Tired of plagiarizing you mean. You know, a simple cut-and-paste along with giving a citation would have saved your poor fingers a lot of work, and additionally would have prevented you from getting caught dishonestly presenting someone else's writing as your own post.
Freepers are invited to compare "Hootowl's" above post with the following:
(The preceding is from Creation Or Evolution? Part 1 by Winkie Pratney.) No, I didn't make up that name.We had Miller and Ureys' experiments, shooting little sparks through organic gases in concentrations carefully picked to favor the formation of some of life's building blocks. Not surprisingly, some were formed. Never mind that Earth's original atmosphere couldn't hold HEAVY gases like xenon and krypton (shades of Superman!) let alone the LIGHTER ones used in the experiments (like methane and ammonia), or that a REAL lightning bolt would effectively FRY a darling little amoeba-in-the-making. It is bothersome also that ultraviolet light from our sun knocks out ammonia faster that it can form, and old sedimentary rocks ought to show significant amounts of organic stuff in them if this is the way it was, but they don't.8
A Left-handed Creation?
Add to that what Louis Pasteur, Linus Pauling, and Francis Crick (evolutionist co-discoverer of the DNA structure) all pointed out: The amino acids of life, from mold up to Man, are all of ONE SPECIAL FORM. John Maddox, English biologist, calls this "an intellectual thunderbolt": Randomized experiments always give a "racemic" mixture,9 approximately EQUAL proportions of D- and L-, right-handed and left-handed amino acids (chemically identical, but "mirror images" of each other) - whereas life proteins consist of LEFT-HANDED MOLECULES ONLY!10
But now I'll address your arguments (oh, excuse me, *Pratney's* arguments that you presented as your own) one by one:
Urey and Miller used a carefully selected variety of organic gases in concentrations designed to favor the formation of soem of life's building blocks.
Horse manure. They used the basic materials believed at the time to be present in the primordial Earth. They chose the mixture they used because it was the one proposed by Aleksandr Oparin in 1924, as a result of then-current discoveries of large amounts of methane on Jupiter, which Oparin and others believed may have been present on the primordial Earth as well.
So unless you (wait, I mean *Pratney*) want to claim that Urey-Miller "carefully selected" their mixture by using a time machine to travel back 31 years and suggest it to Oparin...
Nor suprisingly, they got the result they wanted.
"Not surprisingly" my hind end. It was such a surprise at the time that the submissions reviewer at _Science_ magazine set their paper aside and ignored it because he thought it was too preposterous (based on what was conventional wisdom at the time).
However, did it replicate actual conditions on earth? No.
And who in the last several decades has claimed that it exactly "replicated" such conditions?
Earth's original atmosphere (as posited by scientists, not creationists) couldn't hold heavy gases like xenon and krypton, let alone the lighter ones like methane and ammonia.
Wow, that's remarkably misleading. Was it on purpose or by mistake, I wonder? While it's true that the Earth lost most of its "original atmosphere" thanks to the enormous temperatures present during planetary formation, the composition of its "original atmosphere" is an irrelevant straw man, since the Earth had acquired its secondary atmosphere (mostly via crustal outgassing and vulcanism) by the time it had cooled enough to a) retain an atmosphere and b) for early life to begin its first steps.
And at *that* time, contrary to your (oops, *Pratney's*) highly misleading statement, there was *abundant* ammonia, methane, carbon dioxide, and other gases in Earth's atmosphere. In fact, the vast amount of nitrogen in today's atmosphere (76% by volume) is primarily the "fossil" remnant of the primordial ammonia -- atmospheric ammonia can photodissociate into N2 and H2, plus once plant life began generating oxygen and filling the atmosphere with it, the atmospheric ammonia combined with the oxygen and produced nitrogen gas (N2) and water.
Gee, that sounds a lot like Urey-Miller's experimental composition after all.
Urey and Miller's experiment subjected the test gases to carefully controlled electrical stimulation to get their result. A real lightning bolt would have fried the potential result.
Surely you *can't* be naive enough to make such a misleading statement by accident. Although I guess you could be naive enough to copy such a thing from Pratney...
Quick, Einstein, when a lightning bolt lands, are nearby materials subjected to either the full force of the bolt or no effect whatsoever? Is it "all or nothing"? No...
Instead, while material directly at the strike site will experience energy fluxes on the order of the surface of the Sun, as the imparted electrical energy grounds itself, the surrounding area (for a considerable distance) is subjected to varying amounts of electrical energy depending on its distance from the strike site. In other words, as the current from the lightning "spreads out" and dissipates, locations close to the site will experience nearly 100% of the current, while those farther away will experience 50%, 40%, 10%, 2%, etc.
So what Hootowl has missed (while copying from Pratney, who missed it also) is that while a direct strike is likely to "fry" whatever it hits, indirect strikes will provide any lesser amount of electric potential you care to name -- and over a larger area to boot.
There's nothing wrong with Urey-Miller's electric potential.
Going farther, Urey and Miller carefully screened their experiment from real-world concentrations of ultra-violet light,
No they didn't, nor does even Pratney say that they did. You made that up.
which would have been as plentiful then as now.
Gee, really? Even in an atmosphere much more dense than today's, filled with organic compounds which are less transparent to both visible and ultraviolet light? (See: "The Early Faint Sun Paradox: Organic Shielding of Ultraviolet-Labile Greenhouse Gases", Sagan and Cyba, 1997) Fascinating.
They did this because ultra-violet light breaks down ammonia faster than it can form,
That's sweet and all, but even if that were true (see the above citation), it's irrelevant since the ammonia in the early atmosphere was outgassed, not "formed".
It's also irrelevant because you (oops, *Pratney*) make a frequent creationist error. Although creationists like to derisively chant "organic soup" until they're blue in the face, they somehow seem to still concentrate on the dynamics of the prebiotic *atmosphere* instead of the "soup" (the seas). While it's true that ammonia in the *atmosphere* is subject to photodissociation by ultraviolet light, no one is proposing that early life formed in the *air*. Something Pratney "forgot" to mention is that another way that ammonia is readily removed from the atmosphere is by solution into *water*. And the ammonia which would have been taken up by the oceans, seas, and lakes would have been largely protected from any ultraviolet rays.
so in the real world the combination of ingredients used by Urey/Miller wouldn't have had a chance of working.
Uh huh... Care to try any arguments that actually aren't full of holes?
Maybe even try some of your own this time, instead of cribbing from Pratney, since Pratney doesn't seem to be too reliable a source.
Plus, if all these things were in on the beginning, sedimentary rocks ought to show significant amounts of organic stuff. They don't.
Okay I'll bite -- exactly how would "organic stuff" represent itself in precambrian sedimentary rocks?
But if you want geochemical differences in precambrian rocks that indicate the presence of a reducing atmosphere, see for example Geological and trace element evidence for a marine sedimentary environment of deposition and biogenicity of 3.45 Ga stromatolitic carbonates in the Pilbara Craton, and support for a reducing Archaean ocean (2003) by Van Kranendonk, Webb, and Kamber. Excerpt from the abstract:
The geochemical results, together with sedimentological data, strongly support: (1) deposition of Dresser Formation and Strelley Pool Chert carbonates from Archaean seawater, in part as particulate carbonate sediment; (2) biogenicity of the stromatolitic carbonates; (3) a reducing Archaean atmosphere; (4) ongoing extensive terrestrial erosion prior to 3.45 Ga.A "reducing atmosphere", for those in Rio Linda, is "An atmosphere of a planet or moon which has a high hydrogen content, either in the form of free hydrogen or hydrogen-containing compounds, such as methane or ammonia", according to the Encyclopedia of Astrobiology, Astronomy, and Spaceflight.
Need more?
Yes, since the other points have fallen so flat.
Real life amino acids are all of one special form, called left-handed molecules.
That's not so "special", but yes, amino acids in living things are mostly (not "all") of the same chirality.
Urey/Miller's experiment produced a "racemic" mixture of amino acides, approximately equal proportions of left- and right-handed amino acids. If that had been the case from the beginning, we'd still have left- and right-handed molecules,
Nonsense. For the most part biological mechanisms work best when they primarily use one "handedness" of amino acid, and thus early life had a strong incentive (via natural selection) to "choose" one variety (either left or right) from the "primordial soup" of naturally occurring mixed amino acids, and use that one exclusively thereafter. Subsequent biological (as opposed to the initial non-biological) synthesis of amino acids, which makes up most amino acids we encounter in the world today, would then be almost exclusively of that chosen "handedness".
There's nothing mysterious about it.
And when you (excuse me, when *Pratney*) says that "If that had been the case from the beginning, we'd still have left- and right-handed molecules", it implies that we *don't* have any right-handed amino acids today. But we still do, so there goes *that* line of argument...
but we don't find right-handed molecules in any life form today.
You mangled that even from Pratney's incorrect version, which says "whereas life proteins consist of LEFT-HANDED MOLECULES ONLY!". At least Pratney was competent enough (*cough*) to include the word "proteins". Your leaving it out makes your statement sheer nonsense, since there are plenty of "right-handed molecules" in "life forms today" -- Pratney's original narrowed the claim to *protein* molecules (i.e. amino acids) which is a much more sensible assertion.
But still flat wrong, unfortunately. Let's look at that claim one more time: "whereas life proteins consist of LEFT-HANDED MOLECULES ONLY!" Um, no, sorry, but thanks for playing. It has long been known (since at least 1969, see Corrigan J J 1969 D-amino acids in animals; Science 164 142– 149) that many life forms use right-handed amino acids as in their tissues and processes. For example gram-positive bacteria use right-handed Isoglutamic acid as a component of their cell walls. See for example Comparative analysis of naturally occurring L-amino acid osmolytes and their D-isomers on protection of Escherichia coli against environmental stresses. More recently it has been found that most animals, including humans and other mammals, incorporate right-handed amino acids for various functions (see for example D-Amino acids and D-Tyr-tRNATyr deacylase: stereospecificity of the translation machine revisited).
All for now. I'm tired of typing. ;^)
Just as well, you weren't supporting your original claim very well.
And next time, save yourself a lot of typing by just doing a cut-and-paste on your source material, and post a citation, instead of spending the time to slightly rephrase it in order to give the false impression that it's your own work. Not only will this save you a lot of typing, but you'll find that the chief advantage of properly referencing your sources is that although you don't get personal credit for the material (and if it's not yours you shouldn't), you also get to pass blame for any flaws it contains back to the original author instead of appearing a fool yourself. And in this case, that would have been indeed the wise course.