Posted on 01/13/2005 8:33:37 AM PST by SoFloFreeper
So then, what Dr. Maddox is really saying is that it's impossible for chimpanzees to be alive. After all, if you take human DNA and modify 3 nucleotides, then that's fatal. A chimp has human DNA with 1.6% of its nucleotides modified. This is far greater than 3 nucleotides, so a chimp must not be able to survive. Since this is an obviously ridiculous conclusion, there must be something wrong with Dr. Maddox's argument. One glaring fallacy is that he assumes that ANY change of a nucleotide will have harmful effects. The genetic code is such that every group of three nucleotides forms a codon which encodes a particular amino acid. In many codons, the third nucleotide is irrelevant. That is, if you change the third codon, the same amino acid is coded for. Therefore, you could potentially change any number of these redundant nucleotides without any effect whatsoever on the organism. Furthermore, much of human DNA has been shown to serve no purpose. Changes to this "junk DNA" would have no effect on the survivability of the human. Additionally, even if we restrict consideration to the functional DNA and to nucleotides which are not redundant, Maddox's argument would seem to imply that the DNA of every person must be identical to within 3 nucleotides. This is entirely untrue. Otherwise, everyone would have the same eye color, hair color, height, etc. Natural selection will select those mutations that are not lethal to the organism. It is entirely possible to make mutations that allow the organism to survive. Even lethal mutations can survive in a population for long periods of time. For example, it is estimated that every human has about 1000 lethal genes in their genome. Why doesn't every human die immediately, then? The key is that these are recessive genes. A normal allele is present along with the lethal one. The normal allele masks the presence of the lethal one, allowing the person to survive. (This is the reason, from a biological standpoint, that marriages between close relatives are a bad idea). It is entirely possible that the DNA of humans could diverge by 0.8% without lethal effect. We know for sure that it's possible for it to diverge by 1.6%.
That is absurd. Fortunately you said it, not me. Take out the word "proves" and replace it with "does not falsify" and you might be on to something.
The salient point is that according to creationists transitional forms don't exist therefore human/not-human classification of fossils should be easy, yet creationists cannot agree on the classification of fossil hominids. Difficulty in classification may not "prove" evolution but it does make a good falsification of creation.
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