“an unsupervised, impersonal, unpredictable and natural process of temporal descent with genetic modification that is affected by natural selection, historical contingencies and changing environments.”
Criticism can be leveled at several parts of this definition. Scientists such as Simon Conway Morris, for example, would argue against the unpredictability of evolution. The biggest trouble with the definition, however, came from two words: “unsupervised” and “impersonal.”
As Karl Giberson notes in Saving Darwin, these words seem far more at home in a theological textbook rather than a scientific one:
“If the NABT read the definitions of other concepts in science, it would certainly have noticed that nobody uses the descriptor unsupervised. Do students learning chemistry or geology have to understand the natural phenomena of those discplines as ‘unsupervised’?”
One would think that such objections would have caused the association to rethink its definition. However, in a 1997 meeting, the NABT voted unanimously to keep the wording. It remained a part of the NABT until Eugenie Scott, the executive director of the National Center for Science Education, convinced the body that its definition would cause more harm than good in combating creationism.
The removal of the two words changed none of the definition’s scientific content. The only thing lost was a misguided attempt to impose theology on high school biology classrooms.