Posted: Dec 20, 2017 3:04 pm
by Calilasseia
Wortfish wrote:
Calilasseia wrote:

But it's typical of creationist apologetics to misrepresent said research, not to mention peddle the usual duplicitous pairing of responses to the outcome, namely:

[1] If the reactions in the experiment fail to produce a relevant result, claim that this purportedly "proves" testable natural process cannot be responsible for life;

[2] If the reactions in the experiment succeed in producing a relevant result, claim that this purportedly involves "design", when it does nothing of the sort.

What part of "we don't know if it will work when we begin, let's try it and see" equals "design" of the sort creationists routinely pontificate about? Oh that's right, it doesn't, because the sort of "design" creationists routinely pontificate about, involves perfect prior knowledge of the outcome. Except that, oops, scientists have never had this.


A controlled and designed experiment hardly involves trial and error, as you ridiculously suggest.


Except that this manifestly duplicitous apologetic pseudo-response, fails to take into account that the reason experiments are "designed", is to ensure that only a well-defined set of variables has an effect upon the outcome. This does not in any way presuppose that those designing the experiment, know in advance what oucome those variables will produce, the determination of which is the whole point of the experiment. Then, having determined that one, restricted and manageable set of variables delivers an observed outcome, the researchers then move on to other experiments, that include other variables excluded from the first experiment, to see how that modifies the outcome.

But of course, those of us who paid attention in science class already know that the purpose of experimental design, is to determine which extant variables affect an outcome, and then to let those variables act as they will. In case you don't understand this elementary concept, selecting a variable to observe doesn't equal directing that variable's behaviour. Though I'm familiar with the manner in which creationist apologetics are deliberately constructed to mislead the audience with respect to this concept.

Wortfish wrote:The experimenters may not know the final outcome


Exactly. Which at a stroke destroys creationist attempts to portray the requisite experimental work as having anything to do with "design", of the sort creationists routinely pontificate about, as I've already dealt with earlier.

Wortfish wrote:but they select materials and reagents with a good view to what may happen, as Sutherland obviously did when he first published his results in 2009.


Oh, wait, what did Sutherland actually state in his 2009 paper? Let's take a look at this shall we?

First, the citation:

Synthesis Of Activated Pyrimidine Riboucleotides In Prebiotically Plausible Conditions by Matthew W. Powner, BĂ©atrice Gerland & John D. Sutherland, Nature, 459: 239-242 (14th May 2009) [Full paper downloadable from here]

From the paper:

Powner et al, 2009 wrote:Because they comprise phosphate, ribose and nucleobases, it is tempting to assume that ribonucleotides must have prebiotically assembled from such building blocks. Thus, for example, it has previously been supposed that the activated ribonucleotide β-ribocytidine- 2',3'-cyclic phosphate 1must have been produced by phosphorylation of the ribonucleoside 2, with the latter deriving from the conjoining of the free pyrimidine nucleobase cytosine 3 and the furanose form of ribose 4 (Fig. 1, blue arrows). This mode of assembly is seemingly supported by the facts that cytosine 3 can be synthesized by condensation of cyanoacetaldehyde 5 and urea 616 (the hydration products of cyanoacetylene 717, and cyanamide 818, respectively) and pentoses including ribose can be produced by aldol reaction of glyceraldehyde 9 and glycolaldehyde 108,9. The insuperable problem with this approach, however, is that one of the presumed steps, the condensation of ribose 4 and cytosine 3 does not work11. The reasons for this are both kinetic (the N1 lone pair of 3 is unavailable owing to delocalization) and, in water, thermodynamic (the equilibrium constant is such that hydrolysis of 2 to 3 and 4 is favoured over condensation). The same is true for ribosylation of uracil, which has also not been demonstrated.

We have considered a large number of alternative ribonucleotide assembly modes, including those that extend back to the same small-molecule precursors as the traditionally assumed route described above19. By systematic experimental investigation of these options, we have discovered a short, highly efficient route to activated pyrimidine ribonucleotides from these same precursors that proceeds by way of alternative intermediates (Fig. 1, green arrows). By contrast with previously investigated routes to ribonucleotides, ours bypasses ribose and the free pyrimidine nucleobases. Mixed nitrogenous–oxygenous chemistry first results in the reaction of cyanamide [b]8 and glycolaldehyde 10, giving 2-amino-oxazole 11, and this heterocycle then adds to glyceraldehyde 9 to give the pentose amino-oxazolines including the arabinose derivative 12. Reaction of 12 with cyanoacetylene 7 then gives the anhydroarabinonucleoside 13, which subsequently undergoes phosphorylation with rearrangement to furnish β-ribocytidine- 2',3'-cyclic phosphate 1. In a subsequent photochemical step, 1 is partly converted to the corresponding uracil derivative, and synthetic co-products are largely destroyed.[/b]


Note the part I've highlighted in blue above - namely:

We have considered a large number of alternative ribonucleotide assembly modes, including those that extend back to the same small-molecule precursors as the traditionally assumed route described above19. By systematic experimental investigation of these options

In other words, what they did was "let's try lots of different options, and see if any of them work". Which they did because the assumed mechanism was found NOT to work.

So, the experimental procedure here consisted of:

[1] We know what we need to start with, and what we need to end up with;

[2] We also know that the original planned means of getting from A to B does not work, and we have found reasons for this;

[3] Do other routes from A to B exist, and if so, can we find them?

[4] Let's try out lots of options for getting from A to B, and see which ones work or don't work.

Again, your apologetics are completely destroyed.

Moving on ...

Wortfish wrote:
But if no one is around to observe whether or not the reactions are actually working, what's the fucking point of doing the experiment? That's the whole fucking point of experiments in case you failed to read the memo - try something out, and learn from the outcome!


Observation is fine. But setting up the stages of the experiment in such a way that isolates the materials from each other, is just form of artificial selection for non-living chemicals.


Illiterate drivel. Because, wait for it, the researchers have to introduce the reagents in question to each other, to see if they will react!

But. once again, the whole fucking point of choosing reagents of known purity to start with, is so that the researchers know that the molecules they've chosen have been the sole participants in the reaction, and not something else they didn't know about. Only a fucking idiot would launch into an investigation of any chemical reaction, without knowing in advance what molecules he was dealing with.

Wortfish wrote:
Try because the moment one set of reactions works, and produces viable protocells, those protocells are going to interfere with any subsequent different sets of reactions that might work. At the very least, by consuming the reactants or products as food.


At the moment, protocells are being purposefully designed as proofs of concept. Do pay attention.


Model protocells are being thus synthesised, with the aim of finding out what could have happened with real, past protocells, precisely because we don't know the latter yet. Once again, what part of "let's work with as simple a precursor as we can, and move on incrementally to the desired objective" do you not understand?

Once again, those model protocells were synthesised, because the researchers didn't know in advance what they would do. Years of observing other chemical reactions gave them some basic ideas to work with, but, as was the case with the Sutherland paper above, they're open to surprises.

Indeed, for years, many people thought that if you dropped a light ball and a heavy ball from the top of a building, the heavy ball would hit the ground first. It took Galileo to turn round and say "Let's try it out and see shall we?" Whereupon, whoops, what a lot of people thought beforehand was wrong.

Wortfish wrote:
This is why scientists are looking for other venues, to see if life appeared there. So that they have more than one instance to work with. Because the moment any set of chemical reactions succeeds in producing life, the products of that set of reactions will, by definition, shut down any other options.


Nobody is trying to produce life through a series of chemical reactions.


Actually, that's the ultimate aim - to see if a working replicating protocell can arise from prebiotic reactants. But to get to that stage, the researchers have to solve a lot of lower level jigsaw puzzles before solving the big one. Once again, what part of "incremental steps" do you not understand?

Wortfish wrote:They are trying to break up the huge problem into smaller parts that may or not be solvable.


So why did you post the previous drivel?

Wortfish wrote:The first stage is producing lipids, amino acids and nucleic bases. That's still a long way from "life".


But since these molecules are manifestly a part of living organisms, it's a good place to start. As opposed to assuming that mythology magically has the answers, which it doesn't.

Wortfish wrote:
A statement whose fatuous nature will only become even more apparent, the moment life is found on Titan, Enceladus or Europa.


Well. You are basing your claim on faith.


Bollocks. I merely introduced a conditional. Namely, "if x, then y". I issued no statement on whether or not x was true. Because, like everyone else here on Earth at the moment, I don't know. Which is one of the reasons NASA is planning to send spacecraft to the requisite venues, - to find out.

Wortfish wrote:But the fact remains that - here on Earth - the process has never been repeated.


You know this for sure, do you?

Only it's entirely possible that more than one instance of the requisite reactions took place in the past, but only the final instance was successful at leaving present day descendants.

Wortfish wrote:Naturally-occurring phenomena tend to happen more than just once in 4 billion years.


Particular instances, however, only ever occur once. The goal of science is to find the classes of interaction that generate the instances. Or did you miss this elementary concept in school?

Wortfish wrote:Miracles, by their very nature, do not happen with any regularity


Wrong. It's entirely possible, if miracles exist, for them to do so, if the generating process for them occurs more than once.

Wortfish wrote:...which is what we see with the origin of life.


Poppycock. What we see with the origin of life, is one successful instance, with as yet, no data telling us about any previous failed instances.