Evolution's Hidden Wildcard: The Single-Cell Bottleneck
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- Опубликовано: 9 июн 2024
- #Evolution, #Darwin, #Mystery
The paper this video is based on can be found here: www.pnas.org/doi/10.1073/pnas...
Credits:
Tyler Proctor | Sound Design
www.tinkleinthesync.com/
Anthony Danza | Music
proofavenue.com/
Ashleigh Griffin | Science Advisor
www.biology.ox.ac.uk/people/p...
Jack Howe | Science Advisor
www.researchgate.net/profile/...
Jon Perry | Writing | Illustration | Animation | Voice Over
www.statedclearly.com/about/j...
The zygote is a single cell with half its DNA from the mother, and half from the father. Why is it that we gamble everything on a single cell each time we reproduce?
Here we dive deep into this question, learning why the single-cell bottleneck is so important in the evolution of multicellular animals, the function of genetic clonality, and we examine what is still a mysterious case of a population of animals that reproduce through fission instead of use using a single-cell bottleneck.
Note:
Many people are taking interest in the concept of sperm competition and what it does to insure the health of potential offspring. This new paper in Science does a great job diving into this complicated process: www.science.org/doi/full/10.1...
The title is great:
"Widespread haploid-biased gene expression enables sperm-level natural selection"
Here's another killer line from the publication:
"Genes expressed in spermatogenesis are known to experience heightened selective forces on average, but a subset of GIMs experience further increases, as evidenced by statistically significant enrichment for signatures of selective sweeps, loss-of-function intolerance, and transmission ratio distortion in humans, mice, and bulls."
As some viewers have noted, in some cases, sperm competition might select for traits good in sperm but bad in animal building. This potential problem is addressed in the paper:
"For GIMs with functions both in sperm and in somatic tissues, this could cause an evolutionary conflict for genes because optimal function in highly specialized sperm cells may be detrimental in somatic cells. We identified evolutionary pressure to avoid this conflict, because GIMs are significantly enriched for testis-specific gene expression, paralogs, and isoforms."
I should note: The conclusions of any single paper are tentative, especially a new paper like this one. Passing peer review doesn't mean the contents are "capital-T True", it simply means the peer reviewers think the argument is worth considering and the data seems legit. This is how the slow but powerful scientific process works!
Lots of people are showing interest in the part of this video where I mention the implications of sperm competition. Because of this, In the video description I added a link to a 2021 paper on the topic. There, you'll also find a link to the main paper this video is based on. Enjoy!
Evolution is a lie,
Reincarnation is a lie,
Religions are lies,
Is there more to say?
We all been deceived on a major scale. Whence the truth been known, it can stop a heart. Truth can blow a mind, as the lies collapse. The reality is opposite to what we been told. Many live in delusions and proudly so.
Can a soul survive, on the path to truth?
Can the faith be found, when life take its turns?
Will the heart in the chest keep beating warm?
What a wonderful testimonies from souls, who got saved.
What a heartbreaking tragedy from those who stayed lost.
BIBLE, every time and everywhere, as it to be only book which:
heals, guides, judge, warns, helps.
❤I like 👍 this video 📹
How do the genes of the sperm create better/faster sperm? Shouldn't there be genes of the sperm that make for better/faster sperm but that aren't as beneficial for the organism as a whole?
PS. i didn't read the paper you mentioned
@@bumblebee454 If better/faster sperm allows you to out-produce your competition, then it would be passed on. Everything depends on offspring. I would say, better/faster equates to more fertile, more fertile, more offspring.
I also heard somewhere that one of the benefits of starting from a single cell is that the new lifeform isn't infected with any parasites from the parents (for the most part). For plants and animals that bud though, the parasites can easily infect the offspring.
Well,but this reason is not actually a reason for the single-cell bottleneck because lifeforms infected with parasites cannot reproduce.
Parasites can stay, as long as they are "beneficial" to the offspring, like herpes and anything else that infected a fertilised cell, and didn't kill it that is now part of us. (What was it, like 90% had herpes in dormant state.)
Remember, neutral is fine, only bad is bad.
Having a 7-th toe ain't gonna hinder you enough to get out of the gene pool.
Just as living 90 vs 85 vs 120, since 40 is enough to stop reproducing, and 60 enough to stop helping with grand-children, and most will die earlier, not from old age. So as a cell, why waste resources on old age when you'll live shorter life for the benefit of the organism as a consequence.
Same goes for human unity inside a country, the more united the less longevity of each individual inside it (because being different is not tolerated, even by "your own"). But longer life of the government, without external pressures on it by the environment shortening it. We all choose what fate will bring. (Sexual selection, in this case-politics, determining the size of the antlers, military budget only there for war with your lookalikes and higher chance of being selected by a mate that has that kink (with very low other utilities), but in other cases being a hindrance, minefields on farmable lands, antlers in trees, more testosterone making people more trigger happy)
Yes, thats right. Thank you for adding this point to the discussion! [Ashleigh Griffin - sci advisor on the film]
never thought of that. that's super cool, thx!
I like how clearly stated this video is.
Badumtss
Truly one of the stated videos of all time
couldn't have described it better
The best example is bananas. We took bananas and made them seedless. That means every banana tree is a clone of every other, taken from a cutting and grown into a new tree, every time. Bananas can't grow on their own anymore because of it. Good for us, terrible for the bananas; a fungus went after the Gros Michel strain of bananas and, since they're all identical plants, nearly wiped them out entirely. Now we grow the Cavendish strain (which I'm told is less flavorful), but it has the same potential vulnerability.
Sexual reproduction, even for plants, mixes things up, so such single point of failure vulnerabilities are eliminated. It has its own risks, but it's a huge benefit.
When the Cavendish was introduced people noticed that now banana milkshakes actually taste like the bananas they buy in the store. Turns out the molecule used as artificial banana flavor to just approximate the taste the original bananas had, is the same molecule the Cavendish produces naturally...
BTW, nitpick you might find interresting: bananas aren't trees. Trees have a single woody stem, schrubs have multiple woody stems, but bananas have no wood at all. They're really big herbs. Also, bananas are mobile; they move something like a meter during their lifetime. Can't recall why though.
@@nagranoth_ I thought about mentioning both those things but I went for brevity instead, so thanks for filling in the gaps I left.
Artificial banana flavor is great. Those little marshmallow banana candies and the flavor in children's antibiotics being based on Gros Michel is one of my favorite little facts. I also once sat on an elephant's neck while it ripped a small banana tree out of the ground, peeled it, and ate it whole. It really is just a stack of leaves. A bit terrifying, honestly, sitting there watching this monster rip something as big as me out of the ground. _With its nose._ With me sitting on its neck. Poor critters, being used like that for tourists' enjoyment. Wasn't my choice at all but I couldn't refuse at the time.
But yes, thank you for your addition.
On the Canary Islands I had small green bananas, they tasted great. More like fruit. I wished other types of bananas were on the market
@@nagranoth_ The trees move because their neighbors are bananas.
Cavendish taste like shit, bananas from tropical countries are the best
Many thanks to the Max-Planck Institute for Multidisciplinary Sciences in Göttingen and the VW foundation for funding such great content on RUclips and helping to make science accessible to the public through great content creators and educators like Jon. I'm proud to have studied and earned both my MSc and PhD in Göttingen; Stadt der Wissenschaft.
What did you study?
Well, the person growing from a single cell had an adult human whose fuel system kept the subdivisions fed. A cut off finger would have a hard time accruing the energy required to grow a replacement person.
As a previous commenter pointed, it will have to eat a lot of finger food.
@@StatedClearly 😂😂😂
This is a really good point. Planarian flatworms which divide by fission have to solve the problem of one feeding tube, two halves. The individual that forms from the tail-end has to shrink and re-cycle the resources into producing a new feeding tube before it can feed and start to grow again.. An ingenious solution that might not be available to a finger... [Ashleigh Griffin - sci advisor on the film]
Your animations (and clear narration!) make it so easy to absorb the concept at a high level. Love your work.
I'm surprised you didn't go into the genetic recombination aspect and the resulting diversity more. Mixing two genomes pretty much requires a singular cell to do so - the alternative would be to do it across all cells, which would end up with each having a different combination, further increasing the risks you mentioned... And it ensures that even if the entire population was _very_ closely related, you'd never end up with a colony of clones, keeping them overall more resilient to changed selection pressures.
I suppose I could have added that here (I did a few little tangents so it would not have been too out of place). We decided to skip it here, though, until a future vid specifically on sexual reproduction. The reason is that lots of animals (lots of insects and some reptiles) use a bottleneck without genome mixing when reproducing through parthenogenesis. We wanted a talk mostly about the universal functions of bottlenecks here.
@@StatedClearly That's fair. Though, didn't pretty much all those examples emerge from ancestors that were so adapted to sexual reproduction that they entirely lost other forms of cloning? I imagine it's "easier" to adapt an existing reproductive system to do that - with close to no impact on the behavior or physiology that could pose as a disadvantage. It's basically just a small tweak to the fertilization step.
While quite a lot of species can regrow limbs, those are often defensive adaptations. Storing the equivalent energy to an egg in limbs you discard as a distraction (like a lizard tail) or otherwise lose due various threats, just for the off-chance that it survives to grow into an new individual, feels like it would be quite a hurdle before it could become beneficial enough to stick around. Similar for other methods. I can't think of any other forms of asexual reproduction that wouldn't come with such a hurdle for complex organisms, or emerge from basically nothing (like the Gremlins "budding" from their backs in the movies).
If you liked this, check out the paper it was based on. Some of the authors here advised on this animation: www.pnas.org/doi/10.1073/pnas.2120457119
The video is so fluid that we don't even realize the incredible quality !!
It's so great that the internet gives us access to educational resources like this.
Outstanding production and learning value. Superbly narrated, John Perry. Well done!
As a scientist, I found this to be a nice simple explanation. I wish a number of my colleagues could communicate a concept so concisely. Thanks.
You aren’t a scientist. You are an online commenter.
@@jarrettesselman8144 Oh, how special; the opinion of a dimwit.
Beautifully done. Thank you Jon!
I am amazed at how complex, yet clearly stated, this educational video is!! Nature and science are awe-inspiring!
rebooting a computer fixes problems very much like the single cell bottleneck described here, by discarding all the information which may have acquired errors during operation, and recalculating everything from scratch
I like what you do. Hope your channel grows.
Absolutely amazing video on a very fascinating topic! Bravo 🎉🎉🎉
awesome video, helps explain such a complex topic in a digestible manner whilst also maintaining audience engagement
I'm always amazed by your ability to make these complex concepts understandable. You're awesome!
Excellent video, very informative. Thanks for posting!
I hope that Finger Kid is living his best life!
Finally.
Finger named kid
I really enjoyed this video. Thank you very much!
Great voice, easy to listen to video. I wish these were longer.
Great great work man well done
That was plain beautifully presented
Dr. Michael Levin's work on Flatworms and Bioelectricity comes to mind here.
I was thinking about his work instantly 😅
Mistake one is imagining evolution as a player in some game with some predetermined goal. There is only the individual trying to survive each day and for long enough to instinctually complete biological replication. It is only when looking backwards in time where we place human-like goals and biological motivations in and make this a game with players.
That's completely true, however, evolutionary biologists use intentional language "this behavior evolved to increase fitness.." as shorthand: the optimization process of natural selection makes everything look AS IF it is trying to maximize its fitness. Make sense? An example would be the concept of The Selfish Gene - genes act AS IF they are selfish but of course it's just a metaphor. [Ashleigh Griffin - sci advisor on the film]
Brilliant! Thank you.
Welcome back my mentor
Nice work. Does are way of thinking go through evolution?
Super interesting!
Thanks for the video :)
"If a measure becomes the goal, it ceases to be a good measure."
Meaning there might be a issue with the "first come, first served" goal for sperm cells.
I recently watched a Show Video, "Corn Shouldn't Be Food, But It Is" that gave me some interesting ideas.
Teosinte - the ancestor of modern corn - was originally domesticated for the sugary sap. The seeds were totally inedible as they were designed to survive a animals digestive tract.
But while domesticating it, I think we also _accidentally_ selected their seeds to become edible. That "survive digestive tracts" adaptation was not necessary when we plant it. So it got lost, making that part of the plant edible. And thus the main reason we plant it.
Selecting breeding partners on how well they do in life? Good idea.
Selecting sperm cells based on how quick they are? That might actually be a issue.
"Quick" isn't the deciding factor here, "functional" is. A malformed sperm cell can't swim as well as a properly formed one. Determining the *absolute* fastest out of the properly formed sperm cells isn't as important as weeding out the malformed ones.
@@silentcaay Who says those contain bad DNA?
They are cell housing for half-set of DNA, produced by your body.
It's your phenotypic self that is doing the arguing here. From an evolutionary point of view the fitness of the single cells going through the bottleneck is equally important
Tell that to a ruler
@@eljanrimsa5843is is true, but sperm cells aren't complete organisms compared to your somatic cells or a single-celled organism. They're incapable of reproducing on their own. And the same reason that conditions during development can affect an organisms physiology while still having perfectly fine genes shows how motility being the only criteria for a sperm with good genes is incomplete, as a sperm carrying bad genes can still form perfectly if its genes related to meiosis are completely fine. And not sure if this is true as I've only seen articles about it, but ovums can seemingly choose from the successful sperm and "attract" them using chemical signals if it finds that sperm favorable.
i also rip myself in half when i can't find a mate 😢
I can’t help but see tiny googly eyes on the flat worms XD
No missing link. A relatively smooth process from primordial ooze to me.
Design
Also growing an entire organism from a single cell is a complex recipe involving a precise sequence of action from developmental genes, and the zygote is not abandoned in the wild, there is a whole machinery to ensure its good conditions of development (whether in an egg or womb).
It would be hard for a animal to support the enormous additional genetic complexity to regrow a complete body from any split that can happen to the organism, without taking into account the needed energy and matter (plants are better at this as they can quickly produce roots to extract nutrients form the soil and have a "body structure" which is far more plastic).
And thks to Wolswagen for funding this kind of content, we absolutely need the input of a corporation which lies on its CO2 emission for almost a decade !
The entire atheist religion is state sponsored
@@jarrettesselman8144hahahahah atheist religion
@@nuno7249 it’s recognized religion, with 401C status, here in the states
Great stuff!
Glad you enjoyed it! Thanks!
I love this Chanel. I just rediscover it.
I think this could be very useful for software systems, especially AI. Simulating a single cell bottle neck to avoid weird bugs and/or bizarre behavior
It is already done.
Genetic algorithms already start new generations with identical clones based on the single most successful individual from last generation.
In practice it's the same principle, investing in cohesion for the first stages of development instead of the diversity the last stage produced.
Great video!
Interessantíssimo!!! Interessantíssimo!!! Interessantíssimo!!!
Excellent video, but what happened to the outro music?
I think this is a good example of evolution working through adaptation rather than perfection. Flatworms adapted to their situation like that and it worked so they didn't need to adapt further to another system that might have been more beneficial. Nature shows us so many systems can work even though not all of them as optimal. It goes on till it needs to adapt or go extinct.
very interesting!
I would gusess a single cell is easiest mechanism to combine genes from both parents, thus increasing diversity and helping to spread helpful genes within population.
But why use that mechanism exclusively? Why not both?
@@tofu-munchingCoalition.ofChaos Because of unecessary complexity? When you can already reproduce sexually, why build another complex system to reproduce asexually? I can imagine a complex multi-cellular oranism having much harder time adapting an asexual reproduction, due to complexity of coordination of growth patterns and having to use non-aged cells.
@@RFalhar unless you find yourelf at the bottom of food chain and or being constantly having to experience huge boom bust cycles in population that force you to keep the original trait around.
I say that because pre eukaryotes (prokaryotes) only use asexual reproduction. They sure would like to mix things up (and bacteria do seem to have found a mechanism to horizontally transfer limited genes - but nothing like the full shuffle). Once sexual reproduction was discovered only less complex organisms like protists and simple multi cellular organisms (and plants cause they can't move to find mates?) seem to have kept it around. In the race of cambrian I guess the less useful traits (and more risk with higher complexity?) were lost. It's very hard to get back something you've lost in evolution it seems.
(edit) PS - Went down the archea rabbit hole (fascinating creatures). They seem to have precursor fusogens that are used within eukaryotes for gamets fusion for sexual reproduction (also in many viruses!! - which in turn is used by placental organisms!! what?!). I love learning new stuff like this and being able to connect the dots so to speak.
@@RFalhar Why not partially swap out genes (hand, eyes, ...). That would be a more directed optimisation of diversification without the single cell bottle neck.
@@RFalhar Are you suggesting that the sexual reproduction came first? Why do you think so?
Otherwise why abandon a second system that worked and gave your individual genes more reproduction success instead of less than (non-viable) 50% chance from sexual reproduction? Naïvely (more than twice the reproduction success rate and no nurturing needed) I would have guessed evolution favours the multicellular asexual approach and would hold on to it.
Why would evolution remove this when it's already established? I needed an explanation for this and the video gave it.
The video and the mathematical analysis seem to suggest that genetic clonality alone is a sufficient reason to favour the single cell bottle neck.
I don't see how diversification necessarily is a reason for the single cell bottle neck.
Please could you do a video on how we know mutations are random.
I got stuck on this and struggled to find the studies showing so and now can’t find them again anyway.
Thanks.
I have a series on this on my lecture channel:
- First is on essential genes: ruclips.net/video/rLGam7Lx1Z4/видео.html
- Then how random mutations are: ruclips.net/video/sXXH71rQRKo/видео.html
- Then a video on how some essential genes seem to be extra protected from mutation: ruclips.net/video/9OZ3JKtOU1k/видео.html
@@StatedClearly
Fantastic Jon. Cheers.
@@frankcardano4142 probably also interesting for you: The Luria-Delbrück Experiment from 1943. An great experiment with elegent design and math, but in its own relatively simple: en.wikipedia.org/wiki/Luria%E2%80%93Delbr%C3%BCck_experiment
It made the proof, that mutations are spontaneous and not responsive.
In a nutshell, it introduced a bacteria-killing virus (phages) to a bacteria population. It killed most of the population, but the bactera recovered PLUS the new bacteria showed a resistence against the virus. The question is now, WHEN the mutation with the resistence happened. If it happened before the introduction of virus, then it must be spontaneous. If it came after, it was responsive. While we know the answer today and see it as obvious, it in fact isn't and wasn't known for sure back then.
Also the experimentors were lucky: There are phages, which increase mutation rates and thus could look like they induce mutations which generate resistence. Luckily, these were not used in the experiment.
It depends what do you mean with random. If you mean that every base in a DNA sequence has the same probability to mutate it’s obviously false
Thank you
A bit of a nitpick here, but I'm not sure I entirely agree with your statement at 0:33: "You started life as a single cell. Once that cell was fertilized it..."
I'd be inclined to argue that my life didn't start until after fertilization, not before. An unfertilized egg is not itself an organism, nor is a sperm cell. A gamete on its own does not fit the criteria for life until they combine to become a zygote.
I’m weirdly proud of myself for figuring it out before I watched the video
Best youtube channel
liked and subscribed
This video only glances at the notion of sexual reproduction, which can only happen through paris of gametes, and which is the most import factor in creating genetic diversity through pairing and recombination. This is the actual reason why a single cell stage is extremely beneficial for the species.
Awesome
😂😂😂 my dumb ass was subscribed to both channels and only now noticed this was Jon Perry. The voice is so obvious.
nice video, it does show a feature of biology that seems strange at first but works very well
but how are you? your voice seemed a lot tired, is everything ok?
Thanks for asking! I've been spread thin but I really am doing well.
@@StatedClearly glad to see your answer, the subject was very interesting but the sound of your voice kept me worried
Wow that was stated... clearly
Finger baby 💀
The thought process is perhaps more important than the fascinating biology
When you cant find a mate, do not rip yourself in half.
"The blind process of Evolution" Ironic; The only blindness here is in the presenter.
God damn this was good
The cat's leg damaged by his umbilical cord would not be passed on regardless. That defect was not genetic but developmental. Losing a leg or finger doesn't alter your DNA. A clone of you would still be whole. A genetic defect could be passed on, but the single-cell bottleneck reduces the chances it will be passed on.
And at 1:53 it's specific, not pacific.
It was great and thought-provoking.
The exterior process to engage all 5 senses even the idea to reproduce down to the specific intervals these intervening. Forces are required are just as complex or greater than the actual biology itself lol
If any of these carpementalized steps get distributed along the way its problematic
pretty freakin cool
"Finger-kid". This guy knew what he was doing
Consider how important death is in removing accumulated defects from the population. Combating aging, which is equivalent to trying to prevent death, could create huge unforeseen changes in the population. The example of the liver cell that develops a way to extend it's own life but then no longer plays it's role in maintaining the body's health seems analogous. What happens if billionaires discover how to extend their lifespans, as many are trying to do, then continue to soak up all of society's resources and influence politics to their own benefit for centuries?
Even more interesting, those flatworms are colloquially called immortal
There is an electrical energy that controls their development and carries a completed blueprint within the energy field, which is communicated from cell to cell during division
@@jarrettesselman8144No that's not how cell division works its not magic grow up. 😂
@@WokeandProud why are you brave enough to get my attention but not brave enough to use your name?
@@jarrettesselman8144 Because I'm not interested in breaking my anonymity especially with a dunning kruger effected creationist l0ser on the internet.
Plants tend to get their energy from the sun. Bacteria survive by reproducing quickly. Animals survive by moving their muscles and having a nervous system. There might be a way over reproducing that involves mixing a bunch of totally different strategies. However it would be very difficult for one species to evolve to reproduce in a totally different way. Once a method of reproducing is found, that method gets improved upon by future generations. Starting from scratch tho is difficult. Likewise I suspect that the single cell bottleneck is not the most efficient way to reproduce: It is merely a way that has some advantages that animals have evolved to exploit effectively. It likely more like a hangover which once had really strong advantages, which from that point on were fixed in all animals, even though other ways of reproducing would be a lot more complex but better.
That's a really cute cat, though
Subscribed
Interesting material, but I still want to grow back my finger.
It prevents heritability of undesirable acquired traits.
Flatworms look surprisingly cute.
Tripod. fucking tripod, sir you made my day
Next time someone asked me how I am:
"Im doing well in the struggle for existence"
Stated clearly hath returned
Starfish can also recover from being cut in half.
Would parthenogenic birds and non-avian reptiles have similar issues?
They still use a single-cell bottleneck.
Within cells interlinked
Kid named finger
We're starting over. Fresh start Morty, Fresh start!
Fission could result in a try-again if the offspring fails. Also, the risk for jizzing is much lower than fission
8:55 Exactly WHY is it that the fastest sperm cell is considered the “best” sperm cell? I can see that a faster sperm cell might be considered stronger or more coordinated, but that characteristic seems like a very limited way to evaluate fitness. Has anyone ever attempted a study of the internals of fast vs slow sperm cells? I’d be interested in understanding what characteristics the slow sperm cell may have that are being lost simply because others are faster.
They have better designed and machined parts
How does dna regenerate the damage of aging when going though mitosis. Like whyba newborn not as aged as its parent despiye there aged code making them?
My guess is it doesn’t. A lot of animals use budding as a secondary option
Molecular aging can be measured by the DNA ends, the telomeres. As each cell divides telomeres shorten because they can't be replicated. Once they are too short, DNA damage can occur at these ends and the cell will eventually die once it can't correct these damages. Formation of sperm and egg cells create genetically unique combinations of genes so each sperm (and egg) is genitally different from each other. This is an advantage of sexual reproduction and the bottleneck cell theory. Genetic recombination leads to an increase in genetic diversity. Genetic diversity correlates with species/population strength.
Usually, the dna damage is prevented/fixed via a very complex mechanism while replicating (for eg, some polymerases have self-proofing mechanisms, correcting the mistakes they did quickly after doing them). Also, for a whole organism, there are some basal cells (which just divide, without being turned into specialised cells, eg liver cells) responsible for generating other cells which will specialise (generally irreversible, excluding plants and some other groups which are capable of dedifferentiation, eg flower cell to dividing cell under certain conditions).
Now regarding the age, that is usually (the most reliable way discovered so far) measured by CpG methylations (marks on dna, methyl groups on certain CG sequences on the dna). Here's the thing, sperm and egg cells go through some cycles where most of the genetic marks from them are erased and rewritten (based on the kept ones and certain signals from the mother) and so they go from a fully assembled lego to some pieces and back to normal.
It is much more complex and way harder to understand what's happening exactly, we need much more research to figure out what's going on there for sure (the more we found about it, the more complex it became). Hope it answered to your question clear enough.
@antoniolaza736 thank you for that. It was very helpful. It's amazing that we still don't know such an important part of even our own reproduction.
@@evilcow666 yeah, we are like: the more you know, the more you realise how little you actually know.
But still, the science discovered a huge amount of information in the previous years and the field evolved faster than ever, so i'd say we are on the right path, it's just that we can't read properly the signs (yet).
I live in America. I need to know what to do if I lose my pinkie!!!
Ice?
Within 3 days!
Check out the article.
"Mouse eggs made from skin cells in a dish' by David Cyranoski
Nature volume 538, page301 (2016)"
A mind did that.
0:25 Kid named finger:
There is a much more practical and less complex reasons. Your cut off finger doesn't have the mechanisms to create energy and mass. Where would it get the materials needed to create cells? Or put another way. Can you imagine the complexity of a system that can supply energy and mass to every big that could be cut off. If they did, we would be back to a colony of single cells. Which, Ok. But we already have that.
give it a little finger food
Flatworms can be cut into over 100 tiny pieces, each will re-arrange whatever cells it happens to have into a tiny flatworm with all the organs it needs to eat. They "get materials needed to create cells" by searching for food and eating.
@@StatedClearly Yes, That is exactly my point. They have to distribute the required systems everywhere. That doesn't scale with size. Even in the flatworm you can't take a single cell and expect it to reproduce itself. For the same reasons you can't in humans. As you scale up you can't keep increasing redundant systems in case you need them.
There are other, bigger organisms that blur the line between single cell (self sufficient) and multi cell. That long mass of cells that kind of acts like a sea snake jumps to mind.
@@lakrids-pibe taco CHIPS and chicken FINGERS seems fitting.
This is a good point. Going down to a single cell enables the new organism an amount of time to build more specialized structures with protection from the egg/mother instead of immediately facing competition. This leads to huge advantages like lungs, which absolutely prevent any kind of reproduction by fission. Looks like those lungs are worth the trade-off.
We found him
We found the kid named Finger
9:50 not to mention organ transplants, of all important things
Me trying to resist the urge of saying kid named finger
👏🙂
Charlie seems like a great cat. He's not defective, just different. Things like that don't define us, it's how we deal with differences that sometimes come with challenges. ❤
Evolution wants to turn us into fast swimming sperms. ;)
I am not sure how much diversity in fitness there is across the filter stages of fertilization. Could it be more a process of getting foreign bodies into the body while ensuring it is of the same species? Even going as far as to cap it off at the fewest amount that can reliably enter in the proximity of the egg (but also considering the parents could try again)?
ruclips.net/video/_5OvgQW6FG4/видео.html
Gatekeeping vs another testing ground for fitness