Ancient Genetics that Still Occur Today: Atavisms Explained
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- Опубликовано: 12 сен 2024
- Did you know that traits in animal species can re-appear in a new generation hundreds of years later? These ancient reappearing genetics are called Atavisms, and they can help us understand amazing things about biology and evolution, like how limbs actually grow! Join us for a fascinating new episode of SciShow, hosted by Hank Green.
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Sources:
Dollo’s Law/Atavisms
pubmed.ncbi.nl...
doi.org/10.101...
doi.org/10.100...
Cetacean Hind Limbs
doi.org/10.100...
doi.org/10.107...
doi.org/10.104...
Limpet Shell Twists
pubmed.ncbi.nl...
doi.org/10.109...
Soil Mite Sex
doi.org/10.107...
doi.org/10.100...
doi.org/10.101...
Big Bone Worm Males
doi.org/10.101...
doi.org/10.101...
doi.org/10.103...
doi.org/10.118...
Images:
commons.wikime...
link.springer....
link.springer....
commons.wikime...
www.inaturalis...
www.inaturalis...
www.inaturalis...
www.inaturalis...
www.flickr.com...
www.flickr.com...
eol.org/media/...
www.flickr.com...
www.flickr.com...
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I love how you're enthusiasm for everything science is so catchy.
Doesn't matter if it's biology, chemistry, physics or space - you manage to make any topic the most interesting thing of my day
Franziska Baiker Hank and Olivia Are amazing
He even has a song about it
ruclips.net/video/RECuQaaGGfA/видео.html (explicit version)
ruclips.net/video/NLY-j85gFTU/видео.html (clean version)
The dolphin with hind flippers is weirdly adorable.
I agree.
I thought so too. It was really cute 😆
Not to mention SO COOL!!
my brain just went iCTHYOSAUR??????
aw 2:24
Muscle Hank is an atavism of regular Hank.
Every once in a while he expresses himself, with many people scratching their heads wondering how and why.
I think it's an evolutionary adaptation that occurs when there's a niche opening to harvest the energy of making clichkbaity thumbs! XD
Nobody will ever know. You don't ask Muscle Hank for questions. Never.
@@DamascoGamer You don't tug on Superman's cape...
The Incredible Hank
Hustle Hank on the other hand ditched regular evolution altogether and went for expressive cultural evolution
7:40 "It is extremely unusual for a species to regain the ability to have sex after being asexual for so long." that hit hard
I felt so attacked.
Haha i came to the comments looking for the fellow asexuals that have been personally attacked
Well, good thing you are individuals and not species, so this does not apply to you.
oMg i mAdE iT 69 LikEs ahhhhh also ya that can hit hard but im straight not asexual so i cant relate ig like loving after not loving
Who made it 70???
Hank: 8:29 “Bone or zombie worms.”
My brain and ears: “BONER-zombie worms!”
Literally same lol, I was checking to see if anyone else noticed 😂
@@kalechapo Same here haha
Yes. Boner zombies!
Yep, heard that too... :P
Wait. He didn't actually say that?? Oh...
Hmmm hind leg genes... What to name it... HAND2!
Foot?
Nah. *HAND 2*
Makes sense if you are a non-human primate
Well, it _is_ also responsible for forelegs/arms, but yeah, that's funny.
I figured Hand1 was for the front limbs/hands. Probably wrong tho.
I can't believe they actually named those HAND2.
Like, who are the scientists that did it? I'd like to have a chat with them.
For scientific purposes, of course.
Love how a species named Osedax priapus (Priapus was a Greek/Roman god of fertility, and particularly, male genitals and was depicted with giant phallus on the regular) is a kind of bone worm.
I'm pretty sure the species was named after the god. 😊
I’m pretty when he said “a species named Osedax priapus” he meant that he loved that it was named that and was referring to how it was named in relation to the god and not the time, he’s not saying the species named the god just that the name of the species is Osedax priapus. Just for anyone confused
@@thederp9309 bro you confused me
Struck me immediately how entirely (in?)appropriate, clever, and hilarious this specific name truly is!
And Osedax comes from Latin, ōs ("bone") + edāx (devourer). So the name literally means Bone Devourer Wiener God.
Fish: *climbs out of water and starts to live on land*
Whales: uno reverse
not only whales, but plenty of reptiles from the Jurassic and Cretaceous. Probably triassic too.
@@rogeriopenna9014 Ah yes forgot about ichthyosaurs
@@rainbow_vader And turtles/tortoises/terrapins... this reversal probably happened a few times in the Order Testudines.
Lmao
Smooth Brain: Return to Monke
Wrinkle Brain: Return to Fishe
Well the pre-human primates had traits that made them relatively pretty stupid, I've met a couple people, myself included, who brought that trait back stronger than ever
Good one!
🤣🤣🤣
I think corvids are more intelligent than any ape.
That example of the snails that keep their coiled shells into adulthood reminds of of axolotl salamanders which never progress to an adult stage, so they have gills all their life.
yeah I love axolotls !! I think that's called neonatalism or something
@@chloesibilla8199 neotony
they evolve from trade probably
@@jeffs1571 thank you!!
@@weedmantrudeau5783 what does this mean?
This is fascinating, and I think it’s safe to say I would never have looked this up myself, even if I knew what I was looking for. Thanks SciShow for making me love our weird and wonderful world even more!
The whales and dolphins are growing legs again to come back onto land to tell us to freaking stop.
They should hurry up about it.
Hopefully they will start with telling us to stop projecting motivation onto evolutionary processes ;)
Humankind: You're coming onto land?
Legged Whales: We can't kick your asses without legs.
Not gonna lie. I’m not surprised.
The way things are going, im expecting them to say "So long, and thanks for all the fish."
"left around wasting genetic space" makes me think of "left around wasting hard drive space" which leaves me wondering, when we learn to code like RNA can code, will we discover that "a little bit of space" is NBD in terms of DNA's ability to hold code? I still remember when a gigabyte was theoretical and a postage stamp was only a postage stamp, not your family's entire video and slide catalog from the 20th century.
Probably, although DNA is Quaternary rather than Binary like computers, so that helps significantly already. 10 2 bits is equal to 5 4 bits in total storable values
I had the thought, while he was talking, 1st: The genes didn't "decide" anything, and 2nd: Our genes already contain a bunch of "junk DNA," so what genetic cost would there be for just a little more?
Well it's not like they can just drag the useless DNA into the 🗑 to clear up space
@@ixchelssong Approximately 8% of the average human's DNA is the remnants of ancient retroviral infection of human reproductive cells.
So clearly, not a whole lot.
@@ixchelssong Vast majority of the genes is junk. Which is why the One Percent DNA difference between Humans and Chimps and Bonobo is an exaggeration the difference is way greater if you don't count the Junk that is identical.
Hippo: *Will murder u on sight*
Whale: "I am a gentle beast of the sea human, I will protect u from shark, even though you ate my ancestors"
When did humans eat whale ancestors?? Didn't they already evolve to spend their whole lives in the ocean millions of years ago?
Scishow: “Gentle Giants of the Sea”
Orca: “Hey! I’m swimming here!”
Orcas are the New Yorkers of the sea... New Yorcas, if you will.
Orcas are more closely related to dolphins than whales, though, even though their name suggests otherwise.
Swat Me Dolphins are a subset of whales, so the name isn't wrong.
@@woodfur00 Not really, the group as a whole is called Cetacea, whales and porpoises are mutually exclusive subsets of the set Cetacea.
Orcas aren't whales.
This kind of thing got me so interested in genetics as a child! And of course Dolly the sheep and Ear-backed Mice....
Wow, I'm old! LoL
If you're like me, you realize that it's a roll of the dice, and we dont have the control we think we do.
madtabby66 I prefer denial 😉
Just remember that animals don't exactly choose the way they evolve, though much of the language of evolution gives that implication
Language always gives misleading implications. That cannot be helped, it's an imperfect system.
Unless you're a peacock.
But yeah, I agree with you. The language of genetics drives me nuts sometimes. Genes don't "want" anything. The are not sentient demi-gods.
The GenetiGods do not like your dismissal!!!! 😂😂😂😂😂
@@colleenforrest7936Are you referring to sexual selection of male tail feathers? Sexual selection is the one part of natural selection the animals have some control over, but there are other factors that narrow down the individuals within the population who can reproduce. Besides, they're just choosing what they're attracted to, without having an understanding of evolution and a vision for the future evolution of their species. Also you could argue that such a large part of what an animal finds attractive is determined by their own genetics that they aren't really choosing anyway.
If you could choose how your descendents evolve, how would they evolve?
I brought this up 6 years ago in my biology class once. And everyone looked at me like "what you talkin bout?"
That's awesome
@@AxxLAfriku pls stop
your classmates had atavistically small brains? :P
@@TragoudistrosMPH Erm. Not too sure. They have their own strenghts I guess.
In school, the main point was to pass the class and get good grades on exams, so we were taught what was in our text books. The bare minimum.
Not everyone was interested in learning new things, or reading for the matter. I just happened to be one of the weird ones who did.
@@notareallin620 That's the exact problem with the current education system. Students are taught what they were told to, nothing else. There's also heavy emphasis on math, science, language subjects, but a lack of attention towards other more creative or art driven subjects. The combination of these aspects creates students that hate extra learning, seeing it as unnecessary and pointless.
I've read that the "leg-genus" is also still present in snakes and can cause some to be born with teeny tiny stumbs ... nature is frickin' awesome !
Just imagine snakes with long legs ... cool and terrifying at the same time ! 🐍🐉
I mean, monitor lizards exist, and they're not particularly snake-like, but reptilian and pretty fascinating/terrifying, so I can kinda picture it.
So house centipedes just gigantic and scalier?
@@josephburchanowski4636 I mean, there were giant centipedes in prehistoric times, so maybe it would still be possible for insects and other small animals to become that big again ... maybe if the oxygen supply in the air gets higher again ! 🤷🏻♀️🤔
But god condemned the snake to be on its belly, so reverse god move? Yikes!
@@amazinggrace5692 "God" did no such thing, 'cuz god doesn't exist. Snakes evolved to have no legs to fit into an ecological niche, not 'cuz some imaginary friend 'cursed' them. There's a clear progression from lizard to snake where limbs get progressively smaller. Legless lizards or skinks: one has no legs, the other has a long, snake like body with tiny legs. Mexican Mole lizard: long, snaky body, tiny front limbs, no back legs at all. These animals aren't directly in the snake lineage, but they are examples of species that are evolving into snake-like forms. Your imaginary friend had no part in this.
Bone worm male: "I'm a strong independent man who needs no woman!"
No, science
BWGTOW
More along the lines of "I need more than one woman in my life."
Worman*
@@DRida64 it got tired of being inside a woman with 606 others
Males living as harems inside the female of their species, the bone worm sure has an appropriate name.
Leftuitiveness
@commandZee: Reminds me of male deep-sea anglerfish.
I didn't understand what this comment meant until they explained harems inside the female
@Marisa Nya *_Excuse me?_*
The weirder part is that they live inside their mothers. Inseminate their mothers, and maybe, maybe they'll get eaten by their sisters and inseminate them. Bone Worms are literally worse than Alabama.
4:22 "...to become the gentle giants of the sea..."
Orcas: Ha!
Orcas are actually a kind of dolphin, mistaken for a whale if my memory serves correclty
@@emmawhite6263 yes, and they're mistaken because of the name killer whale, but the reason they have that names is because they will eat baby whales
Ignoring orcas:
*[crying in krill]*
Also, other kinds of dolphin, which have proven hunting for sport isn't a human-exclusive activity.
> a fluke appearance of a long-lost trait.
I see what you did there.
hmm?
Same! Glad I'm not the only one.
@@redcoat4348: Whales have flukes.
There is always a pun at the start of the summary. This is one is a fair bit more subtle than most.
I want a sound clip of Hank saying "bone or" from 8:29 to use out of context.
I couldn’t have made this episode without making fun of those species names “fornicata” and “priapus”
Priapus, biggest male bone worm ever.
I don't think I could have gotten past 8:52 without making a "your mom" joke.
08:29
For a moment I had to ask my self "Wait, what kind of Zombie worms?!" 🤔
Absolutely heard "boner zombie" worms. LOL
I had to rewind on that also lol Haha. Probably listened to it 10 times wondering how they thought that sounded ok lol Haha. :D
"But it's extremely unusual for a species to regain the ability to have sex after being asexual for so long."
you and me both, bro.
11:50 "a fluke appearance" ... I see what you did there.
(Returning hindlimbs in an aquatic animal.)
Came to make that observation... I see you're the first of two already.
This is why some humans are born with a tail.
Atavism my ass!
@@copypaste3526 *(applause)*
wat
Chimps or monkeys? That is the question. Both lemur and chimps are strong and intelligent.
But I have not seen any cases of humans being born with ape like jaws and sculls. I guess the head is more importnat.
At 3:36 it's heterotopy, as in topos, not heterotropy.
"tropos" by the way means "trope/style/manner"
Also not to be confused with heterotrophy and homotropy.
This is one of the most fascinating vids I've seen in this channel (and that's saying something!)
4:42 Limpits... Do they swim with chocolate starfish?
Brb going to make a limpit biscut
Underrated comment
Finally I've been waiting for you to do a video on atavisms for years!!
Sometimes humans are born with a tail!
Sun Wu Kong that you?
Not a tail. There are no bones in it. Just an extra lump of flesh.
Spend any amount of time on internet, and you'll discover that sometimes humans are born without a brain.
@@jaroslavsvaha6065 Some humans are actually born with a brain. Is hard to believe but it happens to be some cases.
Pxn it a vestigial tail meaning it is absolutely useless and doesn't even look like a normal tail.
I learned about atavism in yu yu hakusho. Good ol' weeb years paid off.
I learned about it in psychology, specifically Lombroso's research.
I came to the comments looking for this reference. :)
Same.
What does a series about a spirit detective have to do with creatures evolving old traits again?
SPOILERS!
The main character dies at one point, but comes back alive due to some bizarre weirdness involving spirit energy. But instead of coming back as a human, he comes back as a demon, because one of his human ancestors from many generations back, had children with a demon. And he met some activation conditions by accident for those traits through lots of training. *_shifty eyes_* It might not be especially realistic, but the word "atavism" was specifically used in the explanation.
That was absolutely fascinating. I'm sure what was shown was just the tip of a very big research iceberg. Thanks SciShow team for doing all that work for us.
It's amazing that you're still here making great content, you deserve some kind of internet creator lifetime achievement award (if you don't have one or fifty already). I first found your work some time ago and there's nothing that's missed the mark. I can't remember where or how I originally found you, but I definitely remember listening to Dowdy Smack at some point. Is there anywhere I could find C'est Bon Ça to relive a bygone time?
8:30 Actual: "Taken to calling them bone or zombie worms"
Sounds like: "Taken to calling them boner zombie worms"
@ 2:06
that is an Anthracotherium, it's from a lineage paralel to hippo's and whale but not the ancester of whales,
that was a little animal called indohyus looked a bit like a chevrotain with a long tail
Have you done a video on aphids?
They reproduce through parthenogenesis and have a pretty odd life-cycle.
They also get farmed like cattle by ants for their secretions...
Fun etymology fact: the word “Parthenogenisis” comes from the Greek word for “virgin,” and is often associated with the goddess Athena. Athena was not only a virgin goddess, but was also concieved and “birthed” by Zeus alone (being formed from Zeus’ thoughts as a sort of receptecle for the vast wisdom he obtained after becoming ruler of the cosmos).
(Athena’s association with virginity is also why her greatest temple was named the “Parthenon).”
Now I'm trying to remember why I looked up atavistic, I know it was long enough ago it was i a printed dictionary.What ever the reason, it allowed me to understand atavism.
It also plays a part in defining fascism, which came back in a big way in recent years.
You might hear “atavism” used in art, culture, society, theology, technology, and biology. It can be regarded as positive, negative, or neutral depending on the context.
I personally found the term while I was indulging in that “noble savage” thirst, looking for primitive arts and cultures that weren’t so far removed from nature and might more purely express humanity and freedom. I was disappointed that many of the results involved societies indulging in our uglier tendencies of distrust, war, ignorance, tyranny, and hate.
Actually I remembered, to make along story short it was in a line from a play.
As a hoarder, I understand the soil mites. "I'm sure I'll use this Y chromosome eventually...."
I’d love to see a video on the opposite of this: Traits that emerged but then lost
Or traits that commonly emerge with no precedent that are never kept; the real messy noise of evolution. Like sixth digits and so on.
They have done vids on lost traits
Vitamin C production in humans, for example.
the genes for legs appeared somewhere in the lineage and almost got lost
for whales too
Idk if it’s the reverse per se but there is vestigiality. Where a trait no longer serves their purpose and is on their way to disappearance. To mention a few:
- Halteres in insects, which is nubs (protrusion) that used to be wings
- Wisdom teeth in humans, many recent generations have lost them completely
- Small non functional eyes in many cave animals
- Pelvic bone in snakes
And many more..
As for the one that have been lost completely, geomagnetic sense is something that humans no longer have .-.
GREAT EPISODE!!
I know this wasn't how it was intended to be said, but "BONER ZOMBIE WORMS" is both a cool band name and a terrifying ailment to think about
Thanks, Hank and crew, for another fascinating video!
"Scishow: “Gentle Giants of the Sea”
Yeah, tell that to a Liviathan Melvillei whale.
I am so happy there are scientists that care about snail shell characteristics
Wonderful show! First time watching, and enjoyed it. I was wondering if most of these ancestral genes are pseudogenes? I was also wondering about the role of viral infestation may cause in the activation of Atavisms. Like Zika virus attacks the fetus and effects the development. There may be viruses that may reactivate these genes creating evolutionary effect that lead to Atavisms. Any information on this in your studies?
HEY HEY!!! 3:24 Mysticeti did NOT just skip right along from Ambulocetus >:D Don't forget the INCREDIBLE evolutionary history of whales all between those two. Dorudon is one of my favorites.
Atavism of the Mazoku. I Can't believe Anime has taught me so much stuff.
So you knew what the word meant before? Or just knew the word and not actually what it really meant, therefore not being taught anything.
Marcus Lindgren got him
@@MuscarV2 actually, no, it was used in a way that the meaning could be learned through context clues.
Even if all it did was them curious enough to look up the word, that's still a good thing.
You think disparaging things that get people curious enough to learn makes you look more intelligent? (It doesn't)
Regular Old Plumbus S-SH-SHOTS _FIRED_
These bone worms remind me of a squid species that I think I also learned about on this channel which also has extreme sexual dimorphism. Similarly, the females are enormous while the males are incredibly tiny. It makes it all the more amazing to me then how similar the sexes are in humans, knowing that such extremes can exist in other animals.
Maybe you
"BOOOner... Zombie worms"... definitely listened to that like 15 times wondering how they didn't catch the way that sounded during edit lol. I am soooooo glad they missed it haha I needed a good laugh lol. :D
Bold of you to assume that they didn't catch it.
I've noticed that nestlings of a few birds have a digit and claw still protuding from their wing pinions, but the only one that retains it into adulthood and can use it with two more for climbing is the Hoatzin of S.America. in the vast majority of birds, the digits that were there in Archaeopteryx have become fused into the skeleton of the wing. Have there in recent times ever been young birds with teeth like Archaeopteryx? Large pythons routinely have vestigial hind legs, usually limited to a few digits with claws..
@Mark Aspen Modern birds are not born quadrupedal, but their ancient ancestors were. This is why some modern birds have claws on their wings.
"Heh heh heh heh heh heh. Bone worm."
-Beavis
Those bone worms blew my mind and I have an exam in 7 hours and I have to sleep
good luck!
ruclips.net/video/CZzQhiNQXxU/видео.html
ruclips.net/video/Jrp-flp_CMg/видео.html
"ancestral coil" is a kickass metal band name
It's interesting that male/female dimorphism exists in species across most phyla, even across kingdoms- but the mechanism by which the differential arises is wildly different. X and Y chromosomes in humans and other mammals, ZW in birds, UV in algae, temperature of the nest in alligators and turtles, plants that can change sex... but all these different encoding methods all have very similar results. Only a relatively few species have sexes that are not simply male/female, and most of those are cryptic male/female "impersonators" such as Hyenas. Only a few really odd ones do odd things like Tetrahymena, with 7 sexes and 21 combinations. Perhaps it's just that the simplest binary split achieves most of the benefits with the least complexity that could malfunction.
I have wondered about that ... the same solution in so many variations.
What's hard to imagine? Even bugs get bored after 20milion years.
One of the coolest topics I’ve seen in a while. I’m fascinated and need to go read up on it more.
It may also be important to recognize atavisms that may exist epigenetically through the expression of temperature sensitive enzymes and proteins that stop producing some hand2 similar genes in an adult: warmer temperatures globally may cause a shift in the species, because the reduction of global temperature sensitive genes is being reduced with warmer winters. In other words, the expression of legs, may be a result of global species wide gene changes that indicate a beneficial global change that would allow for the re-introduction of fully grown legs.
The archeological record shows warmer temperatures, and the gene records of the entire species may also show the same traits with the expression of wings or legs in larger herbivores when the availability of food goes way up because of global tropical weather ranges. I can't speak about this from research, but I'd think that nature would work with an entire species this way as easily as an individual.
Changes always seem to have multiple causes, I think we spend way too much energy wondering 'which thing' caused something to happen when the answer is almost always 'all the things happening together'
Alice spitting straight facts here.
Huh, I always assumed limpets were a very basal snail that hadn't yet developed coils rather than a specialized derived snail.
Is that how some humans are born with tails?
Katie B Yes. But they're not much use.
Katie B
Yeah, it must be.
Pretty much.
OMG!! This part in biology i love the most....specially their by born survival expertise
Not cause you won but because you survived. N why some have the same evolvements upon different genetic pathways.
I what hoping you would make a video about Atavisms for a long time. Finally!
I'm totally for a second one !
I really dislike when playing around evolution seems to imply cognitive choice, rather than proliferation of a beneficial trait.
So true.
A trait shows up. If it's useful, the animal thrives and reproduces. If it's not useful, you either dont make it to breeding age, or you're rejected as a mate.
But we are arrogant bald monkeys who think we control a heck of a lot more than we actually do.
@@madtabby66 it's really more like biochemistry really. Thinks of them not as organisms but chemical machines and you'll see evolution is really just a chemical game
@@meghanachauhan9380 meh, I'm a dog breeder. We study blood lines, research back a minimum of 5 generations. Look at previous litters produced (if any) and still end up with a "where the hell did that come from" pup. Or we get a pair we think would be perfect, and they have no interest in each other.
We're playing with 76 sided dice and hoping to win.
@@madtabby66 Not only are we arrogant bald *apes, but we also have an innate need and desire to categorize into helpful and unhelpful.
@@meghanachauhan9380 I lost the game.
I actually have a coiled limpet shell! When I was little I played with it and called it the volcano shell.
I love atavisms! They are so cool! Professor Jack Horner is working on using atavisms in Chickens to make a dinosaur! Keep up the good work, SciShow!!
Wow! That's facinating, as all your content is!
As apes, we once had tails but lost them. I want mine back and I want it prehensile. This is non-negotiable. I just need new pants.
"life uh, uh, finds a way'
8:29 is what I wake up with
Fascinating! Thanks for uploading!
8:30 dude, pause for slightly longer after the word "bone" and before the word "or" to avoid sounding like you're saying the word "boner". lol
lol "boner, zombie worms with sexual dimorphism" sounds like a freaky parasite.
A boner zombie worm. It's a .. i don't know exactly. Mental images does not compute.
Fascinating. I think Darwin would be impressed with how much progress has been made in the field of genetics, but humbled by how much is yet to be learned.
Mostly he'd just be horrified by how our leaders are letting the natural world and all its lifeforms be destroyed in pursuit of eternal quarterly profits. Darwin understood the value of life
@@Backinblackbunny009 👍
I feel like if you compare the genetic code to computing systems, most of the more frequently seen atavisms are more like recovering an instruction to paste a certain process at a different place rather than recovering an entire database that was lost (e.g. having multiple nipples (where your body knows how a “nipple” is constructed) or an extended spine/tail (where your body already knows how to make vertebrae) etc.)
Hank, You are my Fav science communicator.
Hank: Gentle giants of the sea
Sperm Whales:
This was one of the best written episodes of Sccie show I've ever seen.
8:04 I've never bought the idea that storing genes is wasteful... because genetic mutation is random, and waste requires a detriment on a case by case basis, rather than in principle... at least that's my hypothesis.
Having options might or might not hurt.
Genetic mutation is random, but natural selection is not. That's the variable you've looked over.
@@cortster12 natural selection is a variable with 3 outcomes 'Positive, Negative, or Neutral'
That's why I say might or might not hurt.
What proof is there that having additional genes hurts an organism? Are there any examples?
Remember that some organisms have obscene numbers of genes (randomly looked up) Paris Japonica has a genome 50x larger than the human genome. Is the plant suffering for it?
@Bazagi Derp I agree that it's potentially true, and such a cost should be measurable.
A benefit is more genes means more chances for mutation/diversity. If all you genes are essential, you can't afford mutation.
Some organisms have 10,20,50 or 1/4 of the genes that we do. Is there evidence that extra genes are a bad thing? :)
7:03
You're telling me there are 1,000 species of soil mites? Damn
I'm a lil tired and read that as 1000 soul mates. Lol
To me seeing atavisms makes just as much sense as seeing future traits yet-to-be-selected-for. The future-beneficial gene(s) don't exist in any meaningful density before selection and yet we see extra digits that aren't selected for (as an example). To me it then seems actuallly more likely to get a throwback; we've never had a functional sixth digit but whales have had functional hind limbs; their genes have definitely had that capability; a vestigial form of a functional element should be more common than a vestigial non-functional element. Throwbacks then should be less alarming unless there is a strong selection against them... Or am i missing something?
There are humans with functioning fully sixth digit it not too hard they work the same way the other digits work. This fully functioning sixth digit is he rare for of it the most common has no bone in it and thus removed as soon as possible.
And some cats have a working although way too short thumb in effect on both front and rear paws separate from the other digits on the side lower in. Seen them on and used by the Hemingway cats at Key West. In my case to pick up and run off with a piece of paper on the other three legs grasping the paper with one paw. Guides told us they can turn nobs and other hand like tricks with them making securing things much more difficult than with normal cats. I imagine given time the thumb digit will get longer and bigger and they probably lose one of the others as the primate five work good.
One of my fav vids about evolution Imo nice work.
I'm thinking the conditions in trees change more quickly than conditions underground, and sexual reproduction can lead to more rapid evolution. Beneficial genes can be shared, genetic drift, rather than surviving individuals being of only one ancestral line.
This was so cool! Love learning cool things like this :)
I knew about this because of my Embryology class. 😎
This was super fascinating thank you!
I remember when I first learned that whales have very small leg bones sticking out of their pelvis, my mind was just blown
Dang you guys are always on point. Really interesting stuff!
10:00 "eating egg and pumping out sperm" - life goals.
Hank's "surprise!"/gotcha voice tickles me lol
One of the limpets looked more like a "slipper shell". Is a slipper snail a limpet?
I've heard them called "slipper limpet" and not "slipper shell", so maybe! Who can say with common names though lol
Another fascinating video. Thank you!
"Life finds a way"
Jeffery beaty 😂😂😂
Whales find a way to grow legs again to kick our asses for polluting the oceans
Wait... So if Ativism causes snails to recoil due to the activity of a coiling gene prior to adulthood, would that also mean there's a likelihood of Ativism being the cause of medical conditions like Dwarfism? I.e. the skeletal dysplasia specifically?
I’d really like to see a creationist explain a whale with legs
"miracles" they "happen"
Or an evolutionist
They are there to test your faith.
I used to be a non evolutionary creationist. they would often say that because they sometimes help the whale when reproducing (not sure if thats true) they aren't technically "vestigial" bc they have a use. 🤷
God creates through evolution. There you go.
I had a bristlenose plecostomus randomly be born with legs instead of pectoral fins. She even walked instead of swimming along the glass. Unfortunately she died in a tank accident. I would have loved to see where that was going.
Do you have any way that I could see it? That sounds super cool!
I'm really curious how the heck someone can figure out what a whale embryo looks like. Underwater ultrasound? Dissection of whales that happen to be found both pregnant and dead? Also, if whales are huge, are their embryos big too? I can't help but imagine a shrimp shaped whale embryo the size of a frisbee.
Most likely a combination of captive whales receiving ultrasound and finding wild and captive miscarried embryos/fetuses.
I’d imagine captive dolphin populations get way better medical care than most working class American humans. They probably give pregnant dolphins regular ultrasounds with those portable ultrasound machines that made female infanticide so popular in China and especially India.
They simply culture animal sperm and eggs and grow them in the lab, the embryos aren't viable after a certain amount of time, but long enough for study
Sounds terrifying when you think about it
Probably lots of them were collected when whaling was more common.