Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Mitochondria Are Alive

asimov.press

Post reply on HN
Print view View original

141–150 of 412 posts

Re: Mitochondria Are Alive

#141

Post by dylan604 »

JumpCrisscross wrote: post #133
maxerickson wrote: post #89

Earlier quoted context omitted.

So only a few billion planets with complex life?

> only a few billion planets with complex life? 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.)

The astrobiology schtick is just a what if thought experiment though, and nothing proven nor claimed to be fact. It's just a way to show that the scale of the universe is "hugely, mind-bogglingly big" while trying to pull a number that our squishy lobes could comprehend. If 1% of mind-bogglingly huge number, then 1% of that, then 1% of that yields a still mind-bogglingly big number. The laws of large numbers would suggest something as well. Otherwise, "its an awful waste of space"

Re: Mitochondria Are Alive

#142

Post by dylan604 »

rsync wrote: post #125
roncesvalles wrote: post #119

It's such highly unlikely chance events that make me think we really are alone in the universe (we = a sentient civilizational lifeform). There's just no way the long series of extremely improbable events that led to our rise was replicated anywhere else, and it took the sheer vastness of this universe for it to have emerged even once.

There is ~1M bacteria in a single drop of seawater. 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.

The issue here is that the interactions over X billion years are not the same. Each event that happened on this rock would also need to happen else where to have the same evolutionary pressures applied.

Re: Mitochondria Are Alive

#143

Post by marcosdumay »

outworlder wrote: post #80
marcosdumay wrote: post #36

Earlier quoted context omitted.

> 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.

They "behave as" bacteria. Are they bacteria? Are they 'alive' by themselves? That's the distinction.

> 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.

Re: Mitochondria Are Alive

#144

Post by joshuahedlund »

JumpCrisscross wrote: post #118
casenmgreen wrote: post #97

Earlier quoted context omitted.

I may be wrong, but I recall reading recently it had been found the same event had occurred again, fairly recently (hundreds of thousands of years, could be millions) in some species of bacteria or something like that. Here's a thought, also; maybe once this has happened, it tends to crowd out needing to happen again.

> it had been found the same event had occurred again, fairly recently Would love to know the source if you have it.

Might be referring to this: https://newatlas.com/biology/life-merger-evolution-symbiosis...

Re: Mitochondria Are Alive

#145

Post by wrycoder »

MostlyStable wrote: post #56

>Defining mitochondria as “nonliving” isn’t just a classification mistake, nor a question of word choice. Rather, it is a fundamental misunderstanding of the nature and role of mitochondria. It inherently undermines our understanding of biological systems and deeply influences the tools we build to study them. This assertion is made but not supported. I don't think I understand the importance of this distinction, ass…

From an article cited in the OP [0],

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.

[0] https://pmc.ncbi.nlm.nih.gov/articles/PMC23071/

Re: Mitochondria Are Alive

#146

Post by hshshshshsh »

JumpCrisscross wrote: post #78

Mitochondria are why I’m a Rare Earther. 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 l…

If reality can emerge out of nowhere I don't see it unlikely for life to emerge in some other planet.

Re: Mitochondria Are Alive

#147

Post by JumpCrisscross »

dylan604 wrote: post #141
JumpCrisscross wrote: post #133

Earlier quoted context omitted.

> only a few billion planets with complex life? 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.)

The astrobiology schtick is just a what if thought experiment though, and nothing proven nor claimed to be fact. It's just a way to show that the scale of the universe is "hugely, mind-bogglingly big" while trying to pull a number that our squishy lobes could comprehend. If 1% of mind-bogglingly huge number, then 1% of that, then 1% of that yields a still mind-bogglingly big number. The laws of large numbers would su…

Sure. The point is 1% is a huge fraction for a lot of things. Market share. And many reaction cross sections.

Re: Mitochondria Are Alive

#148

Post by olddustytrail »

Teever wrote: post #81
adastra22 wrote: post #44

Earlier quoted context omitted.

Why are you insisting on this comparison to ribosomes? They’re both interesting.

I'm just wondering why we always see pop-sci mitochondria content but no ribosome videos. 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.

Then go ahead. Make those videos. Sell that vision. There's no one stopping you except you.

Re: Mitochondria Are Alive

#149

Post by exe34 »

eboynyc32 wrote: post #136
outworlder wrote: post #86

Earlier quoted context omitted.

Mitochondria seems to have been an 'accident', yes. 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 organism…

It’s so pathetic to keep hearing that dna is an accident , life is an accident, mitochondria is an accident. What is an accident that natures says “oooops”. When will we take our heads out of the sand and realize the universe is alive and creating everything. There are no goddamn accidents !!!!

all happy little accidents!

Re: Mitochondria Are Alive

#150

Post by pieter_mj »

outworlder wrote: post #86
JumpCrisscross wrote: post #78

Mitochondria are why I’m a Rare Earther. 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 l…

Mitochondria seems to have been an 'accident', yes. 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 organism…

Mitochondria are bacteria that were endosymbioticized into what became the eukaryotic cell. Mitochondria can still survive (live) independently and functionally in the blood when they're separated from platelets and microvesicles. Mitochondria are the software that epigenetically switch nuclear DNA genes on and off. That sofware can be tweaked by light, for instance UV light or IR light. mtDNA mutates x1000000 more rapidly than nuclear DNA.
Post reply on HN