Mitochondria Are Alive
asimov.press
asimov.press
In Earth’s history, mitochondrial endosymbiosis occurred once. Without that you don’t have the energy budget for complex life. Moreover, there may be a narrow window where it can happen: modern microbiology has defences and selection pressures that it make inhospitable to the hobbling chimeræ the first mitochondrial cells would have been.
Until mitochondria, the emergence of life from nothing is plausible. With mitochondria, its progression to complex, multicellular and intelligent life makes sense. Both processes in small steps can be replicated, more or less, in the lab. But that one moment is not and has not been. As a result, I think the universe has lots of living slop but very few plants and animals.
(Aside, look at ATP go: https://www.youtube.com/watch?v=lUrEewYLIQg&t=939s)
That does not mean that other lifeforms in different planets require mitochondria or equivalent organelles. As long as they can perform the necessary chemical reactions (which could be different in a different environments) and extract enough energy, they should be good.
How did mitochondria evolve in the first place? Could they have remained as independent organisms and use their massive energy budget to evolve independently?
That mitochondria are conserved as an independent organelle across almost [1] all eukaryotes, across billions of years of history, suggests this is something the nuclear can’t easily in house.
That could also suggest that any other strategies were just out competed by this one and lost the opportunity to develop further.
Absolutely. It also means--however--that any niche where alternative did exist, when exposed to mitochondrial life, they lost.
Now that I think about it, it would be pretty funny if we're this universe's cheela [1], a freakishly overclocked biosphere that runs faster not because it had to but because it happened to.
It's perfectly possible that mitochondria are the dinosaurs of "cell powerplants" that just haven't encountered the asteroid to let other (ultimately better) solutions develop.
True, it's an anaerobic ersatz cnidarian [1] that may be an escaped cancer [2].
wow. we could be surrounded by so many extraordinary organisms and not even know it because there's so much variety just in our own backyards
https://www.theatlantic.com/health/archive/2012/12/1-458-bac...
>It is the first eukaryotic genus to be found to completely lack mitochondria, and all hallmark proteins responsible for mitochondrial function. The genus also lacks any other mitochondria related organelles (MROs) such as hydrogenosomes or mitosomes. Data suggests that the absence of mitochondria is not an ancestral feature, but rather due to secondary loss.
Everything exist by " accident", and that means that is the result of random events that happen unexpectedly in unimaginable places, leading to an environent were the outcome of this events causes more random events.
Why universe insist in making life so uncommon if it has the secret to create and replicate?
DNA isn't just abstract information, it's also where the first step of protein / enzyme construction occurs. DNA location matters.
SFI Complexity podcast has a few great episodes on this
This presumes that their energy budget was massive to begin with, rather than being selected for over time.
There are independent mitochondrial relative. They are mostly parasites that live inside cells.
From https://en.wikipedia.org/wiki/Mitochondrion
> The proto-mitochondrion was probably closely related to Rickettsia.
From https://en.wikipedia.org/wiki/Rickettsia
> Being obligate intracellular bacteria, rickettsias depend on entry, growth, and replication within the cytoplasm of living eukaryotic host cells (typically endothelial cells).
> Most notably, Rickettsia species are the pathogens responsible for typhus, rickettsialpox, boutonneuse fever, African tick-bite fever, Rocky Mountain spotted fever, Flinders Island spotted fever, and Queensland tick typhus (Australian tick typhus).
Or trillions or tens or ones. Depends on what number you put in the exponent. Currently, we don't have useful constraints on that figure.
(A lot of popular astrobiology pulls the "if we could only get 1% of the market we'd be billionaires" schtick.)
Here's a thought, also; maybe once this has happened, it tends to crowd out needing to happen again.
Would love to know the source if you have it.
> The first occurred about 2.2 billion years ago, when an archaea swallowed a bacterium that became the mitochondria.
> The second time happened about 1.6 billion years ago, when some of these more advanced cells absorbed cyanobacteria that could harvest energy from sunlight.
> And now, scientists have discovered that it’s happening again. A species of algae called Braarudosphaera bigelowii was found to have engulfed a cyanobacterium that lets them do something that algae, and plants in general, can’t normally do – "fixing" nitrogen straight from the air, and combining it with other elements to create more useful compounds.
So, tremendously rare, at least to our knowledge at this time, but not a one-off.
More broadly, it leads me to wonder whether cellular life might eventually/might have at some point specialize towards hosting novel endosymbioses.
Either scenario, assuming what I'm saying isn't just total nonsense, would seem to make the state of mitochondria less of a one-off event and more of the instance of that event we are around at the right time to observe.
Those other membrane bubbles inside out cells don't have any of the machines we expect to be associated with cellular life- but you never actually know!
Also, this is def not a 1-off, and happened many times, including chloroplasts in this new nitroplast we found https://en.wikipedia.org/wiki/Nitroplast
If everything however unlikely is likely because creation is unfathomable, sure.
There is nothing specific about our consciousness that makes it unique to earth.
"Mistaking the map for the territory is a logical fallacy that occurs when someone confuses the semantics of a term with what it represents. Polish-American scientist and philosopher Alfred Korzybski remarked that "the map is not the territory" and that "the word is not the thing", encapsulating his view that an abstraction derived from something, or a reaction to it, is not the thing itself. Korzybski held that many people do confuse maps with territories, that is, confuse conceptual models of reality with reality itself."
But how did anyone verify there is an underlying reality outside consciousness? It's just an assumption right?
It's the stuff which continues existing when we stop believing in it.
https://m.youtube.com/watch?v=0lKliaFllPA&t=910s (timeatamped)
We don't. But we know we can't replicate it, have never observed it, don't seem to find half-assed attempts at it in the wild and that there weren't multiple competing chemistries that found themselves co-existing, there was one.
I find it remarkable that chlamydia cells, fully enter host cells and live there stealing of resources.
I would call it evolutions “half-assed attempt” at endosymbiosis. (Disclaimer: evolution has no goal)
Chlorophyll probably outcompeted retinal [1]. (The stuff in our eyes.)
The reduced form of my claim is that mitochondrial life so freakishly outcompetes its competitors as to be in a class of its own. Which still yields a rare Earth, albeit a first among many.
We don't know the fundamental energy requirements of complex life. The threshold may be 2%. It may be 19.995%. If non-mitochondrial metabolism is common, the Earth would still be rare in that we'd be the "fast" biosphere. The high-octane species. Given how power-intensive intelligence is, that might be material. (Or it might not.)
More fundamentally: we have no plausible alternate chemistries that don't bootstrap on mitochondrial life. (We do for photosynthesis.)
100%. The evolutionary pattern of our solar systems formation and earth ending up, temporarily, in just the right spot isn't rare but (was) a matter of time/timing.
Now one could argue that the stellar objects carrying specific components necessary for life did not hit every or many solar systems but every single simulation (in my head) of the big bang's aftermath reveals that it's at least multiple hundreds of thousands, given how much the observable universe has revealed so far in the places that we looked.
I’m not convinced there’s a reason to think intelligence is inherently power-intensive. Based on our limited samples, it’s certainly energy intensive, but there’s no reason it couldn’t be slowed down. In a world with less power available to life, one would expect speeds of e.g. predators and prey to be slower, allowing a slower intelligence to still provide an advantage.
Sure. But we know it empirically is. Our brains are expensive.
But our brains have mitochondria. As do our prey, and our predators. Is there any reason to suppose that the absence of mitochondria implies less potential for intelligence, instead of the potential for equal but slower intelligence? Mitochondria are about power production, not energy production -- they are a very dense source of ATP, but the reactions they use would provide equal energy even if less concentrated.
What are you basing this on?
I say cannibalized, because avoiding eating your own species is a higher brain function that would've came far later, so it came down to eat or be eaten. Still is frankly.
>I say cannibalized, because avoiding eating your own species is a higher brain function that would've came far later,
Species (maybe only [di?]morphic ones) rarely kill other instances of their own species, only maim - usually to the point of socially/reproductive shame/selective behavior; as infra-species violence is usually done for sexual signaling.
Like squirrels neutering each other, giraffes ruffling neck-fights, etc, it is not generally advantageous to actually hurt the opponent more than needed to signal dominance in a social hierarchy - this "gentleman" agreement is similar to all emergent collusion behavior exhibited by "free agents" in a limited pool; even without communication, the self-interested incentive to all follow a convergent rule will eventually emerge. Whether it be price fixing, social norms, or any other system where partially-regulated complex systems compete.
Additionally, for cannibalizing to be a positive-selective-trait, the species would had either adapted to eating the liver - the "resilience/filter" of a system, or had been "lucky" enough to identify/delineate/get repulsed by it.
Eating your own species liver would be nearly self-defeating-ly impossible from an evolutionary point of view and avoiding it but still eating your own species is too "taboo" (evolutionary artifact) of a benefit to ever randomly stumble into, especially against the benefits of 'good-sportsman-ship'.
Anyway, an interesting point about evolution is that things had to have been eating other smaller things long before the brain had enough processing power for "Species Recognition". It would've initially been a simple brain and rod/cone eye neuron and motor neuron in a fish that executed primary the rule of "See movement then execute tail wag, open mouth, close mouth" in that order. It takes like 5 neurons wired in a specific way to accomplish that. The first neurons had to have been that simple. Indeed the chain reaction of "input photon and convert energy into motor neuron charge potential" had to have been the actual chemical process that eventually developed the first neuron to begin with.
It was only after MUCH more evolution that avoidance of eating one's own species would've been possible by visual inspection of the prey. However, it's true it could have been a 'taste' signal where the scales of your own species had a bad enough taste that you spit it out rather than eating it, and that can be accomplished also with a brain of only a few neurons.
I am not a biologist obviously.
Because of the "food chain" actually being a pyramid, those organs contain the same "toxins" that are to be avoided, exponentially accumulating in whatever "organ" had the function to add resiliency by storing these toxins.
However, liver eating is a moot point regardless, because evolutionary theory would suggest eating toxins would have a bad taste/smell, so that organ would simply be avoided, while eating the rest. So it has no bearing on whether cannibalism happens or not.
>>> ...for cannibalizing to be a positive-selective-trait, the species would had either adapted to eating the liver - the "resilience/filter" of a system, ...
>I have no idea what you meant by liver. Maybe it's a biology term I'm unaware of. Certainly you didn't mean the organ. lolz.
>writes a very unclear sentence and then blames the reader...to accuse the reader of bad-faith motivations....
Did we both edit our posts....to improve accuracy, increase resiliency, and to compete ideas?
literally mesa-Q.E.D.
neither of us had the incentive to either acknowledge our edits nor call the other out,
nor face the (perceived, social, higher-order) dissonance of being slightly unclear or "wrong" due to our own ego/self-interest (conscious, lower ordered self);
the emergent behavior then (gentleman's agreement) was to preserve our own ego's and not call out each other edits - which most people would never do, because:
our slightly varied ideas compete more fiercely for the same finite pool than other, completely niche-unrelated abstractions.
we are 4 layers deep now, but ill reduce for conciseness (for lurkers fwiw)
dont shit where you eat <- evolved trait to avoid waste-by products
dont hit a man when he's down <- highly effective altruism is still beneficial
morality is cowardice <- ties this all together from highest order (ego) to the id (fear of being replace)
we are now full circle.
A decently display of faith should at least warrant a re-parsing of my (actually perfectly unambiguous) grammatical clarity, of which you implied was less than so.
Warrants the question, why not admit my posit:
That slightly-varied entities competing for the same/similar finite/limited supply pool of resources/demands will tend towards -- as an emergent behavior of both short-term disorderly self-incentivization and the stochastic long-term higher-order unconscious collective collusion -- the tendency to compete until dominance over **reproductive** rights are secured, but no more. The more fiercer the competition, the more selective the sieve, the more the dominant traits propagate: up to a plateaued point. Further complexity/order can than be more efficiently achieved by lessening the furiousity of the competition to a point of cooperation, which then innately lends itself to more hierarchy, efficient use of energy.
Take it from Roko the Replacer:
According to Sigmund Freud's psychoanalytic theory, the "fear of being replaced" is most closely linked to the concept of "castration anxiety," particularly within the context of the Oedipus complex, where a young boy fears his father will punish him for desiring his mother by castrating him, essentially rendering him "replaced" in her affections.
Free to continue discussion; but the under the Ego lies the Id, and I'm not well versed in that science yet, still approximating.
>However, liver eating is a moot point regardless, because evolutionary theory would suggest eating toxins would have a bad taste/smell, so that organ would simply be avoided, while eating the rest. So it has no bearing on whether cannibalism happens or not.
We have nothing but confirmation bias and little time to test anything macro.
However, we do have contra-positives and the like; in this case, we (ourselves) avoid Liver in some animals, and notice the M.A.D-avoidance agreement among more socially-complex systems.
You shouldn't eat your young, you should eat your rival tribes young.
Especially because the young hand't accumulated much toxins yet, relative to the adults. And it is easier to bash babies over rocks than grown adults.
(per Carl Sagan)
It is advantageous to beat a rival and take their energy even within a species. That's part of the whole 'survival of the fittest' thing. Preserving them for cooperation or something like slavery happens, but it's a rare strategy specific to intelligent animals like the GP implies.
>reserving them for cooperation or something like slavery happens, but it's a rare strategy specific to intelligent animals
I should had clarified, this is lower, more intuitive behavior. It is not, which is why it arises emergently in lower-complexity/class systems.
>beat a rival and take their energy even within a species
And if done with literal, figurative, social, and complex "CLASS", it is literally sexy too!
National Geographic is entertaining for many dimensions of reasons.
Actually dismembering your sexual-rival and literally consuming their poor caloric conversion is pitifully inefficient compared to making them a sub-ling, whether it be via hen-pecking or innate dominance. It made sense before sexual dimorphication (moreso), but less so now.
Ladies like a gentleman, and gentleman's agreements are literally non-colluding emergent behavior to abide by unspoken higher-order rules for one's own explicit conscious self-incentive (lower order, high entropy), but also the implicit collective unconsciousness incentive (higher social order, lower entropy)
Both are reslience traits, which only emerge when selected for.
But really, and "slightly" varied instance of yourself is the "most" likely to compete for the same, infinite pool of resources.
There is also secondary endosymbiosis, where the endosymbiont organelles of one eukaryote are engulfed and incorporated into another eukaryotic cell to create a new type of endosymbiont. This has happened at least 8 times.
There are also theories that some other organelles are the product of other endosymbiosis events, many of which also have some of the hallmarks like their own genetic material. These theories are more speculative though.
It's also worth noting that while eukaryotes obviously gained some important capabilities from incorporating these endosymbionts, the endosymbionts they incorporated obviously managed to just evolve to perform those functions directly. Further, while one of eukaryotes' distinguishing features are mitochondria, there are several other major differences, and mitochondria are not believed to be what made eukaryotes better able to evolve complex multicellularity. Prokaryotes have indeed evolved multicellularity dozens of times, and we arbitrarily set our definition of complex multicellularity to distinguish from what prokaryotes have achieved.
Observation of prokaryote/prokaryote endosymbiosis would be real evidence against the rise of eukaryotes being the or one of the main limitations in the number of intelligent species in our galaxy.
There are no known modern prokaryotes capable of phagocytosis. Presumably the extinct prokaryotes who were capable, including those from the same lineage as the eukaryotes but which did not pick up mitochondria, were outcompeted by the eukaryotes who occupied the same niche.
Other changes like the origin of the cell nucleus and many other organelles can be readily explained by other malfunctionings of the phagocytosis process. Basically once you have the ability to pinch off parts of your cell wall into internal structures, you suddenly get a bunch of internal structures made of stuff that look surprisingly like cell wall.
I would argue that the type of event that produced mitochondria is likely not rare at all, but certain pairings will so outcompete others that we should expect only one to survive and dominate.
People have theorized even a 50 base pair segment of RNA might be capable of building exact copies of itself, either by snapping in half and auto-forming the same other half, or by other means. Since there's two sexes, it was perhaps a "halving" at that level, that early on, which led ultimately to TWO sexes, but that's a side point.
We can even predict the probability of any 50 base pair ordering. It's 1/(4^50). That's 30 zeroes in the denominator. Now consider that a single glass of water has 10^23 molecules. That's 7 orders of magnitude difference. So the amount of water you need to cross that magnitude threshold is 7. Turns out that's exactly the size of an Olympic swimming pool. 10 million cups of water.
So statistically, a planet with an ocean volume only as large as a swimming pool has the "Statistical Power" (power of large numbers) to find ANY 50 base pair combination (give or take an order of magnitude or two) Once it finds a replicator, life has started, and so has evolution. And that's guaranteed within the first minute or so, at reasonable temperatures. Now multiply that time by the average age of a planet, and you begin to realize, statistically life is guaranteed, in any chemically diverse scenario with reasonable temperatures.
You can wave big numbers around but none of that makes a convincing argument; it's not hard to construct any number of scenarios where self replicators are started but don't lead to true life.
Also you're comparing a gram of water to a bunch of bases; H2O is not DNA.
Insofar as your H20 vs DNA comparison, I merely used water as a way to show relative "scale". That is, HOW MUCH fluid volume (relative to the order of magnitude of size of atoms) would it take to contain the requisite number of RNA. Because when it comes to probabilities of finding astronomically unlikely combinations, astronomically large numbers is key. I think in a mole of random Rubicks cubes, hundreds will be "accidentally solved" (I forgot those numbers, so check my math, on that one)
The reason I threw in the "give or take 2 orders of magnitude" caveat was precisely because I knew someone like you would accuse me of relating H20 to RNA in a way in which I didn't. Other planets will have different atoms, not necessary water-based life, but planets even the size of a swimming pool have the "numbers game" power to create life.
For example, if you ask most people how many randomly occurring Rubiks Cubes will just be accidentally solved even with Avogrdro's number of them, their answer is usually zero; and unsurprisingly they're the same ones claiming there had to be a God to create even the initial replicator.
Those RNA molecules are also going to be ~two orders of magnitude larger than a water molecule, so you're going to need a bigger pool...
To actually replicate, some loose ingredient molecules must also be present, and in reasonable quantities to be at hand in any given place in the pool.
The argument you are actually making is that a vessel that is filled with randomly assembled chunks of RNA not shorter than 50 base pairs each, the quantity of which equal the number of molecules of water in an Olympic pool, would contain life with probability ~1.
Now, the ocean is large, and a billion years is a long time, but I'm a long way from convinced that the chance of life is 100% on any given suitable planet.
Especially when you multiply by the number of swimming pools of all ocean water (10^14) by the number of minutes of the history of Earth (10^15), and consider that the probability of the accidental 50 base pair replicator forming needs to have those 29 extra zeroes, in the numerator (not the denominator). So the likelihood, now that I add more info, has just gone up 29 orders of magnitude. lol. (BTW. the 1 minute assumption will be temperature dependent, and is a guess at how long it takes reactions to take place).
The whole thing is a rough approximation like the Drake Equation is, and each number is an estimate. If you want to attack the Thought Experiment, at it's weakest point, just question the initial assumption, which is the biggest guess of all, that some unique 50 base pair RNA can replicate itself.
I don't think it is a very persuasive argument, because it is possible that modern microbiology has defenses because it has mitochondria. I know almost nothing about cells from a few billions years ago, but it seems plausible to me that they were ambivalent towards intrusions of other cells, it can be beneficial or disadvantageous depending on an intruder. Moreover beneficial intruders could give a lot of evolutionary advantage, not like today, when all important things (like mitohondria) are already here. In theory, bacteria could benefit a lot, but there are no ecological niches for a bacteria with mitochondria, all are claimed by some eucaryotes, which are highly adapted.
It is a very common thing in evolution. For example, there are bats, but they cannot evolve and replace birds, because there are birds. Bats have their niche, but they cannot outcompete birds at being more birds than birds. If they were given a chance, then maybe they could try to catch up with birds, but they didn't have a chance and they will have it only if some cataclysm will wipe out birds and leave bats.
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.
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!
>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!
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.
This seems to require a high amount of curation of training inputs, but I haven't done real digging into it, just going off the more casual "all of stackoverflow" or "all of reddit" type comments frequently thrown around. But if there is such a curation I'd agree, I just don't think there is that curation.
And my grandmother is a bicycle.
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.
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?
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.
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])
mito is like <100k bp vs 3000000k bp in human genome (bp = base pair = "character" in a string)
principle derives from the concept of "the selfish gene" or "the red queen" these famous books on the topic. Arms races between X and Y chromosome. Arms race between nucleus and mitochondria, and so on.
or put it this way. why do all animals have sex? because it generates gene sequences that confer fitness more efficiently than self-replication (which is the typical repro method of unix programmers)... .. generates such gene sequences for NUCLEAR DNA that is, mito DNA comes from mom only (the red queen.. .. "mitochondrial eve" ... "y chromosomal adam".. etc). and thus the mito is fundamentally unable to wield the power of evolution, completely evolutionarily outclassed by those nuclear chromosomes. thus exporting all its genes to the nucleus, conferring advantage to all such progeny with their superior power supply
Energy flow is the difference. but then everything has an energy flow. Losing and gaining electrons. So it is possible that literally everything is alive, don’t you think? Maybe the problem is is that we’re trying to make a definition where none ultimately really exists.
Defining an arbitrary line and then attaching labels does not really add to understanding.
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.
I have no idea in what context “mitochondria are alive” notion might be useful (but it doesn’t mean there is none).
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.
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.
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
Since all humans were just 2 cells at one point. It seems to follow that the entirely of the code for what a human is, is contained in just those 2 cells. Not just code for a finger. But even code for our deeply ingrained fear of snakes. Was just at one point contained in those 2 cells. Kind of blows your mind.
If they are separate living organisms, then there seems something recursive about humans if they can be just 2 cells at one point.
To reframe it: what you’re really doing is arguing about the definition of alive. In this case my opinion is: who cares. I fail to see how expanding the definition or being precise here adds anything.
Refining the definition of something often helps provoke new understanding and tests of the limit of that refinement. It seems like a critical requirement in the "form a hypothesis" step of the scientific method.
It seems to me that the alternative to people being alive quite quickly reduces to nothing is alive by way of information theory.
It is more related to the philosophy of science.
P.S. I'm not implying his grandfather was Gimli even if Gimli theoretically had two grandfathers.
The philosophy of science is something that has only existed since the practice of science became widespread.
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
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.
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
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.
There has been debate over whether mitochondria can be called alive since at least 1890. For many years the vast majority of mitochondrial biologists have avoided the binary alive/not alive classification because there is a spectrum of 'livingness' and we can draw the line anywhere we like.
Picking a different line position is not scientific, it is semantics. What do we mean by the term 'alive'?
The article presented a profound new way of viewing the living state of mitochondria that was going to transform the world. It said nothing new, and failed to make any reference to the long term debate.
But it was a nicely written interesting article and mitochondria are going to be hugely important therapeutic area in the future.
"Clinical potential of sensory neurites in the heart and their role in decision-making"
https://www.cam.ac.uk/research/news/11000-year-old-living-do...
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?
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:
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.
(1) “Someone hypothesizing a very dramatic theory with weak evidence was considered wrong by most colleagues but later vindicated when strong evidence emerged”. (No mention of thousands of other dramatic hypotheses that turned out wrong.)
(2) “You may have heard in unsophisticated popularization that [philosophical claim ultimately hinging on semantic distinction] was false, but really it’s true [assuming my preferred semantics]”.
Aren't we all tired of this yet? Aren’t science journalists embarrassed by this stuff?
Firstly, the one who makes the logical fallacy inference that this implies all or most dramatic hypotheses are true is ... You. Not the author of the article. The author of the article is only talking about one specific theory. If I tell you a story about a chicken crossing the road, I'm not obligated to tell you about all the chickens who don't cross any roads.
Second, there are plenty of examples of established theories that started this way, and so it is important that scientists consider controversial hypotheses with an open mind. Speaking in any context, it's very easy to dismiss evidence that contradicts your views prematurely. It's sort of a defense mechanism we all do. It's important to recognize such a bias and be willing to acknowledge where your own theory could fall short when you see it.
In other news, Local Man Didn't Win Lottery
Excellent book!
I’ve only read The Vital Question, but I felt it was a great introduction to biochem for someone not in the field.
This assertion is made but not supported. I don't think I understand the importance of this distinction, assuming that everyone already agrees about the evolutionary and mechanical facts about mitochondria, but as far as I can tell, no one disagrees that mitochondria were originally free living cells, or that they have their own DNA, or any of the other relevant facts about their origins or how they work in the cell. It's merely an argument about what it means to be alive. Which is philosophically interesting, but practically unimportant for the practice of biology.
This seems like a purely semantic debate with no broader importance.
More than 95% of all proteins located in the mitochondrial compartments are encoded by the nuclear DNA, synthesized in cytoplasmic ribosomes and imported into mitochondria. These include factors that regulate mitochondrial DNA (mtDNA) gene expression such as mtDNA and RNA polymerases, mitochondrial transcription factors, RNA processing and modifying enzymes, transcription termination factors, mitochondrial ribosomal proteins, aminoacyl-tRNA synthetases, and translation factors (1, 2).
It's clear that a mitrochondrial element can't live for long without the presence of the host cells, so, like a virus, it doesn't meet all the requirements to be considered fully living.
The question posed is whether we consider mitochondria to be "alive". It's just a word, who cares. What do we do differently given this assumption?
What practical purpose does studying ancient civilizations have? Why do we send expensive telescopes into space to study faraway galaxies and try to uncover mysteries of the big bang? When can we expect the results from number theory to lower the price of gas at the pump?
Knowing that mitochondria have their own DNA is knowledge. Knowing that they reproduce independently of their home cell is knowledge. Learning whether they evolved from a separate viable organism would be knowledge. Learning whether we can make them viable, or breed them separately, and use them in therapies -- all knowledge.
Whether they are "alive" or not is just the definition of a word.
A subset of scientists want to come up with an operational definition of "What is life", which may or may not include things like viruses and mitochondria. As you say, it's mostly definitional, but by defining this, we can potentially make our understanding match up with the latent reality.
2) By "organism" I assume you mean "cell" since humans have several thousand different species with their own DNA living on or inside the body at any given moment. We can speak of animal cells, which have two (species and mitochondria) - and plant cells, which have three (species, mitochondria, and chloroplasts). If there can be one two or three, I don't see why there couldn't be even more.
3) Mitochondria are usually sequestered within the cell, which limits their exposure to immune cells. The immune system primarily targets pathogens that are outside the host cells. In fact, some pathogens can exploit mitochondrial pathways to evade immune detection - the most famous of which is HIV.
And chloroplasts have separate DNAs from the species ones? That really is also eye-opening.. Biology is full of wonders.
Once you accept mitochondria as alive, you might be motivated to explore its "potential" niche, as described by the author. The example of implanting cross-species mitochondria in human cells (e.g. from a gorilla) might lead to novel therapies.
It's about breaking outside the box of mitochondria having to live inside specific environments.
Edit: to your point, there are plenty of scientists interested in studying viruses and much debate about whether or not they are alive. Ultimately it probably doesn't matter.
I do think when you consider mitochondria to be alive, it broadens the scope of your thinking because you start considering each characteristic of life in relation to mitochondria. You might not be motivated to do that without thinking in those terms.
I think the main point the author is making is to not fall prey to reductive thinking about mitochondria's potential and less about the question of "aliveness". We were all taught about mitochondria producing ATP, but it sounds like it serves many other functions and there's a lot more to explore about its potential in synthetic biology and therapeutics.
This meant, importantly, that we learned cells did not always need to evolve a functionality from scratch, but could acquire it through phagocytosis.
It's also a useful tool for studying evolution for many reasons.
We know they have DNA, we know they reproduce independently of the host cell, we know to a degree why they tend to move to both sides on cell division. We know lots of stuff about them and we can always learn lots more. Whether they are "alive" or not has absolutely no bearing on that, other than to naval-gaze.
This sort of definitional argument is not interesting to me.
For example I could easily see a scientist asking the question, "if mitochrondira are not alive, at which point did the phagocytosis of the initial prokaryotic cell lead to the mitochondria not being alive?" "What components were lost in the cell that lead to the loss of life?" I agree these aren't particularly useful, and are ultimately definitional, but definitions matter a lot in science, especially when paradigms change.
The question in the abstract is not really useful except to answer trick questions in bar trivia.
> It seems Mitochondria are not bound to their host cell; they can travel between different cells. Although different species carry distinct mitochondria, experiments show that mitochondria from one species can be transferred to another.
> In 1997, scientists isolated mitochondria from chimpanzees and gorillas and showed that they are naturally internalized and integrated into human cells. Notably, the addition of external mitochondria even showed therapeutic benefits in heart failure and spinal cord injury. Thus, the potential niche that mitochondria can live in is greater than their effective niche.
So it seems like they are more symbiote than organelle, that's amazing.
A good example of a memetic equivalent of endosymbiosis could be Christianity - Catholicism in particular. Historically, as Christianity spread around the world over the two millenia, it would often adapt and absorb indigenous beliefs and practices of converted populations[0]. Many would die out over time, but some got integrated into the core and exported globally.
It's just the right time of year to think about Christmas[1]. Can you imagine Christianity without one of its two core holidays? That makes it probably the closest memetic equivalent of a mitochondria - you can still see in it the distinct outline of an ancient Roman festival that was absorbed early on, but all of its memes live on in Christianity. In our times, the holiday is vital to the overall faith, and itself could not exist independently[2].
--
[0] - I've always been taught that this was intentional slack to make it easier for people to accept a new religion, but nowadays I feel it might have been a fundamentally unavoidable outcome. Maintaining organizational coherence and belief consistency at a scale of a whole continent requires communication and bureaucratic technologies that didn't exist until the last 100-200 years.
[1] - Or at least so most shops would have me believe; in western commercial calendar, Christmas starts when Halloween ends.
[2] - Well okay, I admit this might be a weak part of the analogy - in the western world, Christmas got commercialized to the point it could likely survive as an independent secular tradition.
Certainly, in the Eastern Orthodox church it's commonly called "baptizing the culture". The idea was/is to take what is good from a culture and to incorporate it to help people become Christians. Also it's a core part of Christian missionaries to learn the language and translate the scripture, and if needed to create a written form of the language.
So I'd agree Christianity has always been a bit of a symbiosis of cultures, analogous as you said to endosymbiosis. It started purely Judaic, incorporated large parts of hellenism, and spread globally and imported more bits. The Jewish and Hellenic pieces aren't completely mixed, sort of similar to a mitochondria actually.
Then again it makes sense of a religion with a core belief that God became man and created a symbiosis of the two as their savior.
Name a single biological entity that has a better PR department. The only one that comes close is Athlete's Foot, which makes the victim sound cool.
My biology classes did have us gene editing bacteria to chance its color. That was fun!
> The only one that comes close is Athlete's Foot, which makes the victim sound cool.
The best cure for athletes foot is a 30 minute soak in diluted bleach. Get a wash basin, fill it with warm water, and add enough bleach so that it tingles a little bit.
Do this every other day 3 times, e.g. Monday, Wednesday, Friday. Problem solved.
Make sure to clean out the shoes as well, ideally not wearing any infected shoes for a few days at least, and soak the insides with Lysol a few times to prevent reinfection.
The basis of this technique is that you have skin to spare, and your skin regrows.
Unlike the fungus.
Are there mitochondria in neurons?
Yes [1].
RBC's don't need them because they are incredibly low-metabolism. It's energetically cheaper for the organism just to make them, let them go for a few months, and then recycle the components.
As far as I’m aware we’ve never worshipped mitochondria. And unless you want to count eating which is technically true but not philosophically so, we don’t sacrifice plants or animals to mitochondria.
The explanation doesn't get much better at higher levels. You have the Krebs cycle which biology people religiously memorize but it doesn't really explain much either. The actual interesting part is usually handwaved away as "magical enzyme/protein" catalysis. Understanding how the mitochondrial proteins/enzyme catalysts function would usually require a graduate degree, and maybe a background in biochemistry and biophysics.
Love this line! Phoenix Worm came to mind.
Also interesting: mitochondria can join (often to rescue one failing due to transcription errors) and be transported to other cells across bridges (to supercharge the recipient, as they want to do now for immune cell therapy).
Now multiply that by (the ocean) and multiply the interactions by X billion years.
It seems impossible for a symbiosis like this not to have happened.
No matter how low the odds are, the counts of those potential interactions bring this outcome to a certainty.
https://www.reddit.com/r/spaceporn/comments/1af4prs/if_you_w...
Which really should tell people how rare the development of mitochondria was if it has only happened once here.
1. Died off or regressed
2. Plateaued
3. Is sufficiently far away or stealthy enough for us not to notice them (whether intentionally or not)
I've often thought about the whole communications bubble argument... I don't buy it. I'd imagine, like wifi, other civilizations will maximize their communication bandwidth, which essentially also maximizes entropy which looks like noise to us. Compression, encryption, redundancy, multiplexing over frequency and amplitude and time, directional antennas and signalling... That's what we've done in under 100 years.
I know there's stuff like organic markers etc, but if machines are doing most of the heavy lifting I don't think that would matter. Same with stuff like hydrogen emissions lines. Whatever is abundant will be used for "settled" and "dead" solar systems alike.
That is simply not true. Events are classified by probabilities, and there are a whole lot of things with a probability a lot less than will happen across the whole ocean across however many billion years.
All the higher-probability events will occur, yes. But a specific sequence of multiple extremely low-probability events? That then continues to replicate before it gets wiped out by chance?
Not a certainty, absolutely not. Contrary to what you say, it matters very much exactly how low the odds are.
> No matter how low the odds are, the counts of those potential interactions bring this outcome to a certainty.
"No matter how low", really? Are you suggesting that your multiplication result is infinite? Otherwise, no matter how big the result is—even if it's Graham's number or TREE(3)—but as long as it's finite, there are odds so low that bring the outcome extremely unlikely.
The thing is we don't know even a ballpark estimate of the odds, but you were saying like we have a lower bound of the odds. The universe is unfathomably huge, true, but we also don't know if abiogenesis is less unfathomably unlikely.
Are we saying that mitochondria have their own life cycle inside of a cell? living/dying/replicating in the span of the "life" of a single host cell? When a host cell reproduces, how does the mitochondria get produced in the new cell to get things started?
Cant wait to research this later.
Each half of the cell keeps the mitocondria that were living inside it.
But I have never been a fan of that argument either, both seem alive to me.
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.
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.
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.
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.
... 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.
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.
If a mitochondria is not "alive," then is it dead? Even if it is taking part in an active, living cell?
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?
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.
> A mitochondrion (pl. mitochondria) is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi.
and the "classification" is introduced with
> There are two hypotheses about the origin of mitochondria: endosymbiotic and autogenous.
But if you wanted classify them based on functionality rather than evolutionary history, I'd say they're more like viruses. They have only a handful of genes themselves, and exploits the nucleus' genetic material for all the other proteins it needs to function.
General acceptance of the endosymbiont theory is a relatively recent (much less than 50 years) phenomenon.
"Alive" is a fuzzy boundary in concept space that helps humans navigate a fractally complex world. It's not a fact about mitochondria that either hides or reveals structure. We can harness the potential of viruses, and reasonable people can disagree on whether they are alive.
This statement is very interesting for two reasons:
1) We not consider mitochondrial DNA as part of the human genome when it's clearly is and can be used to establish the maternal genetic lineage.
2) Traditionally, we always think of telomere reduction and genetic mutations as the root cause of aging but not mitochondrial genetic damages.
A lot of research is looking into the role of mitochondrial damage as causes for a number of conditions.
There seems to be a strange, half-hubris, half-pride vein that runs through Humanity that would see us as lesser for being hosts to benevolent bacteria, despite us very obviously being unable to survive without benevolent bacteria.
Maybe we should think of it like we do for other forms of energy and how I be thought we did think of it already but was of biochemical energy expressions. Along with kinetic energy, potential energy, chemical energy. Surely there is a number determined for the maximum lifetime energy output potential (work) of a single mitochondrion. While it is plain and simple, that's just life for you
Maybe we should think of it like we do for other forms of energy and how I be thought we did think of it already as biochemical energy expressions. Along with kinetic energy, potential energy, chemical energy. Surely there is a number determined for the maximum lifetime energy output potential (work) of a single mitochondrion. While it is plain and simple, that's just life for you.
Even if you stretch the others real hard, I don't see how you'd argue that the Earth "reproduces." Especially not the more rigorous definition of reproduces fertile copies of itself which can evolve.
Maturana and Valera gave a brilliant definition of “living” in Autopoiesis and Cognition: The Realization of the Living” (1980). But their writing style will make this a tough read. Terry Winograd write a useful summary if Maturana’s philosophy in his computer science classic “Computers and Cognition”.
Interesting analogy, made more interesting still if one replaces "heart" with "brain."
And what if you reverse mitochondria and host cell? If you remove the mitochondria, is the host cell still alive? The analogy would be to remove the heart from its 'host' environment, and asking if the remaining body still can be called alive.
"for a man cut open is, so far, not a man. And if you do not sew him up speedily you will not see organs, but death."
https://x.com/niko_kukushkin/status/1854593093636350387 and https://web.archive.org/web/20170506064530/https://inference...
To me the far more interesting organelle is the ribosome. This elegant self-replicating machine that is highly conserved across lifeforms is fascinating and much closer to the origin of life than mitochondria.
How did ribosomes evolve? Are the ribosomes that we see in modern organisms the first design that did evolve? Why are they highly conserved?
Are ribosomes alive as well?
I think it's the catchy nickname "powerhouse of the cell."
Ribosomes don't have a catch nickname so they get a lot less content produced about them.
If I was a highschool biology teacher I'd probably call them "The assembly line of life." That would stick in people's minds I bet.
My intention in asking the question isn't to create animosity. I'm just curious why the thing that I've observed is a thing.
One is a subset of the other. We're talking about the same thing man, I'm just making the point that I feel that there should be greater emphasis on the subset.
Look at the top thread in this post, people are doing a very similar thing.
I truly think that the pop-sci interest in mitochondria stems from the nickname and for no other reason and to me that's a very interesting thing.
It's a little confusing to look into, because there's a bunch of separate theories about the nature of aging that all involve mitochondria in some way. You will find news articles saying that the mitochondrial theory of aging was discredited because of some study done, but when you look into it, it turns out that what was shown was that some specific variant of the theory was insufficient for accounting for all forms of aging, which is not the same thing. Each mitochondrial theory of aging is a theory about one pathway by which mitochondrial function or dysfunction results in aging damage, the reality is that many or all of these theories are true and aging is the aggregation of damage from all of them, and more pathways we have yet to discover.
Generally speaking, the vast majority of aging damage comes, directly or indirectly, from the accumulating damage from healthy operation of mitochondria over long periods of time, or the accumulation of cells with unhealthy mitochondria that produce damage more rapidly. The ELI5 is that mitochondria produce free radicals, free radicals chemically alter basically anything they touch, and aging is simply the slow accumulation of intercellular and intracellular damage, and if you follow the history of these molecules back to when they diverged from being in a healthy state, it is almost always the result of oxidative damage (e.g. free radicals of the sort produced by mitochondria).
Another ELI5 way of looking at it: you may not know this, but mitochondria only live a couple of days. They are constantly being refreshed in your cells because of the severe oxidative stress they undergo. They also sometimes break or leak, letting those reactive oxygen species into the cell and causing damage. Aging is the accumulation of this damage.
But I said aging was "downstream of" mitochondrial dysfunction. That's because not all aspects of aging is due to reactive oxygen species leaking out like I seemed to claim above. That's just one example. There are cells in your body that have lost all mitochondria, often due to a freak genetic mutation in the mitochondrial DNA of that cell. Surprisingly these cells don't die, but rather switch into a mode of operation where they slow down and live off energy extracted from the intercellular medium and converted into ATP by various molecular systems embedded in the cell membrane. These processes, as it turns out, free radicals out of the cell during operation, spewing reactive species into the body. This ends up being responsible for hardening tissue, lack of energy, and many other symptoms of aging. But the root cause? The mitochondria stopped working in that cell, so still a mitochondrial issue.
Or, the aging of heart cells and the hardening of arteries is largely due to the collection of dysfunctional lysosomes that are full of garbage they are unable to break down. These clutter cells, harm their efficiency, and eventually have enough collective effect as to make the tissue as a whole less viable. Leading to heart attacks and other cardiovascular disease, which is the leading cause of age-related death alongside cancer. Want to guess what these defective lysosomes are full of? Mostly undigested mitochondria, specifically the highly damaged structures of mitochondria that suffered too much oxidative damage from long operation.
Oh, and what about cancer? Well cancer needs A LOT of energy to keep replicating, and so it should be no surprise that many of the mutations among common cancers have to do with genes in the nucleus affecting mitochondrial function, or the various signaling pathways between the nucleus and the mitochondria of the cell. This article covers some of the ways that cancer uses mitochondria: https://pmc.ncbi.nlm.nih.gov/articles/PMC4371788/
The best lay introduction I know is "Ending Aging" by Aubrey de Grey and Michael Rae. The book is meant to be an enumeration of all the things that need to be done to biologically reverse aging, but ends up being more than 80% about mitochondria and mitochondrial dysfunction, because of its out-of-proportion impact on the aging process.
But it's possbile they are descendants of some self-replicating self-catalyzed RNA chain (RNA world)
> Are ribosomes alive as well?
Nah [1]. They do single task. They just read RNA, pick amino acids [1] and make proteins. If a cell were your house, it's like a 3D printer.
Mitochondria are much bigger, they have their own DNA, they reproduce, have a lot of internal structure, they do all the task of a normal cell. If a cell were your house, it's like having a bunch of squirrels trained to wind the clocks in exchange for peanuts.
[1] The definition of alive is complicated, so I prefer a "Nah" instead of a super hard "No".
[2] There are some details I'm hiding, like mRNA, tRNA and even rRNA.
Reminds me of sea slugs that eat plants and then integrate their chloroplasts to produce energy, or my dad who kept swapping the same Honda motor through all our go karts because it was too good to get rid of.
Single cell bacteria have thousands of genes. MT have a few dozen genes. Many of the genes that regulate MT are contained in the cell's nucleus.
I’ve yet to see a convincing argument that information has independent existence. The notion is ontologically absurd on its face.
We see the exact same things also when discussing what is a species and also completely disregarding the reality of horizontal gene transfers etc in the strict, traditional trees.
The models are quite wrong and even reduced wrong.
There is this one famous article that shows how traditional biology would go and analyze a transistor radio, namely just label its assumed components!
Here is the discussion: https://news.ycombinator.com/item?id=31697757
> control bioenergetics across the eukaryotic tree of life.
What types of outcomes do we unlock when we can control bioenergetics?
With that level of proofreading, I'm not sure what else was wrong in the article...
It is a videogame based on/continuing a cheesy scifi novel that played with the concept of mitochondria being alive (also sentient). Sure it's not quite scientifically sound, but it still explains the concept with enough actual facts (very easy to distinguish from the fictional ones), and the ludicrous nature of it all makes it so you won't *ever* forget that mitochondria are in fact a part of the cell and their normal function is being involved in energy production.
I can warrant 90% of people who ever thought about the mitochondrion's existence and function (beyond basic school formation) that aren't working or studying in related fields are just people who played this game. I can bet there's a non-zero amount of scientists that got into this stuff because they played the game as kids or teens.
> If we think of mitochondria as non-living organelles, how will we ever harness their full potential?
Whenever anyone uses the "harnessing [its] full potential" cliché, my bullshit alarm starts buzzing. I don't think this article is bullshit, but...we can "harness" as much "potential" as mitochondria have whether we consider them alive or not.
These things do happen. I was in my 30s before I learned what the "firewall" of a car was...
So maybe the original usage has been subsumed by "power plant", but I think the word has alternative meanings which persist.
Powerhouse is a common way to describe an athlete, a high performance engine, or a very strong stock buy -- it has just moved away from the infrastructural uses.
Kek.
ATP sheep.
I want to help these businesses. Instagram and Facebook have shopping features, but only for a few brands, and they are not available in many regions like India. India has the world's second most active social media users and millions of businesses trying to acquire customers using social media. I want users and buyers to be able to shop directly from posts without leaving the app. I want my payment model on these platforms to create more convenience for customers and reduce business costs.
So, if someone who has worked at Facebook, Instagram, or any other company has valuable advice for me, please share.
How can I make this happen?
Will these platforms allow me to?
Thank you