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"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 fr

"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
Organelles are alive too. All active biological systems are alive. Mitochondria have for many generations now been known to have their own DNA and replicate on their own. So I’m not sure what new distinction is being drawn?
- twothreeone 2y ago
  I _think_ what they mean is it's not typically listed as a "life form" in its own right, i.e., there's no Domain under which one would classify Mitochondria - maybe just calling them bacteria would capture the article's intent? So, the modification would be that we are living in symbiosis with mitochondrial bacteria, similar to how we live in symbiosis with our gut bacteria, rather than them being classified as "organelles" of eukaryote cells.
  - pleurotus 2y ago
    That's more a flaw of classification systems though. Because even if they comprise a distinct life form does not mean they need to have a unique species. Consider lichen, which comprise two (or more!) separate "species" which becomes a meaningless distinction when they cannot survive on their own, or even if they could, not in a form recognizable in any wayas they were when they were a part of the symbiotic system
    - hughesjj 2y ago
      I mean at that point what do we consider multicellular organisms? Did you see what was going on with those frog skin cells and "xenobots"? Also, our gut bacteria kinda makes us a symbiote at a larger scale.
  - pishpash 2y ago
    Of course it is classified. In Wikipedia itself there is a phylogenetic tree listing its closest relative the alphaproteobacteria: https://en.wikipedia.org/wiki/Mitochondrion#Origin_and_evolution https://en.wikipedia.org/wiki/Mitochondrion#Origin_and_evolu...
agumonkey 2y ago
I was looking for specific notions explaining the emergence of this kind of endosymbiosis, anybody has links ?

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

Organelles are alive too. All active biological systems are alive. Mitochondria have for many generations now been known to have their own DNA and replicate on their own. So I’m not sure what new distinction is being drawn?

twothreeone 2y ago
I _think_ what they mean is it's not typically listed as a "life form" in its own right, i.e., there's no Domain under which one would classify Mitochondria - maybe just calling them bacteria would capture the article's intent? So, the modification would be that we are living in symbiosis with mitochondrial bacteria, similar to how we live in symbiosis with our gut bacteria, rather than them being classified as "organelles" of eukaryote cells.
- pleurotus 2y ago
  That's more a flaw of classification systems though. Because even if they comprise a distinct life form does not mean they need to have a unique species. Consider lichen, which comprise two (or more!) separate "species" which becomes a meaningless distinction when they cannot survive on their own, or even if they could, not in a form recognizable in any wayas they were when they were a part of the symbiotic system
  - hughesjj 2y ago
    I mean at that point what do we consider multicellular organisms? Did you see what was going on with those frog skin cells and "xenobots"? Also, our gut bacteria kinda makes us a symbiote at a larger scale.
- pishpash 2y ago
  Of course it is classified. In Wikipedia itself there is a phylogenetic tree listing its closest relative the alphaproteobacteria: https://en.wikipedia.org/wiki/Mitochondrion#Origin_and_evolution https://en.wikipedia.org/wiki/Mitochondrion#Origin_and_evolu...

agumonkey 2y ago

I was looking for specific notions explaining the emergence of this kind of endosymbiosis, anybody has links ?