Natural Selection and Evolution

This Simple Example Shows that Evolution Does not Work Quite Like Darwin Imagined

When Darwin introduced the theory of evolution, he envisioned everything being guided by natural selection. The following quote conveys his thinking:

"If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down." - Charles Darwin

Darwin should be applauded for this particular statement. This quote is right on target. Darwin wanted to explain evolution with small continuous steps. He took a very simplistic approach. The legs of reptiles can gradually over many generations evolve into wings. The fins of fish can gradually evolve into legs for reptiles. He thought all of these changes were guided by natural selection. This simplistic approach is still taught in high school and college biology. Whether true or not, it is a great way to teach evolution because it minimizes the role of chance and makes the theory seem more reasonable.

       Some biologists do not realize that useful information (any door’s combination) is locked by natural selection. The fins of a fish are not free to evolve into the legs of a reptile. The legs of a reptile are not free to evolve into the wings of a bird, and it is natural selection that makes this a certainty.

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