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This article is framed as if there is something novel and profound here, but the "aliveness" of mitochondria is simply a matter of how we choose to apply the la

This article is framed as if there is something novel and profound here, but the "aliveness" of mitochondria is simply a matter of how we choose to apply the label "life" - a human linguistic construct that exists independently of the biological phenomena. This is not a new discussion - science has been considering this question for many decades, just as it has with viruses. These all come down to arguments about semantics and don't add anything to the science. Mitochondria are fascinating and there is still a huge amount to learn about them but they are totally dependent on the cell's machinery. Most of their genes, the code for their structure, are in the nuclear DNA. A glaring omission if you are trying to make the case that mitochondria are independently living. My heart can exist independently of me, and be transplanted into other people, but does it mean that it is alive? The implication of the whole article is that there something we have missed. This really isn't the case. Lynn Margulis's endosymbiotic origin of mitochondria was challenged by many, and it did spark a scientific debate - that's how science works. She won the argument comprehensively decades ago and is well established science. There have been many such endosymbiotic events in the history of life - there are subfields of evolutionary biology that study these processes.

blurbleblurble 2y ago
It's wild to me that today's popular biologists like Michael Levin don't give Lynn Margulis credit in every single podcast/interview.
- freetime2 2y ago
  Can you elaborate on this comment? What should popular biologists like Michael Levin be saying on every podcast/interview and why? Serious question from someone who is familiar with Lynn Margulis but not Michael Levin.
liyamchitayat 2y ago
Hi! I agree with you, which is why I wrote this- but if you google "are mitochondria alive" gemini says it isn't. And yes, the cells in your heart have an effective and potenitial niche! We seem to have many tools to engineer viruses, but few to engineer mitochondria- perhaps considering them as alive could change that!
- tim333 2y ago
  I just tried that and it said: >Yes, mitochondria are alive, though they are not considered "living" in the same way as a cell because they can't function independently... Maybe it's learning!
  - jpk 2y ago
    Or maybe the temperature is set too high! Probably don't start with a single LLM response as the basis for your understanding of scientific consensus.
  - _yb2s 2y ago
    Eukaryotes generally can’t survive without mitochondria either. It seems silly to discuss if different subsystems in a living organism are independently “alive.” It’s a bit like arguing if just the wings or just the engine of an airplane are flying machines.
- dragandj 2y ago
  "Gemini" says? So what?
  - tim333 2y ago
    It shows there are misconceptions out there, if only in LLMs.
- satvikpendem 2y ago
  I am not sure you should be relying on an LLM as any indication of anything... More seriously, considering something as being alive in order to engineer them better does not necessarily change the fact of them actually being alive or not, in my opinion.
  - dekhn 2y ago
    If LLMs work the way I understand them to, they are trained on large corpora which contain a statistical preponderance of statements which are consistent with the current scientific mainstream, so it may not be completely crazy to try doing this; you'd get the scientific mainstream explanation, and possibly a few alternative hypotheses if they had enough literature support.
sroussey 2y ago
Mitochondria are weird. Look at 3-parent baby (human).
aeturnum 2y ago
> The implication of the whole article is that there something we have missed. I think this article is talking to people who haven't internalized the details of the scientific consensus. Those people are still going around, talking about "life" and making decisions based on the flawed understanding this article is critiquing. I think it's likely that the thing that "has been missed" is not narrowly scientific in the way you seem to be thinking - but more about broad implications and worldview.
- meneton 2y ago
  I am not sure what exactly the 'broad implications and worldview' are here that are being challenged. The article is presented as a scientific opinion and references scientific research and has a doi number for citation (Cite: Liyam Chitayat. “Mitochondria Are Alive” Asimov Press (2024). DOI: https://doi.org/10.62211/38pe-75hu https://doi.org/10.62211/38pe-75hu). What do you think that the article was challenging?
  - Jerrrry 2y ago
    Life is just an arbitrary number of magnitude of complexity
  - legel 2y ago
    Obviously the article is challenging the view — scientific or not — that mitochondria are not living. Side note: previously I was funded by NSF and NASA to study such questions from biophysics and astrobiology. That said, this was a delightful read. I did not realize or conceive of mitochondria as, like bacteria in our bodies, independent living networks with unique genomes, evolution, and flows of information and energy. Reading about the health benefits of “external mitochondria” made me think about when I hug my dog: are we exchanging mitochondria, perhaps?
thinkling 2y ago
> Most of their genes, the code for their structure, are in the nuclear DNA. Are they? I was under the impression that mitochondria are closer to pseudo-cells living inside human cells. Wikipedia seems to confirm this [1]: > Although most of a eukaryotic cell's DNA is contained in the cell nucleus, the mitochondrion has its own genome ("mitogenome") that is substantially similar to bacterial genomes. [1] https://en.wikipedia.org/wiki/Mitochondrion https://en.wikipedia.org/wiki/Mitochondrion
- kylebenzle 2y ago
  OP above you is correct. Maybe you are thinking about it wrong?
  - deleted 2y ago
    [deleted]
- bonzini 2y ago
  See below on Wikipedia: "Most proteins necessary for mitochondrial function are encoded by genes in the cell nucleus and the corresponding proteins are imported into the mitochondrion. The exact number of genes encoded by the nucleus and the mitochondrial genome differs between species."
  - melagonster 2y ago
    yes, Human mitochondria only generate less than 20 types of protein; all other things they need are from cytoplasm.
- ale42 2y ago
  There's a specific page on Wikipedia about Mitochondrial DNA [1], where it is clearly said that: In the cells of extant organisms, the vast majority of the proteins in the mitochondria (numbering approximately 1500 different types in mammals) are coded by nuclear DNA, but the genes for some, if not most, of them are thought to be of bacterial origin, having been transferred to the eukaryotic nucleus during evolution. (citing [2]) [1] https://en.wikipedia.org/wiki/Mitochondrial_DNA https://en.wikipedia.org/wiki/Mitochondrial_DNA [2] https://doi.org/10.1016%2Fj.cels.2016.01.013 https://doi.org/10.1016%2Fj.cels.2016.01.013
dekhn 2y ago
what about obligate intracellular parasites like mycoplasma? They are awfully close to mitochondria but we think of them as alive. They've lost many of their genes and can't survive without the host. Looking at those, you could almost see a path from an obligate intraceullular parasite to an organelle derived from a phagocytosed prokaryote.
- colechristensen 2y ago
  But that’s exactly what they are, former endoparasites which gradually lost their independence and became more specialist in their function. Defining an arbitrary line and then attaching labels does not really add to understanding.
  - deleted 2y ago
    [deleted]
  - d0mine 2y ago
    But it does. How many grains of send form a heap? How many atoms form a fluid? Is it something a particle or a wave? The line can be drawn depending on specific problem, on how useful a heap/fluid/particle/wave model for this specific application. A label (abstraction) allows us to bring corresponding tools that were developed for it. If you can count trees then the same math can be useful to count people.
    - meneton 2y ago
      Arguing about where you draw the line doesn't advance anything, it just muddies the water. We have robust definition of what is and isn't alive built by consensus. Mitochondria fall into the 'not alive' category by our definition. Presenting decades old scientific views as evidence that this categorisation is wrong doesn't add anything. This article has had far more exposure than some really groundbreaking science and it adds nothing.
      - d0mine 2y ago
        My point is more general: there may be multiple useful descriptions of “reality” depending on context. It is almost _trivially_ (tautologically) true. Ask two different programmers to implement something and look at what abstractions they create depending on unrelated non-functional requirements. Here’s specific example: imagine you are writing “what-if” type of article about a table: if you are interested in whether it holds your weight then you might talk in terms of tension, compression, mechanical forces. If you are interested in whether you can hide behind it from x-rays then terms such as radiolucent, atomic composition might be useful. I have no idea in what context “mitochondria are alive” notion might be useful (but it doesn’t mean there is none).
beambot 2y ago
> These all come down to arguments about semantics and don't add anything to the science. This accurately describes much of science... > My heart can exist independently of me, and be transplanted into other people, but does it mean that it is alive? The cells that comprise your heart are very much alive, but they will die without support infrastructure. They live, they replicate, they die -- like every cell in your body. If I relocate you to the moon without support infrastructure, you would die too -- and yet (I think?) you are probably alive.
- staplers 2y ago
  Best argument I've heard for Gaia theory, intentionally or not.
  - TeMPOraL 2y ago
    We probably can keep a heart alive outside of body, through artificial means, for minutes, maybe hours - and I mean keep it functioning, not just chilling it to slow its death. It's plausible we'll learn to be able to keep it alive for days, months, years, decades. At which point we could say that the "supporting infrastructure" of the rest of a human body isn't necessary for the heart to be independently alive? What if we do it all on the Moon, or Mars? How does Gaia feel about it? We already know that it's theoretically possible, if not yet achievable in practice, to create artificial environments capable of supporting human life indefinitely - or, on a long enough timescale, bootstrap an independent, self-sufficient biosphere. The two are, in the limit, the same thing anyway. Or are we going to argue that human technology is, by extension through causality, a part of life on Earth, and therefore a part of Gaia itself? Is Gaia in all of us, and will it persist after Earth dies if humanity is still around somewhere else? All in all, I suppose the correct definitions of terms are the ones that are most useful in a given context :). "Categories were made for man, not man for the categories", and all that.
    - staplers 2y ago
      At which point we could say that the "supporting infrastructure" of the rest of a human body isn't necessary for the heart to be independently alive A human body would be supporting it, inside of itself or not. Similar to Earth and its "independent travelers" today.
type0 2y ago
> There have been many such endosymbiotic events in the history of life - there are subfields of evolutionary biology that study these processes. Exactly, if mitochondria is alive then so is chloroplasts and who knows what else. The line needs to be drawn somewhere, also life and death isn't as clear-cut as many used to believe
xphos 2y ago
I think questions like this make science fun for the uninitiated because it represents both the uncertainty and the intense investigation and evidence discovery process involved in tearing hazy things and recovering concrete truths in the process
dr_dshiv 2y ago
I’m not sure what you are arguing against. For me, the article offered a lovely reminder that life is special. Life involves mechanisms but it is more than a machine. And with an attitude that our lives our symbiotically bound to another living organism (or 10^17 of them) we gain a valuable humility — one that might afford us new perspectives on how to make them all happy and flourish. That’s the promise— not just a spiritual connection to the aliveness of mitochondria, but a pragmatic orientation towards their health and wellbeing. And there is a lot of scientific opportunity to explore there.
- jsvlrtmred 2y ago
  I think they are arguing against the subtitle of the article: "Recognizing that mitochondria are alive will open new horizons into how we learn about, and build with, biology." Which seems a stretch based on semantics.
- meneton 2y ago
  As I said in another comment, I think that mitochondria are fascinating, understudied and a rich area for research. We are bound to the myriad other pieces of DNA that all have different evolutionary histories within us, we are symbiotically bound to many strands of life on many levels. We are just one strand, a part of a singular whole, bound to all strands of life beyond us. This view of life led me to science. I totally think that this view of biology is not properly appreciated by most scientists. But this article was presented as a scientific piece and made the explicit claim that mitochondria were alive which is a semantic argument that doesn't have a scientific answer. It is a well written piece that made it to the top of hacker news and it's great to see the debate. But it just isn't true that mitochondria are alive by our currently accepted definition of alive. This is an old debate in biology that was settled years ago. There is nothing in this paper that wasn't known to mainstream science decades ago, but it is presented as a novel scientific viewpoint.
  - dr_dshiv 2y ago
    > it just isn't true that mitochondria are alive by our currently accepted definition of alive. This is an old debate in biology that was settled years ago. Sorry, but that’s an overreach. There are many “accepted” definitions” of life across different scientific fields. According to Wikipedia, there are at least 123 definitions of life — and there is not scientific consensus. Mitochondria are alive based on some definitions and not alive based on others. https://en.wikipedia.org/wiki/Life https://en.wikipedia.org/wiki/Life Expecting life to have total autonomy in self-sustainability is absurd. Otherwise somatic cells or even people would be not alive. And the argument that mitochondria are not alive because they can’t encode all their own proteins — well, I’ll point out that humans can’t produce all amino acids, either. As a thought experiment, if humans couldn’t produce a certain essential protein — and had to rely on a symbiont, would that mean humans weren’t alive? Finally I’ll point out that Mitochondria can be healthy or flourishing — and they can be sick and die. How can something that is not alive, die? It’s ok to argue for a narrow definition. But please don’t present this argument as though you are the defender of clear scientific conclusions. There simply isn’t consensus on this across the sciences.
rgbswan 2y ago
You might find this interesting: "Clinical potential of sensory neurites in the heart and their role in decision-making" [] https://pmc.ncbi.nlm.nih.gov/articles/PMC10896837/ https://pmc.ncbi.nlm.nih.gov/articles/PMC10896837/
ElFitz 2y ago
This "aliveness" debate reminds me of the "11.000 years old dog". Basically a tumour that has been spreading from one dog to another for thousands of years. https://www.cam.ac.uk/research/news/11000-year-old-living-dog-cancer-reveals-its-secrets https://www.cam.ac.uk/research/news/11000-year-old-living-do...
lo_zamoyski 2y ago
> My heart can exist independently of me, and be transplanted into other people, but does it mean that it is alive? Your heart cannot exist independently of you as a heart. It is only a heart in name, as it does not function as a heart. Its identity as a heart depends on its ability to function as a heart within some organism. The same can be said for any part or organ. A severed hand is a hand in name only. A corpse is not a body, as it no longer functions as one. A transplanted heart becomes a heart once more. A reattached hand becomes a hand once more. If you think this is weird, then you haven't done your metaphysical homework. Why should it be weird? It could only be weird if you have made certain (unexamined) metaphysical presuppositions. The structure of a heart removed from an organism persists long enough that it can become reintegrated into an organism such that it functions once again as a heart. But also note that the matter composing a heart itself isn't fixed. About 1% of heart cells are replaced per year in the young. So if function and structure can survive transient material change, and the matter that makes up a heart can assume and lose and reassume its identity as part of a heart, then why can't a heart lose its identity as a heart when removed, and regain its after it is implanted back in?
monktastic1 2y ago
Are you not "totally dependent" on the air you breathe, the water you drink, the sunlight that gets turned into your food, ...?
softfalcon 2y ago
I don’t disagree with your take. The concept of the semantics of “what is alive?” has been going on for a long while now. Have you considered that this is a more formal version of a Bill Nye science explainer, but for adults? The reason I say this is that while unintended (I think) your post has a, “of course they’re alive, we’ve known this forever” vibe, which can inadvertently come across as condescending. I don’t mean to pick on you, we’re all guilty of such speak when we deem concepts to be obvious or well known. Your post reminds me of the “1 in 10,000” XKCD comic: https://xkcd.com/1053/ https://xkcd.com/1053/ Again, I don’t disagree that your knowledge of history and science is correct. Am just curious why you wrote your explainer in the way you did.
deleted 2y ago
[deleted]

blurbleblurble 2y ago

It's wild to me that today's popular biologists like Michael Levin don't give Lynn Margulis credit in every single podcast/interview.

freetime2 2y ago
Can you elaborate on this comment? What should popular biologists like Michael Levin be saying on every podcast/interview and why? Serious question from someone who is familiar with Lynn Margulis but not Michael Levin.

liyamchitayat 2y ago

Hi! I agree with you, which is why I wrote this- but if you google "are mitochondria alive" gemini says it isn't. And yes, the cells in your heart have an effective and potenitial niche! We seem to have many tools to engineer viruses, but few to engineer mitochondria- perhaps considering them as alive could change that!

tim333 2y ago
I just tried that and it said: >Yes, mitochondria are alive, though they are not considered "living" in the same way as a cell because they can't function independently... Maybe it's learning!
- jpk 2y ago
  Or maybe the temperature is set too high! Probably don't start with a single LLM response as the basis for your understanding of scientific consensus.
- _yb2s 2y ago
  Eukaryotes generally can’t survive without mitochondria either. It seems silly to discuss if different subsystems in a living organism are independently “alive.” It’s a bit like arguing if just the wings or just the engine of an airplane are flying machines.
dragandj 2y ago
"Gemini" says? So what?
- tim333 2y ago
  It shows there are misconceptions out there, if only in LLMs.
satvikpendem 2y ago
I am not sure you should be relying on an LLM as any indication of anything... More seriously, considering something as being alive in order to engineer them better does not necessarily change the fact of them actually being alive or not, in my opinion.
- dekhn 2y ago
  If LLMs work the way I understand them to, they are trained on large corpora which contain a statistical preponderance of statements which are consistent with the current scientific mainstream, so it may not be completely crazy to try doing this; you'd get the scientific mainstream explanation, and possibly a few alternative hypotheses if they had enough literature support.

sroussey 2y ago

Mitochondria are weird. Look at 3-parent baby (human).

aeturnum 2y ago

> The implication of the whole article is that there something we have missed. I think this article is talking to people who haven't internalized the details of the scientific consensus. Those people are still going around, talking about "life" and making decisions based on the flawed understanding this article is critiquing. I think it's likely that the thing that "has been missed" is not narrowly scientific in the way you seem to be thinking - but more about broad implications and worldview.

meneton 2y ago
I am not sure what exactly the 'broad implications and worldview' are here that are being challenged. The article is presented as a scientific opinion and references scientific research and has a doi number for citation (Cite: Liyam Chitayat. “Mitochondria Are Alive” Asimov Press (2024). DOI: https://doi.org/10.62211/38pe-75hu https://doi.org/10.62211/38pe-75hu). What do you think that the article was challenging?
- Jerrrry 2y ago
  Life is just an arbitrary number of magnitude of complexity
- legel 2y ago
  Obviously the article is challenging the view — scientific or not — that mitochondria are not living. Side note: previously I was funded by NSF and NASA to study such questions from biophysics and astrobiology. That said, this was a delightful read. I did not realize or conceive of mitochondria as, like bacteria in our bodies, independent living networks with unique genomes, evolution, and flows of information and energy. Reading about the health benefits of “external mitochondria” made me think about when I hug my dog: are we exchanging mitochondria, perhaps?

thinkling 2y ago

> Most of their genes, the code for their structure, are in the nuclear DNA. Are they? I was under the impression that mitochondria are closer to pseudo-cells living inside human cells. Wikipedia seems to confirm this [1]: > Although most of a eukaryotic cell's DNA is contained in the cell nucleus, the mitochondrion has its own genome ("mitogenome") that is substantially similar to bacterial genomes. [1] https://en.wikipedia.org/wiki/Mitochondrion https://en.wikipedia.org/wiki/Mitochondrion

kylebenzle 2y ago
OP above you is correct. Maybe you are thinking about it wrong?
- deleted 2y ago
  [deleted]
bonzini 2y ago
See below on Wikipedia: "Most proteins necessary for mitochondrial function are encoded by genes in the cell nucleus and the corresponding proteins are imported into the mitochondrion. The exact number of genes encoded by the nucleus and the mitochondrial genome differs between species."
- melagonster 2y ago
  yes, Human mitochondria only generate less than 20 types of protein; all other things they need are from cytoplasm.
ale42 2y ago
There's a specific page on Wikipedia about Mitochondrial DNA [1], where it is clearly said that: In the cells of extant organisms, the vast majority of the proteins in the mitochondria (numbering approximately 1500 different types in mammals) are coded by nuclear DNA, but the genes for some, if not most, of them are thought to be of bacterial origin, having been transferred to the eukaryotic nucleus during evolution. (citing [2]) [1] https://en.wikipedia.org/wiki/Mitochondrial_DNA https://en.wikipedia.org/wiki/Mitochondrial_DNA [2] https://doi.org/10.1016%2Fj.cels.2016.01.013 https://doi.org/10.1016%2Fj.cels.2016.01.013

dekhn 2y ago

what about obligate intracellular parasites like mycoplasma? They are awfully close to mitochondria but we think of them as alive. They've lost many of their genes and can't survive without the host. Looking at those, you could almost see a path from an obligate intraceullular parasite to an organelle derived from a phagocytosed prokaryote.

colechristensen 2y ago
But that’s exactly what they are, former endoparasites which gradually lost their independence and became more specialist in their function. Defining an arbitrary line and then attaching labels does not really add to understanding.
- deleted 2y ago
  [deleted]
- d0mine 2y ago
  But it does. How many grains of send form a heap? How many atoms form a fluid? Is it something a particle or a wave? The line can be drawn depending on specific problem, on how useful a heap/fluid/particle/wave model for this specific application. A label (abstraction) allows us to bring corresponding tools that were developed for it. If you can count trees then the same math can be useful to count people.
  - meneton 2y ago
    Arguing about where you draw the line doesn't advance anything, it just muddies the water. We have robust definition of what is and isn't alive built by consensus. Mitochondria fall into the 'not alive' category by our definition. Presenting decades old scientific views as evidence that this categorisation is wrong doesn't add anything. This article has had far more exposure than some really groundbreaking science and it adds nothing.
    - d0mine 2y ago
      My point is more general: there may be multiple useful descriptions of “reality” depending on context. It is almost _trivially_ (tautologically) true. Ask two different programmers to implement something and look at what abstractions they create depending on unrelated non-functional requirements. Here’s specific example: imagine you are writing “what-if” type of article about a table: if you are interested in whether it holds your weight then you might talk in terms of tension, compression, mechanical forces. If you are interested in whether you can hide behind it from x-rays then terms such as radiolucent, atomic composition might be useful. I have no idea in what context “mitochondria are alive” notion might be useful (but it doesn’t mean there is none).

beambot 2y ago

> These all come down to arguments about semantics and don't add anything to the science. This accurately describes much of science... > My heart can exist independently of me, and be transplanted into other people, but does it mean that it is alive? The cells that comprise your heart are very much alive, but they will die without support infrastructure. They live, they replicate, they die -- like every cell in your body. If I relocate you to the moon without support infrastructure, you would die too -- and yet (I think?) you are probably alive.

staplers 2y ago
Best argument I've heard for Gaia theory, intentionally or not.
- TeMPOraL 2y ago
  We probably can keep a heart alive outside of body, through artificial means, for minutes, maybe hours - and I mean keep it functioning, not just chilling it to slow its death. It's plausible we'll learn to be able to keep it alive for days, months, years, decades. At which point we could say that the "supporting infrastructure" of the rest of a human body isn't necessary for the heart to be independently alive? What if we do it all on the Moon, or Mars? How does Gaia feel about it? We already know that it's theoretically possible, if not yet achievable in practice, to create artificial environments capable of supporting human life indefinitely - or, on a long enough timescale, bootstrap an independent, self-sufficient biosphere. The two are, in the limit, the same thing anyway. Or are we going to argue that human technology is, by extension through causality, a part of life on Earth, and therefore a part of Gaia itself? Is Gaia in all of us, and will it persist after Earth dies if humanity is still around somewhere else? All in all, I suppose the correct definitions of terms are the ones that are most useful in a given context :). "Categories were made for man, not man for the categories", and all that.
  - staplers 2y ago
    At which point we could say that the "supporting infrastructure" of the rest of a human body isn't necessary for the heart to be independently alive A human body would be supporting it, inside of itself or not. Similar to Earth and its "independent travelers" today.

type0 2y ago

> There have been many such endosymbiotic events in the history of life - there are subfields of evolutionary biology that study these processes. Exactly, if mitochondria is alive then so is chloroplasts and who knows what else. The line needs to be drawn somewhere, also life and death isn't as clear-cut as many used to believe

xphos 2y ago

I think questions like this make science fun for the uninitiated because it represents both the uncertainty and the intense investigation and evidence discovery process involved in tearing hazy things and recovering concrete truths in the process

dr_dshiv 2y ago

I’m not sure what you are arguing against. For me, the article offered a lovely reminder that life is special. Life involves mechanisms but it is more than a machine. And with an attitude that our lives our symbiotically bound to another living organism (or 10^17 of them) we gain a valuable humility — one that might afford us new perspectives on how to make them all happy and flourish. That’s the promise— not just a spiritual connection to the aliveness of mitochondria, but a pragmatic orientation towards their health and wellbeing. And there is a lot of scientific opportunity to explore there.

jsvlrtmred 2y ago
I think they are arguing against the subtitle of the article: "Recognizing that mitochondria are alive will open new horizons into how we learn about, and build with, biology." Which seems a stretch based on semantics.
meneton 2y ago
As I said in another comment, I think that mitochondria are fascinating, understudied and a rich area for research. We are bound to the myriad other pieces of DNA that all have different evolutionary histories within us, we are symbiotically bound to many strands of life on many levels. We are just one strand, a part of a singular whole, bound to all strands of life beyond us. This view of life led me to science. I totally think that this view of biology is not properly appreciated by most scientists. But this article was presented as a scientific piece and made the explicit claim that mitochondria were alive which is a semantic argument that doesn't have a scientific answer. It is a well written piece that made it to the top of hacker news and it's great to see the debate. But it just isn't true that mitochondria are alive by our currently accepted definition of alive. This is an old debate in biology that was settled years ago. There is nothing in this paper that wasn't known to mainstream science decades ago, but it is presented as a novel scientific viewpoint.
- dr_dshiv 2y ago
  > it just isn't true that mitochondria are alive by our currently accepted definition of alive. This is an old debate in biology that was settled years ago. Sorry, but that’s an overreach. There are many “accepted” definitions” of life across different scientific fields. According to Wikipedia, there are at least 123 definitions of life — and there is not scientific consensus. Mitochondria are alive based on some definitions and not alive based on others. https://en.wikipedia.org/wiki/Life https://en.wikipedia.org/wiki/Life Expecting life to have total autonomy in self-sustainability is absurd. Otherwise somatic cells or even people would be not alive. And the argument that mitochondria are not alive because they can’t encode all their own proteins — well, I’ll point out that humans can’t produce all amino acids, either. As a thought experiment, if humans couldn’t produce a certain essential protein — and had to rely on a symbiont, would that mean humans weren’t alive? Finally I’ll point out that Mitochondria can be healthy or flourishing — and they can be sick and die. How can something that is not alive, die? It’s ok to argue for a narrow definition. But please don’t present this argument as though you are the defender of clear scientific conclusions. There simply isn’t consensus on this across the sciences.

rgbswan 2y ago

You might find this interesting: "Clinical potential of sensory neurites in the heart and their role in decision-making" [] https://pmc.ncbi.nlm.nih.gov/articles/PMC10896837/ https://pmc.ncbi.nlm.nih.gov/articles/PMC10896837/

ElFitz 2y ago

This "aliveness" debate reminds me of the "11.000 years old dog". Basically a tumour that has been spreading from one dog to another for thousands of years. https://www.cam.ac.uk/research/news/11000-year-old-living-dog-cancer-reveals-its-secrets https://www.cam.ac.uk/research/news/11000-year-old-living-do...

lo_zamoyski 2y ago

> My heart can exist independently of me, and be transplanted into other people, but does it mean that it is alive? Your heart cannot exist independently of you as a heart. It is only a heart in name, as it does not function as a heart. Its identity as a heart depends on its ability to function as a heart within some organism. The same can be said for any part or organ. A severed hand is a hand in name only. A corpse is not a body, as it no longer functions as one. A transplanted heart becomes a heart once more. A reattached hand becomes a hand once more. If you think this is weird, then you haven't done your metaphysical homework. Why should it be weird? It could only be weird if you have made certain (unexamined) metaphysical presuppositions. The structure of a heart removed from an organism persists long enough that it can become reintegrated into an organism such that it functions once again as a heart. But also note that the matter composing a heart itself isn't fixed. About 1% of heart cells are replaced per year in the young. So if function and structure can survive transient material change, and the matter that makes up a heart can assume and lose and reassume its identity as part of a heart, then why can't a heart lose its identity as a heart when removed, and regain its after it is implanted back in?

monktastic1 2y ago

Are you not "totally dependent" on the air you breathe, the water you drink, the sunlight that gets turned into your food, ...?

softfalcon 2y ago

I don’t disagree with your take. The concept of the semantics of “what is alive?” has been going on for a long while now. Have you considered that this is a more formal version of a Bill Nye science explainer, but for adults? The reason I say this is that while unintended (I think) your post has a, “of course they’re alive, we’ve known this forever” vibe, which can inadvertently come across as condescending. I don’t mean to pick on you, we’re all guilty of such speak when we deem concepts to be obvious or well known. Your post reminds me of the “1 in 10,000” XKCD comic: https://xkcd.com/1053/ https://xkcd.com/1053/ Again, I don’t disagree that your knowledge of history and science is correct. Am just curious why you wrote your explainer in the way you did.

deleted 2y ago

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