From: bivalve (bivalve@mail.davidson.alumlink.com)
Date: Mon Aug 25 2003 - 19:01:40 EDT
>Would the observed process be better called "natural selection" and the theory of the origin of life or the taxa by natural selection be better called "evolution"?<
Probably not in light of general use of the words, although current practice of calling both evolution is somewhat confusing as well.
Natural selection is one of the theories explaining the observed changes in life over time. We can set up computer models or experiments in which natural selection causes changes over time, and we can see that observed evidence of past changes in organisms often matches the predictions of natural selection. However, other factors can also play a role in simulations or experiments and can provide good matches to observed patterns. Thus, one might say that it is a fact that natural selection can cause evolutionary change, and that it is a fact that it provides a good explanation of much of the evolution that we see. However, the relative role of natural selection versus other factors in explaing the observed evolutionary patterns is better identified as theory.
Actually, evolution is perhaps better as a name for the fact, despite the unpopularity of the word. After all, in a general sense it means change over time (e.g., the evolution of an idea or a society).
>Did creation start evolution or not?
>If creation did start evolution, at what taxonomic level did this occur? <
As to the taxonomic level for evolution to start, that is an issue with much controversy. Ultimately, evolution must have its start from some creation event, and all Christians believe that this creation event had a supernatural element in the role of God. Also, we can probably agree that God is smart and powerful enough to figure out how to start evolution using abiogenesis if He wanted to. The question then becomes just how did He go about creating organisms. Two basic lines of evidence are relevant. On the one hand, there are the theological considerations. One who insists that creation occurred only 6000 years ago would have to envision extremely rapid evolution in order to start from abiogenesis, though extremely rapid occurrence of other physical processes is often endorsed by them. In contrast, someone emphasizing God's self-restriction as show by the sparing use of miracles in history (including the Bible), the humiliation of the Incarnation, favoring the weak!
and humble, etc. would tend to expect a relatively non-flashy approach to creation.
On the other hand, there is the scientific evidence for common descent of various organisms. For things with good fossil records, we can trace similarities through transitional forms back to around the phylum level, with some intermediates known between closely related phyla. (Bear in mind also that the definitions of taxa are somewhat arbitrary; e.g., a class of mollusks or vertebrates or bryophytes is not necessarily equivalent). Biochemical similarities extend across all living organisms, from bacteria and archaea to plants and animals. The pattern of molecular and morphological similarities also agrees well with the expectations of common descent.
There is some molecular evidence suggestive of a more primitive system of life than found in any known organism (e.g., the evidence for a possible RNA world or the evidence of stepwise assembly in the DNA translation system). This evidence points towards the possible occurrence of abiogenesis, but does not provide much detail. From the opposite end, experiments building from the initial Miller-Urey experiments show that basic molecules needed fro life can for abiotically. A wide range of possible environments and contributing factors are getting some study today. Thus, the scientific evidence suggests some possibilities for abiogenesis while not coming very close to proof of the details of the process; in fact, there remains much to be learned about what is essential to life that a theory of abiogenesis would need to explain.
Thus, I think that it is currently very difficult to justify a claim that a miraculous step is needed to bridge the physical gap between any two organisms. While the suggestion of Darwin and Behe that the first cell was created miraculously would be very difficult to challenge on scientific grounds at present, the amount of new discovery going on in molecular biology makes it seem inadvisable to draw a line and say This will never be explained naturally.
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
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