From: bivalve (bivalve@mail.davidson.alumlink.com)
Date: Mon Oct 27 2003 - 15:19:34 EST
>Can anyone name a YEcreationist book or a YEcreationist speaker who does not falsify to such an extent that it must be deliberate.<
It is difficult to distinguish between deliberate falsification and gross carelessness with the truth. The abysmally poor quality of many young-earth arguments to me suggests the latter. However, presenting such carelessness as valid work, worthy of serious consideration is dishonest. Of course, there are also numerous individuals for which it is a matter of gullibility in repeating such stuff rather than making the errors themselves.
The universality of the genetic code was also invoked by the Discovery Institute against common ancestry. However, the argument is dishonest (whether or not the arguer knowingly is) because it fails to note that the exceptions to the genetic code typically are found where they would be expected evolutionarily. The mitochondrial genomes of hemichordates and echinoderms shows a change in the code in progress. A different type of change in the code (with an obvious evolutionary mechanism) has been found in certain snail mitochondrial genomes. Anyone trying to argue that exceptions to the universal genetic code are evidences against evolution is either speaking out of ignorance or deliberately dishonest.
There are several reasons why molecular data should be expected to give an imperfect picture of evolutionary relationships. First, some genes do not tell you much, either changing too fast or too slow. Too slow, and there is hardly any difference between them. Too fast, and the sequences are practically random. Second, convergent evolution can affect molecules. Third, various errors are possible, including misidentification, contamination, misalignment of sequences, inappropriate analyses, and inappropriate interpretation of analyses. Fourth, complicating factors such as lateral gene transfer or comparison of paralogous genes can cause the true evolutionary history of the gene and of the organism to not match up. Paralogous genes are genes that are thought to ultimately have a common ancestor, but have been duplicated and transmitted as multiple copies for a while. For example, the various human hemoglobin genes appear to share distant common ancestry, but they have !
been evolving independently for a while. If you compared my alpha hemoglobin to a chimp's alpha hemoglobin and to your beta hemoglobin, the chimp and I would be most similar due to the mix of paralogs and orthologs. (All of these can happen even within "microevolution" and do not require assumption of extensive common descent.)
In general, getting more data and using more sophisticated analyses (if computers can handle them) will tend to fix the problem. However, in the case of somewhat random data, additional data can exacerbate the problem. Another factor overlooked by the antievolutionary argument is that many of the potential sources of trouble can be looked for. Various analyses will alert you to the likelihood that there is a problem. E.g., the published COI sequence for the threehorn wartyback (some mussels have weird names) came out with the mapleleafs instead of where all the other genes put it. I sequenced COI for another threehorn wartyback and found that the published COI sequence was incorrect.
Dr. David Campbell
Old Seashells
University of Alabama
Biodiversity & Systematics
Dept. Biological Sciences
Box 870345
Tuscaloosa, AL 35487-0345 USA
bivalve@mail.davidson.alumlink.com
That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa
This archive was generated by hypermail 2.1.4 : Mon Oct 27 2003 - 15:20:09 EST