Why scientists dismiss 'intelligent design'

Specified complexity
The second major argument for intelligent design comes from William Dembski, a mathematician and philosopher affiliated with the Discovery Institute, a Seattle-based Christian think tank that serves as the nerve center for the ID movement.

Dembski argues that nature is rife with examples of non-random patterns of information that he calls "complex specified information," or CSI for short.

To qualify as CSI, the information must be both complex and specified. The letter "A," for example, is specific but not complex. A string of random letters such as "slfkjwer," on the other hand, is complex but not necessarily specific. A Shakespearean sonnet, however, is both complex and specific.

An example of CSI from nature is DNA, the molecule found in all cells that contains the genetic instructions for life. DNA is made up of four repeating chemical bases arranged into complimentary pairs. The bases can be thought of as "letters" in a four-letter alphabet and can be strung together to form genes, which can be thought of as the "words" that tell the cell what proteins to make.

The human genome is made up of some 3 billion DNA base pairs and contains about 25,000 genes. DNA is obviously complex. The fact that humans always give birth to humans and not chimpanzees or naked mole rats shows that DNA is also specific.

The fact that CSI exists in nature is evidence for design because intelligence is necessary to produce CSI, Dembski says. This is the part of Dembski's argument that many scientists have trouble with.

The nylon problem
There is a way to settle this, however, because like Behe's irreducible complexity, the concept of specified complexity can also be tested.

"If Dembski were right, then a new gene with new information conferring a brand new function on an organism could never come into existence without a designer because a new function requires complex specified information," Miller said.

In 1975, Japanese scientists reported the discovery of bacteria that could break down nylon, the material used to make pantyhose and parachutes. Bacteria are known to ingest all sorts of things, everything from crude oil to sulfur, so the discovery of one that could eat nylon would not have been very remarkable if not for one small detail: nylon is synthetic; it didn't exist anywhere in nature until 1935, when it was invented by an organic chemist at the chemical company Dupont.

The discovery of nylon-eating bacteria poses a problem for ID proponents. Where did the CSI for nylonase—the actual protein that the bacteria use to break down the nylon—come from?

There are three possibilities:

• The nylonase gene was present in the bacterial genome all along.
• The CSI for nylonase was inserted into the bacteria by a Supreme Being.
• The ability to digest nylon arose spontaneously as a result of mutation. Because it allowed the bacteria to take advantage of a new resource, the ability stuck and was eventually passed on to future generations.

Apart from simply being the most reasonable explanation, there are two other reasons that most scientists prefer the last option, which is an example of Darwinian natural selection.

First, hauling around a nylonase gene before the invention of nylon is at best useless to the bacteria; at worst, it could be harmful or lethal. Secondly, the nylonase enzyme is less efficient than the precursor protein it's believed to have developed from. Thus, if nylonase really was designed by a Supreme Being, it wasn't done very intelligently.

‘Death of science'
After examining ID's two main arguments, the answers to the original questions — what does ID offer? And what can ID explain that evolution can't? — is not much and nothing, leading scientists say.

"The most basic problem [with ID] is that it's utterly boring," said William Provine, a science historian at Cornell University in New York. "Everything that's complicated or interesting about biology has a very simple explanation: ID did it."

Evolution was and still is the only scientific theory for life that can explain how we get complexity from simplicity and diversity from uniformity.

ID offers nothing comparable. It begins with complexity — a Supreme Being — and also ends there. The explanations offered by ID are not really explanations at all, scientists say. They're more like last resorts. And, scientists argue, there is a danger in pretending that ID belongs next to evolution in textbooks.

"It doesn't add anything to science to introduce the idea that God did it," Provine told LiveScience. Intelligent design "would become the death of science if it became a part of science."

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