Newmark wrote:

rainbow wrote:

Newmark wrote: Now, isn't it time for you to go home, since you obviously don't understand the posts you reply to?

I certainly don't understand what point you're trying to make, since it's all been covered.

My point was that "having evidence that something is possible doesn't mean that it's probable" had no bearing to . But since you didn't understand the conclusion you argued against, it is perfectly reasonable that your argument made no sense.

rainbow wrote:

Newmark wrote:

rainbow wrote:

Newmark wrote: Now, isn't it time for you to go home, since you obviously don't understand the posts you reply to?

I certainly don't understand what point you're trying to make, since it's all been covered.

My point was that "having evidence that something is possible doesn't mean that it's probable" had no bearing to . But since you didn't understand the conclusion you argued against, it is perfectly reasonable that your argument made no sense.

Rubbish. Where did I argue against Just a Theory's conclusion?
Do you have to make this up simply because you don't have any better argument?
If you can't argue properly, I won't bother engaging with you any more.
Am I clear?

rainbow wrote:

hackenslash wrote:It's fairly clear English. He's saying that, until there is a robust competing hypothesis, it seems reasonable to pursue the hypothesis that has actually provided some evidence, as that is more likely to provide some answers.

It then goes back to the weak argument, strong argument scenario - which has already been discussed.
Please learn to scroll back.

pensioner wrote:I have just wasted half an hour reading 15 pages on this topic. This is what a critique is supposed be, is it? I think I will give them a miss from now on.

95Theses wrote:

pensioner wrote:I have just wasted half an hour reading 15 pages on this topic. This is what a critique is supposed be, is it? I think I will give them a miss from now on.

If you are looking for something approaching a valid discussion, it's not the 'Critique' you should be avoiding its the 'Posted by Rainbow' you should be avoiding.

byofrcs wrote:The peculiar view I have is that the (essay?) starts "In the earliest period of the history of the planet, it was a body devoid of life, and conditions on the planet were far from conducive to the appearance of life,..." but from my materialist view, the very fact that we have matter and whilst the conditions in the universe mean that this matter can order itself and with a suitable energy source then this means that this matter can be more ordered (is there any limit at all ?).

I think the concept of thermodynamic depth can easily be applied to any system and certainly a pre-biotic Earth whilst we have a stable Sun.

Just A Theory wrote: We pursue abiogenesis as a research field because there is no viable alternative and no conclusive evidence that abiogenesis is a non-starter as far as the origin of life goes.

rainbow wrote:

Cali wrote:In the earliest period of the history of the planet, it was a body devoid of life, and conditions on the planet were far from conducive to the appearance of life, particularly during the episode termed "The Late Heavy Bombardment"[1] by scientists, which saw intense bolide impact activity taking place on the planet's surface. Once this episode, and subsequent episodes postulated to have taken place, were complete, the Earth cooled, a solid crust formed, and liquid water in quantity began to appear. Thus, the stage was set for the processes that were to result in the emergence of life.

There is no evidence to support the conclusion that there was no life during the bolide impact period, it is pure speculation.
What is clear is that the bolide impacts would have removed any evidence of life before this period.
...so we simply don't know.

rainbow wrote:

Calilasseia wrote:It was Darwin himself who first speculated about the origins of life, with his short remarks about a "warm little pond"[2], but, in the middle of the 19th century, this would remain speculation, as the means to determine the mechanisms that might apply had not yet been developed. However, it made eminent sense to scientists following Darwin, to hypothesise that any natural mechanisms responsible for the origin of life would be based upon organic chemistry, since life itself is manifestly based thereupon - millions of organic reactions are taking place within your body as you read this, and indeed, the cessation of some of those reactions constitutes the end of life for any organisms affected. Alexander Oparin, the Soviet biochemist, was the first to publish hypotheses about the chemical basis of the origin of life[3], and based his own hypotheses on the notion that a reducing atmosphere existed on the primordial Earth, facilitating the production of various organic compounds that would then react further, producing a cascade of escalating complexity that would ultimately result in self-replicating entities. Back in 1924, his hypotheses remained beyond the remit of scientists to test, but that would soon change.

The idea that life will be based on organic Chemistry is rather stating the obvious, though it doesn't follow at all that a reducing atmosphere is a requirement for the existence of life.

rainbow wrote:

Calilasseia wrote:The first indications that Oparin had alighted upon workable ideas came in 1953, with the celebrated Miller-Urey Experiment[4], in which electrical discharges in a reducing atmosphere composed of simple molecules produced measurable quantities of amino acids. Miller himself only cited the presence of five amino acids, as he was reliant at the time upon paper chromatography as his primary analytical tool, which was only sensitive enough to detect those five amino acids cited. However, Miller had been more successful than he originally claimed: after his death, preserved samples of his original reaction mixtures were subject to state-of-the-art analysis, using gas chromatograph mass spectrometry, a technique millions of times more sensitive, and regarded as the 'gold standard' in modern organic analysis. That subsequent analysis yielded not five, but twenty-two amino acids[5].

Now this gets more interesting. The GCMS reveals that indeed some of the more exotic amino acids are formed, but at concentrations of a millionth or less of the concentration of lysine.
...so the more sensitive analysis isn't really such good news, since it does show that certain amino acids weren't produced in sufficient quantity for further reaction.

rainbow wrote:

Calilasseia wrote:Early criticism of Miller's work in the scientific community focused upon the requirement for a reducing atmosphere in accordance with the Oparin model. However, subsequent workers determined by repeat experimentation, that a range of atmospheric constitutions would be suitable for a Miller-Urey type synthesis on a prebiotic Earth[6], several of those constitutions being only mildly reducing, expanding the range of conditions for which the Oparin model would be viable. More recently, work has suggested that the prebiotic Earth could have developed an atmosphere containing considerably more hydrogen than originally thought[7], making the Oparin reducing atmosphere once again more plausible. Indeed, the range of conditions under which amino acids could be synthesised has since been expanded to include interstellar ice clouds, courtesy of more recent research[8 - 14], and the Murchison meteorite was found to contain no less than ninety amino acids, nineteen of which are found on Earth, which were obviously synthesised whilst that meteorite was still in space. Other data from meteorites adds to this body of evidence[10, 15, 16].

What this does illustrate is that simple organic compounds, including amino acids - are indeed quite easily formed under quite a range of conditions, as long as the elements carbon, hydrogen, oxygen and nitrogen are present - in approximately the right ratios.
Nothing really surprising about that if you understand the Chemistry.

rainbow wrote:

Calilasseia wrote:The formation of amino acids itself, whilst an important step in any naturalistic origin of life, would need to be accompanied by some means of linking those amino acids into peptide molecules[17] - the process by which proteins are formed. A significant step forward with respect to this, arose when researchers alighted upon the fact that carbonyl sulphide, a gas that is produced in quantity naturally by volcanoes, acts as a catalyst for the formation of peptides, increasing yields dramatically[18]. This would facilitate peptide formation not only in the vicinity of hydrothermal vents, but in the vicinity of terrestrial volcanoes close to bodies of open water.

There is no explanation as to why the formation of amino acids should be 'an important step in any naturalistic origin of life', nor is it stated why they would need to be formed into peptide molecules. I can't find a single paper of any serious current researcher into Abiogenesis that still supports the Protein First Model.

Indeed, Miller had produced the 22 amino acids found in some of his reaction mixtures by extending the synthesis to include volcanic input, though not carbonyl sulphide - the addition of carbonyl sulphide would, however, facilitate peptide formation rapidly once the amino acids themselves were formed.

A bit of a confused statement if ever there was one. If Miller had included COS in his experiments, he might have made some polypeptides, but he didn't.

rainbow wrote:

Calilasseia wrote:One additional problem to be overcome was the 'chirality problem'. Amino acids, with the exception of glycine, are chiral molecules, existing in two forms that are mirror images of each other in space (stereoisomers). Initially, methods for producing one form preferentially over another were something of a puzzle, but chemists working in an entirely different field established that a process called 'chiral catalysis' exists, indeed, this work led to a Nobel Prize for the researchers in question[19]. The demonstrated existence of working chiral catalysts[20] led abiogenesis researchers to seek such catalytic processes in their own field, and, in due course, these were alighted upon[15, 21- 24].

This is quite a vast subject, and it would be difficult to do justice to it here. I can however find no papers that show that 'chiral catalysts' exist in nature outside of living systems.

rainbow wrote:

Calilasseia wrote:However, amino acids are not the only molecules required for life, important though they are. Some form of self-replicating molecule, providing the basis of an inheritance mechanism, is required. Given the difficulties involved in synthesising DNA as a total synthesis, researchers turned to RNA instead, a molecule that still forms the basis of the genomes of numerous extant taxonomic Families of viruses today. RNA, being easier to synthesise, was considered a natural first choice for the basis of primordial genomes, and thus, attention turned to the synthesis of RNA under prebiotic conditions. This was soon found not only to be possible, but to be readily achievable in the laboratory, and indeed, catalysis plays a role in these experiments. Natural clays formed from a mineral called montmorillonite provide a ready natural catalyst that would have been present in quantity on a prebiotic Earth, and the catalytic chemistry of RNA formation whilst adsorbed to such clays is now a standard part of the scientific literature[22- 42].

Unfortunately there is no explanation of how we get from the simple molecules formed in the Miller-Urey experiments to something rather complex such as RNA. Certainly there isn't a shred of evidence to show that RNA forms if you add some montmorillonite to a Miller-Urey reactor.
It is somewhat more complicated than that, and the statement:

This was soon found not only to be possible, but to be readily achievable in the laboratory, and indeed, catalysis plays a role in these experiments.

- glosses over the actual problems involved.
How were the reagents formed?
What were they and how could they have got to the concentrations required to make a nucleotide?
How did they get purified to the point where the required reactions were not overwhelmed by side reactions?
How did one step get to the next?
Really we need a bit of detail here, rather than just waving at 20 or so scientific papers, in the hope that the answers may be contained in there somewhere.

rainbow wrote:

Calilasseia wrote:Having established that RNA was synthesisable under prebiotic conditions, researchers then turned to the matter of establishing the existence of self-replicating species of RNA molecules. This was duly successful[30, 43, 45 - 47], establishing that such species could have arisen among the extant RNA molecules being synthesised on a prebiotic Earth, and of course, once one self-replicating species exists, the process of evolution can begin, which has also since been demonstrated to apply to replicating RNAs in appropriate laboratory experiments[48].

It is rather unclear what is meant by 'synthesisable'. If it means that some of the steps have been shown to be possible by laboratory experiments, then it is entirely correct. What it certainly not the case, is that it is possible to set up a reactor set to prebiotic conditions, and then have any measurable yield of RNA.
Of course the term 'self-replicating species of RNA molecules' needs a bit of explanation. This doesn't mean as it might be assumed that these RNA molecules will simply copy themselves if left in a solution of prebiotic soup. They can make copies of themselves if they are fed with high concentrations of nucleotides under the right conditions and purity.

rainbow wrote:

Calilasseia wrote:Once a self-replicating molecule that can form the basis of an inheritance mechanism exists, the next stage scientists postulate to be required is encapsulation within some sort of selectively permeable membrane. The molecules of choice for these membrane are lipids, which have been demonstrated repeatedly in the laboratory to undergo spontaneous self-organisation into various structures, such as bilayer sheets, micelles and liposomes. Indeed, in the case of phospholipids, they can be stimulated to self-organise by the simple process of agitating the solution within which they are suspended - literally, shake the bottle[49 - 53].

Yes, it really is that easy. However 'lipids' describes a very large range of compounds, not all of which show the self organisational ability of phospholipids. There is no evidence that phospholipids could've formed under prebiotic conditions.

rainbow wrote:

Calilasseia wrote:Whilst scientists naturally accept that 'joining the dots' between these individual steps is entirely proper, particularly on a body the size of a planet over a 100 million year period, the absence of experiments actively coupling these stages is a matter remaining to be addressed, though such experiments will be ambitious in scope indeed if they are to produce complete working protocells at the end of a long production line starting with a Miller-Urey synthesis.

There is nothing to support the argument that the origin of life would've required an Earth-sized planet, or a 100 million years. Molecules are very small and the Original Replicator could've formed in the tiniest of puddles, or even in a moist crack within a particle of clay on a dried out lake, or a micron-sized pore in a volcanic vent.

Calilasseia wrote:starting with a Miller-Urey synthesis

Doesn't follow at all. We have more convincing evidence that building blocks for RNA and protocells could form in volcanic vents. Miller-Urey doesn't have to be involved. Maybe even the organics came from space in the form of chondrites.

rainbow wrote:

Calilasseia wrote:A 'grand synthesis' of this sort in the laboratory is not high on the scientific agenda at the moment, which is more concerned with validating the individual hypothesised steps, but once those steps are accepted as valid in the field, doubtless one day a 'grand synthesis' will be attempted, and the success thereof will establish beyond serious doubt that our pale blue dot became our home courtesy of well-defined and testable chemical reactions.

If this experiment will 'establish beyond serious doubt that our pale blue dot became our home courtesy of well-defined and testable chemical reactions', then it follows that there is serious doubt at present.

rainbow wrote:

Calilasseia wrote:Even so, no one conversant with the literature seriously considers any more that magical forces are required to produce life: just as vitalism was refuted by Wöhler's classic experiment, that gave rise to organic chemistry as an empirical science in the first place, so it is likely to be rendered ever more irrelevant in abiogenesis research, as the steps leading to life's blossoming on our planet are traversed and studied in ever greater detail.

The concluding sentence contains a number of logical fallacies, and has a bit of confusion as to the object and subject. If it is to say that 'magical forces are required to produce life', then that strawman appears to be knocked over, but then is miraculously resurrected by saying it is 'likely to be rendered ever more irrelevant'. This suggests that it has some relevance.
This makes the concluding sentence rather ambiguous.

tturtlebutt wrote:It seems to me that some will push their agenda even in the face of rock solid evidence. I have hung around this and the old RD forum long enough to grow quite fond of some of the regular posters and certain moderators. People like Rainbow can be useful because of the tremendous amount of useful information found in the replies to his sillyness. So...thanks for giving me a different perspective to consider.
The way he keeps asking for links to science papers and proof of various claims makes me wonder if his agenda is to learn........? If so, isn't there a more subtle way to go about getting the info?? After all, I find the folks here quite generous with their knowledge, time, and access to scientific documentation.

Rumraket wrote:

tturtlebutt wrote:It seems to me that some will push their agenda even in the face of rock solid evidence. I have hung around this and the old RD forum long enough to grow quite fond of some of the regular posters and certain moderators. People like Rainbow can be useful because of the tremendous amount of useful information found in the replies to his sillyness. So...thanks for giving me a different perspective to consider.
The way he keeps asking for links to science papers and proof of various claims makes me wonder if his agenda is to learn........? If so, isn't there a more subtle way to go about getting the info?? After all, I find the folks here quite generous with their knowledge, time, and access to scientific documentation.

I agree. I haven't learned so much science in my life as I have debating creationists or arguing with Rainbow

rainbow wrote:
The real point of this thread is to show that Abiogenesis is a Creation Myth, and like the others is based not on solid facts but supposition.

rainbow wrote:It is an evaluation of another work, not necessarily critical. It does however examine in detail the arguments presented and offers a comment on them.
It is NOT intended as argument for another point of view. If I wish to present an alternative Thesis, I've done this elsewhere.