You started off with some good questions, the same questions I have myself. And the best one's to question my position. I just cannot answer them with the limited knowledge of chemistry I currently have. I do think I can help you formulate them more accurately. And then perhpas an actual PhD like MattP can hlep us answer them. Though he seems to have stepped aside.
Razd:
And some studies also state that adenine has been found. The fact remains that most studies extracted adenine while one we know of (using water extraction) did not. We also know that there is a very good reason for the water extraction to have failed, that not only was this theoretically possible but it was tested and verified.
That is a bit confused.
I don't know that
most studies found adenine. The formic acid extractions found adenine but couldn't be quantified because of the
unknown UV barrier. Your either forgetting the data already covered, or rewriting history for late-comers to the thread.
There were at least two water tests, and at least one direct sample test that I cited in the OP that came up negative. And from what I gather, the earliest tests of Murchison were negative btw. It was the later tests that had
marginal results, and then Glavin and Bada found a way to supposedly sublime away the
unknown barrier to reveal adenine; but it requires the additional acid prep over and above the initial incubation.
The other tests that found adenine used very hot HCL extraction methods.
Razd:
Adenine is formed by combining molecules of HCN into a ring formation: so it is not synthesized by HCN but from it. That would tend to make using HCN for extraction purposes questionable, but you would need to show how it can form adenine under the extraction process.
I wandered the same thing... but Glavin and BAda mentioned the possibility, so I assmue that in some of these exchanges chemically, the HCN itself must be possible to produce durring the extraction. The other question is about temperature. They say that at 100c it is an inneficient reaction. And even though the extraction was incubated at 100c, the sublimation was done at 450c (if I remember right, for 5 minutes).
I not only do not understand the effect this might have on the experiment, I also do not know (and assume they do not either, as they invoked the possibility) if the unknown composites in murchison could have skewed the results...
Now for some of your other comments:
Razd:
Several such experiments have been run, and each one adds to the knowledge of what is required to
set up a self-replicating molecular system.
I accused you of "trying to move the goalposts" because your post was essentially rejecting any and all experimental studies involving self-replicating molecules as being tainted by the input of "intelligent chemists" rather than
looking at the facts of the self replicating molecules.
Finding excuses to use in ignoring data does not make the data go away.
That's right Razd! Maybe it's good enough for you, because you like to see what you want to see but the
facts that I supposedly ignore are...
that intelligent chemists set up the conditions.
The molecules replicated... big deal. But not by them
selves. They are therefore not self-replicating. They are designed.
And you never answered my first question on the matter: Where did these scientists get these molecules? Were they taken from existing biological life? Or were they designed in the lab? Either way, it doesn't prove anything pertaining to abiotic chemistry. It's an illusion perforemd by modern magicians and though the crowds may marvel at your genius; count me out!
Razd:
We can also look at the Lake Tagish meteor: in this case no amino acids were found at all. What this demonstrates is that the material carried by meteors is highly variable.
Well no one is denying that amino acids were found in Murchison, though they are racemic mixtures predominantly. But that is not the same thing as finding purines like adenine.
The rest of your reply concerns mobiogirl's professer Rainer Glaser. I already covered this with her at the end of the last thread. My exuberance to refute her earned me a suspension since we were supposed to be giving summaries. Evidently she didn't know that and continued to offer debate points.
She also took his word for it based on authority. But glaser is running beyond the evidence.
Razd:
Conclusion: adenine forms in space from readily available HCN molecules, thus it is available to be on meteors or on dust that sprinkles down on earth.
No Razd... No! Adenine doesn't
form in space. Did you read what your own links said? Let me highlight them for you (whoah! I'm having
deja vu!) It's a debate with molbiogirl all over agian:
Instellar clouds
may produce a component of DNA
According to an article in New Scientist,
researchers in Calcutta claim that interstellar clouds
may produce large amounts of adenine. Their findings
suggest that the raw materials of life
may be common in other planetary systems.
As astronomers have long known, collapsing interstellar clouds produce something else as well: stars, planets, and comets. Adenine
may have been present when the Earth condensed from dust and gas. Or, adenine
may have been carried on the comets that showered the early Earth. A ready supply of adenine from space
may help explainsigns that other raw materials for life
may be present in space. For example, observations have revealed complex organic molecules in interstellar clouds. Researchers with the NASA Astrobiology Institute
have even produced membrane-like structures inside a
simulated comet. Evidence from observations, laboratory experiments and
computer simulations increasingly
suggests that the ingredients for life
may be abundant throughout the universe.
I am going to be sick (Percy, a 'puke emoticon' would be nice for moments like this)...
A new
computer model indicates clouds of adenine molecules, a basic component of DNA,
can form and survive the harsh conditions of space,
and possibly sprinkle onto planets as the stars they orbit travel through a galaxy.
"There
may be only a few molecules of adenine per square foot of space, but over millions of years, enough
could have accumulated to help make way for life," said study co-author
Rainer Glaser, a molecular chemist at the University of Missouri-Columbia.
Glaser and his team's
findings (Findings? Don't they mean 'theories') are detailed in a recent issue of the journal Astrobiolog
Adenine is one of four "letters" of DNA's alphabet used to store an organism's genetic code.
Glaser said the idea that large, two-ringed organic molecules like adenine formed in space may seem outrageous, but current evidence leaves the possibility wide open.
"You can find large molecules in meteorites, including adenine," Glaser said. "We know that adenine
can be made elsewhere in the solar system, so why should one consider it impossible to make the building blocks somewhere in interstellar dust?"
Using computer simulations of the cold vacuum of space, Glaser and his colleagues found that hydrogen cyanide (HCN) gas can build adenine. Like pieces in a set of tinker toys, hydrogen cyanide serves as adenine's building blocks; the small molecules bond together into chains and,
with a little wiggling, eventually assemble into rings.
Although adenine's first ring needs a tiny energy boost from starlight to form, Glaser said the second ring of the molecule self-assembles without any outside help...
(btw had to point out that it needs the first step first. That's why it's called
first. No self involved...)
...Glaser said adenine's ringed shape helps it absorb and release any excess energy without breaking apart, making it stable enough to form concentrated clouds that planets can drift through.
Too bad it's just a computer model. Seems to need a lot of
wiggling to me...
Theory is not evidence Razd. Nor are models. We call that theory too. Evidence is what you need the theory to match. That is what empiricism is...
This stuff is not empiricism. This is methodological naturalism run amuck! It's not scientific. It's scientific theory in a world of it's own
design.
Edited by Rob, : No reason given.
Edited by Rob, : No reason given.
Edited by Rob, : No reason given.
Edited by Rob, : No reason given.
Edited by Rob, : No reason given.
Edited by Rob, : No reason given.
Edited by Rob, : No reason given.
.
™ Version 4.2