Abiogenesis

[Poita (Peter)]

Ah, I see. Organic molecules have long been known to be belting around in space, we had a meteorite with plenty aboard land in Australia during the year of my birth.

This article is an interesting read re that and other stuff related to the discussion.
http://www.scientificamerican.com/ar...or-life&page=2
End of page 2 and start of page 3 talks about that directly, but the whole article is a good read.

[avandonk]

We are here. Get over it.

Are we alone? Yes we will soon be at the rate species other than us are going extinct. We will very soon follow! As our existence relies on them.

As Abbott said to Costello 'this is another fine mess you have got us into'.

Or was that Laurel and Hardy?

The questions remain the same and we have no real answers! Meanwhile Rome burns!

Bert

[Poita (Peter)]

Agreed!

To me, the current fact that we have not found any other life anywhere, and that we may truly be alone in the universe is more impetus to get off our arses and stop wrecking the joint.
For us to snuff out what may be the only sentient life in the universe is a bad joke.

If there is something else out there, I hope it has more sense than us

[CraigS]

I'm not so pessimistic (or sentimental) about species going extinct.

It seems to be part of the process.

Cheers

[Alchemy (Clive)]

Originally Posted by CraigS

I'm not so pessimistic (or sentimental) about species going extinct.

It seems to be part of the process.

Cheers

Actually, I'm rather sentimental, particularly as Bert says, we are all interconnected, and that means goodbye humans too. Although getting rid of humans would be beneficial to the planet

[marki]

Speculating on the origins of life is nowhere near as much fun as carrying out our major biological function...the continuation of our species. Imagine a world where we all so focused on the job at hand that we didn't have time to fight .

Mark

[CraigS]

Originally Posted by Poita

Ah, I see. Organic molecules have long been known to be belting around in space, we had a meteorite with plenty aboard land in Australia during the year of my birth.

This article is an interesting read re that and other stuff related to the discussion.
http://www.scientificamerican.com/ar...or-life&page=2
End of page 2 and start of page 3 talks about that directly, but the whole article is a good read.

Hi Peter;

Ok .. read through that article.

Its a beauty ! Thanks very much for that contribution .. it gives a very good outline for the arguments behind the view of the implausibility of Abiogenesis.

The implications of the Abiogenesis line of thinking also appear to lead towards a universe which seems to favour the emergence of life. This would call for an explanation of some sort. If this were so, then I would think life would be very common in Habitable Zones throughout the universe. However, one cannot ignore the implausibility factor behind it all, which has been your point throughout this discussion.

I've mentioned in the other thread, the 'no exo-life' perspective is, in my view, as equally as valid as the alternative 'pro exo-life' view, and that both seem to be ultimately driven by beliefs … as opposed to science. I remain of that view.

One issue arising from this discussion is one of the integrity of the arguments:

i) If one is arguing the 'pro exo-life' view, one cannot abandon the implausibility factor, nor the consequent abundant exo-life implications. With this line of argument, accumulated evidence of non exo-life findings in HZs should not be simply ignored, (IMHO), as accumulated evidence does eventually become a significant factor. When and how many non-findings, then becomes the question, for me.

ii) If one is arguing the 'no exo-life' view equally, one should not ignore the complete absence of an explanatory theory for the emergence of life on Earth (IMHO). There is none, from what I can see, and without it, one derives no guidance as to where to search for a second instance of life. The search is completely, hap-hazardly random, is guided equally by faith, and comes at an extremely high and ultimately unjustifiable cost.

iii) The third argument purely driven by faith .. 'we have no idea what life is .. therefore we don't know what we're looking for when we look for exo-life, … but it exists' … leads to the same problems as outlined in (ii) above.

This has been a most interesting thread (for me).

At the end of the day, "we are here" .. but before we "get over it", we should realise that justifiable statements of certainty are very few and far between.

Cheers

[CraigS]

I'll add one more post with my best attempts at statements of certainty (a duplicate from the 'I don't know what I saw' thread):

In the hunt for exo-life discussion, I find three curious statements which can be stated with certainty:

1) the uniqueness of life to Earth can be instantly 'disproven' with the first confirmed exo-life discovery;

2) the existence of exo-life in the universe, can never be 'disproven' with multiple negative discoveries, no matter how vast in number these are;

3) purely mathematically speaking, the numbers of habitable environments throughout the universe, tells us nothing about the uniqueness or otherwise, of exo-life in the universe, until a single instance of exo-life is discovered in an exo-habitable zone.

Inference from beliefs taken from non-insular Earth modelled habitats, is what keeps the search going.

Cheers

[Robh (Rob)]

Originally Posted by CraigS

I'll add one more post with my best attempts at statements of certainty (a duplicate from the 'I don't know what I saw' thread):

In the hunt for exo-life discussion, I find three curious statements which can be stated with certainty:

1) the uniqueness of life to Earth can be instantly 'disproven' with the first confirmed exo-life discovery;

2) the existence of exo-life in the universe, can never be 'disproven' with multiple negative discoveries, no matter how vast in number these are;

3) purely mathematically speaking, the numbers of habitable environments throughout the universe, tells us nothing about the uniqueness or otherwise, of exo-life in the universe, until a single instance of exo-life is discovered in an exo-habitable zone.

Inference from beliefs taken from non-insular Earth modelled habitats, is what keeps the search going.

Cheers

Agreed! Hi Craig.

However, there are generally two opposing groups in this type of discussion. The first believes that life is rare or perhaps even unique to the Earth in this Universe, the result of almost impossible convergent events: a case of the right ingredients being in the right place at the right time. For the Creationists, I'll include you in this group (no religious discussion intended)!

The second believes that there are so many planets in habitable zones in this universe that life is bound to be commonplace. The "life is inevitable" group.

Scientific deduction is often the result of statistical evidence. Thus, in an increasing sample size, a continued negative result would lead one to believe the proposition is less likely to be true.

Any confirmation of life at the moment would consist of an intelligent signal from afar or perhaps soon, detection of the "by-products" of civilisation. At some time in the future we might be able to travel to these exo-planets in reasonable time- who knows how. Continued failure to find life on planets in habitable zones (or elsewhere for that matter) would give increasing support to the first group's view. It can never make their view definitive (unless there is a finite number of habitable planets in our discoverable Universe) but it does imply that life may not be as common as the second group believes.

Regards, Rob

[CraigS]

Hi Rob;
Good to have you aboard ! I'm really trying my hardest to maintain this as a 'no-one can win' conversation. Your help in this regard would be very much appreciated .. its not as easy as it sounds !

Originally Posted by Robh

For the Creationists, I'll include you in this group (no religious discussion intended)!

Yikes ! I'm no Creationist ! Have I given that impression ?
I'm happy to declare right up front that I'm no Creationist ! (And that's not saying that there's anything wrong with having Creationist beliefs).
What I believe one way or the other, is basically irrelevant anyway. I'm just an intrepid explorer! (… who frequently gets into trouble )
Having said this, some of the ID ideas do come from Complexity Systems theory. The 'irreducibility' function from Complexity is more or less defined as:
"The new produced qualities are not reduceable to or derivable from the level of the producing, interacting entities"
.. and is demonstrable in certain complex systems. Its fairly easy to characterise life as a complex system. Perhaps the origin can be similarly characterised.

The ID folk relate what they observe to this phenomenon, (of complex systems), but the relationship may be tenuous, and is certainly debatable.

I personally don't see a big problem with following the complex systems direction. It doesn't at all lead to the existence of a 'Creator' as many folk seem to think. Deterministic extrapolation of the random/chaotic components of a complex system is actually as odds with complexity/chaos behaviours (and this principle is supported by hard evidence). So extrapolations leading to a 'Creator' would actually be coming from somewhere else, again … (ala determinism beliefs .. ).

Originally Posted by Robh

The second believes that there are so many planets in habitable zones in this universe that life is bound to be commonplace. The "life is inevitable" group.

Scientific deduction is often the result of statistical evidence. Thus, in an increasing sample size, a continued negative result would lead one to believe the proposition is less likely to be true.

I think the statistical argument is necessary in order to overcome the improbability aspects against the argument.
At best, I find it difficult to see it as deduction, also. Its more like 'inference', as 'deduction' requires the confirmed discovery of another instance of exo-life .. which doesn't presently exist.

Originally Posted by Robh

Any confirmation of life at the moment would consist of an intelligent signal from afar or perhaps soon, detection of the "by-products" of civilisation. At some time in the future we might be able to travel to these exo-planets in reasonable time- who knows how. Continued failure to find life on planets in habitable zones (or elsewhere for that matter) would give increasing support to the first group's view.

Other than the temptation to use it as 'evidence' against exo-life, I'm not at all sure that their case even requires this, as their counter argument (the 10^30,000 statistic, or whatever), seems to far outweigh, and render a few cases of non-discovery as irrelevant, anyway.

Originally Posted by Robh

It can never make their view definitive (unless there is a finite number of habitable planets in our discoverable Universe) but it does imply that life may not be as common as the second group believes.

Yes .. and it seems the logic in the 'pro exo-life' argument, predicts the abundance of exo-life (if one follows the pre-biotic organic compound/self replicating RNA/etc line.

Interesting.

Cheers … & good to have you around.

[Robh (Rob)]

Originally Posted by CraigS

Yikes ! I'm no Creationist ! Have I given that impression ?

My original statement ...
"For the Creationists, I'll include you in this group (no religious discussion intended)!"

Craig,

My apologies for the ambiguity. The statement was meant to be interpreted as "For those of you who are Creationists, I'll include them in this group."

Rob

[tonybarry (Tony)]

It might be instructive to see a chemical oscillator at work. These kinds of oscillators are frequently seen at university open days, and amount to a large vat of liquid, well stirred, which exhibits long range order and cyclic changes over time scales quite at odds with the size of the individual molecules that make up the oscillator.

When I first saw one (at the uni where I did my undergraduate) I recall being badly disturbed by the implausibility of the whole setup.

My chemistry prof. pointed me in the direction of Iliya Prigogine, a Nobel Laureate who first explained their chemistry and kinetics. And the key is to have environments which are far from equilibrium. In an equilibrium state, the 2nd law of thermodynamics is in force and you can't get order out of chaos. In far-from-equilibrium states, it becomes possible to produce remarkable order (at the overall expense of other things descending into great disorder). When we observe these environments, it is not difficult to imagine abiogenesis actually occurring.

We have not seen it yet, mainly because we have been looking for such a short time in the overall scheme of things. It is the hubris of humanity to think that just because something is unlikely, to our time sense, it becomes impossible for all time and all places.

While the Creationists may be in error in requiring a Divinity to create life, they at least have humility as a virtue. And that might be one area where we could take a leaf from their folio.

Regards,
Tony Barry

[CraigS]

Greetings Tony !

Cool words ..

I've personally never seen one of the oscillators but I have seen chemical experiments which appear to 'undo' or 'reverse' what appears to be a system in the state of equilibrium (perhaps these are the systems you speak of).

There also appears to be a fair amount written along the lines of enquiry into whether life is a far from equilibrium system (or degrees therefrom).

I find it interesting to note also, that there are measuring concepts, like the 'Lyapunov exponent', which aids as a 'measuring stick' to quantify the exponential divergence from equilibrium, sometimes measured in bits per time step, averaged over a large set of samples. A positive Lyapunov exponent is considered mathematical proof of chaos. It also acts as a bound for the quality of predictions from a chaotic system.

I really do think these 'tools' give us a way better method of quantifying disorder, (or degrees of distance from equilibrium states), than the combined laws of thermodynamics (including entropy). The laws of Thermodynamics originated from deterministic physics and have thus always had difficulty exploring degrees of chaotic or non-linear behaviours, eh ?

I agree with your statement about imagining abiogenesis actually occurring resulting in the order plainly visible in life. (.. Which could be why I, myself, appear to oscillate between these two competing views ! ).

Thanks for your input … very interesting dimension.

Cheers

[CraigS]

The following point raised from the ‘no exo-life’ perspective, as presented by Peter, and argued by Robert Shapiro, (in the Scientific Amercian article), has gotten me thinking some more:

Originally Posted by Poita

that if life is bound to happen given certain conditions, i.e. that we have a bio-friendly universe, then that is an incredibly profound, and shocking statement, and I don't see how it could be codified or incorporated into the current theories of physics. I'm not at all saying the universe isn't that way, I agree that it could be, we just don't know, but if it is then that would turn current theories on their heads.

So one observation taken from nature is the asymmetry or chirality of life supporting molecules:

Originally Posted by Physicsworld

Processes taking place in outer space, and not on Earth, are likely to have led to the biological molecules found exclusively in either a left-handed or right-handed form. That is the conclusion drawn from recent experiments carried out at the SOLEIL synchrotron facility near Paris in which a number of simple molecules found in star-forming regions exposed to polarized radiation created amino acids with an imbalance of left- and right-handed molecules.

They go on to say that other organic molecules also exhibit this asymmetry, but it is the imbalance of left or right handedness between the sugars and amino acids comprising DNA, which has a large impact on the fundamental protein folding process in cells. The polarisation-caused-resulting-chirality, would thus have existed way before life got underway and thus, would not be particular to life.

I can see how the presence of chiral differences between sugars and amino acids in DNA, would conjure up a perception that this chemical signature results in a ‘bio-friendly’ universe, but I think this perception is caused by a logical fallacy:

Protein folding is caused by chirality. (Supportable/'true').
Chirality is caused by polarisation. (Supportable/'true').
Polarisation is caused by the Universe. (Supportable/'true').
Therefore the Universe favours protein folding. (Not supportable/'false').
The universe is thus ‘bio-friendly’. (Not supportable/'false').

The final point put forward in the Physicsworld article, and specifically by Laurence Barron, however is:

"Whether this latest work has anything to do with the origin of biological chirality is not clear," he says. "But it certainly merits inclusion in future discussions of the problem."

Also, as an aside, interestingly, others are even building remote sensory devices to detect the chirality difference:

A right-handed molecule has the same composition as its left-handed cousin, but their chemical behavior differs. Because many substances critical to life favor a particular handedness, Thom Germer and his colleagues think chirality might reveal life’s presence at great distances, and have built a device to detect it.

Interesting.

Cheers

[CraigS]

So here's another interesting snippet (just for the record) ... this may not be relevant to the abiogenesis topic, but the numbers involved caught my eye. I guess one could say this is a snap-shot of what stands about 3.5 to 4 bill years after abiogenesis got underway on Earth , (if it all happened that way, that is .. oh and also putting aside panspermia hypotheses for the moment).

Surprisingly, this figure has never been known to any certainty, either .. (and it still isn’t).

"How Many Species are There on Earth ?"
Answer:
8.74 +/- 1.3 million (Eukaryote based .. no viruses etc included in this figure):

When applied to all five known eukaryote* kingdoms of life on Earth, the approach predicted:

~7.77 million species of animals of which 953,434 (12.4%) have been described and cataloged;
~298,000 species of plants of which 215,644 (72.4%) have been described and cataloged;
~611,000 species of fungi .. moulds, mushrooms of which 43,271 (7.1%) have been described and cataloged);
~36,400 species of protozoa .. single-cell organisms with animal-like behavior, eg. movement, of which 8,118 (22.3%) have been described and cataloged;
~27,500 species of chromista including, eg. brown algae, diatoms, water moulds, of which 13,033 (47.4%) have been described and cataloged).

Total: ~8.74 million eukaryote species on Earth.

* Notes: Organisms in the eukaryote domain have cells containing complex structures enclosed within membranes. The study looked only at forms of life accorded, or potentially accorded, the status of "species" by scientists. Not included: certain micro-organisms and virus "types", for example, which could be highly numerous.

Within the 8.74 million total is an estimated 2.2 million (plus or minus 180,000) marine species of all kinds, about 250,000 (11%) of which have been described and catalogued.

Just goes to show how little of the total life we've discovered during our own era, on Earth!

Cheers

[xelasnave]

Thank you Craig for posting on such an interesting matter.

I started wondering about how the first cell may have been made under "natural" conditions (and ((probably because I have been following stuff related to Bert,s pointer on the latest research into water)) it occurred to me that a single droplet of water seems similar to a cell..the alignment of water molecules at the surface offers the droplet a simple shell..a method of containment.. perhaps the very first initial containment..

Within a droplet of water it seems we can observe the pushing of material to the centre..this would seem a simple machinery to cause other molecules within the droplet to meet and provide the best possible environment providing opportunity to bond.
Berts water material tells us that this simple shell apparently holds a charge...a charge can regulate exchange and perhaps even cause a larger droplet to split..whatever but the fact that there is an available charge opens many doors... anyways from such simplicity if you start to consider the complexity and opportunity it does your head in...thanks again.
alex

[xelasnave]

http://www.sciencedaily.com/releases...1006113408.htm

Maybe we can observe the creation of the first cell...

alex

[CraigS]

G'Day Alex;

I had decided to let this thread lay for a while … I'm glad you've found it interesting .. there are certainly a lot of aspects which I was not aware of, and have subsequently found out, since leaving this thread. (I may add these when I get the chance).

For the record, post #22 on this thread is Bert's reference to what you were mentioning.

I find it quite amazing how many life supporting mechanisms have been identified by following the 'exo-life exists' line of speculation. I'm sure there are many others, and I can certainly visualise the relevance of this one (as far as cell membrane forming, and dissociation, mechanism analogies go).

The "water saturation in Mars' atmosphere" article also chases another possible mechanism which could be used to infer the existence of past exo-life. In this one however, I find there are many questionable usages of "if confirmed", "would have consequences", "is known", etc .. so I'll take this as more attempts at applying verifiability to a logical proposition (for the positive exo-life argument), than actual evidence in direct support of the 'exo-life-on-Mars-in-the-past' proposition. (This being because we have no idea as to whether water causes the emergence of life, or whether it is merely correlated with the only instance of life we know of).

Cheers

[xelasnave]

I suggest a shell mechanism seems important but may not be exclusive of other mechanisms but it would seem the first step must be the creation of some type of seperation from the outside... a drop of water would seem perfect.
This thread causes one to embrace just how very complex something, we take to be simple, can be...a mere cell (modern one) yet so much to it...and applying russian doll imagination down to the atoms and their parts and how those parts can be described as a point movement via string theory you need a good deal of imagination just for a very simple overview.

The chemistry (my old love) appeals to me.


alex.

[CraigS]

I was reading a freely available, widespread document the other day by an Astrophysics-type scientist who declares his religion to be Catholic (Dermott J. Mullan, is his name). D. J. Mullan is a member of the Bartol Research Center in the Department of Physics and Astronomy at the University of Delaware, where he has been Professor since 1982. His Biography is here.
The paper is quite a good read, and its all over the web at the moment.

Here is part of his conclusion:

With all of these assumptions, we find that the probability of assembling the RNA required for even the most primitive (12-14) cell** by random processes, in the time available, {1.11 billion years}, is no more than one in 10^79.

Note**: A (12-14) cell is defined as being a cell that is able to function with only 12 proteins and that each protein consists of a chain of no more than 14 amino acids (ie: highly minimalist when compared with a modern-day cell). There are a bunch of other assumptions behind this figure .. a read of the paper reveals each one, as well as the sensitivity of varying them compared with this final figure. (Note that he also assumes that the RNA sequence, from which these proteins are derived, is already present, and is thus not included in the above probability estimation, as trying to generate this sequence randomly, results in an absurdly small probability figure).

He also eventually manages to whittle this down to one in 10^63.
By way of comparison, the number of atoms in the universe is estimated to be about 10^80, (I think).

Even with all of the simplest definitions of life we can come up with, there is still some explaining to do in coming up with a modern day cell .. and I think we all recognise this. I, for one, am happy to leave it at this point, without jumping to any further conclusions.

Its an interesting read .. and an interesting point.

Cheers