| Creation Truth Outreach, Inc. Pamphlet |
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| Chapter 3. Sixteen Fatal Roadblocks against a Purely Natural Formation of Life. Fatal Roadblock Number 16. Jerky Relationship between Amino Acid Sequence and Enzyme Shape. Enzymes are long chains of amino acids. However, the relationship between amino acid sequence and enzyme shape is not a smooth relationship, but is “jerky” and erratic. Suppose a specific enzyme is needed to perform a new, specific function. You cannot change an existing enzyme shape into an arbitrary, new target shape by making smooth gradual changes, one amino acid at a time, such that each change produces a shape closer to the target than the preceding one. There will inevitably be steps somewhere along the way where an amino acid change needs to be made in order to produce the final target shape, but which results in a disruptive change in the immediate shape of the enzyme. For example, Enzymes are made of coils and sheets. Suppose an existing enzyme with a particular shape has 6 coils and 4 sheets. We mentioned earlier that coils average about 10 amino acids each and sheets about 36 each, although tremendous variation in this is possible, both smaller and larger. The desire is to change this enzyme into a new shape by eliminating one of the sheets and using the sequence of amino acids that formed it to form two more coils plus some loops. Suppose the existing enzyme uses about 220 amino acids and the new one will have 180 amino acids in common with the old one. 40 amino acids need to be changed to make the transformation. According to the principle of cumulative selection presented by Dawkins, it will take an average of only 18,826 mutative events to the enzyme to effect the change. That seems trivial compared to the astronomical numbers we have been looking at. But, is it really so simple? Here is the problem. Dawkins’s methodology assumed that every time a mutated enzyme was even a single amino acid closer in sequence to the final target than its unmutated parent, that there would also be a selective advantage to the mutation. In real life, it does not work this way at all. Changing one amino acid in a sheet will not make that portion of the enzyme begin to function like a coil. Thus, there is no selection advantage to implement it. Nor will two or even three changes be adequate to give an advantage. However, at a certain point before a new coil can be formed and properly positioned, the sheet will fall apart into a “nonsense structure.” It will be neither a sheet nor a coil. This will be so disruptive that the entire enzyme will fold into a useless shape, not effective in either its old function or new function. So, there is a problem. A required change to match the new sequence was implemented by a new mutation. However, this change was so disruptive to the enzyme’s immediate shape that the enzyme was useful in neither its old nor new capacity. Therefore, natural selection will select away from the change. The new amino acid sequence was closer to the target, but the shape was further. Natural selection will then eliminate a specific change needed for overall progress. So, in this case, natural selection is not the friend of evolution, it is its enemy. It prevents progress. Here is where Dawkins went wrong in The Blind Watchmaker. Dawkins did not recognize that the relationship between amino acid sequence and enzyme shape is jerky, it is discontinuous, it is not smooth. He treated it as though it were smooth. The above observation has far reaching consequences. If there exists an inherent quality in enzyme structure that systematically causes natural selection to select away from required steps to transform one enzyme into a significantly new one and different one, evolutionary theory breaks down. The discontinuous nature of enzyme shape is sufficient to effect such a break down. The first cell cannot have evolved from a soup. Reptiles cannot have evolved into mammals. To restate the issue: if it is impossible to change one enzyme into another, one amino acid at a time, while also having a selection advantage driving every step of the transformation, then macro- evolution is impossible. Building the first cell is impossible. The underlying value of having a self-replicating molecule was to provide a first step of information and copying, one that could eventually become the seed of a cumulative selection process. Once it was underway, it would be straightforward to make all kinds of new products with little effort. What we have just observed about enzyme discontinuity, though, effectively prevents this from happening. Instead, there is such a huge gap between a self-replicating molecule and a living cell that the existence of a self-replicating molecule would be irrelevant. It would be useless. It appears that the jerky relationship between amino acid sequence and enzyme shape effectively requires an enzyme to be sequenced properly in a single step. Consider an enzyme as complex as the 1,100+-amino acid succinate dehydrogenase. It is far too complicated to create by natural processes in a random, single-step event. It is far too complicated to form its strings and coils and loops one amino acid at a time from an unrelated enzyme. In short, science can tell us why it should not exist. It cannot tell us why it does exist. The things we observe from science make a purely natural origin of life impossible. Hence, the origin of life must come from a source greater than the universe and which is not bound by its laws. The existence of physical life points to and requires the existence of a living, Creator God. |