But I certainly have the right to explain why I'm not aboard, and ask those interested in the discussion or piloting the vessel, why they believe in the ride.
People said that about human flight in 1902. Throughout the entire thread, people have been trying to explain to you that what hasn't been discovered yet has no bearing on what will be discovered tomorrow.
If you have nothing to add as for understanding the chemistry involved....
If you were really interested in learning the chemistry involved, you'd be asking questions about the chemistry, not second-guessing the conclusions.
As I mentioned in an earlier post, either adenine came to earth on the Murchison meteorite or it was accidentally synthesized during the analysis. Do I have that right?
If I do, then adenine is formed somehow "out there" OR it's easily formed by simple reactions here on earth. Do I have that right?
If I do, what is your question about the chemistry involved?
Should I again quote your claim that truck drivers make better peer reviewers than scientists?
I'll do it myself because I didn't say that. Your so offended that you can't see straight.
I'm not offended. Like probably most other people in this thread, I'm bewildered at how you can so boldly misrepresent without blushing. Once again you've provided a nearly perfect example of declaring "black is white", this time claiming I misrepresented you. Here's what you just claimed you said:
Rob supporting his claim that he wasn't talking about peer review writes:
Rob:
Or does it take a truck driver with a high school education, to do a thorough and objective job of moderating the work of men with 'doctorates'?
Yet you appear to have left something out:
Rob's full statement with the portion he left out writes:
Was this paper peer reviewed? Or does it take a truck driver with a high school education, to do a thorough and objective job of moderating the work of men with 'doctorates'?
So we see now that you were talking about peer review after all, just like I said. You were misrepresenting facts again, I see, and issuing accusations that were untrue.
Yet, even so... I have already admitted to my own stench. I am only human. How about you Percy... got any human stench in you?
Please stop comparing yourself to others in this thread. Pointing out that that we're all human, an undeniable yet irrelevant fact, doesn't change the fact that the person demonstrating ignorance of the subject matter, making misstatements and misrepresentations, and time and again making the discussion personal by casting aspersions at every turn, is you.
You've been nothing but a distraction in this thread from the beginning. You've done nothing but question my motives rather than debate the issues. There is only 120 or so posts left. Please engage the subject or move on.
If you'd prefer more time be spent on the topic then please stop making blatant and erroneous "black is white" declarations that can't be ignored. Stop getting your facts confused and wrong. Stop digressing down rat holes about the nature of science. That's all it takes.
The plain fact of the matter is that casting doubt on the presence of adenine in the Murchison meteorite is a meaningless exercise unless you intend to go on to then cast doubt on all other possible sources of adenine, both known and those we haven't figured out yet. This is what is called attempting to prove a negative, which can't be done. But you continue on anyway, maybe in the belief that though you can't prove a negative, you can get close enough for all practical purposes. That, too, is untrue.
I want to know and learn...
It would be so much more convincing if you would demonstrate this by your conduct instead of treating us to empty claims like this.
I was then trying to find out if anhydrous reduction was equivilant to hydrolyisis. I read all kinds of papers. then I thought, 'Wait a minute... what is that other 5%?'
Hydrolysis may still be an issue...
After asking you about it, I then pointed out that the 95% formic acid obtained from Sigma-Aldrich is indeed 5% water. I figure you found that out before I did, since you didn't respond. Why didn't you or Percy come forward with that information? I suppose I shouldn't assume you knew...
Actually I knew the acid was mixed with water, but I was not concerned about it. There is no hydrolysis in 95% formic acid, because there are no free water molecules in the 95% formic acid solution, or did you not comprehend the point in Message 175:
quote:The reaction is best thought of as forming hydronium ions, by
H2SO4 + H2O ’ H3O+ + HSO4-,
and then
HSO4- + H2O ’ H3O+ + SO42-.
Because the hydration of sulfuric acid is thermodynamically favorable, sulfuric acid is an excellent dehydrating agent, and is used to prepare many dried fruits. The affinity of sulfuric acid for water is sufficiently strong that it will remove hydrogen and oxygen atoms from other compounds;
In a "95% Sulfuric Acid" what you would actually have is an ion mixture composed of roughly
92.5% pure Sulfuric Acid (H2SO4 in ion form: H+ + HSO4- + SO42-)
7.5% H3O+ + SO42-
0.0% pure water (either as H2O or ionized as H+ + OH-)
Similar reactions occur in all concentrated acids (but may be one stage instead of two), and will continue to occur until the acid has fully reacted with the water. After that water molecules will be freely available for hydrolysis of other molecules.
What part about sulfuric acid being used to suck water out of fruit makes you think there would be water available for hydrolysis? Formic acid at 95% concentration is not much different:
quote:Safety The hazards of solutions of formic acid depend on the concentration. The following table lists the EU classification of formic acid solutions:
Stable. Substances to be avoided include strong bases, strong oxidizing agents and powdered metals, furfuryl alcohol. Combustible. Hygroscopic.
R34 Causes burns. R35 Causes severe burns.
And just for clarification in case you don't have the picture yet:
The 95% formic acid is not going to be making water available to be used for hydrolysis, rather it is going to be absorbing any extra moisture it can find.
Seriously Rob. Let me repeat again: you do not have any hydrolysis in the 95% formic acid extraction. The water that was mixed with the acid to stabilize it is not water in the solution that remains.
Again, you fail to explain the existence of adenine, hypoxanthine and xanthine in the extract solution.
Actually I knew the acid was mixed with water, but I was not concerned about it. There is no hydrolysis in 95% formic acid, because there are no free water molecules in the 95% formic acid solution, or did you not comprehend the point in Message 175:
Well that's what I thought... You knew all along.
I guess I have met my match and have to concede defeat. My stupidity and zeal has finally got the best of me. My lack of compehension is there for all to see...
I gotta hand it to you Razd... you're relentless in your executions!
Razd:
Seriously Rob. Let me repeat again: you do not have any hydrolysis in the 95% formic acid extraction. The water that was mixed with the acid to stabilize it is not water in the solution that remains.
Again, you fail to explain the existence of adenine, hypoxanthine and xanthine in the extract solution.
I see it now... there is no hydrolysis occuring in the acid extractions.
Oh wait!
What's this from Robert shapiro?
The isolation of adenine and guanine from meteorites has been cited as evidence that these substances might have been available as "raw material" on prebiotic Earth (18). However, acid hydrolyses have been needed to release these materials, and the amounts isolated have been low (17-19).
He cites footnote 18 as the work of Stoks and schwartz: 18. Stoks, P. G. & Schwartz, A. W. (1981) Geochim. Cosmochim. Acta 45, 563-569.
That is the comparative study done and referenced by Glavin also:
It is important to emphasize that the purines identified in formic acid extracts of Murchison were not detected in water extracts [4]. This suggests that the purines are either bound to other organics, or were produced (e.g. oligomerization of HCN) during acid extraction.
And his footnote 4: [4] Stoks P. G. and Schwartz A. W. (1981) Geochim. Cosmochim. Acta., 45, 563-569.
We have a match!
And in case you think they are refferring to water extractions (don't even try and say that), see here:
We analyze the abundances of purines and pyrimidines in the formic acid extract of Murchison (Table 1) and Orgueil, compare it to those reported by Stoks and co-workers [1,2] and to the results obtained by Glavin et al.
And their footnote 2: [2] Stoks, P.G and Schwartz, A. W. 1981. Geochimica et Cosmochimica Acta 45:563-569.
You remember your table right?
Table 1. Recovery of Nucleobases from Murchison Meteorite Formic Acid Extracts (in ppb). Nucleobase This Study* Schwartz [3,4] -------------------------------------------- Adenine 204 267 Cytosine < 11 < 30,000 Thymine < 255 < 3 Guanine < 16 234 Uracil 145 63 Hypoxanthine 232 215 Xanthine 356 530 *sublimed at 450C for 5 min
And the footnote here again from Glavin and Bada includes [4] as above. It's formic acid!
Appearently Shapiro thinks that acid hydrolysis is an issue. But maybe he is just misrepresenting like me. Maybe he is a secret creationist who likes to infiltrate the institution and throw monkey wrenches into the great materialist wheel in the sky.
Or, maybe he is just objective.
I am sorry to be messing with you Razd, but I simply do not understand the tone. I have been accused of mirepresentation, of ignorance, of being unable to comprehend, of being unqualified to ask these questions, of having a predetermied belief anchored only in desperate emotional need and delusion. Every mistake and misspelling of mine has been exagerated in an attempt to discredit my entire argument.
Yet, here we are...
And as I have said, I am not accusing you of misrepresentation. We're all human.
What I am saying, as I did in the OP:
So, as I said in message 1 of the parent thread OP that spawned this thread: "I think that some of you have simply moved past the evidence and take for granted that it is possible based upon your 'methodological naturalist' bias."
I am sorry to be messing with you Razd, but I simply do not understand the tone. I have been accused of mirepresentation, of ignorance, of being unable to comprehend, of being unqualified to ask these questions, of having a predetermied belief anchored only in desperate emotional need and delusion. Every mistake and misspelling of mine has been exagerated in an attempt to discredit my entire argument.
Everyone makes mistakes, but you keep trying to excuse your mistakes as if they don't affect your arguments. How many times have you said in this thread (paraphrasing), "We're all human here, we all make mistakes, so we're all doing equally well in this discussion." How well do you think arguments like this would be received in court, Rob: "Sure, your honor, I murdered him, but I'm human, you're human, we're all human, we all make mistakes, so let's just call it even, okay?"
The best approach for calling attention to a mistake is denial, so if you don't want your mistakes forgotten then just keep denying them. After enough posts explain things to you, you shift from denying the mistake to claiming that your mistakes are of no matter because "we're all human". You want people to stop calling attention to the mistakes? All it takes is saying, "Oh, you're right." Then merely incorporate the correct information into your arguments from that point on.
We're all more than willing to forget your past mistakes as long as you stop ignoring the rebuttals because "we're all human" and other such nonsense. Sheesh! "Gee, teacher, I know I wrote 5+4=10 on my math test, but we're all human, we all make mistakes, it really isn't fair to mark it wrong." Give me a break!
Everyone makes mistakes, but you keep trying to excuse your mistakes as if they don't affect your arguments.
That's right! They don't affect my arguments.
I mispelled empirical.
I didn't understand hydrolysis properly yet it is still an issue even after a corrected understanding.
I thought HCN was an abbreviation for NH4CN though the two are essentially equivocable in terms of the synthesis of adenine.
All of the other arguments you and I have had, were irrelevant to the issue of Murchison, and were pertaining to philosophy of science and general difference of opinion.
Your just a distraction. There is plenty of time left for more discussion and summation, which will go along way to refining my criticisms of the paper in question.
Now contribute to the discussion or get out. Your participation here would not be tolerated if you and I were standing in opposite shoes. If I were saying the things you're saying, jar would be accusing me of off topic nonsense at every turn.
Razd is at least raising some very good questions and challenges and otherwise doing a bang-up job of engaging the issue. He is doing research, reading papers, and srutinizing details much in the same manner as I. I may not like him, but that is the truth. He is doing the job.
The isolation of adenine and guanine from meteorites has been cited as evidence that these substances might have been available as "raw material" on prebiotic Earth (18). However, acid hydrolyses have been needed to release these materials, and the amounts isolated have been low (17-19).
This article is all about Cytosine and only has the one paragraph on adenine. You remember that the experiment involved both formic acid and hydrolysis.
That is the comparative study done and referenced by Glavin also:
It is important to emphasize that the purines identified in formic acid extracts of Murchison were not detected in water extracts [4]. This suggests that the purines are either bound to other organics, or were produced (e.g. oligomerization of HCN) during acid extraction.
quote:Although a previous study has shown that the synthesis of adenine from HCN in acid is highly temperature dependent and inefficient at 100C [8], we cannot rule out the possibility that some purines may have been synthesized during formic acid extraction of Murchison. We found that in previous formic acid extraction and sublimation experiments using pure nucleobase mixtures, thermal deamination of the nucleobases did not occur [5].
If you remember, this means that you might get adenine but you would not get it degrading to hypoxanthine and xanthene, you need hydrolysis to get the degrading, and you do not have hydrolysis in the half sample that we are talking about.
The issue is that you cannot get both adenine AND hypoxanthine or xanthene from this process.
I am sorry to be messing with you Razd, but I simply do not understand the tone.
What tone? Yours? The biggest problem Rob is that you keep going over old territory as if you haven't understood a single part of it.
You chastise Percy for taking up precious posts when 50% of the posts (or more) are your repeated assertions that amount to a hill of beans. That bit about self-replicating molecules being due to an intelligent design and unnatural was a particularly amusing waste of time on your part.
The experiments on Murchison, Murray, Orgueil, and Tagish meteors show that either adenine was there on Murchison, Murray, and Orgueil, OR that the materials needed for the ready formation of adenine with a simple acid bath (similar to the extraction process) were on the Murchison, Murray, and Orgueil meteors but not on Tagish.
Further, IF it was formed, THEN there were still the molecules from which it was formed available for the formation of adenine.
Now that I can agree with...
and
Message 65 That is true... And good evidence to support the potential of adenine undiscovered. But it still doesn't preclude the adenine from being synthesized rather than extracted.
And we still don't know how the unknown material, or unique composition of substances in the meteor would affect the reactions, if at all.
Material that was shown to be "adenine-phylic" enough to prevent extraction of adenine with water, and material from which, logically, the adenine was synthesized IF it did not exist as complete adenine molecules, as the extraction process chemicals (formic acid, for example) are inadequate for forming adenine on their own.
Which is when you started pulling the nonsense that 5% water in the 95% concentrated formic acid could cause the degradation of adenine into hypoxanthine and xanthine.
Message 142 You still end up with these two possibilities:
(1) adenine is\was present on the meteor and it is degrading into hypoxanthine, and xanthine, the extraction process also causes degradation, OR
(2) adenine is produced by the extraction process -- from compounds like hypoxanthine, and xanthine -- which at the same time is degrading the adenine it just made into hypoxanthine, and xanthine ... (see any problem here?).
Given the results of the three different processes noted above, I'll stick with my previous conclusions: the existence of hypoxanthine, and xanthine on the meteor can be taken as evidence that adenine used to be on the meteor in greater quantity than today; that it is extremely highly unlikely that the extraction process both synthesized and degraded adenine ... leading to the conclusion that adenine was on the meteor in the past if it is not there today.
What I am saying, as I did in the OP:
... is that you haven't learned much of anything, or made a point that has not been evident from the start:
Either adenine existed on the meteor
OR
It was easily synthesized from molecules on the meteor.
In EITHER case adenine was available for pre-biotic earth.
Can you definitively say that there was absolutely no adenine on the meteor?
Can you definitively say that there was absolutely no hypoxanthine on the meteor?
Can you definitively say that there was absolutely no xanthine on the meteor?
Can you definitively say that these molecules were produced during the process?
Of course not!
So stop beating around the bush and accept the results:
Either adenine existed on the meteor
OR
It was easily synthesized from molecules on the meteor.
In EITHER case adenine was available for pre-biotic earth.
Or are you going to go around the whole sturm und drang again? You're not questioning Rob, your spinning your wheels trying to find traction for a position that is not supported by the evidence (and not supportable by the evidence, because it relies on the evidence not being there).
It was easily synthesized from molecules on the meteor.
I have no problem accepting that. That is precisely what happened as far as I can tell.
If that is the case, then the discussion moves on to the problems with the atmospheric models to accomplish the synthesis.
OR adenine existed on the meteor and synthesis on earth is not necessary.
However, IF synthesis from HCN rings and polymers similar to hypoxanthine and xanthine in an kerogen-like organic polymer matrix that were delivered by the meteors needs to be done with an acid bath, there are many such available on the surface of the earth today -- in spite of the earth now having an oxidizing atmosphere, and so should be even less of a concern for a pre-biotic earth.
quote:Does this mean we have no source of acidic environments on earth? We can look at sources of natural acid in todays world to see what they could be like and how prevalent they could be. A google on "acid springs" presents a prolific list of sites, from which I picked (you'll see why):
quote:Life at High Temperatures by Thomas D. Brock
Each hot spring is unique. Even springs that look the same differ in characteristics such as temperature, flow rate, and chemistry of the water. One chemical property is so important that it has great influence on the kinds of organisms present: the acidity of the water. Some springs, such as those at Norris and Mud Volcano have very acid, sour-tasting water. They contain sulfuric acid, derived from the sulfur-rich gases emanating from the earth. Acid springs are usually concentrated in special basins, such as that of Sylvan Springs shown below, an important feature at the west end of Gibbon Meadow.
The microorganisms in the acid springs are entirely different from those in the neutral to alkaline springs. Indeed, the organisms of acid hot springs have two environmental hurdles to overcome, high temperature and acidity. These organisms, called thermoacidophiles, are probably derived from some of the first organisms that arose on this planet.
... Most acid springs in Yellowstone have pH values between 2 and 4, and the neutral/alkaline springs have values mostly from 7 to 9. ...
We also see that the "extremophiles" found in these hot springs are probably closely related to the first kinds of life, and they do not use oxygen in their energy cycle so they could survive in the early atmosphere\environment.
These hot springs are of geo-thermal origin, a process that was ongoing on early earth up to the period of meteoric impact.
This would easily replicate what happened during the extraction process of the experiment, thus resulting in adenine being available.
Piece of cake. Time to move on?
Enjoy.
ps -- use less keystrokes: type [qs=RAZD]quotes are easy[/qs] and it becomes:
RAZD writes:
quotes are easy
tip-of-the-day from your friendly neighborhood evilootionist.
Everyone makes mistakes, but you keep trying to excuse your mistakes as if they don't affect your arguments.
That's right! They don't affect my arguments.
No, Rob, errors significantly affect the value of arguments. Arguments with errors in the form of mistakes of fact or illogic or containing logical fallacies and so on, usually render the argument worthless, and such is the case with most of your arguments.
I mispelled empirical.
And now you've misspelled misspelled. Both Google Toolbar and Firefox have spellcheckers. dBoard 3.0 will have a robust search feature (I've been working on it tonight, in fact), and so if in the future you'd like to find your old discussions about empiricism it might help you to spell it correctly.
Your just a distraction.
Spellcheckers won't help you find that you really wanted to use "you're" instead of "your". Maybe someday.
I'm just responding to your own distractions, Rob. There is no point to offering rebuttals to your flawed arguments if you're going to claim that flawed arguments do not affect the strength of your position. If you're going to continue to do this then I really feel I have no choice but to point out this error in the way you assess arguments.
And so if you want to help maintain the focus of this discussion more closely on the topic, then the next time someone points out an error, just say, "Oh, you're right," and move on. Don't post nonsense about how we're all human and all make mistakes and so your mistakes don't really matter, because that forces a response that that's just not so. This isn't a game of pre-school T-ball where everyone wins. When the ball goes through your legs and into the outfield, you lose. Claiming that it shouldn't matter that you failed to field the ball and that opposing players should therefore stop crossing the plate is just silly.
OR adenine existed on the meteor and synthesis on earth is not necessary.
So you are having a hard time making up your mind?
Seems that hydrolysis is an issue according to Shapiro irrespective of how many sentances he commited to the subject.
The extractions were done with acid hydrolysis. That is why they are suspect. Glavin and Bada didn't mention it for nothing.
Verdict?
Inconclusive!
Razd:
This would easily replicate what happened during the extraction process of the experiment, thus resulting in adenine being available.
Unfortunately the same processes that synthesize it, would hydrolyze it further. You need a near neutral pH for stability, and a great deal more adenine than we're discussing here. And even if there was an explanation (which there is not), it takes more than adenine to make an organism. We've not yet even scratched the surface of this problem. That's just the way it is...
razd writes:
ps -- use less keystrokes: type [qs=RAZD]quotes are easy[/qs] and it becomes:
RAZD writes:
quotes are easy
tip-of-the-day from your friendly neighborhood evilootionist.
Got it! Thanks for that...
Let's leave the rest for another thread. It's more than off topic here.
And so if you want to help maintain the focus of this discussion more closely on the topic, then the next time someone points out an error, just say, "Oh, you're right," and move on.
Sorry Percy, but I cannot do that when they (I mean you), say in addition, that because of the error my whole argument is wasted. Sorry about the misspellings.
OR adenine existed on the meteor and synthesis on earth is not necessary.
So you are having a hard time making up your mind?
Nope, just being sure that both options are fully represented. You can't say the results are {a} or {b} now let's look at only {b} ... (wasn't that your whole point?).
Razd:
This would easily replicate what happened during the extraction process of the experiment, thus resulting in adenine being available.
Unfortunately the same processes that synthesize it, would hydrolyze it further. You need a near neutral pH for stability, and a great deal more adenine than we're discussing here.
No, you don't need to cover the earth with adenine, you only need adenine in the right place at the right time. Once you have a life process it can produce its own (as you have observed). Apparently it took up to 1 billion years for life to form. Now we know of at least one mechanism for producing adenine.
And even if there was an explanation (which there is not), it takes more than adenine to make an organism. We've not yet even scratched the surface of this problem. That's just the way it is...
There is a lot we don't know, but that does not make the task impossible. But as we have seen with the Murchison meteor there is more information every year.
Let's leave the rest for another thread. It's more than off topic here.
I thought you were done: adenine available directly or indirectly due to meteor delivery from space does result in adenine on earth.
Message 1 In molbiogirl's last post of the thread she repeated the claims (that turn out to be plentiful) that adenine has been found in the Murchison meteor. I wish to challenge that claim.
So what’s the deal with Murchison? In my opinion, the complex mixture of compounds and the unknowns about Murchison make quantifiable and accurate results questionable. There is much that remains a mystery. For those who have broad interest in constraining the issue and finding adenine . It’s not time to celebrate yet.
Answer: adenine is available directly or indirectly due to meteor delivery from space.
Now we know of at least one mechanism for producing adenine.
And what was that process again?
Wasn't it the same process that Stanley Miller discovered long ago that results in racemic mixtures of amino acids that are irrelevant to biology that posesses chiral molecules?
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