Does "Intelligent Design" Threaten the Definition of Science?

John Roach
for National Geographic News
April 27, 2005
Where did we come from? It's one of the oldest and most profound questions. Now "intelligent design" theory may change the very definition of science by allowing the supernatural into the lab.

"Ever since the birth of science as we know it, a cardinal rule for theists [believers in the existence of a god or gods] and nontheists alike has been to limit scientific explanations to natural causes," said Ronald Numbers, a science historian at the University of Wisconsin-Madison.

Numbers studies the 140-year struggle between evolutionary biologists and anti-evolution movements.

Evolutionary theory—that acts of random mutation and natural selection over millions of years gave rise to us humans and all other life—is the best answer scientists can give to the question of life's origins.

But the answer is hardly satisfying to many Americans. A recent CBS News poll found that 55 percent of respondents did not believe in the theory of evolution at all—and even most scientists agree that the theory leaves some questions about biological origins unanswered.

Most career evolutionary biologists delight in the unexplained (for one thing, it means they'll have jobs for at least a while longer as they search for answers). More and more people, though, are gravitating towards an alternative explanation: intelligent design.

Intelligent-design theory states that certain features of the natural world are of such complexity that the most plausible explanation is that they are products of an intelligent cause rather than random mutation and natural selection. Supporters of the theory say the nature of the intelligent cause is outside the scope of the theory.

"It matches what a lot of people see. It matches peoples' intuitions about biology," said Michael Behe, a biochemist at Lehigh University in Bethlehem, Pennsylvania.

Behe is a senior fellow at the Discovery Institute's Center for Science and Culture, a Seattle, Washington-based organization that rallies much of the intellectual muscle behind the intelligent-design movement.

The movement's success comes from the way it "appeals to peoples' sense of unease about science and technology," said Kenneth Miller, a biologist at Brown University in Providence, Rhode Island.

Miller is a defender of evolution who has taken a seat against advocates of intelligent design in the struggle over how evolution should be taught in U.S. public schools.

The struggle's next round will play out over a six-day hearing next month in Topeka, Kansas, hosted by the state board of education. Miller, like most scientists and science organizations, including the American Association for the Advancement of Science (AAAS), will not participate.

In a media statement issued April 12, Alan Leshner, chief executive of the Washington, D.C.-based AAAS, said the association is concerned that rather than contributing to science education, the hearing "will most likely serve to confuse the public about the nature of scientific enterprise."

Teach the Controversy

John West is the associate director of the Discovery Institute's Center for Science and Culture and an advocate of the institute's "teach the controversy" approach to teaching evolution in U.S. public schools.

The approach steers clear of teaching intelligent-design theory in the schools (the Discovery Institute believes the theory is too new to be required). Instead, "teach the controversy" promotes teaching "all the evidence relating to evolutionary theory," West said.

Included in the evidence are what the Discovery Institute views as legitimate criticisms of evolutionary theory, such as the limits of natural selection and random mutation in explaining the explosion of new body plans during the Cambrian period (about 570 million years ago).

"If high school or college students are capable of understanding evidence for evolution, certainly they could understand scientific criticisms of key parts of the theory, particularly the limit to the creative power of selection and random mutation," West said.

Eugenie Scott is director of the Oakland, California-based National Center for Science Education, which defends the teaching of evolution in schools. She said the problem with the "teach the controversy" approach to teaching evolution is "there's no controversy."

According to Scott, anybody who surveys the peer-reviewed scientific literature will uncover articles documenting disagreements over the pattern and process of evolution, "but they won't find arguments over whether living things have common ancestors," she said.

Behe, the Lehigh University biochemist, said, "Everybody agrees Darwinian theory does explain some things. The question is, is it a good explanation for everything? That is where people start to disagree."

Numbers, the University of Wisconsin-Madison science historian, said that, on the face of it, teaching the strengths and weaknesses of evolution looks innocuous and in fact is what science teachers should try to do when discussing any theory.

"I'd be in favor of it if I didn't realize this as a rhetorical ploy to get teachers to undermine evolution," he said.

According to Scott, any scientific views presented by the intelligent-design community have the same chance as any other scientific idea of landing in the classroom, but they first must be accepted as viable by the scientific community. High school teachers, she said, are limited to teaching the consensus view of their subjects.

"What you'll find is ID [intelligent design] has not gone anywhere in the science community," she said. "The scientists have looked at ID and said, Hmmm, not ready for prime time."

Stifling Education?

According to Behe, the biochemist, recognizing the signature of the intelligent agent is like recognizing that the faces of the U.S. presidents carved into South Dakota's Mount Rushmore is the work of humans, not chaotic, random events.

Advocates of intelligent design say certain things in nature (such as the complex molecular "machines" found in a cell) cannot be explained by evolution. Such features have the earmark of an intelligent agent, ID advicates say.

"The justification for design is that these systems seem to have features we associate with designed systems," Behe said. "They have intricate parts that interact with each other."

Until these complex components of nature are proven to result from evolution or some other process, Behe said, scientists ought to allow the plausibility that they are the work of an intelligent agent.

"Many people in academia, in the sciences, take it as a principle that they should not resort to an explanation that has a strong philosophical, theological ramification," he said. "But that is not so in the case of the general public."

According to Miller, the Brown University biologist, academia is opposed to explanations that rely on God as a causal agent because they go against the very definition of science: seeking a natural explanation for natural events and phenomenon.

The intelligent-design movement, Miller said, seeks to allow a non-natural explanation into science. "By altering the definition of science, they seek a playing field where the supernatural can have scientific meaning."

Numbers, the science historian, said doing so would be disastrous for science education. "The heart of scientific enterprise is to try to solve these problems naturally, not just say, OK, this is intelligently designed, so we're giving up."

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