on Earth. Saturn's moon Titan is not much bigger than the Moon, and yet has an atmospheric pressure 50% higher than the Earth. So a planet like a cool Venus or warm Titan could allow airborne jellyfish.
I always figured it was just easier for nature to do half the work and copy itself, making two unique sides would take more dna encoding.
But our insides are asymmetrical.
4:59 'When the left tropical fish is SUS'
"Bilateral symmetry is good for moving forwards", then shows a crab, that only can walk sideways
Something I've always noticed but never thought of. Thanks for the video!
I don't know why, but I almost cried at the thought of that fractal body plan....it's just so beautiful man xD
I’ve thought about this question a lot but never had an answer, so thank you
"Why are animals simetrical"
Owls: **awkward puppet monkey meme**
The idea that direction is just so advantageous that it produced the variability we have today is so fascinating. I think it also wouldve been interesting to address dominant sides, like how most of our species favors our right hand, how that might manifest in other species, etc.
In cats it is gender specific. Female cats tend to favor their right paw while males tend to prefer their left paw.
It's so obvious to me.... a cell, when dividing, the first thing it does is create bilateral shape...then splits ..extra
How do you explain asymmetrical organs?
@@morganirosonna2871 --- Is kind of interesting. Two lungs, two kidneys, but only one stomach, one heart. Yet we can survive with just one lung or one kidney. How much better off would we be with two hearts? Probably a lot less people would die from a heart attack. In a way the digestive track is just a long tube that is basically just folded up to fit into the body cavity so if it were stretched out in some ways it would be bilateral. The large intestine is somewhat bilateral. Also the stomach to some extent, just turned sideways.
your content is really well written, and your insights on everything are always thought provoking!
4:51 That's a gorgeous donkey.
I had no idea echinoderms were bilateral! Neat.
Very Interesting! i didn't know starfish where technically bilaterians, i wonder if their madreporite(at least the ones that only have one) give any clues as to their real orientation.
XXXORIENTACION
The interesting thing is they start out bilateral in the larval state and turn radial as the grow up, adding extra arms. Interesting to know why would this happen. What is the advantage?
@@Fazzel It’s possible that all echinoderms evolved from a species in a genetic bottleneck, and that it had relatives that may have lacked radial symmetry.
My zoology teacher taught me that sea stars have radial symmetry 💀
One of your best videos!
This channel is incredible.
this is probably the most interesting video you've done so far!!
OH MY GOD THAT COINCIDENCE IS AWESOME. I had stopped this video right as the loading bar lined up perfectly with the line in the thumbnail
Animals: **Are symmetrical**
One-handedness: "You challenging me boi?"
Fun fact: Did you know that in some species of Owls, the left and right ear holes are located at different elevations on their skull?
The more you know.
Is that to make each ear specially better at picking up vibrations from certain angles whilst using the information to create an "image" of its surroundings?
@@strrawberrytekken3698 With the face of Owls being shaped like radar dishes, yes. Most importantly having the ear holes located at different elevations allow them to pinpoint where exactly a noise is coming from on a vertical plane.
@@L0calLEGEND so damn cool
4:18 is the cutest squirrel I've ever seen
I agree Goku
If that’s the cutest you’ve ever seen let me introduce you to the grey ones that hang around my garden fence
@@Anon1370 wtf
@@Angel-Pizzaeater theres nothing wtf about it i do have squirrels
@@Anon1370 do you have cats
holy keyed janny
before watching the video the only creature i can think of that isn’t symmetrical is the flounder, it has both eyes on one side.
Rangeomorphs look beautiful, it's a shame they don't have descendants.
I read a paper about them and their complex social network, it was an interesting read
they're called plants for all intents and purposes. you might also look into deep sea corals, same vibe
@@dewinmoonl I believe rangeomorphs are animals though
@@dewinmoonl definitely not plants. Corals are animals and rangeomorphs are believed to be stem animals.
I guess scientifically illiterate people will call them plants, as they might call dolphins fish, or call bats birds, still not correct.
@@pansepot1490 corals are pretty plant like, in that they filter their surrounding for nutrients and photosynthesize with internal algaes. i was just making an analogy of convergent evolution to make a point that those funky designs exhibited by earlier animals are also the same design that made plants and corals, aka convergent evolution.
I'm not scientifically illiterate haha I studied biology as undergrad so I'm well aware that corals are not plants, those earlier animals are not plants, and dolphins are not fish, and bats are not birds, you name it.
You know you appreciate the content when you purposefully watch ads so you could give the creator some dough. Keep it up, great content as usual.
I love when a video pops up that answers questions I‘d never even come up with.
Very well made video! I learned a lot from this actually!
Amazing video, this channel keeps blowing my mind
i like your videos so much! it's always clear how the questions you answers are relevant or interesting!
8:05 this adaptation is not entirely unique, in fact, most male hominids species have much larger wrists and forearms on their right sides rather than left; in order to compensate for their lack of sexual activity. 😂
Me : Time to sleep
Also me : Why are animals symmetrical? Let's find out!
Starfishes and sea urchins being bilateral was totally new to me. Thank you for the info!
Owl ears- "Am I a joke to you"
I was just wondering how much symmetry is needed to count as truly symmetrical. It's on a spectrum for sure, so I wonder what the cutoff is.
this is the coolest thing i’ve ever seen thankyou
Somehow, I lost all my youtube data including all the channels I was subscribed to. Moth light was one if the first I could remember and search to resubscribe to. I wonder why? 😉
You're intelligent, and that's dangerous to certain people. Thats why you're shit was erased.
Animals who break their bilateral symmetry be like "I caught a dab, not bad!"
Don't dab backwards, it's bad.
It amazes me that I can even understand this and appreciate it so much.
That squirrel pressing its fists against its chest is beyond cute.
Thanks, this will really help drawing aliens. Something as simple as shifting how they are symmetrical is both sensible and something I'd never really considered.
"perfect to propel forwards in a straight line"
video shows a crab!
8:16 except for hermit crabs, as not only do both genders have a big claw, they use it to block Predators from getting into their shell. Although they still have the only being able to eat with one claw problem.
This documentary is just so good. A hundred times better than 4 minute-long badly researched documentary about the golden eagle with pictures from bald eagles, peregrines and even buzzards.
Last time i was this early animals were asymmetrical
NEW VIDEO LETS GOOOOO
animal facts Lets goooo
I’m curious what something like a flat fish would be considered? They start off symmetrical but then an eye migrates over so they’re both on the same side as they mature and they do only really use one side to get around. Does that exclude them or are they technically still bilaterally symmetrical🤔
Ah, you mentioned it!
Sea cucumbers evolving from bilateral symmetry to radial symmetry and then back to bilateral symmetry: "parkour!"
Quality content as always, thanks you!
"With such ancient creatures, relationships with other animals are difficult to work out."
* laughs in Hallucinogenia *
To be fair, we do know what they are related to: velvet worms
Aot fans: DID SOMEBODY SAYS *HALLUCINOGENIA*