Posted on 05/30/2002 7:40:53 AM PDT by Gladwin
Edited on 09/03/2002 4:50:34 AM PDT by Jim Robinson. [history]
I heartily agree. What is the Theory of Intelligent Design? How does it explain the fossil record? What predictions does it make? How can it be falsified? What tests, experiments, or observations are implied by the Theory of Intelligent Design that would be able to verify it?
[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.
Why would a flaw (or flaws), in a scientific theory suggest a non-scientific approach as a rational option? For ID to be scientific, it must be falsifiable. There have been no tests suggested which might be used to falsify the theory, so the statement quoted above makes about as much sense as saying, "Once the Copernican theory of heliocentrism is shown to be flawed, students might then be able to look into astrology with more of an open mind."
Who says astrology ain't science? What's YOUR sign?
Yet the presence of these remarkable deposits does not mean the oceans were oxygen-rich. On the contrary, BIFs were nearly always deposited in large basins, hundreds of kilometers in length and breadth, and the dissolved ferrous iron from which BIFs form could be spread over such vast distances only if carried by waters that were oxygen-poor. Huge amounts of molecular oxygen were pumped into the environment by oxygenic (cyanobacterial) photosynthesis, but except locally, near where it was produced, amounts of oxygen were kept low by its capture and rapid burial in the oxide minerals of BIFs.You ignore the pyrite and uraninite evidence which also refute your claim of an oxiding early atmosphere. You concentrate instead upon misinterpreting the BIF evidence, the nature of which is explained by Schopf. To continue in this line, you fill up the thread with big pictures, resumes, funny colors and fonts, pretending not to remember or understand the text of the rebuttal.
Are there no lies in a jihad?
I was trying to be charitable and phrase the thing so that people such as yourself without the math background could grasp it. The precise terms are countably/uncountably infinite. Nor for that matter do I see a problem in using such terms in the context of the odds against macroevolution via mutation and "natural selection". It's been adequately demonstrated that no amount of time which you could fit into the history of the universe would suffice for that kind of theory yet the evos keep crying "Gee, if we just had a little more time, the whole thing would work...
Feces.
brain letting---tinkerers!
Excuse me? I have a "math background". You're using terms from set theory where a real number is required. Or perhaps there is some context (which I'm not aware of) where it makes sense to say "The odds are aleph-naught to 1", "No, they're really two to the aleph-naught to 1".
Maybe what you need is non-standard analysis.
BTW, there appears to be only a finite number of particles in the Universe, extimated at about 10 to the 80, or 2 to the 256. Furthermore, (assuming that time and space cannot be infinitely divided, which I believe is a consequence of quantum theory), there is no evidence for any kind of infinity whatsoever in the Universe. It's all in our heads.
Flying squirels. They have one minor adaptation (that little flap of skin under their forelimbs) that allows them to glide between trees. They don't need to have all of the rest of the adaptations like light bone structure, specialized muscle groups ect to use the advantage gliding provides. I'm sure that the first "freak squirrel" must have been pretty happy with his little flaps when confronted with a snake or carnivirous sloth!
Consider this.....Every year a few people are born with webbed feet. Now, if for some reason webbed feet were an advantage (a massive dying off of land animals and the need to hunt for aquatic animals for example) don't you think that the webbed foot gene would have a greater than random chance at being spread through a population? Add to that any other mutations like oilier hair (helps keep water off of the skin), predisposition to extra fat layers, stronger swimming abilities, ect that would help a person survive and be succesfull in a new environment and viola, a changing population.
The real mechanism behind the whole mutation thing seems to be pretty well hidden from us but the effectrs are pretty damn obvious even in our own species. You have native african folk with longer lower legs (run faster), bigger lips (moisture retention) and dark skin (protection from the sun). OTOH we have native northern european folk with squat bodies (heat retention) lots-o-body-hair (again for warmth) and light skin (no protection from the sun is needed). It seems to me that anyone thinking that evolution, at the very least micro evolution, does not take place has a very limited scope of what they allow themselves to see and question.
I also tend to think that after the original creation/whatever (yet to be seen how it all started) of life took place there was little left to true chance. Environment took over and dictated from then on in what form animal life took.
EBUCK
That's good. I think I had read about that, a long time ago, but it completely slipped away from me. Now, when some bozo shows up and says that Darwin is responsible for the evils done by Stalin, I can toss that little goodie out. (As if either Darwin or the church were to blame ...)
backhoe/operator -- oozing custard -- old socks: you?
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