Amundson (2001) critiques the circularity charge well: This criticism relies on a faulty view of what scientific definition amounts to.A scientific definition is not a semantic stipulation that creates an analytically true statement (i.e.Wells wants you to think that there is good evidence for significant amounts free oxygen in the prebiotic atmosphere (significant amounts of free oxygen make the atmosphere oxidizing and make Miller-Urey-type experiments fail).He spends several pages (14-19) on a pseudo-discussion of the oxygen issue, citing sources from the 1970's and writing that (p. The famous Miller-Urey experiments used a strongly reducing atmosphere to produce amino acids.When they read the scientific literature in their specialty, they can see that the icon is misleading or downright false.But they may feel that this is just an isolated problem, especially when they are assured that Darwin's theory is supported by overwhelming evidence from other fields.20-22), Wells cites some more 1970's sources and then asserts that the irrelevance of the Miller-Urey experiment has become a " None of this is meant to convey the impression that no controversies exist (both Cohen (1995) and the Davis and Mc Kay (1996) article cited by the above-quoted Kral et al.
The historical definition is not viciously circular as long as homologies can be recognized and picked out by criteria other than common ancestry.17) " Why does Wells leave out the converging independent lines of geological evidence pointing to an anoxic early (pre ~2.5 bya) atmosphere? 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.So why does Wells have a problem with the textbooks following the literature? 22) as if the RNA world is an alternative to failed Miller-Urey-style experimentation.Wells wants textbooks to follow the experts, and it appears that they are. He cites no source for this claim, because the claim is pure obfuscation. As we saw in the previous chapter, he will give several topics each a cursory and incomplete treatment, raising doubts about each subject and connecting them together whether they are logically connected or not. Here Wells is running down a path well-worn by his creationist and Intelligent Design colleagues.