The Evolution of Snakes

[@douge2697]

Snakes aren't the only lineage of legless lizards either, there's also the amphisbaenians, dibamids, legless skinks (with some nearly legless transitional species), legless geckos, the list goes on and they all independently lost their legs. It just keeps happening - there's something about the squamate body plan that really lends itself to leglessness.

[@stormevans6897]

Omg thank you, I've had a fascination with the subject ever since I caught my first glass lizard and witnessed the confusion on my dad's face. I had no idea that it had evolved so many times in our modern world, like legless geckos, how did I not know about this? Those are so cool btw.

[@bramstedt8997]

@Atropus Arbaalish you’re thinking of Caecilians

[@frikativos]

Yes! I'm surprised legless lizards were not mentioned in the video. I have also seen lizards with such teeny tiny legs they can barely use anymore.

[@christiancinnabars1402]

All legless/tiny legged reptiles are ones that ended up with very long bodies. My guess is that they all independently evolved to become longer for various reasons, and as a result their legs started to help less and less with locomotion. Being not as useful anymore, their legs slowly grew smaller over generations, then became vestigial and, in some species, eventually disappeared.

[@theperfectbotsteve4916]

Snakes aren’t technically lizards

[@tetryds]

This is by far the best evolution channel I have ever watched. The fact that you don't waste more time than needed talking about classification and that you go around different evolutionary aspects of a given type of animal makes your videos fulfilling and really entertaining.

[@Epidombe]

Yes. Every time I recommend the channel I make this point. Theres no persuasion “this discovery changed the course of history forever.”

[@o_o8203]

Frankenscience has great evolution videos too! Short and to-the-point.

[@OdinComposer]

And the chill vibe

[@danielrusso4468]

If you like this you should also check out PBS Eons :)

[@tetryds]

@@danielrusso4468 What I did not like about PBS Eons is that on the videos I watched it felt like they were discussing classification rather than trying to picture an evolutionary pathway

[@mike-0451]

The snakes lost the evolutionary arms race and the legs race, I think.

[@TheBurningWarrior]

This Just in, Ian.

[@slashr406]

☠☠☠☠☠

[@piuscalvinus]

@@TheBurningWarrior See what you did there.

[@amenawonotaigbe716]

You win the internet today 🤣🤣

[@brainphelps1994]

lol you don't even know what you just said!!!

[@thomast7794]

Same story for turtles. Adaptations for water are useful for burying and vice versa, therefore it's unknown where they evolved.

[@Illlium]

Poor snakes, they just wanted to chill in the ground and other species railroaded them into a genetic bottleneck. Nature really is cruel.

[@kennethsatria6607]

@Atropus Arbaalish There are also big ribbed and shelled reptiles that lived marine lives it blurs the lines.

[@Ponera86]

we actually have a pretty good idea about turtle evolution now. Pappochelys looks to have expanded its chest region and ribs to help with digging. Then you get the first aquatic turtles in china which had only a plastron, which exapted the adaptation.

[@mickwayne3398]

in other video he says they evolved from marine plesiosaurs

[@Paladinpal]

I think it's more likely they pursued prey into their burrows like weasels who have undergone a similar evolutionary path. Losing claws won't make you a better digger; losing limbs and slithering does help pursue small prey items into their own burrows, however.

[@Her_Viscera]

Yeah I really think he should do another pass over the script bc this video was full of that kind of language

[@archdornan4389]

This means there will eventually be a mammalian weaselsnake that will probably be venomous...

[@julianshepherd2038]

@@archdornan4389 who will be elected US president

[@IXSuperRadGamerXI]

@@julianshepherd2038 Or any world leader in the top 5

[@lalehiandeity1649]

@@julianshepherd2038 Please keep politics out of everything that isn’t politics.

[@origaminosferatu3357]

Fascinating! Snakes may be one of those rare occasions where something that is incredibly specialised has enough other useful traits that it ends up diversifying and becoming more generalised.

[@jeromewoods6175]

Okay MyVirginMedia yyeah y

[@Q--_--90909]

Yes I love snakes for that reason

[@lastEvergreen]

Best animal channel in the game

[@AlmedaRen]

Yup

[@mothlightmedia1936]

In the video I mentioned that snakes and venomous lizards may have evolved from the same venomous ancestor, however, newer research has challenged this theory and it may not be correct any more: link.springer.com/referenceworkentry/10.1007/978-94-007-6727-0_4-1?noAccess=true

[@michaelanderson7715]

1:40 "nearly all venomous snakes produce venom to at least a certain extent" - talk about a contradiction! - ALL venomous snakes produce venom, the clue is the word 'venomous', NOT 'nearly' all!

[@b.a.erlebacher1139]

@@michaelanderson7715 It's a tautology, not a contradiction. Most people make the occasional slip of the tongue. Don't you?

[@michaelanderson7715]

@@b.a.erlebacher1139 "It's a tautology, not a contradiction. Most people make the occasional slip of the tongue. Don't you?" - I have zero interest in your defensive posture towards the original statement, other than to say, it's irrelevant to my pointing out the flaw within it -------------------------------- I will take up on your tautology 'correction'; "nearly all venomous snakes produce venom to at least a certain extent". - a tautology is a statement that is necessarily true. Applying this to "nearly all venomous snakes produce venom to at least a certain extent", one sees immediately that not only is it not necessarily true, but that it is actually not a logical statement at all and is indeed false. The false part is 'nearly all'. - ALL venomous snakes produce venom (THIS statement IS a tautology!), not 'nearly all'. A contradiction is a statement that is necessarily false. And "nearly all venomous snakes produce venom to at least a certain extent" is false. A true statement would be without 'nearly'. ---------------- Now, your snarky attitude means I've no interest in you further. Muted

[@b.a.erlebacher1139]

@@michaelanderson7715 Well, I guess you are an expert on snark. These videos are made by a human being. They take a fair bit of work. They are free for everyone to enjoy. I don't expect everyone to be perfect all the time. If you do, you will be constantly disappointed, but I guess it's your way of feeling superior without needing to do anything real to justify it.

[@PonderingStudent]

Species of lizards that evolved leglessness more recently (like slow worms and sheltopusiks) are pretty much universally burrowers. Either in soil or in media like dense undergrowth or the cracks in stone walls etc. So snakes starting out as burrowers is by no means a unique evolutionary scenario.

[@johnscanlon8467]

Slow worms and Scheltopusiks are about the LEAST burrowing-adapted examples of elongate limbless reptiles you could have picked. They may capture prey within the prey's burrows, but don't dig their own (see also Pygopus, Delma, Lialis etc among pygopodid limbless geckoes). There are more specialised burrowers in Anguoidea (e.g. Anniella) and Pygopodidae (e.g. Aprasia), but the most basal lineages in both families are active on the surface. So snakes starting out as surface-active probing foragers would by no means be a unique scenario either.

[@mariastevens6406]

Just when my anxiety kicks in. Love snakes, and your calming voice. Just in time lol

[@sagaramskp]

Relatable. Watched in small window when anxiety kicks esp when moray eel was shown

[@shinobi-no-bueno]

Snakes calming your anxiety sounds like the origin of a supervillain

[@mariastevens6406]

@@shinobi-no-bueno they don't calm it. I like them so that part doesn't bother me. But if they did, so what?

[@ArtsiProductions]

Relate-

[@Gildedmuse]

Nature and History KZbinrs get me through my kidney disease pain (and they anxiety that it causes; I mean, good for people who deal with terrible pain by becoming better people but personally I just freak out.

[@l4430]

Something related to this that interests me is how there's no known limbless mammals or birds throughout history. Seeing how prominent the loss of limbs is in non-avian reptilian and ,lesser so, in amphibian evolution, it seems crazy that it hasn't occured even once in mammals or birds. Is this due to the method of locomotion where the lateral movements of lizards etc just allows for limbless movement better whilst that of other groups does not?? I haven't researched this at all and am just piecing together knowledge from my general studies as a zoology student, so I'd love to hear anyone better educated on the matter give input on this!

[@fannyalbi9040]

because mammals and birds don’t swim zigzag in water, they move their spine up and down, it is impossible to move that way on land unless u r spineless caterpillar 🐛

[@IchCharacter]

Most mammals and birds don't have the bone structure for it. The closest you'd get might be weasels and moles, but there'd be more problems without limbs. For example their skin/feathers/fur, which are usually too soft. Most animals have especially tough skin on their feet/paws, but other skin would get chafed by being in contact with the ground, especially the usually much softer stomach area of mammals needed for breast-feeding. Mammals and birds had pretty different different ways of getting food (often omnivores), hiding and so on, another reason why they need their limbs. One of their biggest advantages was their resistance to cold, due to their fur/feathers and lack of contact with the ground. Finally, also regarding temperature, almost all mammals/birds are warm-blooded, by constantly exposing a lot of skin to the ground they'd waste tons of energy just to keep warm, it's like turning on the heater while leaving the windows open. Fur/feathers isolate air very well, making it easy to keep their body temperature stable, even if it gets quite cold. By sliding around on the floor, their weight would press out the air and they'd lose a lot of warmth to the ground. This is probably the biggest reason why mammals and birds have limbs, to keep their warm bodies away from the cold ground.

[@juanjoyaborja.3054]

Odontocetes and Mysticites have lost their hind legs, however, they still need their front limbs for propulsion. The closest mammals to a snake-like body plan are likely mustelids, and yet losing limbs permanently would be a downgrade. For birds, look at their bones. Their bones are pneumatic, hollow, making it hard for a slithery body.

[@AuliaAF]

@@juanjoyaborja.3054 T-rex almost lose their hands, though. Although it's not for burrowing or slithering, there are also possible situations where bird-like animal prefers aerodynamic shape to free-moving limbs. But then again, rather than losing their hands, birds prefer to change it to wings.

[@Johnnybomb1]

I think it partially has something to do with the fact that birds and mammals are both endothermic, and reptiles are not.

[@SwampApeSci]

Venom injection and constricting are such interesting specialized hunting strategies but there's a few snakes that have just gone back on the 'ol tried and true method of just thrash and maul prey to death. Like the Drymarchon and Masticophis

[@jessehunter362]

The single-origin venom hypothesis isn’t the only one, a lot of the animals which have “reduced venom” don’t use their venom-related proteins as a venom. Limblessness evolved several times in lizards, most often preluded by rib duplication, and it’s quite possible venom has evolved multiple times from the genes which encode the venom-related proteins.

[@frostyglass3738]

Lovely, I didn't know there were snake fossils with tiny legs.

[@zenebean]

Some modern snakes still have slight suggestions of where their back legs used to be. There is something so cursed about seeing prehistoric ones with little baby baby legs just kinda hanging out there

[@stormevans6897]

It blows my mind how effective fangs are, that they so happened to pop up over and over again. Videos like these remind me why I use evolutionary biology to explain just about everything in living things.

[@bakionigeri6414]

Because it's, in my opinion I should probably say, the only real answer to anything. Not to go there LOL but look at dating; it can be quite confusing why people choose who they choose, until you look at reproductive Health in women, and protect and provide for everybody ability in men. It's the only time it becomes clear.

[@shaymich2395]

Question about the evolution of venom from salivary glands: Is it possible that the slight salivary mutation was selected for due to another benefit caused by the same mutation? For example, if all of the lizards fluids were slightly toxic, could bad taste have protected from predation, meaning being venomous would have evolved alongside being poisonous, then either venom or poison lost in certain lineages later on? Alternatively, what if slight toxicity in sperm protected from cloaca bacteria, causing strong sexual selection, and toxic saliva was triggered by the same gene mutation? Do you think any of these scenerios are possible?

[@UniDocs_Mahapushpa_Cyavana]

Monitor lizards are very good burrowers and since snakes often live underground and burrowing animals seem universally good at swimming, mosasaurs would be primed for aquatic life, even if solely terrestrial close to evolving.

[@bkjeong4302]

Cladistically, snakes are lizards-the most successful lineage of legless lizards ever.

[@dinotyrannus]

All squamates technically are lizards and the reason why snakes are excluded from lizards appears to be arbitrary as there are lizards more closely related to snakes than to another squamate that are considered lizards

[@jessehunter362]

@@dinotyrannus snakes aren’t excluded from lizards in most taxonomies. They are just the third group of legless lizards, and are very morphologically diverse and distinct.

[@dinotyrannus]

@@jessehunter362 though most people and even scientific articles doesn't consider them as lizards and snakes are just seen as a relative of lizards, yes snakes are just one of the many lineages of legless lizards and are therefore a type of lizard

[@specific3600]

“Nearly all venomous snakes produce venom to at least a certain extent” ah yes, the floor here seems to be made out of floor Jokes aside, great video. Love snakes ^-^

[@FreedomAnderson]

Some venomous species such as Garter and Hognose Snakes are rear fanged and have more of a toxic saliva than true venom.

[@michaelanderson7715]

Your sarcasm fails to address the _actual_ flaw in the statement! - ALL venomous snakes produce venom, the clue is the word 'venomous', not 'nearly' all! Your comment addresses "all venomous snakes produce venom to at least a certain extent", a statement NOT made

[@emmanuelsanchez9303]

I'm a little bummed out that there was no mention of Titanoboa. I have no idea how that fits into snake evolution, but still, it would have been cool to hear a shout out to the most massive known snake that has ever lived 🐍🐍

[@leahime]

I love how these are about 10 minutes. Perfect to watch on my breaks!

[@spyrofrost9158]

1:43 "But actually, nearly all venomous snakes produce venom to at least a certain extent." Well, can't argue with that one.

[@michaelanderson7715]

" "But actually, nearly all venomous snakes produce venom to at least a certain extent." Well, can't argue with that one." - well, you've failed miserably then, as it's contradictory nonsense! - ALL venomous snakes produce venom, the clue is the word 'venomous', NOT 'nearly' all!

[@omarb7164]

@@michaelanderson7715 no shit

[@michaelanderson7715]

@@omarb7164 I think you missed the point, not that I care, you foul bucket of vomit; muted.

[@LiveActiveCultures]

I’d love to see an evolution of chickens video. With over 20 billion of them on the planet, and our symbiotic relationship, I’m sure people would love to see how the common clucker came to be

[@rickkwitkoski1976]

The southeast Asian jungle fowl is known to be where modern domestic chickens came from. Domestic breeding had changed them a LOT Even in the past 50 years, meat chickens have more than doubled in size.

[@Sathish_12]

t-rex became chicken

[@user-lu6yg3vk9z]

@@rickkwitkoski1976 doubled in size from hormone injection

[@shinobi-no-bueno]

I love the idea of a big ol snake slithering up and around a dead tree, coiling around it and then these stumpy little legs furiously scrabbling as the tail wraps around

[@UniDocs_Mahapushpa_Cyavana]

Limbless squamates have evolved 7+ times, with multiple big groups, so clearly that plan just works. Snakes are unique in that they also cannot chew AFAIK, except for one snake that broke the mold.

[@jessehunter362]

And that a lot of them have protrusible jaws!

[@osiris654]

AFAIK?

[@jessehunter362]

@@osiris654 as far as i know

[@UniDocs_Mahapushpa_Cyavana]

@@osiris654 As far as I know.

[@chuchu9649]

Liking the new editing style with the stock footage.

[@Goudhaantje1993]

Watching your videos is basically therapy. Also very informative.

[@fordprefect80]

In Australia we have a species of legless lizard called Pygopodidae. I've found them in the garden on the odd occasion.

[@b.a.erlebacher1139]

Pygopods are technically a subgroup of geckos. You Australians have so many cool animals.

[@aadhiablink9469]

@@b.a.erlebacher1139 nature chose australia

[@dark_antihero]

Imagine the prehistoric snakes with the tiny legs actually decided to use them

[@ExtremeMadnessX]

There's lizards with tiny legs.

[@Infernoraptor]

RE: Uatchitodon, how do they know it was still a lizard instead of a stem-snake if they only have teeth from it? Or was the lizard otherwise completely unrelated to the toxicofera line and just showed what the evolution of injecting fangs looked like in another lineage? Interesting and well done as always.

[@sterlingmuse5808]

I thought he was saying it was only 4 teeth as in "a total of 4 teeth on the animal" instead of "only teeth have been found"

[@jessehunter362]

We know it only from teeth, and it’s probable that it’s an archosauromorph

[@jessehunter362]

@Jesse Mathis We know for certain that snakes in the strict sense don’t go back so far. Tooth morphology matches best with archosauromorphs. We do not have anything close to the insane record of shark teeth that allows us to make strong inferences about shark lineage and morphology based exclusively on their teeth, but we do have enough archosauromorph teeth that we can determine it is most likely an archosauromorph. They are in a state of evolution between teeth used for chewing venom and injecting venom, are the only teeth of a venomous animal that we have at that point. The particular nature of their cladistics is irrelevant to their use as a tool for understanding snake venom evolution.

[@jessehunter362]

@Jesse Mathis for more information check doi:10.1007/s00114-010-0729-0

[@robrice7246]

I know there was a recent article that came out regarding snake evolution and the K-Pg extinction.

[@RambolifeCheesblocks]

FYI, only about one seventh of venomous snake species have hollow injector fangs. Some species don't even have venom guiding grooves along their fangs.

[@griffinhunter3206]

I do feel like you could have mentioned how many lizards on land have reduced or lost their legs as well

[@griffinhunter3206]

@@sqrt2295 Skinks even do a sort of slither *with limbs*

[@UniDocs_Mahapushpa_Cyavana]

It is pretty much "they got better at underground life" (with simple tunnels and using the tunnels of others)" each time.

[@griffinhunter3206]

@@UniDocs_Mahapushpa_Cyavana Thats not wholly true, sand swimming is a fascinating and similar reason for lizards developing leglessness a lot. Its not true tunneling behavior because there is no tunnel, its just vibing in an enclosed sandly space. THere are also certain advantages for movement through thick brush or other low plant environments, though i cannot say if this actually shaped lizards to leglesness

[@UniDocs_Mahapushpa_Cyavana]

@@griffinhunter3206Being snakes they usually just make/find a small tunnel and stand there for hours on end maximising their extremely low energy usage thing they have going. Snakes don't eat a lot, which is probably why the Bible says they eat dirt, because no one saw them eat meat, especially with their inability to chew. Also, they probably thought earthworms were baby snakes. Apparently, they were not aware of what sea cucumbers eat; one of the reasons why the curse on snakes makes no sense.

[@griffinhunter3206]

@@UniDocs_Mahapushpa_Cyavana Worm/vermin both come from a word which meant snake. Also theres no difference between a snake and any other sort of legless lizard in most anchient people's minds. I personally would not mind if we decided to call all the legless lizards snakes.

[@crazydrummer181]

Neat fact: Ball Pythons have claws!

[@Funkiotologist]

I have always wished we knew more about snakes evolution and sharks. We can only kinda speculate for many but in a way makes it more intriguing. I remember when Aquilamna was found in 2020 it blew my mind as to see a preserved shark fossil nonetheless one that had modified wing like fins was awe-inspiring

[@arcade8706]

I AUDIBLY SCREAMED WHEN I SAW THE NOTIF I AM SO EXCITED

[@guardianoffire8814]

Like a little girl...

[@arcade8706]

@@guardianoffire8814 WHSHGEHEHEV??? im a man

[@jayteah1349]

If you go by the logic of Spore: Snakes sold off legs for to buy venom.

[@Zsy6]

When I saw this pop up in my subscriptions feed I literally said "Aw, hell yeah!"

[@bluetannery1527]

It's fascinating that the snake body plan works as well as it does, but the transition is so fuzzy. it's like, a snake body plan works great, but to be able to develop it gradually from a lizard body plan, you need very specific circumstances and environmental pressures. So once you beat the odds, suddenly snakes (in the completed transition form) are super capable of being super diverse. They got so specialized that they accidentally evolved a super customizable body plan capable of huge diversity

[@Spikklubba]

Reminds me of the old "what good is half a wing"-thing about bird evolution before archeopteryx and the like.

[@NotSoSerious69420]

It just seems that the pressure to be able to burrow leads to losing limbs to be better at doing it. Having limbs doesn’t mean you can’t burrow well but not having them means you can just burrow better.

[@2nostromo]

So good I had to listen twice. When I was a young herpetologist (amateur enthusiast :) 50 years ago there were only 2 venous lizards, beaded and Gila. But I remember an argument even back then between two actual experts about Komodo dragon venom. so interesting.

[@l_donoman_l]

The danger noodle 🐍🐍

[@Jopmasselink]

The information density on this channel is admirably high. Watching this videos feels like studying. And studying I love. Keep it up:)

[@rickkwitkoski1976]

This is SUCH a good channel!

[@lestinmurillo2566]

a snake with tiny limbs, how lovely ❤

[@sassa82]

Great video. Time for me to relax!

[@nicks1451]

This channel is the best cure for anxiety

[@dogeclark2265]

Hell yes Mothlight time

[@iiii4024]

I just got a cornsnake yesterday & this popped up in my recommended lol perfect timing I haven’t even watched this channel before

[@kuitaranheatmorus9932]

I love the evolution of many animals but this is amazing

[@lassebirkhenriksen]

I have some suggestions for future evolution videos: Evolution of: Chickens Sheeps Rabbits Moles Sharks Ducks Lungfish (Mudskippers) Mushrooms Sponges

[@UniDocs_Mahapushpa_Cyavana]

Mudskippers are unrelated to lungfish being ray-finned fish. If you are talking about walking fish in general there are many to choose from and they are all pretty cool.

[@vikorovstock2432]

Aren't Sponges some of the oldest animals around? A video describing the ways they changed throughout the millions of year would be interesting.

[@lassebirkhenriksen]

@@vikorovstock2432 exactly

[@UniDocs_Mahapushpa_Cyavana]

@@vikorovstock2432 Their larvae would probably be the main focus. It probably shows how they relate to other animals through neoteny and transitional forms. Good too, you don't hear much about any larval form, and basically nothing about sponge larvae.

[@michaelanderson7715]

Just don't spew out the "chickens are the closest living T. rex relative", it's NONSENSE.

[@joeshmoe8345]

Great video, thanks for sharing boss!

[@victoralcantar960]

Oh, man. Your videos are usually on point and also like listening to your voice, but I’d love a 15~20 min video on. any of the subjects you choose, particularly one for the evolution of whales, you left me wanting more.

[@truesheltopusik1140]

Just intresting fact i guess, but snakes are not the only land reptiles that lost their legs, lizards have lost their legs on separate occasions as well, to make things like glass lizards and slow worms.

[@Devo491]

'Loose' means 'not tight'. I think 'lose', meaning misplace, or be deprived of, is the word you're looking for.

[@philbydoodle6199]

Evolution is fascinating

[@gregoryt8792]

If Darwin was alive today he would not have even proposed such a ridiculous theory.

[@jamesbentonticer4706]

So do we know if they evolved for aquatic life then came back on land or lost their limbs on land then became aquatic?

[@zebedeemadness2672]

At present it's either, or, we don't have enough info to say either way, but the fact we have legless lizard, that didn't come from Aquatic living ancestry, they came from land burrowing lizards, it's just as likely snake evolved the same way, we haven't got that needed ancestor yet, to tell us for sure, both ways of evolution are plausible.

[@jamesbentonticer4706]

@@zebedeemadness2672 excellent. Thank you for clearing that up for me. I like your explanation.

[@optillian4182]

There are people today who believe snakes' legs were taken away by a magic man in the sky. It's sad.

[@Thewildlifeenthusiast123]

How can najash and any prehistoric snakes with legs coexist with humans :/

[@pablito8568]

Actually its vary stupid

[@pablito8568]

And sad too

[@quinndenver4075]

Unparalleled content 👍

[@lassebirkhenriksen]

thank for doing this video. it was me who requested it

[@tristancoetzee6059]

then thanks for requesting it :D

[@reeven1721]

The snake's evolutionary strategy: "Look guys lol no hands!"

[@gavinwiebe6613]

snakes evolved from lizards? snakes **are** lizards B)

[@ibtiago18]

I remember watching this same subject in Paleoworld in 2000. But in that show, snakes aquatic origins where treated as a known fact while other documentaries at the time treated a possible subterreaneous origing the same way. It's incredible how a 9 min video can treat the subject better than 20 to 50 min documentaries.

[@alixsprallix]

Yay new video

[@shubhanshujain9827]

i never imagined a snake video to be so soothing and relaxing to watch, lol.

[@Scaling_Obsession]

I like snakes. 🐍

[@amyjudy33]

Thank you for all your videos. Your channel is one of my very favorites on youtube. ♡

[@maozilla9149]

great video

[@Major00Tom]

Let me get this straight.. So you like biology books AND detective books too? Fascinating...

[@AifDaimon]

My favorite animals of all time!!!!

[@harleyjudy2850]

praise be the rutern of of moth light

[@brucelee5576]

They could have lost them partly to defensive reasons as well , without limbs you can sneak in to small spaces like holes made by other animals.

[@mirrorblue100]

Superb and beautiful program - thanks.

[@jorgerangel2390]

Quality content, as always

[@mtathos_]

finally getting the recognition that you always deserved, hail the algorithm. Cheers!

[@therealzilch]

Another typically informative and charming lesson, thanks. The importance of gene duplication for evolution, at all levels, including the whole genome, cannot be overstated: it's fundamental. Other examples (as I'm sure you know) are our color vision and blood types. Creationists often argue that the information in a genome cannot increase through evolution, but that's because they don't recognize duplication and subsequent evolution of new alleles. cheers from sunny Vienna, Scott

[@dougthedonkey1805]

I love snakes, they’re such cute little critters

[@elgringo1893]

Legless-ness has occured multiple times, independently in lizards which indicates that there must be something about lizards that causes them to benefit from a legless body plan. We even have the slow worm in the UK which is a legless lizard and not a true snake. It does seem to only happen with carnivorous lizards though so maybe the ability to squeeze into smaller gaps in order to find hiding insects just pushes lizards to this evolutionary pathway? Could it be something to do with them being basking animals trying to compete for niches with other larger basking animals? It's really interesting that we don't see this evolutionary trope in mammals or other groups of land animals, just lizards, possibly something to do with lizards having their hips pointing their limbs out sideways instead of beneath them. Would love to here an expert opinion on this.

[@OST1350]

Finally! I waited 4 years for this video.

[@BruceWaynesaysLandBack]

I think the word “primitive” needs to be phased out in discussions like this. Gila Monsters have their own approach to poisoning prey- it’s not more/less ‘primitive’ than venomous snake fangs. Jellyfish are very similar to the first multicellular life to ever exist- is everything else “primitive” for not copying their success?🙄

[@fleetskipper1810]

Agreed. The word “primitive” is loaded with connotation that doesn’t really fit into a discussion of Evolutionary paths. Some succeed, some don’t.

[@luutas]

Snakes can go in holes that are exactly their diameter. No animal with legs can do that. It's an extreme advantage. You can catch more prey and also hide better when in danger. Both those things are enough to select a new species

[@mechwarrior13]

Thanks for continuing the story of life on this channel, i prefer quality over quantity any day!

[@JuicyJam]

DRINKING GAME!!! Take a sip of your drink when there is: - a time lineage - a genetic tree - a new illustration - a size comparison Take a shot when: - the narrator says "however"

[@ricolibrando8716]

Evolution of chickens plsss ☺️

[@jasonjohnson1404]

Just to add a clarifying comment. Moth Light mentions a "genetic bottleneck". This is not the same thing as an evolutionary bottleneck, though both affect the genetic makeup of populations. An evolutionary bottleneck involves a chance event skewing the genetics of a group (like a hurricane or other cataclysmic event). A genetic bottleneck is one where the path of natural selection eliminates traits that would otherwise be useful and then later on the group radiates out, but has lost traits (like limbs).

[@omarb7164]

Thanks for pointing that out. So it’s a bottleneck in the sense that the trait of having limbs is officially lost, and unlikely to ever appear in species evolved following the bottleneck?

[@demos113]

Very interesting. 🙂

[@rsp7029]

The idea of the first lizard saying "screw it. I don't need legs" and flopping down to roll around on his belly is infinitely hilarious to me.

[@hughbrandreth5637]

I have read that terrestrial snakes smell by wafting their tongues in the air and then resting them against their nostrils inside their mouths. Aquatic animals like cetaceans close their nostrils when submerged, so they cannot smell their surroundings. Could the snakes' use of their tongues to smell be an adaptation to overcome this problem, suggesting that they have an aquatic ancestor?

[@UniDocs_Mahapushpa_Cyavana]

It is their Jacobson's organ. It is different from the nostrils, and detects different smells. By the way, it basically means most tetrapods, including domestic ones, are bisexual if they want to be, as it is how they tend to differentiate gender. They can just close their moth to avoid being repulsed.

[@thelaughinghyenas8465]

Thank you for another great and informative video. Nicely done, nicely narrated.

[@SMHman666]

The L H Yes, he has a relaxing voice and is easy to listen to. Some KZbinrs talk way too fast and it's a battle to absorb the information but this channel goes at a steady pace.

[@striderwhiston9897]

Snakes are still technically legless lizards

[@MartinMMeiss-mj6li]

Very interesting, but I'm not sure why one would say that leglessness evolve to favor burrowing. After all, snakes can't dig. Moles and rodents can burrow only BECAUSE they have legs. It seems to me that leglessness lends itself more to slipping into narrow crevices in rock and for slipping around in dense grass and under a layer of fallen leaves.

[@anon9579]

Evolution of crabs next please

[@rickkwitkoski1976]

The crab form has arisen several times. There are "true" crabs and then some other groups with a similar body plan. Convergent Evolution. This is similar to how tuna, sharks, dolphins, ichthyosaurs are converged on a similar body shape for similar reasons. But your suggestion would be an interesting exploration

[@WanderTheNomad]

*pointing at a monitor lizard* "why does that snake have legs?"

[@heilmadon]

Id like to think part of the reason they became legless was to allow their ability to swallow things much bigger than their mouths.

[@NotSoSerious69420]

That doesn’t have much to do with the other though does it? Aren’t there other lizard/reptiles with non connected jaws (and thus possibly able to eat things bigger than their heads)? Also if that was the evolutionary pressure for them to lose their legs then they would’ve had to have already been able to do it to some degree before they lost them anyway. Seems being able to burrow is the most common trait between all legless reptiles/lizards.

[@heilmadon]

@@NotSoSerious69420 Hear me out while yes the unhinging of the jaw Allowes for swallowing of larger prey there is another part of the body that creates a choke point. The ribcage and collarbone having to use their limbs would need these structures to support them and still lImit the size of their food intake. I am not saying it was the main drive but I feel there could have been a selective pressure with allowing them to consume larger prey that also played the part in developing limblessness. The front limbs did go first after all.

[@jessehunter362]

@@heilmadon The most basal snakes, fully limbless and still alive today, don’t have the jaw changes that allow them to eat large prey.

[@deano1873]

Plenty of skinks are close to legless, and in certain environments tend to get long and skinny like snakes... such as hunting in long grass. I'd say that in a variety of environments losing legs just makes sense, not just o e specific environment. That's why snakes are a pretty common species.

[@hehehehaheheheha9422]

🐍

[@connorpratt4874]

Maturing is realizing moth light media is far superior to pbs eons

[@tylerball665]

If the narrator was a snake I’d let him constrict me to death as long he kept on narrating. So relaxing.

[@Aurora666_yt]

Ikr 🤣

[@petersmythe6462]

Re: why lose the legs? Maybe the legs weren't a decisive factor in hunting prey or evading predators? If the prey can reliably outrun a lizard at both sprint and long distance running, and full stealth ambushes or going for cornered prey in a burrow are a necessity. If chasing is pointless, it matters little how bad you are at it. Instead what matters is stealth, striking range, and not letting the prey go before you deal lethal damage, since, if it escapes, you're not catching it again. Regardless of whether you have legs. And look at snakes? They have evolved to be stealthy, maximize reach, and grapple and constrict and/or envenomate prey. Two strategies that minimize the risk of prey escaping successfully. Having limbs would not help either of these.

[@sickenedwired1934]

We have salamanders today that are going through a very similar process.

[@TomHinsley]

Big up DG, hope you good