". . . I await developments on this front with great interest. But I have to tell you: I’m not holding my breath until such time as the expected confirming “breakthrough” occurs. . . ."
I expect it will take decades personally. It was forty plus years between Stanley Miller's generation of amino acids from inorganic material and the catalyzation of RNA in mineral clays. And not all scientists working upon pre-biotic synthesis agree upon the best strategy to pursue.
". . . 'The very fact that life sprang up on earth constitutes conclusive proof of a primary reducing environment since the latter is a necessary prerequisite for chemical evolution and spontaneous origin of life.' [Manfred Schidlowsky, quoted in Robert Shapiro, Origins: A Skeptic’s Guide to the Creation of Life on Earth, 1986]
This is a great example of circular reasoning: It turns out its conclusion is already actually implicit in its premise. . . ."
That is not circular reasoning at all, since science must account for the oxygen-rich atmosphere present here on earth, which it is theorized was not present in the "Primary Reducing Environment" in sufficient quanities to sustain large ecosystems and higher-order life forms, but had to be manufactured by lower-order life before more complex types could emerge. That line of reasoning is in fact linear:
Primary Reducing Environment -> Abiogenesis -> Lower-Order Life -> Non-Reducing Environment Containing Sufficient Oxygen -> Higher-Order Life
As a scientific explanation the above model is plausible because it proposes a cause and effect sequence of events to explain both the oxygen-rich atmosphere and the development of higher-order life forms. It does not prove abiogenesis, which I think you take the statement to imply, but it does propose a plausible theory into which abiogenesis fits as a necessary step in the evolution of life on earth.
". . . let’s assume I’m wrong about this, and abiogenesis – the spontaneous emergence of life from inorganic matter by sheer random processes – is a viable theory . . . "
I do not in any way accept your definition, perhaps I should say "description," of abiogenesis. From the perspective of the physical sciences there is nothing "spontaneous" or "random" about it and I believe this is the true crux of the debate. Those who attempt to refute the possibility of abiogenesis insist that it is an argument for a spontaneous and/or random occurence, which gives them a "straw man" that is easy to knock down. "Spontaneity" implies the lack of a cause for an effect, and I'll deal with that farther on in this response. As for "randomness," in its simplest form, it is defined (from the dictionary) as "the quality of lacking any predictable order or plan." Now there are separate mathematical definitions which, depending upon which one you use, will present randomness differently, including Chaitin, who denies that randomness can ever be proven, but these definitions are always applicable to a particular systemic construct, and are not suitable to the physical sciences in general -- I'll say more about that in a moment. However the term is used, the concept of "randomness" must always be formulated as "random relative to what?," because it implies a perspective. To take a pertinent example relative to Stanley Miller's experiment which proved that amino acids could be generated from inorganic matter, consider the predictability of when and where lightning will strike. You can take a meteorologist and a physicist schooled in electromagnetism, position them both on the ground while a thunderstorm rages overhead, and ask them to tell you when and where the next lightning bolt will strike. In terms of simple ordinary language they cannot do it, so you might conclude that the timing and positioning of lightning strikes are "random" relative to an explanation you would accept in ordinary language. But those same two scientists could express in the language of Physics an equation that will take into account the variables that go into cloud formation, the density of moisture within clouds, temperature, wind patterns, differentials between the electromagnetic charges of the clouds and the ground beneath, etc. and express to you an equation that will predict where and when lightning will strike and that equation will be accurate, though it will not be understood in ordinary language. Therefore; from the perspective of ordinary language, the lightning strike appears as a "random" event, but from the perspective of the meteorologist and the physicist, it is nothing of the kind, because the location and timing of the strike is governed by the laws of physics as they pertain to meteorological phenomena and electromagnetism.
The same line of reasoning I have just outlined with respect to lightning strikes applies to abiogenesis. Now; there are several theories about just how and why abiogenesis occurred, and I am not qualified to say just which of these theories is the most plausible, because I am not trained sufficiently in the scientific disciplines necessary to explain and differentiate between these theories, though I suspect that James Ferris's "catalyzation of RNA solutions" approach may be the best going at present. But in general form, most theoretical models constructed explain abiogenesis look something like the following:
At each and every one of the above stages listed, and in truth there are many "sub-stages" involved in the transition between those depending upon just which theory you are using, the laws of chemistry, biochemistry, physics (especially concerning energy sources), and in the later stages, microbiology are all applicable. And the ways in which these theories have been constructed is to entertain these transitions as the effects of material causes that occur naturally, which means that from the perspective of the physical sciences, they are in no way "random" or "spontaneous," but the expected result of natural phenomena occurring within a given set of constraints that are plausible in themselves.
Now; for the citations you gave on the implausibility of abiogenesis:
Overman's claim about the state of scientific opinion on the impact of geological opinion on the early earth's atmosphere as defeating the prospects for abiogenesis is flat-out false. I do not like to use Ad Verecundiam arguments, but I must point out that Overman is a lawyer and for that reason I question his credentials to describe the state of scientific opinion on the early earth's atmosphere, because if I have correctly identified the source of his information, and I think I have, then I can say that on one thing I am absolutely certain, the current state of thinking in Geology does not negate the conditions for abiogenesis, which includes the evaluation of the early earth's atmosphere. I will refer you to one online article at the MIT web site that I believe can be held out to contain a much more accurate viewpoint of the current state of Geological thinking on the rise of the oxygen-rich atmosphere we now enjoy. I wanted to present particular evidence from one of the sources they cite at the beginning of the article, J.F. Kasting's work on "Earth's Early Atmosphere," since I found several online articles which cite it, but I cannot find the online source for the article itself. Kasting is a very prominent geologist -- he has co-authored textbooks on the subject -- and he may be the individual Overman refers to because he has been critical of some scientific studies which fail to take into account photodecomposition of methane and ammonia in the early earth's atmosphere, one of the bases for Stanley Miller's theoretical approach, and which Miller has since addressed. The net impact of all of this upon geological thought has not been to discount Miller's, nor Ferris's work, quite the contrary. Geologists find ample geological evidence for the development of several scenarios for the origins of life, as shown within the MIT article, including the transition from an RNA-world to higher orders of life, which Miller and Ferris's combined contributions argue. Overman's statement of the state of geologic opinion does not fit in with what geologists are saying, as the MIT article shows, so I will wait to see if anyone can present geologic scholarship to support Overman's presentation. I can only conclude that Overman did not understand what he was reading.
And to make further discussion easier, I would suggest we be careful with using the phrase "many scientists."
As for the comments/quotes on Overman/Denton and the availability of oxygen, there are early pre-biotic sources of oxygen detectable in the geologic record. See the MIT and Miller articles again, sources of pre-biotic oxygen are directly discussed there.
The objections posed by Brooks and Shaw are also flawed in terms of modern knowledge, because of the timeline involved. Now in part, this may not be their fault, because they were writing in 1973, a year in which the oldest sedimentary rocks may have been dated much later [more recent] in time than those we know today, I don't know for certain. As you quoted them:
". . . we would expect to find at least somewhere on this planet either massive sediments containing enormous amounts of the various nitrogenous organic compounds, amino acids, purines, pyrimidines, and the like, or alternatively in much-metamorphosed sediments we should find vast amounts of nitrogenous cokes (graphite-like nitrogen-containing minerals). In fact, no such materials have been found anywhere on earth."
That may have been true in 1973, but it is not true today. Go back to the MIT article I linked above and scroll down to pages 26 and 27. The evidence in the geological record is for a backwards-revision [to an earlier date in time] of the presence of Carbon isotopes at the dawn of the Archaean Age, which permits extrapolation of its origins (page 26) and the presence of carbon-depleted graphite by 3.8 billion years ago (page 27). You can read more about this evidence by viewing the information on the Isua metasediments of Greenland. Again, I don't think Brooks and Shaw can be blamed for this, because they did describe the evidence, especially graphites, which has been found for the period, and I think, but do not know, that the discovery was after their publication.
Now; Michael Denton again:
". . . Yet rocks of great antiquity have been examined over the past two decades and in none of them has any trace of abiotically produced organic compounds been found. Most notable of these rocks are the ‘dawn rocks’ of Western Greenland, the earliest dated rocks on Earth, considered to be approaching 3,900 million years old. . . ."
Nope. Here's a quote from the preceding article linked on the Isua Metasediments: (note: "Ga"=Billions of years ago, 3.86 Ga = 3.86 Billion years ago)
". . . Akilia (3.86 Ga) and Isua (3.8 Ga) metasediments in southern West Greenland, evidences the existence of liquid water, the prerequisite for life's origin, at the Earth surface at this early stage. It is believed that high-grade metamorphic overprint would not allow the preservation of morphological fossils, permitting tracing of life in these metasediments only from chemical data. Graphitic carbon, isotopically indicative of constituting the remains of primitive organisms, has been identified in both Akilia and Isua rocks (Schidlowski, 1988; Mojzsis et al., 1996, Rosing, 1999). The association of isotopically light graphite with sedimentary apatite crystals has indicated the applicability of such apatite as indirect biomarker in old metasediments. . . ."
Now one may make the argument that the rocks show evidence of the presence of life itself at this stage, rather than just the pre-biotic evidence Denton is commenting upon, but if that was his intent then it is a deliberate deception on his part, which I doubt, because I am convinced that he does not understand what the rocks reveal.
Now Hubert Yockey we must take seriously as a mathematician, because he is a genuine expert on information theory. But he has misapplied the concept of "randomness" to the origins of life, in treating it as a problem in mathematical probability, since probability theory is designed to bring order out of randomness. Abiogenesis is no more the result of random processes than the timing and location of a lightning strike, as I discussed earlier. All steps in the process of abiogenesis function according to the laws of chemistry, molecular biology, physics, and other branches of the physical sciences. Of everything you have posted betty, there is only Hubert Yockey to discuss seriously, but this post has gone on long enough. We will return to Yockey at a later date, but you already know the major issues I have with his theoretical approach as I have just stated them. Since I recognize Yockey as a legitimate scholar -- I did not say "scientist" -- I will give him a much closer look.
And finally, on your question about RNA being a "slave" to DNA, I think the answer is that you may have missed the point that, in addition to being a storehouse for genetic information, RNA acts as a "catalyzing agent" in certain types of biochemical reactions.
I still owe Alamo-Girl a response on the "Atheist" thread, but I won't have time to get there until tomorrow.