Giant Viruses Blur The Line Between Alive and Not
Vložit
- čas přidán 21. 05. 2024
- In 2003, microbiologists made a huge discovery. One that would force us to reconsider a lot of what we thought we knew about the evolution of microbial life: giant viruses.
*****
PBS Member Stations rely on viewers like you. To support your local station, go to to.pbs.org/DonateEons
*****
Produced by Complexly for PBS Digital Studios
Super special thanks to the following Patreon patrons for helping make Eons possible:
Heather Wagnon, Sam & Matt, Kyle Brown, Stephen Patterson, Mark Foster, Karen Farrell, Trevor Long, Raphael Haase, daniel blankstein, Roberto Adrian, Ramirez Flores, Jason Rostoker, Jonathan Rust, Avery Sanford, Mary Tevington, Bart & Elke van Iersel - De Jong, William Craig II, Tracey, James Dowling-Healey, Irene Wood, Derek Helling, WilCatRhClPPh33, Mark Talbott-Williams, Nomi Alchin, Eric Roberto Rodriguez, Hillary Ryde-Collins, Yu Mei, Dan Ritter, 4th_phase, Jayme Coyle, Albert Folsom, Oscar Amoros Huguet, Patrick Wells, Steven G, Dan Caffee, Stephanie Tan, Nick Ryhajlo, Sean Dennis, Ben Cooper, Robert Noah, Matt Parker, Heathe Kyle Yeakley, Jerrit Erickson, Anton Bryl, MissyElliottSmith, Stefan Weber, Merri Snaidman, Gabriel Cortez, Marcus Lejon, Todd Dittman, Betsy Radley, Anthony, Philip Slingerland, John Vanek, Eric Vonk, Jon Monteiro, James Bording, Miles Chaston, Michael McClellan, Jeff Graham, Daisuke Goto, Gregory Kintz, Chandler Bass, Tsee Lee, Robert Hill
If you'd like to support the channel, head over to / eons and pledge for some cool rewards!
Want to follow Eons elsewhere on the internet?
Facebook - / eonsshow
Twitter - / eonsshow
Instagram - / eonsshow
References: docs.google.com/document/d/11...
Being classified as a living organism is very popular. I'm not surprised it's gone viral.
🤣👍
93 93/93
Nice
Elelel bing elellel
lolz
"They went from being a branch of the tree of life to a parasitic vine that wraps around it" such a poetic way of explaining this
And they can take DNA from everything around them and grow bigger.
Possibility of there being an organism like The Flood increased.
My favourite part of this episode!
Very metal 🤘🏻
Overly dramatic. Mad me stop and laugh
They didn't come up with that analogy, I've heard it elsewhere before, but I do think it does a pretty good job of illustrating the relationship between viruses and living organisms.
I love the way the two hypotheses were presented here, as well as the fact that we don't really know if maybe there's another possibility.
Scientific mystery is so much better than sensational mystery. Great writing :)
it's likely they are exosomes as viruses don't exist they know now Virus mania by Dr's trapped by Gov around the world The book so we know the truth
I agree @Tragoudistros.MPH
One query I had was: aren’t the two hypotheses _not_ mutually exclusive? _I.e._ giruses could both have descended from some ancient evolutionary regression (god knows triggered by what stimulus/stimuli) and also zapped up some DNA from their hosts. Nothing precludes both from directing giruses’ biohistorical progression, right?
Science evolves like everything else. All towards being able to better understand the world
It is part of the reason why I like this channel so much. They don’t pretend that findings are the ultimate, unchanging truth, unlike how pop science tend to be.
Science is less Eureka! and more 'Huh, that's weird.'
I loved the line describing viruses as a parasitic vine wrapping around the tree of life. The imagery it brings to mind is like Nidhogg in Norse mythology, gnawing at the world tree's roots.
Interesting!
Níðhöggr or Níðhǫggr gnawing at Yggdrasil for those searching.
and now that you've loved a completely inaccurate analogy, you cannot learn the truth. well done.
Considering how much parasites are able to simplify all across the tree of life, it wouldn't be that absurd for a parasite to reply so much on hijacking hosts that it loses its own ribosomes, but the other way around would also make sense
Yeah this makes the most sense imo.
I am a biologist. But, I have always felt that our definition of what is "alive" is the only reason viruses are not considered living organisms.
It literally is. In fact, some biologists do consider them to be alive.
most of the new biology students are actually alligned with the idea they are indeed alive
me as well, they repeoduce, they change their environment, they generate offspring and they evolve, i think those are the real characteristics of a living beinf
G
My school’s goal is to teach us science. As in teach us about debate. My college taught us that it’s a debate if it’s alive or dead. We even were taught multiple definition of species
@@guifdcanalli a computer program can also do those and still its not alive.
Viruses are not killed. They are destroyed.
They don't possess any living characteristics unless they enter a host cell (which happens by natural chemical processes)
I get what you're saying, but that's a funny way of putting it. Of course if our definition of "alive" was different we'd classify different things as alive. If our definition of a "dog" was "a vehicle with 4 wheels" we'd classify jeeps as dogs.
This kinda reminds me of a previous PBS Eons video a while back. How the Smallest Animal Got So Simple. What if viruses were pioneers, on the verge of becoming living organism but reverted to a simpler form to remain successful at colonializing.
Michelle mention it at @4:35 Regressive evolution.
Sort of a back and forth between the two hypotheses. Interesting idea, I don't know if there's any evidence for or against it that would automatically be for or against one of the parent ideas, but it's an interesting one nonetheless.
Virus should be classified as living things they evolve just like all life.
Like European settlers.
Wouldn't that still make it a type of life form? Lol
The idea of horizontal gene transfer being much wider and cross-domain than we thought is fascinating. Tree of life may just become all tangled and looped when it comes to microlife
I think even horizontal gene transfer between plants and insects has been found.
YEAH ! CAUSE IN THE END ALL YOU GOTTA KNOW IS " LIFE FINDS A WAY " !!!😌
After finding out that Darwin's finches were all breeding with each other instead of the nice evolutionary tree that Darwin came up with, I'm not surprised...
I’m new to this channel, but this woman is an _excellent_ speaker. I didn’t miss a single word, and she had my attention and interest from start to finish.
For all the argument about viral life, a much better debate is if mitochondria are alive. I mean, they undergo cellular division (of a sort), have their own DNA and cellular machinery, and even have inarguably alive free-living relatives. Plus, they are the direct descendents of living organisms, and so _should_ be phylogenetically classed as living things independent of the rest of the eukaryotic cell they reside in.
Most likely exosomes as viruses don't exist Virus Mania book by Drs around the world Gov trapped medical and now so are Dr's around the world the book was written so we know the truth
I don’t think we can say for sure whether mitochondria are alive or dead, but what we do know for sure is that the mitochondria is
T H E P O W E R H O U S E O F T H E C E L L
They're also completely dependent on the cell around them because many of their parts are made in the cytoplasm and nucleus and then shipped to the mitochondria. And they never leave the cell. They lost those capabilities in their long evolutionary history. So they are even more dependent on the cell than typical microbial symbionts.
Is your kidney alive? Pretty similar question (not exactly, given the history).
@@andrewfleenor7459 Yes, but it is not an organism.
We love how open to true scientific mystery most Digital Studios shows are, its easy to forget nowadays that the driver of science is questions not answers
Well said.
Questions based on answers*
answers are the source of new questions.
Reminds me of the recent discovery of the giant bacterium found in a swamp in Guadeloupe, which has its own membrane-bound organelles!! Nature never ceases to amaze and humble us!
Something I will never forget from undergrad is a professor that referred to viruses as “something” that self replicates, not something alive. It blew my mind back then.
I was taught that in my honors bio class. I thought it was fascinating yet wrong. Almost like a gatekeeping on what we consider alive or not. Nothing inorganic behaves this way so why shouldn't viruses be considered living beings? Because it makes us justified in killing them? Well we kill more complex organisms with far less concern. Seems like more of an ethical argument rather than a scientific one.
Sounds like the professor didn’t understand the difference between life and death ! Has anyone ever seen a house brick self replicated ?
@@TonyWhite22351 Viruses are just instructions to copy those instructions on the wetwear they are on. They are not the complete set of wetwear that uses energy as a motor does to do the work entailing the whole process that is life.
@@TonyWhite22351 are you.. Implying that people call bricks "viruses"?
@@TonyWhite22351 No - because it doesn’t happen. Viruses subvert other living matter to replicate themselves. Bricks don’t include the instructions to make other bricks…
Excellent work, I love how much effort they put on putting together such explanatory videos of high scientific quality but also style. The narrators add to the whole thing. As a biologist I've been following this channel fiercely
Most likely exosomes as viruses don't exist Virus Mania by Dr's around the world Gov trapped medical and now so are Dr's the book written so we know the truth
You've done episodes on blood and hearts (which are great), but I would love it if eons made an episode about the evolution of spines/notochords. Thank you for the great show!
Yes! Notochords!
Oh, and grases.
Well we were able to trace our earliest known ancestor to a inch long worm that lived in the Cambrian period
I really appreciate the small pauses in between sentences. It might sound like a very tiny detail, but it really helps me absorb and later recall the content. Great work.
I'm glad it was useful to you, but I found it harmful to my enjoyment and absorption of the information in the video. It really dragged and made me lose a grasp on the overall information being presented, making me not as engaged in the topic as much as other videos. Speeding it up to 1.25 speed helped me focus so much better
Agreed. I need pauses to absorb the information better. Well done.
Anything to get to 10 minutes
@@jimsmith3715 you honest think they could not just add more technical information if they wanted? The small pauses do not seem to serve that purpose.
@@MrMakae90 bro with the length of the video, the script is specifically written and read to reach it 😂
Love to see Eons talk about virophages. Which are small viruses which are parasites of larger viruses.
Fortunately I'm not a giant, so I can't catch one of these viruses.
Big talk
>Me, a Dutch person.
Ah crap.
Compared to an amoeba, you ARE a giant
What I love about Eons is the combination of very simply explained complexities without dumbing down, with always being certain to explain the elements we don't know and the presence of alternative hypothesis. That they can do this in 10 minute videos is truly an art.
This was so beautifully explained, I can't imagine all the hard work that must be put into these videos behind the scenes! Much love 💛
Omg didn't expect to see you here!
Agreed-- we're so lucky to be living in a time where we can watch these videos and learning this information for free
Thank YOU. For your hardwork! We wouldn't be here if you didn't decide to co-operate with that Archeon that swallowed you!
It's a funny thing:
Us humans function through categorising everything, it's a necessary part of our cognition. One consequence is we tend to think the world around us really is made up of these categories and so we are continually surprised when things pop up that don't fit. This should be no surprise at all.
It's called scientific progress based on new evidence. Science does not work without classifications. This postmodernist deconstruction thing doesn't help anybody and makes scientific progress impossible. Previous classifications that are no longer used are simply the scientific conclusions from times with less evidence (often because they did not have the technologies of today) available and made (though imperfect) sense based on what was known then.
Surprise, curiosity and wonder are nothing bad.
*We humans
PBS Eons people are so cool. If only I could listen to them for hours in a podcast... Wait
"We found a new type of virus in your water tower lol" might sound like HORRIFYING news, but it was reassuring to hear later in the video that most giruses target smaller and simpler organisms.
Regressive evolution was exactly my first suspicion when i'd heard of the existence of these larger complex viruses
The unprecedented volatility of virus replication makes me think that any and all viable methods to evolve into a giant virus have been achieved by life, possibly many times thanks to convergent evolution. I'd debate with my very limited biology education that viruses *are* life just because they have natural interactions with species and possibly even contribute to evolution by accelerating random mutations within any populations.
But "life" is just a label that we human beings use. Things can exist without necessarily fitting neatly into one of our conceptual boxes. So I'm not sure why the label is such a big deal.
@@Bill_Garthright I think the label is such a big deal because that's our main tool in making sense of the world around us. We try to fit everything into different boxes and fit with things that have similar, yet different concepts.
I love all the videos that they host! And viruses are endlessly cool
Only as long as they stay out of my cells...
What if viruses are there own branch on the tree of life? In there own domain since they are so different, and they do have a lifecycle from just rna and capsid to infecting a cell, overriding and reproducing inside the cell. Just a thought,
Great presentation, writing, and comparison. Thanks Eon
If they were once cells, does it mean they're living dead? Zombies?!!!
I've always suspected that viruses are the original zombies.
John Davison Ng has been carrying this show for years
The idea that viruses can be the remains of cells is a very good one, I like it.
It would be something like the phenomenon of a fresh corpse being able to move and perform small actions before it rots.
I just realised this is slowely but surely becoming my favourite channel of all time.
Yer name haha.
I don't think there should be a "too simple" to be alive. The ability to act against entropy in an organized manner, for me, is special enough to count.
But that's the point. The thing you think of when saying virus does nothing to prevent the internal increase in entropy. Only the infected cell does anything like that.
Viruses are as alive as a mouse trap and when you step on it you look down and see a sticky note on it that reads "wouldn't it be funny if this happened to other people? Here's how to build me, and don't forget the note: ...". Your common sense to not waste your and your friends time is your immune system in this analogy.
@@Madrawn bad analogy.
And it does work against disorder. It works to reorder and replicate its surroundings in order to replicate. Just because it uses the system of a cell to do that, like a parasite, doesn't mean it's not doing something against the flow of natural disorder.
@@Madrawn Consider the following:
*viruses contain genetic material, it can be replicated and it can mutate
*they are subject to Darwinian evolution
*they aren't mere inanimate objects like crystals, fire, or your mousetrap
@@regulate.artificer_g23.mdctlsk The note in my example contains information regarding the mousetrap, similar to what the virus dna does for the virus. And the information contained in the note can mutate, either by the environment (for the note it might be a raindrop, for DNA a stray ray of radiation), or by copying error, just like DNA can.
The virus shell and the DNA record it stores 'does' absolutely nothing a note on a mousetrap doesn't also "do". If the virus shell and DNA is to be considered "alive" while it's waiting for a cozy cell to infect and mutate in, then we might as well call pictures of memes alive while they wait for a cozy mind to infect and mutate in.
I'm not saying there isn't something alive within the reproductive cycle of a virus that is distinct from the cells it hijacks, but the string of 4 character text inside box of dead material isn't it by any definition of alive.
@@Madrawn It's still a pretty bad analogy, and the argument isn't _viruses are alive because they have genetic material,_ the argument is _we should define life based on whether or not it can evolve and participate in natural selection._ The mousetrap in this analogy doesn't have a "purpose" in its ecosystem - it just expects that whatever it ensnares is sapient enough to read the instructions it has written on it and _actually_ follow what it's suggesting to the reader to do.
The way I see it, it's the genetic material (DNA/RNA, single strand/double strand) that really matters here. The fact that nucleic acid molecules on their own can't do anything is irrelevant - and that is true to all current living things - lest we get to a point where only ribozymes can be called "alive".
Most of the time, the only reason viruses need to get a host is for resources; they already have genes for replication proteins and sometimes transcription proteins - they can even carry those with them - and in some cases, they have genes for ribosomes - specifically ribosomal proteins. This doesn't make them any different from single celled parasites that invade other cells, which are very similar, up until the motility part perhaps. Although there are some parasitic bacteria that are nonmotile ("cystic" IIRC).
Really enjoyed this episode and appreciate what you do to help understand our world
Mind blowing. I’ll never get over how complex the universe is both on the large and small scale.
Thanks for all the cool videos you guys put out🙏
I don’t know how but the eons crew always make explaining science sound like poetry
Now that I think about it, I don't think it's coincidence that when humans try explaining That Which Resists Explanation, we often resort to art and poetry✨
the science teacher we all wanted❤️
microbiology is not my favorite but wow this video was exciting! bravo PBS Eons!
Interesting video! Great subject. I'd love one of the evolution of galls
Great video on the strange viruses recently discovered. So could you say that through genetic mixing this virus is a hybrid and possibly a separate classification in itself?
The think that's crazy to me is that giruses are so large some of them have their own viruses.
What? That’s not correct. At all.
@@ricardoavila3113 That's a virophage, which isn't a "virus" for a "giant virus". The mechanism of action is completely different.
wonderful video... and the art is beautiful!
I LOOOOOVE your Program! Great Video!
PBS Eons, can you do something about prions next? I don’t understand what they are, and when I asked an old doctor, he said he didn’t honestly know either. (not his specialty and far less was known about them, if any, when he was in med school)
They are misfolded proteins which can cause other proteins to misfold. The Wikipedia article is pretty decent. Id say I want a video on prions too but they're terrifying
The idea is that proteins depend on two things to do what they are supposed to do: their chemical composition AND their physical structure. A certain chemical composition might behave in COMPLETELY DIFFERENT ways depending on it's shape.
yes, when I went to medical school in the late 70s, those diseases caused by prions were thought to be caused by a "slow virus". I recall some Survivor type show on TV once, were contestants had to eat something yucky - worms, bug, raw cow brain. I thought, If I got selected for brain, I"d just quit on the spot, I'm not eating anything's brain due to prions.
Thank you for those thoughtful replies, Stine W and Yuki Nagato.
One of the things that I don’t comprehend about prions is their transmissibility. I understand how they can infect a new host though ingestion, but are they able to pass from one to another by different means? The prions that I know of are usually ingested by humans when they eat herbivores, but how are they passed from one deer or cow to another? Are they transmissible by any means other than ingestion?
@@ugaladh Absolutely. I cannot believe that this hasn’t happened to someone on one of those shows after eating raw brains yet (that I know of).
It's not often I like new host's to PBS shows, but she's awesome=)
Fantastic video as always. 👍
Another interesting & informative presentation
I remember in school that when giant viruses were brought up, they never delved into what they actually are. They're just given a name and we were to memorize it for one question on a test.
Why don't schools teach like this?
I love these videos ❤️🥰
This is so interesting! On another note tho, your blouse looks absolutely gorgeous.
great episode!
This video helped connect a lot of dots for me about viruses in general. Thanks for putting it together! Also: love the outfit.
There's giant virus inside her
Any more "enlightened speculations" about weather mimiviruses, or giant viruses, could have been the original evolutionary prototype(s) of the eukaryotic cell's nucleus? That is, just as mitochondria and chloroplasts are organelles derived from bacteria, could what passes for an eukaryotic nucleus' be derived from an invading giant virus, replete with "translation" functions of changing RNA into amino acids/polypeptides? That is something that Lynn Margulis, with her endosymbiosis theory, might smile upon.
I was sort of expecting that to be touched on in this video... I mean, it's the bajillion-dollar question, isn't it?
I certainly buy into viral eukaryogenesis personally. It answers a lot more questions than other such theories.
@@aplaceinthestars3207 Yeah, but it is just a tad beyond the scope of this video, which is, after all a tad beyond nonprofessionals.
This makes no sense
@@tfsheahan2265 Aww, it's not THAAAT tough to grasp, though it certainly wouldn't enable anyone to go about using the info on this episode alone to do anything directly practical (which is why kids who say EONS IS BETTER THAN SCHOOL make me sad and nervous).
Besides time/money constraints, I figured perhaps the Eons team didn't want comments to go in a totally different (and possibly more controversial) tangent than the video...? But I'm blissfully unaware of the current sci consensus on the idea.
Nice presentation by the host. Good job! 👍
Clear presentation of the two hypotheses. I’ll go with the smorgasbord amoeba one.
Is it possible that DNA & RNA viruses have entirely separate origins?
Yhea, Ive always taught there is no reason to assume all viruses share a common origin
Yes, All RNA viruses seem to have a common origin, separate from DNA viruses, which might have multiple independent origins, at least some among unicellular organisms gone parasitic.
Maybe some viruses are closer to us compared to other viruses, the same way a chimpanzee is closer to us than a gorilla.
I'm wondering... If the RNA Hypothesis of how life evolved is considered a valid possibility, wouldn't it follow that these Giruses are maybe just primordial RNA-lifeforms that were on their evolutionary path to becoming DNA-based lifeforms? I mean, it seems like gene-hacking isn't really all that much different than selective breeding through mutations... 🤔
AFAIK, all giruses are made up of double stranded DNA; some other related and unrelated viruses are too. Giruses aren't in the path to becoming DNA-based lifeforms, they *are* DNA-based lifeforms. Perhaps what you mean to say was they're in the path to becoming cellular, like, becoming like early prokaryotes?
While enjoying this intriguing episode, I also love ur outfit! Thanks for bringing this topic.
Good presentation. I no longer ask if it is 'alive', more a position on a continuum...
Imagine all other forms of "life" in the universe. We wouldn't know where to start if we encountered them.
End of the World theory: Giant viruses grow to the size of humans and compete with us for dominance over earth
Love these weird virus videos. Also not to detract from the great content, but that outfit today was a whole vibe!
Fantastic video as al👍
I don't like either of the explanations proposed for the giant virus origins in this video. I think this video shows that the only major component missing from the translation process in viruses across the virus spectrum is rRNA, but they have mRNA and some tRNA. So that's 2 out of 3. Who is to say the ribosome evolved first and mRNA and tRNA evolved to match the ribosome? We know that bacterial ribosome is different than eukaryotic ribosome so maybe the ribosome evolved last and giant viruses are actually the precursor to eukaryotic and bacterial life evolving as seperate branches from giant viruses which are the missing link between micelles and complex structure?
That's a 4th domain theory. You're proposing that a 4, more ancient domain of life gave rise to viruses, although you propose a different placement for it
YOUR OUTFIT IS SO COOL! YOU LOOK AMAZING!!!
Also this episode is fascinating! Well done!
looks so tacky
Great content!
giruses seeing other genes after infecting an amoeba: “jot that down, jot that down!”
Let's help make this video go viral.
Star Trek voyager thought up MACRO VIRUS in an episode long before these were actually discovered… kinda cool.
these things are terrifying
Excellent video
It always struck me as weird that viruses are considered to be non living. They evolve and succeeds in ways life does. Their ability to reproduce and evolve makes me think viruses are alive, I believe our definition of life is limited, or too narrow.
Its because they can't reproduce without hijacking a cell, without life, they are just inert particles
Like how Prions aren't alive
Well, the thing is, they don't reproduce (and therefore evolve) through their own means, they depend on their host's genetic machinnery to do that, unlike true living organisms. If you consider viruses to be alive, then where do you stop? Because prions do the same thing, except they are just misfolded proteins. Would you consider a lone protein to be a living being too?
@@zddxddyddw I don't think the phrase "by their own means" is very compelling. I am a male. I can't evolve or reproduce without a female, does that mean I am not alive? At the level of cells, sure some cellular organisms can reproduce and evolve under their own means, but only my undifferentiated stem cells can reproduce any of the cells in my body and some of my cells can't reproduce at all "by their own means", while almost none of my cells can "evolve" by their own means, because only germ cells can do that, but of course sperm cells can't reproduce on their own so.... It's not a pathway, applying the currently terrible definition of "reproduce and evolve on their own" to more or less things isn't the right answer. The right answer is coming up with a better definition of life. I don't think a sperm is alive the same way a dog is alive is the same way an amoeba is alive is the same way a brain cell is alive is the same way a bacteria is a alive is the same way fetus is alive is the same way a virus is alive is the same way prion is alive is the same way a plant is alive. For that matter, none of these things are alive the way a planet with water and breathable atmosphere is alive. Finally, if something is hibernating for 100,000's of years is that alive the same way as it is when it's in its exponential growth phase? You can say that all of these things except prions, viruses, and planets have the ABILITY to reproduce and evolve on their own in some part of their lifecycle regardless of whether they currently do or are evolving and reproducing, but under that amended definition, viruses DO have the ability to evolve and reproduce on their own, it's just that 99.99% of the time virus is not actively using cellular machinery from a host cell to produce virions, but when it is, then it does have the ability and can therefore be called alive. Just like a woman can evolve and reproduce once she has sex but the other 99.99% of her time she isn't alive, and if she's castrated or goes through menopause then she is dead?
@@zddxddyddw I don't know if it's even important that something reproduce by it's own means, as long as it reproduces. A protein doesn't have genetic information, so it can't reproduce. It can only be constructed by something else. A virus can reproduce, it inserts its own DNA into a cell, and uses that cell to reproduce, before the cell bursts open. It's not too dissimilar from parasites on larger scales.
There is a parasite for fish, I forgot which, but it started out as an independent living animal, but evolved into a parasite. It didn't need eyes, so it lost them. It didn't need its own stomach, so it lost it. If viruses evolved from giruses, but adopted a parasitic life style, on a cellular level, there are a lot of adaptations it wouldn't need. Why spend the energy doing reproduction yourself, when you could make your host do it for you?
The problem is that scientists defined what makes something "alive," before virus' nature was known. There's nothing that works quite like a virus, so they can be considered a 4th branch on the tree of life or an anomaly equally easily. No one pretends that they're just some kind of chemical reaction, even if they're not considered "alive." It's an entirely semantic argument, not a biological one.
GIANT VIRUSES HELL YEAHHH!
Found in a cooling tower. The most amazing things found in some very mundane places.
Yo you gotta add a link to your playlist it’s amazing
Personally I blame squirrels
in every simulation made of any ecosystem, parasitic behavior was always among the first behaviors that emerged. basically, the partial or total loss of the genes coding for machinery that is no longer operating, but probably initially present in the Gyruses, with some remnants, that could be random or perhaps advantageous for some unknown function or in some particular environment or occurrence, is undoubtedly the more likely hypothesis between the 2.
There's also the hypothesis that viruses predate organismal life (which I think you touch on in another video). From this view, mimivirus could be more of a "living fossil", something that existed as an intermediate from when communities of symbiotic genes were starting to coalesce into larger genomes. While the lineage that lead to all organismal life would have packaged the full translational machinery into a set that allowed self replication, these viruses would represent a lineages that stopped short of the final step of integrating the whole transcriptional machinery.
Really dig the music used for this episode
I don't understand: if they are descended from an ancient extinct 4th branch of life...wouldn't that branch not be extinct and be occupied by them?
Alternatively:
I don't understand: if they are an amalgamation of the three branches of life and don't belong to any, wouldn't they be a 4th branch of life?
Eukaryotes descend from archaea which engulfed bacteria (ancestors of our mitochondria), so we are a mashup of the two endosymbiotic prokaryotic domains.
No because they aren’t alive so they wouldn’t be on any branch of life
@@masonloeffler8064 If some DNA viruses descend from degenerate cellular organisms, then they are on the Tree of Life and indubitably alive, phylogenetically.
They would be if they were considered alive.
The problem with viruses and "life" is that our current definition of life includes that the organism has to be able to reproduce itself. Viruses cannot reproduce on their own, so they aren't considered "alive" by that definition., They do reproduce but by hijacking a cell. Basically, we find that our definitions have become inadequate to cover all we can discover now, but an accepted new definition hasn't yet been made.
Thank you. I think horizontal gene transfer is the answer. But if it is true, the evolution tree is nor a simple tree anymore. There branches sometime touch each other and create new species with endless possibilities.
Well summed up. ❤️
Maybe our definition of "alive" is too specific, and viruses should be included
For what?
Like the definition of "planet", as we uncover more knowledge, we find that our human reductive catagorization made in the past is now too general for scientific heavy lifting.
Another one is the imprecise definition of "human". Should this include H. neandethalensis, and the Denisovans, since we contain recent chunks of their DNA? What about all the rest of the latter day H. Erectus morphs we keep uncovering?
The one main thing viruses lack, that everything else we consider alive has, is a metabolism. If we do manage to push the "tree of life" back to abiogenesis, we are going to have an even harder time defining "alive", and may have to start admitting mere chemical reactions into the family....
@@NullHand Us humans thrive on categorization. If only we weren't so bad at it lol
“It’s evolving, just backwards”
What is “forwards” in evolution?
Evolution only goes forward, if having a "regressed" life cycle is best suited for survival then that is how a species will evolve.
Thanks!
Awesome episode
Hihi, I actually have an unrelated question. Did insect leave the ocean or evolve after its ancestor left the ocean? If it is the latter, what was it? Many info on fish leaving the ocean; I still wonder what animals made it to land first? Thanks
Hi , insects are believed to be evolved from a crustacean called Remipedes , the oldest insect fossil found is believed to be 385 - 400 million years old and was a type of Silverfish , if I remember correctly it was wingless (but I may be wrong) .
Also I doubt wether the crustacean Remipedes made it out of the water and turned in to the silverfish , there’s probably many more steps that we currently have no information on, sorry that I could not give you a more definitive answer but seeing as we are talking about things 400 million years in the past , this is probably the best answer you will get .
Take care . R .
@@rayzorrayzor9000 The oldest insects did not have wings, there are two extant orders of insect without wings so we know wings were not a feature that initially defined insects. There are also a few other groups like spring tails that have six legs but aren't insects.
@@TheRedKnight101 hi , thanks for the clarity , I use to have perfect recall on anything I read but I’m getting much older now and alas my memory is becoming fallible , I know that either the crustacean or the Siiverfish was venomous , but I couldn’t recall which one it was , I suspect it was the crustacean but cos my memory failed me I left this information out .
Thanks again for the info
Take Care . R .
@@rayzorrayzor9000 thanks for sharing. 👍
@@whoisincornell hi , glad to help even if it wasn’t quite the answer you was looking for .
Take Care . R .
The host is doing a fantastic job!
Oh, my gerd! That submitted joke was so painful. I love it!
I like this new host. She speaks camly, giving you time to understand and appreciate the topic discussed in the videos
Hello from Egypt
Will never go there due to police
@@nodical802 what do you mean by police?
@@omarwaheed9359 your country has very aggressive police
@@nodical802 how do you know that?
@@omarwaheed9359 he's been there
Really well presented. Like this new teacher. Great job :)
cool stuff :) i love viruses so much, they're really cool!
Fascinating! And great outfit!
To be fair, viruses in general blur the lines on what counts as a living organism. When classification into discrete categories depends on a constellation of criteria, definitions get hazy. Any lines drawn at that point are, to a certain degree, arbitrary.
Look up the video “do chairs exist” by Vsauce, it goes deep into this idea.
@@jaredf6205 Good video. That is my point, but in regards to biochemistry in this case rather than ontology.
Life is special but not as special as we think and viruses really seem to illustrate this. There’s obviously some kind of important dynamic between matter and energy in the universe and life is a complex manifestation of that
I love this channel
That episode had the best joke you have had in quite some time.
Maybe we should redefine and change the rules for what it means to be life.
Or create a new category/domain.
Occam’s razor, horizontal gene transfer is the simplest explanation until more evidence is found.