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 PrintableVersion Darwin's chemistry setWe have looked at a number of Darwin’s comments in his book and correspondence during this series of articles. It is clear, of course, that he was a strong advocate of evolution through natural selection, but he did highlight some of the difficulties he saw with his theory, though he imagined that forthcoming research would clarify the problems. In fact, we believe that the subsequent research has raised the level of these problems. Pond of lifeOne area that had not yet begun to be tackled was in the field of chemistry. How did inanimate matter give rise to the first living cell? Charles Darwin commented on the matter in a letter to Joseph Hooker (1871): ‘If (and oh! what a big if!) we could conceive [of] some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc. present, [so] that a protein compound was chemically formed ready to undergo still more complex changes, at the present day such matter would be instantly absorbed, which would not have been the case before living creatures were found.’ He saw the difficulty in conceiving of such a process. If it could be found it would not be a feasible source of life as the process only occurs in living cells today and not in test-tubes! Much research has gone into this matter over the years, but we are left with the same fundamental dilemmas. Miller’s experimentThere was great excitement in the scientific community in 1953 when Stanley Miller carried out an experiment to produce ‘amino acids under possible primitive earth conditions’, to quote the title of his landmark paper. Amino acids are the chemical units that combine to make proteins. There were a number of problems with this scenario. The experiment was based on the presumption of a supposed atmosphere that is irrelevant to the past history of the earth. The experimental conditions have no counterpart in the early earth, even as assumed by evolutionists. The products (amino acids) were not in the proportions required for protein synthesis and nor were they of the right stereochemistry (molecular shape). The quantities achieved were too low to give any hope of a significant yield of protein and too low to give a viable reaction rate. Also, the products lacked the other building blocks necessary for the first primitive cell that evolutionists propose. Recently another group of scientists re-examined the samples left by Miller after his recent death, using more sophisticated techniques now available. This certainly demonstrated the greater range of amino acids present than Miller realised. However, they were of even lower concentration and the problems listed above still apply. Even attempts to construct living cells by ‘feeding in’ the chemicals such as proteins, carbohydrates, lipids, nucleotides, etc. fail to reach anything approaching the complexity of a true cell. Many alternative approaches have been proposed and tested over the years, especially procedures which would more closely replicate conditions to be found on earth, such as adsorption on clay particles which could also potentially catalyse the reactions. As with Miller’s work, these have had limited success. A different directionRecent work has looked in a different direction. Obviously the chemical processes in living cells (to which Darwin alluded) require the genetic material, DNA. This is the key to the synthesis of proteins from amino acids. However, it is itself a very complex chemical which is difficult to produce under supposed primitive earth conditions. (Readers may wish to challenge the concept of a ‘primitive earth’ in the light of the biblical account of creation!) An alternative scenario has been favoured during recent years. This is based on a chemical closely related to DNA, that is, RNA. If this were available on the early earth, then its properties might be able to trigger the initial processes leading to a living cell and so the proteins, etc. Lincoln et al synthesised an RNA enzyme (an organic catalyst or accelerator), which, they found, was able to replicate itself indefinitely. When they mixed different RNA enzymes, competitive processes were set up. Not surprisingly for those interested in this possible route to the synthesis of life, this has caused some excitement. But, as Professor Gerald Joyce has pointed out, this is a long way from achieving a living system. Of course, it overlooks a fundamental problem: where did the RNA come from? Certainly not from the reaction of simple chemicals in an unaided process. RNA is made up from nucleotides which, again, are not simple molecules and need very careful, planned synthesis. They, in turn, are constructed from an organic base, a sugar and a phosphate unit. Even these defy the simple scenarios required in a supposed primitive world. Fascinating chemical reactions have been reported in attempts to simulate how nucleotides might be obtained, but they still fall short of a realistic route to RNA. One researcher, John Sutherland, summarises their objective as, ‘My ultimate goal is to get a living system (RNA) emerging from a one-pot experiment. We can pull this off. We just need to know what the constraints on the conditions are first’. When intelligent scientists struggle to achieve this goal, we might wonder why they are so opposed to ‘intelligent design’! Along with Darwin we say, ‘and oh! what a big if!’ JHJPReferences © Evangelicals Now - December 2009 |
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