[1] Nic Tamzek is the pen name of Nicholas Matzke.The actual text pointed to by the link I gave you, (not the 1.0 version you found because the author's description is easier to ad hominem.
http://www.geog.ucsb.edu/~matzke/
Nothing you've posted undermines what Schopf said about the spread of the older BIFs indicating the early seas were anoxic. Now pretend you don't understand that.Was the prebiotic atmosphere reducing? Are the Miller-Urey experiments "irrelevant"? The famous Miller-Urey experiments used a strongly reducing atmosphere to produce amino acids. It is important to realize that the original experiment is famous not so much for the exact mixture used, but for the unexpected discovery that such a simple experiment could indeed produce crucial biological compounds; this discovery instigated a huge amount of related research that continues today.
Now, current geochemical opinion is that the prebiotic atmosphere was not so strongly reducing as the original Miller-Urey atmosphere, but opinion varies widely from moderately reducing to neutral. Completely neutral atmospheres would be bad for Miller-Urey-type experiment, but even a weakly reducing atmosphere will produce lower but significant amounts of amino acids. In the approximately two brief pages of text where Wells actually discusses the reducing atmosphere question (p. 20-22), Wells cites some more 1970's sources and then asserts that the irrelevance of the Miller-Urey experiment has become a "near-consensus among geochemists" (p. 21).
This statement is misleading. What geochemists agree on is that if the early earth's mantle was of the same composition as the modern mantle and if only terrestrial volcanic sources are considered as contributing to the atmosphere, and if the temperature profile of the early atmosphere was the same as modern earth (this is relevant to rates of hydrogen escape) then there will be much less hydrogen compared to Miller's first atmosphere (20% total atm.). Even if this worst-case scenario is accepted, hydrogen will not be completely absent, in fact there is a long list of geochemists that consider hydrogen to be present (although in lower amounts, roughly 0.1-1% of the total atmosphere). At these levels of H2 there is still significant (although much lower) amino acid production.
Also, many geochemists think that these conditions do not represent the early earth, contrary to the impression given by Wells. For example, on p. 20, Wells mentions terrestrial volcanos emitting neutral gases (H2O, CO2, N2, and only trace H2), but he fails to mention that mid-ocean ridge vents could have been significant sources of reduced gases -- they are important sources of reduced atmospheric gases even today, emitting about 1% methane (Kasting and Brown, 1998) and producing reduced hydrogen and hydrogen sulfide (e.g. Kelley et al., 2001; Perkins, 2001; Von Damm, 2001) and potentially ammonia prebiotically (Brandes et al., 1998; Chyba, 1998). Why does Wells exclude oceanic vents from consideration?
Another strange omission is that Wells completely fails to mention the extraterrestrial evidence, which is the only direct evidence we have of the kinds of chemical reactions that might have occurred in the early solar system. For example he neglects to mention the famous Murchison meteorite, which contains mixtures of organic compounds much like those produced in Miller-Urey style experiments, and which constitutes direct evidence that just the right kind of prebiotic chemistry was occurring at least somewhere in the early solar system, and that some of those products found their way to earth (see e.g. Engel and Macko, 2001 for a recent review).
Wells asserts that since the 1970's, non-reducing atmospheres have become the "near-consensus." The latest article that Wells cites supporting this view, however, is a 1995 nontechnical news article in Science (Cohen, 1995). Why doesn't he quote Kral et al. (1998), who write,
The standard theory for the origin of life postulates that life arose from an abiotically produced soup of organic material (e.g., Miller, 1953; Miller, 1992). The first organism would have therefore been a heterotroph deriving energy from this existing pool of nutrients. This theory for the origin of life is not without competitors (for a review of theories for the origins of life see Davis and McKay, 1996), but has received considerable support from laboratory experiments in which it has been demonstrated that biologically relevant organic materials can be easily synthesized from mildly reducing mixtures of gases (e.g., Chang et al., 1983). The discovery of organics in comets (e.g., Kissel and Kruger, 1987), on Titan (e.g., Sagan et al., 1984), elsewhere in the outer solar system (e.g., Encrenaz, 1986), as well as in the interstellar medium (e.g., Irvine and Knacke, 1989) has further strengthened the notion that organic material was abundant prior to the origin of life.None of this is meant to convey the impression that no controversies exist (both Cohen (1995) and the Davis and McKay (1996) article cited by the above-quoted Kral et al. (1998) are about the various competing hypotheses about the origin of life). But textbooks generally mention some of these hypotheses (briefly of course, as there is only space for a page or two on this topic in an introductory textbook), and furthermore generally mention that the original atmosphere was likely more weakly reducing than the original Miller-Urey experiment hypothesized, but that many variations with mildly reducing conditions still produce satisfactory results. This is exactly what is written in the most popular college biology textbook, Campbell et al.'s (1999) Biology, for instance. In other words, the textbooks basically summarize what the recent literature is saying. The original Miller-Urey experiment, despite its limitations, is also repeatedly cited in modern scientific literature as a landmark experiment. So why does Wells have a problem with the textbooks following the literature? Wells wants textbooks to follow the experts, and it appears that they are.
PH: I know you're an avid compiler of this stuff. Note the extensive ad hominem and arguments from authority in the post to which I reply, the absolute exclusion of dealing with the text of the arguments to which IT is a reply. Classic AndrewC smoke-and-mirrors BS.