Date: Fri Jun 18 1993 04:22:00 To: Eddie Johnston Subj: Intro to Evolution EVOLUT

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Date: Fri Jun 18 1993 04:22:00 From: Dr Pepper To: Eddie Johnston Subj: Intro to Evolution EVOLUTION ------------------------------- A Quick Description of the Theory of Evolution for Creationists --------------------------------------------------------------- First we have to distinguish between the theory of evolution, and the fact of evolution. I'll start with the fact. Well you've probably heard the phrase "A change in allele frequencies over time" but that's a little complex. So i'll stick with Darwin's phrase "Descent with Modification", which is still an adequate summation. Descent with modification means that as one observes a population over time, one sees change over generations. The amount of change can vary, but in general, the more time, the more change. We can observe this happening today by direct observation, over relatively short periods of time. And we can observe it happening in the past through the fossil record, over relatively long periods of time. So as you can see, to say that "evolution happens" is pretty much on a par with saying "gravity happens". The theory has to do with *how*. So now i will state the theory. Again, i will use an old and traditional form: DIFFERENTIAL REPRODUCTIVE SUCCESS which means that within a given population, different individuals will, under the same conditions, have different chances to reproduce, and thus pass on their particular genetic makeups. And since genetic makeups are always changing, there are always differences. It doesn't matter how the differences arise, nor the nature of the circumstances that affect reproductive success. As long as both exist, evolution will happen. As you can see, my statements above contained no unfounded assertions, no statements against any other theory, nor was it just a list of predictions. However, it is a basis from which we can go on and make predictions. One important prediction is that for any given physical feature, (to the extent the data is available), we can take a horizontal slice, that is in one time period examine different species that have that trait, and find a range of variants of it. The beaks of Darwin's finches are a classic example of this. Or we can take a vertical slice, that is look at a given trait in through time, and see a sequence of change. Further we can see development, that is to say, if a given trait has a given use we can go back and find in the lineage of the creature that has that trait, an earlier creature that has a less developed version of it, where "less developed" is used in the sense of the later use, not in the sense of it being *totally* useless before then. A fine example of this is the development of the mammalian inner ear from the reptilian jawbone. A faq is available on this. Another, somewhat trivial prediction is the phylogenic tree itself. Now of course, you have heard that there are a number of different theories, plural, of evolution. Yes there are. And all of them are perfectly compatible with "Descent with modification". These theories are intended to fine tune the above and explain the details. This is analogous to the way quantum physics explains electron orbitals without repudiating the idea that electrons are bound to the atomic nucleus by the attraction of opposite charges. 10 2 DR PEPPER 4

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