Posted on 08/21/2006 6:57:26 AM PDT by PatrickHenry
Were the Theory of Evolution even remotely like the grotesque caricature presented by various creationist and intelligent design websites, there would be no debate. It is pernicious that one of the most elegant works of science should be so routinely misrepresented. Before one can evaluate a theory's merits, he is obliged to at least understand what it actually does -- and does not -- state. Failing to understand something before attempting debate against it is absolute folly. Therefore, we offer the following:
1. In every generation, some individuals of a species fail to reproduce. Whether due to biological inadequacy or other mishap, their genetic material is dropped from the species' gene pool. Each new generation is the product of only those individuals that reproduce successfully. ("Success" is a relative term; differential success, like failure, can effect the genetic future of a species.)
2. By eliminating the genetic material of unsuccessful individuals and preserving the rest, nature imposes a filter -- successful reproduction -- on the genetic material of all living things. Because each generation is the result of this filter, the "genetic inventory" of each generation always differs from the one before it. Creationists call this "micro evolution." Please note: individuals never change; they either reproduce or they don't. It's the genetic inventory of a species that changes over time.
3. Mutations occur with virtually every act of reproduction. All genetic material, whether mutated or precisely copied, is subject to nature's filter. If a mutation is neutral or beneficial, or maybe not too harmful, it can endure as part of that species' genetic inventory; otherwise it's filtered out. Mutations that were originally neutral may turn out to be useful or harmful due to changing environmental circumstances, and will be filtered accordingly. If useful, a mutated characteristic can become prevalent within a few generations, and may seem to have wondrously appeared in response to an environmental challenge. In reality, a previously irrelevant feature has become advantageous.
4. Severe environmental changes can enhance the filter's effect, by eliminating numerous individuals that have become inadequate, leaving relatively few individuals whose genetic material will determine the species' future. This will cause rapid changes in the species' genetic inventory. Over thousands of generations, the genetic inventory of a species can become so changed that, by comparison with ancestors in the fossil record, we observe that a new species has evolved from the ancestral version. (Creationists call this "macro evolution" and deny that it occurs.) Conversely, during long periods of environmental stability, there may be only "routine" filtering for continued fitness, and no obvious speciation.
5. As successful species multiply and spread out over a large area, groups can become isolated, forming separate breeding populations. Over great periods of time, depending on environmental factors and the occurrence of mutations, a separate group can (if it doesn't go extinct) evolve into a new species; or it can remain relatively unchanged. The result may be a multitude of species (some living, some extinct) that can be traced to their common ancestral group. Over time, each new species can repeat this process, causing increasingly diverse species to radiate from a common origin.
Commentary: From our point of view, the filter (nature's evolution algorithm) can result in an enormous amount of waste. Uncountable legions of creatures are conceived, but never survive long enough to reproduce. What we might regard as good and useful is sometimes filtered out along with the bad. But the rule is not what we might like: "Everything nice will be preserved." Instead, it is strikingly simple -- as natural laws must be -- functioning with inexorable predictability, with no subjective judgments built in. Simply stated, the rule is this: "Only that which successfully breeds can produce players in the next round." Therefore, when the avalanche is falling, there's no soft voice that says: "Oh, this one has such nice genes, let's whisk it out of harm's way." The evolution algorithm is marvelously elegant in its operation -- but it's not what we would expect of an intelligent designer.
There is evidence that it did happen.
Human Ancestors.
The Evidence for Human Evolution.
Comparison of all Hominid skulls.
Early Human Phylogeny. Relationships among early human species.
Man-chimp evolution. Ichneumon's post 29.
Brain gene shows dramatic difference from chimp to human.
An examination of the DNA shows the changes that occurred. It's like a detective story. You look for clues about the past.
Thanks. I'll read those links.
Just to be clear, I am not a Darwinist, I do not believe that Darwinism can achieve what it purports to achieve. I posted the "fish story" to demonstrate that external forces can directly influence the morphology of an individual.
He doesn't change; he is what his genes determine he will be.(snip stuff about fish that's supposed to be significant about something>
My skin color is lighter or darker depending on whether I've been in the sun lately. Does that disprove evolution too? :-)
Only, if you also get hair on your chest and begin to speak with a deeper voice among other things. ;^)
P.S. The fish story only goes so far as to display that the tale is a bit more complex than some would have us believe. --- A Dr. James Shapiro moment.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.