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I don’t understand the headline (yes I skimmed the article). Why would mitochondria not be alive? What does that even mean?

ssalka 2y ago
I imagine it's similar to how viruses are not considered to be alive, since they cannot reproduce without a host cell? But I have never been a fan of that argument either, both seem alive to me.
- georgeecollins 2y ago
  I think the idea here is that mitochondria developed independent of cells and later lived exclusively inside of them. In other words, they reproduced without cells. I am not sure, please correct me if I am wrong.
  - semperdark 2y ago
    You're not wrong. But over the enormous amount of time since, the "duplicate" organelles and systems needed for independent living were steadily carved out of mitochondria. While they do have their own DNA and replication process, the DNA is basically limited to specific things they need to perform their energy-generation functions and the replication happens when triggered by host cell replication. It's a bit like if you took the heart from an animal and transplanted it into a human: is it meaningful to call it independently alive? Maybe, it depends what question you're trying to ask.
  - dekhn 2y ago
    No, the predecessors of mitochondria were also cells and they reproduced through cellular division.
- adastra22 2y ago
  I don't know of any definition of "alive" that can survive application of a reductive understanding of biology that doesn't either count viruses as being "alive," or decide that nothing is alive. The uncertainty, I understood, was whether to classify them as distinct organisms the way we classify other species, as they are intrinsically parasitic for their replicative capability.
- larkost 2y ago
  Outside of a host cell viruses do not fit any of the definitions of life: - they do not seek or consume sources of nutrients or energy - they do not have a metabolism - they do not grow In fact the only place they fit the definition is reproduction, and that is only through the machinery they commandeer from the cells they infect. To me viruses clearly do not fit the definition of life. But fire... that is hard to exclude from the definition without some mental contortions. I am not advocating that fire is alive for any useful reason, but it is hard to exclude from the definition.
georgeecollins 2y ago
I am terrible at biology but I will try. The idea is that mitochondria is not a component of a living organism, but an organism that once lived independently of the cell.
UncleOxidant 2y ago
"If we think of mitochondria as non-living organelles..." mitochondria were thought to just be a component of the cell. But they have their own DNA separate from that in the cell's nucleus. They replicate on their own like bacteria.
- marcosdumay 2y ago
  > mitochondria were thought to just be a component of the cell. ... hundreds of years ago, for a short time after they were discovered. We know that they behave like bacteria for almost as long as we know that they exist.
  - outworlder 2y ago
    They "behave as" bacteria. Are they bacteria? Are they 'alive' by themselves? That's the distinction.
    - marcosdumay 2y ago
      > Are they 'alive' by themselves? That's a discussion about word semantics that has no relation to biology. Biologists have been occupied with it for centuries, just like computer people have lost time on "what's intelligence?", but neither one is relevant for either field. > Are they bacteria? Once upon a time, their ancestors were. I do not know exactly where biologists trace the line, but this is also about word semantics. It's just a case of it that helps people communicate better, so there is a line, I just don't know what it is.
    - adastra22 2y ago
      What do you mean by "alive?" Because of course they are alive, regardless of whether you consider them bacteria or not. There is a strange definition of "alive" that is being used by you and the author article that I'm not understanding. If a mitochondria is not "alive," then is it dead? Even if it is taking part in an active, living cell?
- adastra22 2y ago

ssalka 2y ago

I imagine it's similar to how viruses are not considered to be alive, since they cannot reproduce without a host cell? But I have never been a fan of that argument either, both seem alive to me.

georgeecollins 2y ago
I think the idea here is that mitochondria developed independent of cells and later lived exclusively inside of them. In other words, they reproduced without cells. I am not sure, please correct me if I am wrong.
- semperdark 2y ago
  You're not wrong. But over the enormous amount of time since, the "duplicate" organelles and systems needed for independent living were steadily carved out of mitochondria. While they do have their own DNA and replication process, the DNA is basically limited to specific things they need to perform their energy-generation functions and the replication happens when triggered by host cell replication. It's a bit like if you took the heart from an animal and transplanted it into a human: is it meaningful to call it independently alive? Maybe, it depends what question you're trying to ask.
- dekhn 2y ago
  No, the predecessors of mitochondria were also cells and they reproduced through cellular division.
adastra22 2y ago
I don't know of any definition of "alive" that can survive application of a reductive understanding of biology that doesn't either count viruses as being "alive," or decide that nothing is alive. The uncertainty, I understood, was whether to classify them as distinct organisms the way we classify other species, as they are intrinsically parasitic for their replicative capability.
larkost 2y ago
Outside of a host cell viruses do not fit any of the definitions of life: - they do not seek or consume sources of nutrients or energy - they do not have a metabolism - they do not grow In fact the only place they fit the definition is reproduction, and that is only through the machinery they commandeer from the cells they infect. To me viruses clearly do not fit the definition of life. But fire... that is hard to exclude from the definition without some mental contortions. I am not advocating that fire is alive for any useful reason, but it is hard to exclude from the definition.

georgeecollins 2y ago

I am terrible at biology but I will try. The idea is that mitochondria is not a component of a living organism, but an organism that once lived independently of the cell.

UncleOxidant 2y ago

"If we think of mitochondria as non-living organelles..." mitochondria were thought to just be a component of the cell. But they have their own DNA separate from that in the cell's nucleus. They replicate on their own like bacteria.

marcosdumay 2y ago
> mitochondria were thought to just be a component of the cell. ... hundreds of years ago, for a short time after they were discovered. We know that they behave like bacteria for almost as long as we know that they exist.
- outworlder 2y ago
  They "behave as" bacteria. Are they bacteria? Are they 'alive' by themselves? That's the distinction.
  - marcosdumay 2y ago
    > Are they 'alive' by themselves? That's a discussion about word semantics that has no relation to biology. Biologists have been occupied with it for centuries, just like computer people have lost time on "what's intelligence?", but neither one is relevant for either field. > Are they bacteria? Once upon a time, their ancestors were. I do not know exactly where biologists trace the line, but this is also about word semantics. It's just a case of it that helps people communicate better, so there is a line, I just don't know what it is.
  - adastra22 2y ago
    What do you mean by "alive?" Because of course they are alive, regardless of whether you consider them bacteria or not. There is a strange definition of "alive" that is being used by you and the author article that I'm not understanding. If a mitochondria is not "alive," then is it dead? Even if it is taking part in an active, living cell?
adastra22 2y ago