by Charles Hughes

Created on: March 02, 2007   Last Updated: March 10, 2009

It's natural that Charles Darwin's theory of evolution, first published in 1859, should provoke spirited debate today. His theory describes a process that cannot be observed, though the results of the process can be. The process itself is veiled by the immense stretches of time over which it works.

Darwin named the process "natural selection," and it is what distinguishes his theory from previous theories of evolution. Darwin described the steps in the process when he wrote, "...many more individuals of each species are born than can possibly survive" leading to a "recurring struggle for existence" and that an individual that varies "however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving" and because of "the strong principle of inheritance ... will tend to propagate its new and modified form." It's very difficult to argue with any of these steps.

Nevertheless controversy immediately arose upon publication because Darwin's theory contradicted the Biblical explanation of life's formation. Adding fuel to the controversy was the idea that mankind was descended from apes.

Today, some of this controversy has abated. In the United States, beginning in 2006, Christian congregations began to celebrate "Evolution Sunday" annually. This movement grew to 530 U.S. congregations in 2007 and spread to four other countries. The view that the Biblical account could be allegorical and that the six days of creation could be viewed as six periods of indefinite duration allows Biblical and scientific versions of species development to coexist.

Still, 2005 brought renewed controversy to the theory of evolution in the United States when a Pennsylvania school district mandated that whenever evolution is taught students must be advised of the theory of "Intelligent Design," a supernatural explanation of why species have their present complex forms. A federal court ruled this to be the teaching of religion in the classroom which is unconstitutional.

As a competitive theory to evolution, Intelligent Design was dealt a severe setback by the trial when a leading proponent, Michael Behe, took the stand. Behe had lent the Intelligent Design movement some credibility because he is a professor of biochemistry and author of the popular book, "Darwin's Black Box" which argues that biological structures, such as the eye and bacterial flagellum, are "irreducibly complex" and must have been designed by some intelligent entity. Under oath, however, he conceded that "There are no peer reviewed articles by anyone advocating for intelligent design supported by pertinent experiments or calculations which provide detailed rigorous accounts of how intelligent design of any biological system occurred." Furthermore, it was revealed that peer reviewed articles do exist for evolutionary explanations showing how flagellum and other complex structures might have evolved.

Darwin's theory will continue to spark controversy because there are still unanswered questions. Why do new species suddenly appear in the fossil records? Where are the "missing links?" ("Punctuated Equilibrium" provides a possible explanation for both these questions.) Why did complex, fully evolved animals suddenly (geologically speaking) appear during the "Cambrian Explosion" 570 million years ago? The lack of satisfactory answers to these questions does not void Darwin's theory, though it does prevent universal acceptance. In the meantime, the controversy benefits us by encouraging a deeper understanding of one of the most puzzling mysteries of life.

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