Thoughts on Abiogenesis

[SelfSim]

If there is no process within an organism that can be described as a metabolic process then how will that organism survive?

'Survival' is a moot question, when 'an organism' there, has not even been distinguished in the first place ... So why even use that term?

These terms are only relevant (objectively evidenced) within Earth's environment/biosphere. They may not even be relevant in some sample of interest beyond that context. They may even be moot .. who knows? .. The point is that we don't have a clue about what might be 'of interest' .. until its 'of interest', or something, or some feature in the landscape, has caught some observer's attention.

Are you suggesting that converting food (in whatever form) into the energy required to run whatever processes are required and using the food to build the material from which the organism is made isn't a requirement?

Requirement for what? Proving what someone believes is there in the first place? Ie: your {hypothetically} imagined 'organism'? What kind of process is that? A miraculous one?

 

[Bradskii]

Requirement for what? Proving what someone believes is there in the first place? Ie: your {hypothetically} imagined 'organism'? What kind of process is that? A miraculous one?

I think it's an eminently fair question. Do you think that any kind of life can exist without some form of metabolism?

 

[SelfSim]

I think it's an eminently fair question. Do you think that any kind of life can exist without some form of metabolism?

If there's no evidence of the components of a base citric cycle, in some non-earthly environment, then both 'life' and 'metabolism' definitions need to be realigned with whatever observables/measurables are demonstrated by some sample (isolate) of interest.

 

[Bradskii]

If there's no evidence of the components of a base citric cycle, in some non-earthly environment, then both 'life' and 'metabolism' definitions need to be realigned with whatever observables/measurables are demonstrated by some sample (isolate) of interest.

Not a redefined metabolism. With metabolism as we have it defined now. Which is obviously a process. It isn't restricted to specific chemicals. It can use whatever is available and whatever works.

So are you saying that alien life can exist without some sort of metabolic process being involved?

 

[SelfSim]

.. It isn't restricted to specific chemicals. It can use whatever is available and whatever works.

Where did the 'It' there, miraculously materialise from? 'It' uses things, eh? What exactly is this 'It' thing then, eh?
'It' can't 'use' anything if there's no actively supporting bio-chemistry, can it?

So are you saying that alien life can exist without some sort of metabolic process being involved?

Sheesh this is getting tiring .. You just don't get it, do you?

 

[Bradskii]

Where did the 'It' there, miraculously materialise from? 'It' uses things, eh? What exactly is this 'It' thing then, eh?
'It' can't 'use' anything if there's no actively supporting bio-chemistry, can it?
Sheesh this is getting tiring .. You just don't get it, do you?

'It' is the process of metabolism. I've given up asking questions so take this as a statement.:

If there is no actively supporting bio-chemistry that the metabolic process requires then no metabolic processes can therefore occur and one of the defining characteristics of life cannot exist.

 

[SelfSim]

If there is no actively supporting bio-chemistry that the metabolic process requires then no metabolic processes can therefore occur and one of the defining characteristics of life cannot exist.

So what? So your thought experiment comes full circle .. and rules out the existence of Earth-life in that environment .. who cares?
We already understand the logic you've presented there, given that this is the only point you're making.

The fact remaining however, is we are none the wiser as a result, about what kinds of physical organic chemical processes can go on in that other environment, and what significance they might have on:
- what we see there and;
- the merely Earth-life definitional contexts your thought experiment solely relies upon .. (which were only assumed in your thought experiment as being universally either true or false, in the first place) .. nor are we any more informed about the impacts such processes/products may have on current abiogenesis hypotheses. All of that depends on the chemistry in that environment.

 

[Bradskii]

So what?

So in my opinion, lack of any metabolic process, one definition of life, will weaken any claim that life has been found. You disagree.

How about growth? Leading on to the evolutionary process. That's another characteristic that if missing rules out another definition of life.

 

[o_mlly]

Sheesh this is getting tiring .. You just don't get it, do you?

This admission explains why. Two often "talk past each other" when their frames of reference are radically different.

I've been an avid reader of sci fi since I was a kid ...

 

[SelfSim]

This admission explains why. Two often "talk past each other" when their frames of reference are radically different.

This is about the inappropriateness and unsupportability of conducting logic based thought experiments based on purely assumed truths vs the objective 'truth' derived from the process of empirical measurements in specific contexts/environments.

 

[Bradskii]

...derived from the process of empirical measurements in specific contexts/environments.

You can let me know when you've got some and we can discuss if they are relevant.

In the meantime, could you tell me what criteria you would use to determine that something alien was alive? And I don't mean a 'take me to your leader' form of alien life. What characteristics would you look for?

 

[FrumiousBandersnatch]

Perhaps we should keep it simple and apply a variant of the obscenity test:

I don't know what life is but I'll know it when I see it.​

On "I Know It When I See It" (yale.edu)

OB

Yes, exactly - I was thinking of that when I posted!

 

[Bradskii]

Yes, exactly - I was thinking of that when I posted!

So if you check out a virus under a microscope? Or a prion?

 

[SelfSim]

You can let me know when you've got some and we can discuss if they are relevant.

I could .. but its clear to me that there won't be any benefits from such a discussion, (namely because you still don't understand the relevance of the key physical principle issues I've laid out here).

In the meantime, could you tell me what criteria you would use to determine that something alien was alive? And I don't mean a 'take me to your leader' form of alien life. What characteristics would you look for?

(Why would you rule out that particular scenario?)
Regardless of whatever your answer to that may be, your question was already answered .. either you're not paying attention, or you just didn't understand.

@Occams Barber appeared to get where I was coming from here, so it appears my communication on the topic must have been clear enough for at least someone to understand.

The message was quite clear and quite simple: We don't know whether life exists elsewhere or not. (Therefore: one should stop stop pretending to oneself by making up irrelevant sci-fi stories that make it appear like we do, and by ignoring how science goes about defining all of its operational definitions .. ie: contextually and provisionally).

 

[Bradskii]

I could .. but its clear to me that there won't be any benefits from such a discussion, (namely because you still don't understand the relevance of the key physical principle issues I've laid out here).
(Why would you rule out that particular scenario?)
Regardless of whatever your answer to that may be, your question was already answered .. either you're not paying attention, or you just didn't understand.

@Occams Barber appeared to get where I was coming from here, so it appears my communication on the topic must have been clear enough for at least someone to understand.

The message was quite clear and quite simple: We don't know whether life exists elsewhere or not. (Therefore: one should stop stop pretending to oneself by making up irrelevant sci-fi stories that make it appear like we do, and by ignoring how science goes about defining all of its operational definitions .. ie: contextually and provisionally).

So how you decide if something is alive is '...measurements (that) are distinguishably dissimilar from those of the backdrop/environment from which that isolate was sampled.' It's then something that 'distinguishes life from its environment'.

So we know it when we see it is how I think OB put it.

So if you have a number of things that are 'distinguishably dissimilar' to the environment, but are also distinguishable from each other, then how do you know which of them is alive and which isn't? What differences between them would you look for to make that determination?

 

[FrumiousBandersnatch]

Do you have a reference there?

I'm afraid not, it was just a mention in an article.

 

[AV1611VET]

I think it's an eminently fair question. Do you think that any kind of life can exist without some form of metabolism?

Affirmative.

Angels.

 

[Bradskii]

Affirmative.

Angels.

Look, I don't want to be rude, AV. But can I say that if I ask a general scientific question then the people to whom it's directed doesn't include you?

 

[AV1611VET]

Look, I don't want to be rude, AV. But can I say that if I ask a general scientific question then the people to whom it's directed doesn't include you?

Ouch! Fair enough.

 

[FrumiousBandersnatch]

So if you check out a virus under a microscope? Or a prion?

Looking at it under a microscope is only part of the story - it's also important to see what it does 'in the wild'.

Personally, if I was forced to choose, I would count a virus as alive because it can evolve, which I think is a crucial feature, and because in doing so it uses the same genetic material as other life; it's a kind of minimalist obligate parasite. It's complex, and it has a significant amount of structural organization with functional specialization (e.g. genetic material, shell, spike). But I understand why some people disagree.

OTOH I don't think a prion counts as life because it doesn't evolve and doesn't share any other 'family' features of life beyond making structural duplicates, via (as I understand it) a relatively simple catalysis reaction; so, for me, it lacks the complexity, structural organization and functional specialization I associate with life. If prions counted as alive, I think we'd have to count any autocatalytic cycle as life... I suggest there's a question about them potentially being alive only because they cause disease by replication.