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Concerned
2013-Aug-29, 12:13 AM
Interesting article http://www.dailymail.co.uk/sciencetech/article-2404416/Life-DID-begin-Mars--travelled-Earth-meteorite-Element-crucial-origin-life-available-red-planet.html. A mineral that is believed only to have come from mars, aided in the formation of life on earth.

neilzero
2013-Aug-29, 12:44 AM
Most experts think life started on Earth, but a slight possibility that it came from Mars or another off planet location. Neil

Concerned
2013-Aug-29, 02:21 AM
Sorry, I think my post was a little open. I think it's likely that life started on earth, but,that the building blocks, or at least some parts, were delivered from meteorites etc.

Colin Robinson
2013-Aug-29, 03:04 AM
An earlier thread about theories that meteorites may have brought life to Earth, Protozoan panspermia (http://cosmoquest.org/forum/showthread.php?121551-Protozoan-panspermia). This thread has references to a number of books and articles.

Concerned
2013-Aug-29, 11:12 AM
An earlier thread about theories that meteorites may have brought life to Earth, Protozoan panspermia (http://cosmoquest.org/forum/showthread.php?121551-Protozoan-panspermia). This thread has references to a number of books and articles.

Thank you for the pointer.

Cougar
2013-Aug-29, 06:17 PM
Interesting article http://www.dailymail.co.uk/sciencetech/article-2404416/Life-DID-begin-Mars--travelled-Earth-meteorite-Element-crucial-origin-life-available-red-planet.html. A mineral that is believed only to have come from mars, aided in the formation of life on earth.

Prof. Benner is kind of a rebel, but not a quack. Apparently his hypothesis is based on the following argument:


...if you add energy such as heat or light to organic molecules (http://phys.org/tags/organic+molecules/) and leave them to themselves, they don't create life. Instead, they turn into something more like tar, oil or asphalt.

Certain elements seem able to control the propensity of organic materials to turn into tar, particularly boron (http://phys.org/tags/boron/) and molybdenum, so we believe that minerals containing both were fundamental to life first starting," says Professor Benner.


The first part of that argument seems pretty simplistic, to the point of being naive. Such an "experiment" has to happen in some environment, and not just some atmospheric environment.

The claim sounds pretty iffy to me.....

Selfsim
2013-Aug-29, 11:35 PM
Such an "experiment" has to happen in some environment, and not just some atmospheric environment.

The claim sounds pretty iffy to me.....I snooped around for more information on where Benner is coming from on this. He's certainly a prolific researcher .. there's heaps of buildup to his conclusions, (ie: like his whole life-work, thus far).

This article summarise the key paradoxes (http://goldschmidt.info/2013/abstracts/finalPDFs/686.pdf).
Ie:
i) The Tar Paradox;
ii) The Water Paradox;
iii) The Single Biopolymer Paradox and;
iv) The Probability Paradox.

Right at the end, he says:
Key are the presence of minerals, including borates and molybdates, that interact with organic species that are intermediates between atmospheric carbon dioxide and dinitrogen and RNA. Productive interaction requires as well a subaerial environment having only intermittent interaction with water. Recent data suggests that such environments might even be found today on Mars.I think the point is that to find a 'best fit' hypothesis, whilst avoiding the constraints imposed by these paradoxes, leads him to a 'subaerial' environment .. (sort of like a 'goldilocks zone' for his hypothesis).

Cheers

Cougar
2013-Aug-30, 01:30 AM
I snooped around for more information on where Benner is coming from on this.

Thanks. So this 'finding' is shortly to be presented, which is why I can't find a paper on it? I'd love to hear the questions from the audience after that presentation. There are lots of news articles about it, I guess because BBC picked it up.

As you quoted: "Key are the presence of minerals, including borates and molybdates...." I totally agree with, in part. :) It's close to what Kauffman divulged back in the mid nineties - a molecular diversity threshold - but he did it with arbitrary ingredients. I just hesitate to make Benner's two particular minerals utterly necessary for "life." But then Benner has studied this area WAY more than I have, and I pay that due respect.

A.DIM
2013-Sep-10, 05:02 PM
In my opinion, the evidence, more and more, suggests life was transported to Earth, not simply the "pre biotic" ingredients. Forcing the origin of life into an earth-sized time frame seems a fruitless endeavor; I doubt we will ever know the processes which ultimately led to life, but I think it more reasonable to assume it happened as soon as was possible in the universe (the right ingredients, temp, etc.), and then spread.

Looking to meteorites as a possible source for life on Earth has come about due to scientists' inability to nail down a rational explanation for the development of life based on theories of how the Earth came to exist. Of course, such theories only move the debate to another arena—if life came here from somewhere else, how did it get started in that other place? Scientists have no answer, but hope studying rocks brought from space will offer clues that may help to someday solve the puzzle.

From Physorg (http://phys.org/news/2013-09-analysis-sutter-mill-fragments-reveals.html).

A.DIM
2013-Sep-10, 05:07 PM
Yet another piece of suggestive evidence: Quantum tunnelling could aid life's chemistry in the coldest places (http://phys.org/news/2013-09-quantum-tunnelling-aid-life-chemistry.html).

"New research has revealed that chemical reactions previously thought to be 'impossible' in space actually occur 'with vigour,' a discovery that could ultimately change our understanding of how alcohols are formed and destroyed in space - and which could also mean that places like Saturn's moon Titan, once considered too cold for life to form, may have a shortcut for biochemical reactions.

We really do know so very little, and assume as much, with regard to the robustness of life in the universe.

PetersCreek
2013-Sep-10, 06:44 PM
A reminder to all: advocacy of panspermia subjects to the proponent to rule 13 burdens. See the stickied thread at the top of this forum.

R.A.F.
2013-Sep-10, 07:14 PM
In my opinion, the evidence, more and more, suggests life was transported to Earth...snip... I doubt we will ever know the processes which ultimately led to life...

Well, which is it??

A.DIM
2013-Sep-10, 08:34 PM
Well, which is it??

Huh? You've presented a false choice...
The idea that life was transported to Earth says nothing about how or where it originated.

R.A.F.
2013-Sep-10, 08:38 PM
Huh? You've presented a false choice...
The idea that life was transported to Earth says nothing about how or where it originated.

I disagree...

A.DIM
2013-Sep-10, 09:07 PM
I disagree...

Should I be surprised?
I don't know what to say, really... but this response strikes me as akin to how creationists conflate evolution with abiogenesis in order to argue against one or the other; most often done out of ignorance with regard to both topics.

R.A.F.
2013-Sep-10, 09:21 PM
Should I be surprised?

...that I disagree with un-evidenced ideas?...no, you shouldn't be surprised.



...this response strikes me as akin to how creationists conflate evolution with abiogenesis in order to argue against one or the other; most often done out of ignorance with regard to both topics.

That's nice, and also irrelevant to this discussion. :)

Selfsim
2013-Sep-10, 09:38 PM
Should I be surprised?
I don't know what to say, really... but this response strikes me as akin to how creationists conflate evolution with abiogenesis in order to argue against one or the other; most often done out of ignorance with regard to both topics.Evolution has evidence backing it. Abiogenesis is hypothetical.

Laws of nature have been proposed which might fill in the gap between how autocatalytic self-replicating molecules transition into Evolvability, (constrained by thermodynamics/chemical kinetics) .. but how such molecules come about in the first place, seems to require significant complexity/functionality.

Paul Wally
2013-Sep-10, 09:59 PM
Abiogenesis is hypothetical.



No, it's logical. If abiogenesis didn't happen then what else could possibly have happened?

Selfsim
2013-Sep-10, 10:08 PM
No, it's logical. If abiogenesis didn't happen then what else could possibly have happened?The details of the process of abiogenesis are hypothetical. That some describable origin once happened, is a good fit in a theoretical causal framework, no?

Paul Wally
2013-Sep-10, 10:15 PM
The details of the process of abiogenesis are hypothetical.

Ok, no problem then.

Selfsim
2013-Sep-11, 12:11 AM
... I doubt we will ever know the processes which ultimately led to life Can't see much of a problem with 'doubting' something ..

However, what if a law can be demonstrated whereby a chemical process has an underlying physicochemical continuity with biological evolution, (which has previously gone unrecognised)?

And, what if the consequences of this law, then infers the untraceability of the original specific constituents, even though the behaviours of the same family of constituents, can be shown to exhibit the same behaviours distinguished by that law?

And what if the consequences of this law infer a common point of origin for terrestrial life? (Thus also corroborating the terrestrial fossil/geological record).

(Paul Wally's gonna love this .. :) )

If such a process is distinguished from a single natural environment, all that would seem to remain then, is a question about its occurrence elsewhere in the universe .. (which would need to be found), and the viability of the outcome, (ie: in terms of being recognisable by us, as actually constituting 'life').

Personally, in the light of such a law being distinguished, the matter of panspermia, would then seem to become a fairly trivial point, no?

Jens
2013-Sep-11, 02:22 AM
Well, which is it??

A.DIM is saying he/she thinks that life might have come to earth from space, but that we may never know how life started (either off the earth or on the earth). It doesn't seem to me to be a which choice. Though of course it may be wrong to say there is good evidence that life came from outside the earth.

A.DIM
2013-Sep-11, 03:11 AM
Evolution has evidence backing it. Abiogenesis is hypothetical.

Laws of nature have been proposed which might fill in the gap between how autocatalytic self-replicating molecules transition into Evolvability, (constrained by thermodynamics/chemical kinetics) .. but how such molecules come about in the first place, seems to require significant complexity/functionality.

Indeed; cram the hardware / software (protein/RNA) problem into a few hundred million years (the time between a habitable Earth and an inhabited Earth) and it seems special pleading is required. An off planet solution proffers far more ingredients and time to reach said complexity/functionality.
As I see it, the laws of nature (26? constants) suggest life is an inevitable outcome in this universe, a natural occurrence.

A.DIM
2013-Sep-11, 03:20 AM
Can't see much of a problem with 'doubting' something ..

However, what if a law can be demonstrated whereby a chemical process has an underlying physicochemical continuity with biological evolution, (which has previously gone unrecognised)?

And, what if the consequences of this law, then infers the untraceability of the original specific constituents, even though the behaviours of the same family of constituents, can be shown to exhibit the same behaviours distinguished by that law?

And what if the consequences of this law infer a common point of origin for terrestrial life? (Thus also corroborating the terrestrial fossil/geological record).

(Paul Wally's gonna love this .. :) )

If such a process is distinguished from a single natural environment, all that would seem to remain then, is a question about its occurrence elsewhere in the universe .. (which would need to be found), and the viability of the outcome, (ie: in terms of being recognisable by us, as actually constituting 'life').

Personally, in the light of such a law being distinguished, the matter of panspermia, would then seem to become a fairly trivial point, no?

Sure, but there are plenty good "what ifs" to establish before it becomes a trivial point, no?

Selfsim
2013-Sep-11, 04:43 AM
Indeed; cram the hardware / software (protein/RNA) problem into a few hundred million years (the time between a habitable Earth and an inhabited Earth) and it seems special pleading is required. An off planet solution proffers far more ingredients and time to reach said complexity/functionality.Why is more time needed to 'reach said complexity/functionality'?
And, I would think matter clumping+gravitation, brings large quantities of ingredients together in one location, thus enhancing kinetic chemistries, doesn't it?

As I see it, the laws of nature (26? constants) suggest life is an inevitable outcome in this universe, a natural occurrence.Well, those laws don't seem to be sufficient for us to conclude inevitability, nor can we say that they'll necessarily reproduce the single result we already know of. They might 'conspire' to produce the essential elements (like 12C), but that's about as far they go. As you say, there's a lot more that has to happen to produce life (or, in my words: a critical mass of Evolution-capable self-replicating autocatalytic molecules).

Is extended time necessary to produce 'said complexity/functionality'?
I was under the impression that all one needs to achieve complexity, is a large number of interacting components, individually behaving in ways described by the known laws? The behaviour of the aggregate, is then not necessarily the sum of either the behaviours of those components, nor the rates of the component interactions. Why is greater elapsed time necessary?

Selfsim
2013-Sep-11, 04:53 AM
Sure, but there are plenty good "what ifs" to establish before it becomes a trivial point, no?I think such a law would always be preferred over a principle of parsimony, no?

R.A.F.
2013-Sep-11, 01:23 PM
A.DIM is saying he/she thinks that life might have come to earth from space, but that we may never know how life started (either off the earth or on the earth). It doesn't seem to me to be a which choice. Though of course it may be wrong to say there is good evidence that life came from outside the earth.

The "how" question and the "where" question in my opinion go "hand in hand". If we "may never know" the answer to "how", then trying to answer "where" seems pointless.


....and before anyone posts how "wrong" I am, may I remind them that there is no right and wrong when speculating....just opinions. :)

Swift
2013-Sep-11, 02:16 PM
Should I be surprised?

...that I disagree with un-evidenced ideas?...no, you shouldn't be surprised.
Should I be surprised that you two would start feuding again?

From any two other CQers, this would not even get a comment, but for you two, I am making an exception. As far as LiS is concerned, you two are on super-secret probation. You will keep the conversation completely non-confrontational and questions and answers will only relate directly to the subject at hand.

R.A.F.
2013-Sep-11, 02:41 PM
Now, I'm NOT arguing moderation, but since I don't know how to disagree without being somewhat confrontational, I see no purpose in continuing in this thread...

A.DIM
2013-Sep-12, 01:19 AM
Why is more time needed to 'reach said complexity/functionality'?
And, I would think matter clumping+gravitation, brings large quantities of ingredients together in one location, thus enhancing kinetic chemistries, doesn't it?
Well, those laws don't seem to be sufficient for us to conclude inevitability, nor can we say that they'll necessarily reproduce the single result we already know of. They might 'conspire' to produce the essential elements (like 12C), but that's about as far they go. As you say, there's a lot more that has to happen to produce life (or, in my words: a critical mass of Evolution-capable self-replicating autocatalytic molecules).

Is extended time necessary to produce 'said complexity/functionality'?
I was under the impression that all one needs to achieve complexity, is a large number of interacting components, individually behaving in ways described by the known laws? The behaviour of the aggregate, is then not necessarily the sum of either the behaviours of those components, nor the rates of the component interactions. Why is greater elapsed time necessary?

I don't know that extended time is necessary but the rapid appearance of life on Earth ~3.6Gyrs ago remains a puzzle to be sure: we have roughly 500Myrs between the LHB, when the Earth is thought uninhabitable, and the appearance of life. It must be understood that that earliest known life, often thought to be "primitive," was essentially identical to life today, biochemically. This seems to amplify the hardware /software hurdle and the countless other steps that led to the complexity/functionality of that earliest known life. Who knows?
Perhaps your "critical mass ..." is easily and rapidly reached. This then would seem to suggest it is easily achieved anywhere an early earth-like environment arises, no? Of course this is simply similar ingredients in similar environments give similar results. I certainly agree chemistry and physics are everywhere the same.
There too, the above linked "Quantum Tunnelling ..." article suggests, to me, it's not necessarily a warm watery environment which leads to your "critical mass;" it may be instead a cold dusty locale.
Again, who knows? We certainly don't.

A.DIM
2013-Sep-12, 01:25 AM
I think such a law would always be preferred over a principle of parsimony, no?

Certainly, if such a law can be demonstrated. How close are you, or anyone, to doing so?

Selfsim
2013-Sep-12, 07:05 AM
I don't know that extended time is necessary but the rapid appearance of life on Earth ~3.6Gyrs ago remains a puzzle to be sure: we have roughly 500Myrs between the LHB, when the Earth is thought uninhabitable, and the appearance of life. It must be understood that that earliest known life, often thought to be "primitive," was essentially identical to life today, biochemically.I don't know that anyone could state that conclusively. In fact, there is evidence to the contrary. For example, the precursors to stromatolite cyanobacteria off the coast of Sth Africa ~2.4Gya, were apparently using manganese-based 'photosynthesis-like' molecular machinery, (this was well prior to the evolution of oxygenic cyanobacteria). There's a biochemical difference, right there.
(I don't know that this "~3.6Gya for life appearance" is fully supported, either(?) Its more like ~2.4Gya, eh)?

Perhaps your "critical mass ..." is easily and rapidly reached. This then would seem to suggest it is easily achieved anywhere an early earth-like environment arises, no? Of course this is simply similar ingredients in similar environments give similar results. I certainly agree chemistry and physics are everywhere the same.(My underline): Well, "no" .. I don't think there's any evidence to reach that conclusion, either. For starters, the details of the precursor chemical conditions, (including micro-environmental), are not retraceble by working backwards in time from whatever the chemical constituents are thought be. (This is basic thermodynamic law (entropy) and equilibrium state irreversibility). So we cannot know the chemical environment/conditions in sufficient detail to make the comparison you draw statistical inference from. Secondly, autocatalysis is highly non-linear and is easily perturbed. There are no assurances that such a reaction will proceed in identical ways on successive trials (actually, I think some types of reactions differ, (albeit by microscopic amounts), even when they produce similar-looking macroscopic effects(?))

All autocatalytic reactions occur in a universe whose behaviours we distinguish via our Chemistry and Physics Laws, too - but citing that, still doesn't explain the unpredictable resultants of such reactions at certain scales, and predictable results at other scales.


There too, the above linked "Quantum Tunnelling ..." article suggests, to me, it's not necessarily a warm watery environment which leads to your "critical mass;" it may be instead a cold dusty locale.
Again, who knows? We certainly don't.Well, Ok .. I missed that article first time 'round. Interesting article, too! :). However, the mechanism also introduces the rarity due the quantum randomness factor, into kinetics. How does that effect others' feelings of the 'likelihood' of abiogenesis? (This is more of a rhetorical question, here).
I also notice they still cite:
... cold planetary atmospheres, star forming regions, stellar outflows and circumstellar envelopes... as the possible environments for such phenomena. We already know even more complex amino acids (Glycine) was found in the tail of at least one comet (Stardust/Wild2?). So, this news comes as no big surprise, and represents less relevance to self-replicating life, than the Stardust findings also, (IMO).

Selfsim
2013-Sep-12, 07:34 AM
Oh .. (and in all fairness), I should add that this is about when another particular LiS contributor usually 'chirps' up, and reminds us that Stuart Kauffman's interpretation from his studies on 'autocatalytic sets' is that, if this is the way abiogenesis proceeds, then in his view, life is an 'inevitable' outcome ... (whereupon I usually remind others, that this is his speculative opinion based on a bunch of assumptions ... which is fair enough too, I might add).

Selfsim
2013-Sep-12, 08:57 AM
Certainly, if such a law can be demonstrated. How close are you, or anyone, to doing so?Dynamic Kinetic Stability: Toward a general theory of evolution: Extending Darwinian theory to inanimate matter. By Addy Pross, June 2011, Journal of Systems Chemistry. (http://cosmoquest.org/forum/showthread.php?146137-Abiogenesis-and-Evolution-Unified&p=2155836#post2155836)
I posted the topic in a new thread in the Science Forum, as its 'hardcore' mainstream science.

A.DIM
2013-Sep-23, 04:34 PM
I don't know that anyone could state that conclusively. In fact, there is evidence to the contrary. For example, the precursors to stromatolite cyanobacteria off the coast of Sth Africa ~2.4Gya, were apparently using manganese-based 'photosynthesis-like' molecular machinery, (this was well prior to the evolution of oxygenic cyanobacteria). There's a biochemical difference, right there.
(I don't know that this "~3.6Gya for life appearance" is fully supported, either(?) Its more like ~2.4Gya, eh)?

I've read C13 ratios suggest life dates to 3.8Gya and earlier this year it was claimed 3.49Gya (http://phys.org/news/2013-01-earliest-evidence-life-billion-years.html). Nonetheless it would appear that earliest known life was as biochemically complex as similar extant life.


(My underline): Well, "no" .. I don't think there's any evidence to reach that conclusion, either.
...
All autocatalytic reactions occur in a universe whose behaviours we distinguish via our Chemistry and Physics Laws, too - but citing that, still doesn't explain the unpredictable resultants of such reactions at certain scales, and predictable results at other scales.

Agreed.
Why then, is there an insistence with forcing the OOL on Earth, on Earth?. We know just about as much on the micro as we do the macro, no?



Well, Ok .. I missed that article first time 'round. Interesting article, too! :). However, the mechanism also introduces the rarity due the quantum randomness factor, into kinetics. How does that effect others' feelings of the 'likelihood' of abiogenesis? (This is more of a rhetorical question, here).
I also notice they still cite:.. as the possible environments for such phenomena. We already know even more complex amino acids (Glycine) was found in the tail of at least one comet (Stardust/Wild2?). So, this news comes as no big surprise, and represents less relevance to self-replicating life, than the Stardust findings also, (IMO).

I think it adds to the ever growing pile of evidence suggesting the universe is naturally geared to produce the ingredients which lead to life, so yes, the news comes as no surprise.

Cheers!

A.DIM
2013-Sep-23, 04:40 PM
Dynamic Kinetic Stability: Toward a general theory of evolution: Extending Darwinian theory to inanimate matter. By Addy Pross, June 2011, Journal of Systems Chemistry. (http://cosmoquest.org/forum/showthread.php?146137-Abiogenesis-and-Evolution-Unified&p=2155836#post2155836)
I posted the topic in a new thread in the Science Forum, as its 'hardcore' mainstream science.

Well, that's a step towards (it's one of many competing hypotheses), but is it a "law?"

A.DIM
2013-Sep-23, 04:52 PM
So if life here started out there, Could life have survived a fall to Earth? (http://www.sciencedaily.com/releases/2013/09/130912092731.htm)

"As you might expect, increasing the speed of impact does increase the proportion of algae that die," Pasini explains, "but even at 6.93 kilometres per second, a small proportion survived. This sort of impact velocity would be what you would expect if a meteorite hit a planet similar to the Earth."

I'd thought other studies already determined ejection and impact were survivable with the question being whether or not the transit times are.

Selfsim
2013-Sep-23, 09:22 PM
I've read C13 ratios suggest life dates to 3.8Gya and earlier this year it was claimed 3.49Gya (http://phys.org/news/2013-01-earliest-evidence-life-billion-years.html). Nonetheless it would appear that earliest known life was as biochemically complex as similar extant life. These rock structures have been hotly debated (and refuted). The ~2.4 Gya figure is generally regarded as the agreed 'baseline' figure by Astrobiologists (when they speak in general terms). There's lots more current research underway probing the extension of this figure further back in time. The '3.5 Gya' WA formations, can be explained as having other non-biologicial causes, AIUI.


Agreed.
Why then, is there an insistence with forcing the OOL on Earth, on Earth?. We know just about as much on the micro as we do the macro, no?OOL(??)
I know I'm not forcing anything there are hypotheses being eagerly pursued, that's all.


I think it adds to the ever growing pile of evidence suggesting the universe is naturally geared to produce the ingredients which lead to life, so yes, the news comes as no surprise.Well it'd be pretty hard to argue that it didn't!

Selfsim
2013-Sep-23, 09:51 PM
Well, that's a step towards (it's one of many competing hypotheses), but is it a "law?"Well, that's an interesting philosophical question.
I read it more of an enabling perspective to 'try on'. If one does 'try it on', abundant evidence appears from nature. This is very much the way systems complexity theory is developing. I think the trajectory of Complexity is very much heading towards being regarded as scientific law. In the end, the definition, ('law' or whatever), may just turn out to be semantical.

The mechanisms causing spontaneous pattern formation from seemingly chaotic phenomena, are slowly being revealed and there are no real surprises. The systems level concept is that many interacting parts obeying very simple rules account for spontaneous pattern formation (at the macro-scales). I view DKS as an an attractor which may link the phase space of thermodynamic self-replicating chemistry and biological Evolution. From other observations of similar systems in nature, as well as computer simulations, the observational evidence drives these kinds of ideas more towards the established 'law' end of the scientific spectrum but I'm not too 'hung up' about that aspect, in this instance

We shall see about it all, I guess I think DKS accounts for one of the essential 'simple rules' for evolving inorganic already self-replicating reactions into evolvable biology. Someone should give it a try in one of those 'life' simulations .. it may produce some interesting results (along the lines of what I understand to be one of Paul Wally's interests, for eg. I'm still waiting for his views on it all, too :) ).

Selfsim
2013-Sep-23, 09:53 PM
So if life here started out there, Could life have survived a fall to Earth? (http://www.sciencedaily.com/releases/2013/09/130912092731.htm)

"As you might expect, increasing the speed of impact does increase the proportion of algae that die," Pasini explains, "but even at 6.93 kilometres per second, a small proportion survived. This sort of impact velocity would be what you would expect if a meteorite hit a planet similar to the Earth."

I'd thought other studies already determined ejection and impact were survivable with the question being whether or not the transit times are.Yeah ... I saw that interesting.

A.DIM
2013-Sep-24, 01:44 AM
These rock structures have been hotly debated (and refuted). The ~2.4 Gya figure is generally regarded as the agreed 'baseline' figure by Astrobiologists (when they speak in general terms). There's lots more current research underway probing the extension of this figure further back in time. The '3.5 Gya' WA formations, can be explained as having other non-biologicial causes, AIUI.

Well, wiki (for eg.) cites several in stating 3Gya is the generally accepted age. As well it points to the other, indirect evidences suggesting an earlier date. Yes, there are proposed "abiotic" processes which could account for what we find, but I don't agree the evidence has been "refuted," as if disproven.


OOL(??)
I know I'm not forcing anything … there are hypotheses being eagerly pursued, that's all.

Sorry, I assumed that was known; Origin Of Life.


Well it'd be pretty hard to argue that it didn't!

So you'd agree the evidence suggests our universe is naturally geared to produce life, by way of it being naturally geared to produce its ingredients?

Selfsim
2013-Sep-24, 07:26 AM
Well, wiki (for eg.) cites several in stating 3Gya is the generally accepted age. As well it points to the other, indirect evidences suggesting an earlier date. Yes, there are proposed "abiotic" processes which could account for what we find, but I don't agree the evidence has been "refuted," as if disproven. Oh, some poor wording on my part. The refutation comes from the contention that the morphology could also be formed via non-biological means. So, its the interpretation of the observation that's not agreed .. not that the observation itself is disputed ..

Sorry, I assumed that was known; Origin Of Life. Ok .. thanks.




I think it adds to the ever growing pile of evidence suggesting the universe is naturally geared to produce the ingredients which lead to life, so yes, the news comes as no surprise.Well it'd be pretty hard to argue that it didn't!So you'd agree the evidence suggests our universe is naturally geared to produce life, by way of it being naturally geared to produce its ingredients?The universe produced all of it .. otherwise we wouldn't be around to discuss this.

How many times it produced it, and what fine tuning of the initial conditions is required to reproduce it (if at all), and how easily the hypothesised process is perturbed, and the effects of such perturbations on the end product, are the more significant questions.

Your term 'naturally geared' implies some sort of repetitive, 'cylical rotation' aspect to the emergence of life, (which also implies predictability) ... all of which has no evidence beyond the single Earth-life instance we know about.

R.A.F.
2013-Sep-25, 02:43 PM
So you'd agree the evidence suggests our universe is naturally geared to produce life, by way of it being naturally geared to produce its ingredients?

Based on only one example?...nope.

A.DIM
2013-Sep-25, 02:50 PM
The universe produced all of it .. otherwise we wouldn't be around to discuss this.

How many times it produced it, and what fine tuning of the initial conditions is required to reproduce it (if at all), and how easily the hypothesised process is perturbed, and the effects of such perturbations on the end product, are the more significant questions.

Your term 'naturally geared' implies some sort of repetitive, 'cylical rotation' aspect to the emergence of life, (which also implies predictability) ... all of which has no evidence beyond the single Earth-life instance we know about.

When I say "naturally geared" I mean no more than the assumption that physics and chemistry are everywhere the same in the universe. Repeatable experiments (which also implies predictability) are what established the laws of physics and chemistry. So whether or not you perceive other "more significant questions," you didn't answer mine.

Selfsim
2013-Sep-25, 10:32 PM
Repeatable experiments (which also implies predictability) are what established the laws of physics and chemistry.Repeated experiments gave rise to only one A.DIM (as far as we can tell). Repeated experiments can thus produce diversity defining a uniqueness for which we have no idea of the bounds. A brick covered in emery cloth, sliding down an incline, never proceeds in exactly the same way twice. Avalanches do not proceed in exactly the same way twice. The weather cannot be predicted beyond ~ 2 weeks.

The scale which we assign to these observations, is what gives rise to our perception that these events (or things) appear to be repeatable. At other scales, they simply aren't. We have no idea of the sensitivities of that scale, when it comes to the repeatability of life's occurrence .. and yet, all of this occurs within a set of rules with which we assign the meaning of 'predictability' (at given scales) and call 'the laws of physics'.


So whether or not you perceive other "more significant questions," you didn't answer mine.I concurred with the first part of this, because the evidence is that terrestrial life exists.

That the 'ingredients' are produced by the universe, is not a sufficient basis for making predictions about repeatability. Clearly, we cannot synthetically reproduce life from inorganic ingredients .. and yet, the universe produced us, as well as life's ingredients. The universe thus produces some things, (us), which are incapable of producing what it has. We can reproduce some of the ingredients of life, but not others. These are facts which demonstrate we are not yet at the point where predictions are possible about exo-life.

Paul Wally
2013-Sep-26, 03:29 PM
That the 'ingredients' are produced by the universe, is not a sufficient basis for making predictions about repeatability. Clearly, we cannot synthetically reproduce life from inorganic ingredients .. and yet, the universe produced us, as well as life's ingredients. The universe thus produces some things, (us), which are incapable of producing what it has. We can reproduce some of the ingredients of life, but not others. These are facts which demonstrate we are not yet at the point where predictions are possible about exo-life.

How do you know we cannot reproduce life from inorganic ingredients? We can say we haven't yet reproduced life in a lab, but you simply have no basis for asserting that it cannot be done or that we are incapable of doing it.

Selfsim
2013-Sep-26, 10:29 PM
How do you know we cannot reproduce life from inorganic ingredients? We can say we haven't yet reproduced life in a lab, but you simply have no basis for asserting that it cannot be done or that we are incapable of doing it.A linguisitic thing methinks 'presently we cannot reproduce life from inorganic components', (if you insist).

The overall argument is still valid though .. "The universe thus produces some things, (us), which are incapable of producing what it has".
Taken in isolation, this is not a particularly Earth-shaking point. However, I'm also reminded of Pross' topologically divergent model (explaining diversification of species in Evolution), perhaps this makes the point clearer(?) Ie: once divergence has occurred which, (I think), means that the 'fork' point was the moment in time where uniqueness appeared, regression to the conditions of the state immediately prior to the fork point, (by way of time reversal), is no longer possible the information needed to recreate the pathway has gone into the surrounding environment and is no longer usable.

Could we reverse engineer A.DIM (using only A.DIM's contents) to recreate his parents? :think:
If the answer is 'No', then the same can also be said for the forward path, which would mean that A.DIM would also be unique if we run time in the forwards direction as well, (ie: into the future) .. A.DIM's offspring could not be used to recreate him

A 'species' however, persists this is what I mean by our selection of the 'scale of study' is what determines whether something is similar or unique and we have no feel for the scale of the distribution of life beyond Earth, so we cannot presume its predictability.

A complex gathering of inorganic compounds could quite easily behave in the same way .. for the same reasons explaining A.DIM's uniqueness

All of that, is my point.

Paul Wally
2013-Sep-26, 11:17 PM
A linguisitic thing methinks 'presently we cannot reproduce life from inorganic components', (if you insist).

A linguistic thing? No, it's a real thing with real consequences. If we think something cannot be done, then we rule out a possibility without sufficient reason, therefore never realizing the possibility. A kind of self-fulfilling prophecy.



The overall argument is still valid though .. "The universe thus produces some things, (us), which are incapable of producing what it has".
Taken in isolation, this is not a particularly Earth-shaking point. However, I'm also reminded of Pross' topologically divergent model (explaining diversification of species in Evolution), perhaps this makes the point clearer(?) Ie: once divergence has occurred which, (I think), means that the 'fork' point was the moment in time where uniqueness appeared, regression to the conditions of the state immediately prior to the fork point, (by way of time reversal), is no longer possible the information needed to recreate the pathway has gone into the surrounding environment and is no longer usable.
The issue was whether we can recreate any life, not life exactly as it started on Earth. The latter is a completely different problem.



Could we reverse engineer A.DIM (using only A.DIM's contents) to recreate his parents? :think:
If the answer is 'No', then the same can also be said for the forward path, which would mean that A.DIM would also be unique if we run time in the forwards direction as well, (ie: into the future) .. A.DIM's offspring could not be used to recreate him

A.DIM is a complex individual. We're talking about recreating the phenomenon of life in whatever simple form possible.



A 'species' however, persists this is what I mean by our selection of the 'scale of study' is what determines whether something is similar or unique and we have no feel for the scale of the distribution of life beyond Earth, so we cannot presume its predictability.

We don't need any of this stuff in order to construct a theory capable of making testable predictions. We don't 'presume' predictability. Theory predicts. It's not a matter of presumption.



A complex gathering of inorganic compounds could quite easily behave in the same way .. for the same reasons explaining A.DIM's uniqueness

All of that, is my point.

"A complex gathering of inorganic compounds" could be modeled mathematically or computationally and also studied in laboratory experiments. From that we could then learn more about how complex chemical systems behave. Saying that it could 'quite easily' do this or that ... what's the scientific value of such an assertion?

Selfsim
2013-Sep-26, 11:54 PM
A.DIM is a complex individual. We're talking about recreating the phenomenon of life in whatever simple form possible.The simplest natural lifeform we know of, is still highly complex. We cannot recreate that lifeform from inorganic chemicals because of that complexity.


We don't need any of this stuff in order to construct a theory capable of making testable predictions. We don't 'presume' predictability. Theory predicts. It's not a matter of presumption.If your 'theory' ignores 'this stuff', then it is not a theory based on the evidence .. it might turn out to be a testable hypothesis, which makes it a tentative statement. Predictions made from a tentative statement which also excludes available evidence, lack optimal reliability.


"A complex gathering of inorganic compounds" could be modeled mathematically or computationally and also studied in laboratory experiments. From that we could then learn more about how complex chemical systems behave. Saying that it could 'quite easily' do this or that ... what's the scientific value of such an assertion?I agree it would be interesting to see the outcome(s) of such a model. One simple rule guiding behaviour of the collective gathering of complex inorganic compounds, might be Pross' DKS (as well as the known chemical laws).

Its easy to say, but from what I've read, these kinds of simulations rapidly outstrip computational capacities.
Quantum computing might facilitate more efficient exploration of the different scenarios, however(?)

Paul Wally
2013-Sep-27, 01:44 AM
The simplest natural lifeform we know of, is still highly complex. We cannot recreate that lifeform from inorganic chemicals because of that complexity.

Indeed it is complex, but that doesn't mean it's impossible to make. But as I said, "the simplest form possible" not the simplest known lifeform.



If your 'theory' ignores 'this stuff', then it is not a theory based on the evidence .. it might turn out to be a testable hypothesis, which makes it a tentative statement. Predictions made from a tentative statement which also excludes available evidence, lack optimal reliability.

Of course it would take into account available evidence. But the stuff you're talking about is not available. "The scale of distribution of life beyond Earth" is not available.



I agree it would be interesting to see the outcome(s) of such a model. One simple rule guiding behaviour of the collective gathering of complex inorganic compounds, might be Pross' DKS (as well as the known chemical laws).

I'm almost done reading the Pross paper, and will comment on that soon.



Its easy to say, but from what I've read, these kinds of simulations rapidly outstrip computational capacities.
Quantum computing might facilitate more efficient exploration of the different scenarios, however(?)

That's because you want to recreate reality in the computer instead making a simplified model.

Selfsim
2013-Sep-27, 03:05 AM
… Of course it would take into account available evidence. But the stuff you're talking about is not available. "The scale of distribution of life beyond Earth" is not available.So you deny 'the availability' of the examples I cite of unpredictability and uniqueness of (in natural environments and at certain scales): a brick covered in emery cloth sliding down an incline (avalanche model), weather a couple of weeks out, A.DIM's apparent uniqueness, Paul Wally's apparent uniqueness, fingerprints, an individual's retinal pattern, an individual's brain morphology, Earth's uniqueness within the Solar System, snowflake patterns, etc, etc?… (The list is virtually endless).

These phenomena are just as real as life … why exclude these classes of behaviours and their unpredictable outcomes at certain scales from consideration, especially when speaking of the time evolution of Kauffman's autocatalytic sets, or Pross' Dynamic Kinetic Stability (DKS)?
I'm almost done reading the Pross paper, and will comment on that soon.Good .. I look forward to your comments/feedback. http://cosmoquest.org/forum/images/smilies/smile.png

That's because you want to recreate reality in the computer instead making a simplified model.I could respond to this, but I'm really not interested in going down that kind of path.
Simulations help us to see through the complexity, in order to arrive at simplicity.
(And I'm pretty sure you already know this .. its not even worth arguing this point!)

iquestor
2013-Sep-27, 02:03 PM
Well, wiki (for eg.) cites several in stating 3Gya is the generally accepted age. As well it points to the other, indirect evidences suggesting an earlier date. Yes, there are proposed "abiotic" processes which could account for what we find, but I don't agree the evidence has been "refuted," as if disproven.

I did finally find the references I was looking for this AM as I was having coffee. Paul Davies, in "The Eerie Silence" States that it is broadly accepted that life began between 3.5 and 4 GYA ago, with rocks at 3.85 GYA which show evidence of transformations generally associated with life processes, buy not deterministic. He cites some references which I will provide when I get home for the 3.5 GYA figure.

A.DIM
2013-Sep-28, 03:34 PM
I did finally find the references I was looking for this AM as I was having coffee. Paul Davies, in "The Eerie Silence" States that it is broadly accepted that life began between 3.5 and 4 GYA ago, with rocks at 3.85 GYA which show evidence of transformations generally associated with life processes, buy not deterministic. He cites some references which I will provide when I get home for the 3.5 GYA figure.

Well, wiki has several, as I said, but I'd think anyone who has done some reading on this topic (evidence for earliest known life) will have come across the generally accepted 3.5Gya.
Here are a few, if you're interested:

Trotman - The Feathered Onion

Shulze-Makuch, Darling - We Are Not Alone

Thomas, Hicks, Chyba, McKay - Comets and the Origin and Evolution of Life


Cheers!

Paul Wally
2013-Sep-29, 09:15 PM
So you deny 'the availability' of the examples I cite of unpredictability and uniqueness of (in natural environments and at certain scales): a brick covered in emery cloth sliding down an incline (avalanche model), weather a couple of weeks out, A.DIM's apparent uniqueness, Paul Wally's apparent uniqueness, fingerprints, an individual's retinal pattern, an individual's brain morphology, Earth's uniqueness within the Solar System, snowflake patterns, etc, etc?… (The list is virtually endless).

You fail to distinguish between individual occurrences and a class of phenomena. That's why I think that even these new examples of individual occurrences are not really pertinent to the question of how life emerges, "life" being a certain class of phenomena with certain general characteristics. All your examples share the same characteristic of being unique individuals. The list is virtually endless but ultimately in the wrong direction.
Take your snowflake example. An individual snowflake has it's own unique evolution, it may even be unpredictable in principle, but that is not relevant to the question of how snowflakes form, under what kind of conditions they form and so forth. In fact, we can quite easily predict the range of conditions under which snowflakes are likely to form, even though we may not be able to predict the evolution of an individual snowflake.



These phenomena are just as real as life … why exclude these classes of behaviours and their unpredictable outcomes at certain scales from consideration, especially when speaking of the time evolution of Kauffman's autocatalytic sets, or Pross' Dynamic Kinetic Stability (DKS)?

I'm not excluding unpredictable phenomena, I just understand where they fit in and when they are relevant to a particular problem. Take statistical mechanics. We cannot predict the the motion of individual particles but we still model a large aggregate of particles by defining macroscopic observables that reflect statistical averages of the individual particles. I suppose the same sort of strategy could be applied to autocatalytic sets and DKS. You cannot just look at one individual microscopic system's time evolution and ignore the rest of the environment.



Simulations help us to see through the complexity, in order to arrive at simplicity.
(And I'm pretty sure you already know this .. its not even worth arguing this point!)

I don't know what that's suppose to mean but it's pretty simple. Simulation is simply calculation of the
consequences of a theory for a particular model derived from that theory, e.g. a model of solar system formation derived from Newtonian mechanics.

Selfsim
2013-Sep-29, 11:49 PM
You fail to distinguish between individual occurrences and a class of phenomena.We're both saying the same thing, (I think).
I have said that uniqueness and similarity are relative concepts ie: it depends on the scales of observation of other comparable things ...

If similarity is posited to be a generally universal phenomenon, then so too should be uniqueness .. (for all the same reasons).

And then, I agree with what you then say. Ie:


Of course it would take into account available evidence. But the stuff you're talking about is not available. "The scale of distribution of life beyond Earth" is not available.

.. we have no available evidence of the scale of distribution .. therefore, neither uniqueness nor similarity can be predicted without such evidence .. so either: (i) both, or neither exist, (in principle).
Which is different from: (ii) similarity exists, but not uniqueness and; (iii) uniqueness exists, but not similarity.

In other words in the universe, in the absence of evidence and in principle, "Ya can't have one, without the other" ..
Their cause is what's universal .. and in any volume limited space, either one or the other, or both,can be present, depending on the artificial selection of the scale of that volume limited constraint.

Paul Wally
2013-Sep-30, 12:07 AM
We're both saying the same thing, (I think).
I have said that uniqueness and similarity are relative concepts … ie: it depends on the scales of observation of other comparable things ...

If similarity is posited to be a generally universal phenomenon, then so too should be uniqueness .. (for all the same reasons).

And then, I agree with what you then say. Ie:


.. we have no available evidence of the scale of distribution .. therefore, neither uniqueness nor similarity can be predicted without such evidence .. so either: (i) both, or neither exist, (in principle).
Which is different from: (ii) similarity exists, but not uniqueness and; (iii) uniqueness exists, but not similarity.

In other words in the universe, in the absence of evidence and in principle, "Ya can't have one, without the other" ..
Their cause is what's universal .. and in any volume limited space, either one or the other, or both,can be present, depending on the artificial selection of the scale of that volume limited constraint.

I have no idea what you're talking about. You're using the terms "similarity" and "uniqueness" and then you continue to make reference to them, but what
exactly are similar too each other, and what is the unique thing or phenomenon that you're referring to?

Colin Robinson
2013-Oct-05, 02:22 AM
So you deny 'the availability' of the examples I cite of unpredictability and uniqueness of (in natural environments and at certain scales): a brick covered in emery cloth sliding down an incline (avalanche model), weather a couple of weeks out, A.DIM's apparent uniqueness, Paul Wally's apparent uniqueness, fingerprints, an individual's retinal pattern, an individual's brain morphology, Earth's uniqueness within the Solar System, snowflake patterns, etc, etc? (The list is virtually endless).

These phenomena are just as real as life


You fail to distinguish between individual occurrences and a class of phenomena.

I agree with you, Paul.

Things might be "unique" in two different senses:

(1) In the sense that no exact duplicate can be found.
(2) In the sense that nothing comparable can be found.

A human individual, or for that matter a snowflake, is unique in sense (1) but not in sense (2).

The same seems to be true of planets. No known planet is an exact duplicate of another, but planets form a class of objects whose members can be compared to one another in terms of size, density, composition, etc.

Life on Earth has evolved thru mutation and natural selection. It is neither strictly deterministic (because the mutation process is not deterministic) nor is it entirely random (because natural selection is not random). If Addy Pross is right, if abiogenesis is a chemical evolution comparable to biological evolution, then abiogenesis likewise is neither strictly deterministic nor entirely random.

Another process of chemical evolution of complex molecules, on another planet or moon, would not produce a duplicate of life of Earth; it would nonetheless be a comparable process whose results would bear comparison, whether or not they corresponded to our preconceptions about "life as we know it".

Selfsim
2013-Oct-05, 04:32 AM
I agree with you, Paul.

Things might be "unique" in two different senses:

(1) In the sense that no exact duplicate can be found.
(2) In the sense that nothing comparable can be found.

A human individual, or for that matter a snowflake, is unique in sense (1) but not in sense (2).

The same seems to be true of planets. No known planet is an exact duplicate of another, but planets form a class of objects whose members can be compared to one another in terms of size, density, composition, etc.

Life on Earth has evolved thru mutation and natural selection. It is neither strictly deterministic (because the mutation process is not deterministic) nor is it entirely random (because natural selection is not random). If Addy Pross is right, if abiogenesis is a chemical evolution comparable to biological evolution, then abiogenesis likewise is neither strictly deterministic nor entirely random.

Another process of chemical evolution of complex molecules, on another planet or moon, would not produce a duplicate of life of Earth; it would nonetheless be a comparable process whose results would bear comparison, whether or not they corresponded to our preconceptions about "life as we know it".Humans are pattern-matching machines. This is what we do.
We look for the similarities (or patterns) in things .. and its precisely because of this, that science has evolved the way it has. This is exactly why you say: "it would nonetheless be a comparable process whose results would bear comparison".

But what if there was a universal phenomenon (or process), which happened every place where conditions were right .. but its outcomes are unique, (at our scales), each and every time, right across the universe. Would we recognise that process? How?

Just because we have evolved to be attuned to recognising patterns, doesn't mean that such patterns must be evident at the scales we can access.

Colin Robinson
2013-Oct-05, 06:04 AM
Humans are pattern-matching machines. This is what we do.
We look for the similarities (or patterns) in things .. and its precisely because of this, that science has evolved the way it has.

I'd agree that looking for regularities is an important part of science.


But what if there was a universal phenomenon (or process), which happened every place where conditions were right .. but its outcomes are unique, (at our scales), each and every time, right across the universe. Would we recognise that process? How?

If we're talking about a process of complex molecules undergoing chemical evolution, then maybe the first step in learning how to recognize and understand the process is

* to find another planet or moon where there are complex molecules interacting dynamically, and then
* investigating with a range of instruments such as mass spectrometers and microscopes.

We already know of one such location in this Solar System, namely Titan.


Just because we have evolved to be attuned to recognising patterns, doesn't mean that such patterns must be evident at the scales we can access.

True, it is quite conceivable that there are fields where no regularities will be evident in the data we can access. Scientists look for regularities, without foreknowledge that they will succeed in finding any.

Selfsim
2013-Oct-05, 08:52 AM
True, it is quite conceivable that there are fields where no regularities will be evident in the data we can access. Scientists look for regularities, without foreknowledge that they will succeed in finding any.... See, there are things going on in certain lifeforms which may well be indicators of previously never understood organic (complex) chemistry. Take this recent article about the RNA "edit" done by Trypanosoma brucei, (http://phys.org/news/2013-10-single-cell-rewrite-essential-life.html) (a parasite that causes sleeping sickness in Africa (and Chagas disease in Latin America)):
"These are changes for which no chemistry is known and has never been described. We don't know what enzyme is involved and that is the million-dollar question: What mechanism is doing this? We haven't a clue," said Juan Alfonzo, professor of microbiology at The Ohio State University and senior author of the study.They 'haven't a clue' about what initiates the edits:
We show that if you don't edit, you don't splice. This editing is required for splicing, and splicing is required for functionality. Otherwise, cells die."Now you might well say that this parasite's RNA has figured out a way to perform this function anyway .. but its just that the scientists studying it haven't figured out the mechanism by which it accomplishes this feat .. in which case, I'd ask: "Why could abiogenesis not also follow similar or different highly unanticipated noncanonical principles(??)":

The editing described here is a swap of three nucleotides for three others that, according to the rules of biology, do not belong where they end up. This is why it looks like a mistake.
Colleagues have suggested that this edit should have been identified by researchers who do deep sequencing, which involves repeated readings of all nucleotides within an RNA molecule, Alfonzo noted. But he is not surprised that technology didn't yield these results.
"In massive sequencing, you match RNAs to the sequence in the genome. Any mismatch is called a sequence mistake and is thrown in the trash. So this noncanonical editing may well be in the trash bin of many of these deep sequencing researchers," he said.What if the mechanism it uses is unique, but it wasn't noticed because it was 'written-off' as being an error (because it didn't match the patterns we expected to see??).

Paul Wally
2013-Oct-05, 01:08 PM
(1) In the sense that no exact duplicate can be found.
(2) In the sense that nothing comparable can be found.



I'd say that pure science is about (2) and not (1). Analysis of the two categories would suggest that (1) is about what are called contingencies whereas (2) is about necessity. This is now also where I disagree with Selfsim on a very fundamental level. For Selfsim (in my assessment) it is sufficient to arrive at a contingent state of a affairs, e.g. Jupiter has a red spot. That in my opinion isn't scientific knowledge, it's geography. Also, in my opinion, knowing the time evolution of Jupiter's red spot isn't scientific knowledge, it's history. Scientific knowledge would be knowing how large superstorms form on gas giant planets. Notice the universality of that statement, and that it doesn't refer to particular times and places. That is what distinguishes pure science from history and geography.

In my understanding of science the question, "How did life form?" is a question of history. The scientific question is: "How does life form?".


Humans are pattern-matching machines. This is what we do.

That is not all we do. Science attempts to arrive at explanations for the patterns we observe in nature. We want to know why a certain pattern exists, and not merely that it exists.



But what if there was a universal phenomenon (or process), which happened every place where conditions were right .. but its outcomes are unique, (at our scales), each and every time, right across the universe. Would we recognise that process? How?

If we knew of such a universal phenomenon, then why wouldn't we recognize instances of it? If you had a concept of what a natural number is and I show you a unique number then won't you be able to tell whether it is a natural number or not?




If we're talking about a process of complex molecules undergoing chemical evolution, then maybe the first step in learning how to recognize and understand the process is

* to find another planet or moon where there are complex molecules interacting dynamically, and then
* investigating with a range of instruments such as mass spectrometers and microscopes.

We already know of one such location in this Solar System, namely Titan.



I agree that Titan would be a valuable source of information regarding chemical evolution on planetary bodies. The scientific aim would be to understand chemical evolution on planetary bodies. Thus it is immediately clear that chemical evolution occurs wherever there is matter, and planetary chemistry (geochemistry) would be concerned with chemical evolution on sufficiently large aggregates of matter where factors like gravity, solar radiation, and large spatial and temporal scales become relevant.

Even the Moon then has chemical evolution. When the Moon was molten, gravity separated the elements from heavy to light. Even today meteorites and radiation interact with the Moon to bring about chemical changes. Venus should be an interesting place chemically. What kind of chemical cycles exist in the Venusian atmosphere? How did volcanism affect the chemical evolution of Venus' atmosphere? But it doesn't end there. We're interested in what role volcanism plays in planetary atmosphere formation and evolution. Juno is going to look for oxygen in Jupiter's atmosphere. The aim is not just to know how much oxygen there is in Jupiter's atmosphere (so that Wikipedia can add more information about Jupiter), but it is about the wider ramifications for the prevalence of water in solar system formation. So my view is that all planetary bodies are relevant to understanding the the emergence of life in the universe.

Colin Robinson
2013-Oct-05, 01:55 PM
... See, there are things going on in certain lifeforms which may well be indicators of previously never understood organic (complex) chemistry. Take this recent article about the RNA "edit" done by Trypanosoma brucei, (http://phys.org/news/2013-10-single-cell-rewrite-essential-life.html) (a parasite that causes sleeping sickness in Africa (and Chagas disease in Latin America)):They 'haven't a clue' about what initiates the edits:Now you might well say that this parasite's RNA has figured out a way to perform this function anyway .. but its just that the scientists studying it haven't figured out the mechanism by which it accomplishes this feat .. in which case, I'd ask: "Why could abiogenesis not also follow similar or different highly unanticipated noncanonical principles(??)":
What if the mechanism it uses is unique, but it wasn't noticed because it was 'written-off' as being an error (because it didn't match the patterns we expected to see??).

It may well be "unique" in the sense that no other organism uses the same specific enzyme working with the same RNA segment in the same specific way. But is it "unique" in the sense of having no common ground with anything else in nature?

Selfsim
2013-Oct-05, 11:47 PM
It may well be "unique" in the sense that no other organism uses the same specific enzyme working with the same RNA segment in the same specific way. But is it "unique" in the sense of having no common ground with anything else in nature?Firstly, I think his use of the term 'enzyme' might be misleading. If its new chemistry, (as he suggests it might be), then no reliance should be placed on the term 'enzyme'. I think he means it in the general sense .. ie: as in" 'What is it which could possibly catalyze this edit of RNA (post translation)?'

Secondly, there are things going on in bio-organics which don't occur elsewhere. This in itself, is a kind of 'uniqueness', and science should pay attention.

The hazy distinctions between inorganic and organic chemistry need to be relaxed, (IMO), when looking at abiogenesis matters. As Astronomers and Physicists, we need to remember that the relative comfort afforded by sciences' classical definitions, are artificially contrived and have only been developed to explain things amongst human scientists. As he implies, canonical 'law' in biology is not necessarily Physical Law in bio-organics. There are many things in biology which cannot be predicted. Why should abiogenesis be any different? There is sufficient complexity in bio-organics to allow for myriads of permutations, many of which could easily lead to cell death, and equally, there may be only unique combinations which lead to cell survival. Fine tuning is relevant here. Why would a universal abiogenesis process be any different from this?

Colin Robinson
2013-Oct-06, 01:37 AM
(1) In the sense that no exact duplicate can be found.
(2) In the sense that nothing comparable can be found.

I'd say that pure science is about (2) and not (1).

Yes, in the sense that science has often shown that things which seem, at first sight, to be comparable to nothing else, are actually members of a much large class of comparable things. For instance Copernicus did that when he argued that the Earth is actually a planet not necessarily identical to any other planet, but an object of the same class, moving around the Sun in a comparable way.


Analysis of the two categories would suggest that (1) is about what are called contingencies whereas (2) is about necessity. This is now also where I disagree with Selfsim on a very fundamental level. For Selfsim (in my assessment) it is sufficient to arrive at a contingent state of a affairs, e.g. Jupiter has a red spot. That in my opinion isn't scientific knowledge, it's geography. Also, in my opinion, knowing the time evolution of Jupiter's red spot isn't scientific knowledge, it's history. Scientific knowledge would be knowing how large superstorms form on gas giant planets. Notice the universality of that statement, and that it doesn't refer to particular times and places. That is what distinguishes pure science from history and geography.

The way I see it, science has two aspects descriptive study of contingencies (akin to history and geography), and the search for underlying regularities and laws (involving pure mathematics, and philosophical principles such as Occam's Razor).


I agree that Titan would be a valuable source of information regarding chemical evolution on planetary bodies. The scientific aim would be to understand chemical evolution on planetary bodies. Thus it is immediately clear that chemical evolution occurs wherever there is matter,

Depends what you mean by chemical evolution. I had in mind the sort of process described by Addy Pross, with systems of complex molecules undergoing a process of mutation and selection comparable to biological evolution. (In fact, biological evolution could be regarded as a subset of chemical evolution.) Such a process would not occur wherever there is matter, as it requires complex molecules, energy gradients, and arguably a liquid solvent.

Colin Robinson
2013-Oct-06, 01:47 AM
Firstly, I think his use of the term 'enzyme' might be misleading. If its new chemistry, (as he suggests it might be), then no reliance should be placed on the term 'enzyme'. I think he means it in the general sense .. ie: as in" 'What is it which could possibly catalyze this edit of RNA (post translation)?'

I think you may be making too much of the term "new chemistry". Perhaps it simply means that a previously unknown enzyme is operating in a distinctive way?


Secondly, there are things going on in bio-organics which don't occur elsewhere. This in itself, is a kind of 'uniqueness', and science should pay attention.

The hazy distinctions between inorganic and organic chemistry need to be relaxed, (IMO), when looking at abiogenesis matters. As Astronomers and Physicists, we need to remember that the relative comfort afforded by sciences' classical definitions, are artificially contrived and have only been developed to explain things amongst human scientists. As he implies, canonical 'law' in biology is not necessarily Physical Law in bio-organics. There are many things in biology which cannot be predicted. Why should abiogenesis be any different? There is sufficient complexity in bio-organics to allow for myriads of permutations, many of which could easily lead to cell death, and equally, there may be only unique combinations which lead to cell survival. Fine tuning is relevant here. Why would a universal abiogenesis process be any different from this?

The point is, evolution selects for combinations that work — those that do lead to survival. The sort of chemical evolution described by Addy Pross likewise selects for combinations that work. As Pross mentions, the process does involve certain laws: e.g. you don't find two species in exactly the same ecological niche.

Selfsim
2013-Oct-06, 10:35 AM
I think you may be making too much of the term "new chemistry". Perhaps it simply means that a previously unknown enzyme is operating in a distinctive way?Nah .. 99% of all RNA splicing occurs by the same process which has fixed rules (ie: in this case, the GU-AG rule for removing the non coding intron from a strand of RNA). 'Non canonical' refers to extremely rare splicing with mechanisms unknown. This is what he means by 'new chemistry'. It is thus far, not known in eukaryotic biology.

If there was a law in physics which covered 99% of all known preconditions, then suddenly something showed up, (with those same preconditions), which did not follow that law (or rules), I think one would be justified in calling it 'new physics', no?


The point is, evolution selects for combinations that work those that do lead to survival. The sort of chemical evolution described by Addy Pross likewise selects for combinations that work.Nope ... Pross' idea is that self-replicating molecules 'select' for a state of dynamic kinetic stability - whether it 'works' or not. The prerequisite is that self-replicating molecules have to exist first.
As Pross mentions, the process does involve certain laws: e.g. you don't find two species in exactly the same ecological niche.Did he say that? (Reference please).

Anyway, my point in raising the non canonical edit prior to splicing, is that science discarded this as 'an error' because it didn't match the pattern (or the GU-AG rule). It is most certainly no 'error' as far as 'Trypanosoma brucei', is concerned.

There's lots of this same type of thing in biology (ie: exceptions to the rule). This differs a lot from Astrophysics and Inorganic Chemistry and it makes things way less deterministic and formulaic.

When probing the bio-chemical origins of life, one needs to address complex 'precursor' chemistry, and the exceptions 'to the rule' .. because there may actually be no set formulae!

Paul Wally
2013-Oct-06, 01:25 PM
The way I see it, science has two aspects — descriptive study of contingencies (akin to history and geography), and the search for underlying regularities and laws (involving pure mathematics, and philosophical principles such as Occam's Razor).


I agree with characterizing science as having both aspects, but for me science wouldn't be science if it concentrates only on contingencies. Even history I would characterize as scientific if for instance it is studied from the perspective of social dynamics and psychology in order to explain historical development of human culture, but if it is just a record of a sequence of events then I can't call it a science.



Depends what you mean by chemical evolution. I had in mind the sort of process described by Addy Pross, with systems of complex molecules undergoing a process of mutation and selection comparable to biological evolution. (In fact, biological evolution could be regarded as a subset of chemical evolution.) Such a process would not occur wherever there is matter, as it requires complex molecules, energy gradients, and arguably a liquid solvent.

I see what you mean, but can we really treat chemical evolution (in the Prossian sense) in isolation from the broader system of other physical and chemical processes? The perspective that I'm coming from, or rather, what I'm supposing is: Shouldn't we look at abiogenesis as a global geochemical process rather than just a molecular process? If we say that life arose very quickly, then that could mean a couple of million years. Can we then model a global process occurring over a couple of million years as a system of molecules?

There are a couple of problems I have with Addy Pross' theory, which I will elaborate on later, but one aspect that I find problematic is his attempt at reducing biological evolution to chemistry. If I understood correctly, his argument is that we cannot reduce chemistry to biological evolution therefore biological evolution has to be reduced to chemistry. I think it makes no sense to reduce any one of them to the other, because evolution through natural selection functions as an autonomous principle, which is already fundamental and axiomatic. It can explain biological evolution as well as chemical evolution, but the same principle could explain phenomena that have nothing to do with either chemistry or biology, for example computer algorithms could be made to randomly "mutate" and then selected on the basis of how well they solve some complex numerical problem. Genetic algorithms have essentially nothing to do with either chemistry or biology, only it uses the same mathematical concept of natural selection.





The point is, evolution selects for combinations that work — those that do lead to survival. The sort of chemical evolution described by Addy Pross likewise selects for combinations that work. As Pross mentions, the process does involve certain laws: e.g. you don't find two species in exactly the same ecological niche.

I don't know if that could be classified as a law. That has been called into question by some, but if it is true then I think it would be a mathematical theorem applicable to a certain class of systems, rather than a strictly chemical or biological or physical law.

Selfsim
2013-Oct-06, 10:11 PM
This conversation has gone way off-topic, (which is why I haven't thus far responded), but it also raises many interesting discussion areas. We really need to start another dedicated thread, (methinks) ..

One avenue I'd personally like to discuss further is:
Shouldn't we look at abiogenesis as a global geochemical process rather than just a molecular process? If we say that life arose very quickly, then that could mean a couple of million years. Can we then model a global process occurring over a couple of million years as a system of molecules?Someone else could raise a new thread on it (I'm a little busy at the moment), but there has been quite a lot of work done along these lines lately.

Just a last point: Pross is not looking to reduce Evolution to chemistry. He has attempted to distinguish a (perhaps) overlooked principle, which can be viewed as underpinning both thermodynamically principled chemistry, (as it pertains to self-replicating molecules), and Evolutionary natural selection. I see DKS as more of a perspective which may lead to other avenues of research. The idea has been extracted from the field of Dynamic Systems theory .. so it already has its 'mathematical theorems' supporting certain aspects it. DKS is an attractor in dynamic phase space.