Biologists often get angry about the publication of studies defending "intelligent design," the notion that biochemical systems could not have been produced by evolution because they are "irreducibly complex," and as such, must have been "designed" by an unknown entity. But a careful reading of some recent studies suggests that researchers haven't been shying away from using the word "design" in a way that can only be described as teleological.

In the Feb. 3, 2005, issue of Nature, for example, Stephan Hetz and Timothy Bradley, of the University of California, Irvine, state that insects' respiratory systems have been "designed to function most efficiently at high levels of O₂ consumption."[1] And in the April 2, 2004, issue of Science, Neil Shubin of the University of Chicago and his colleagues discuss the role of several "appendage designs" in tetrapods.[2]

Hetz and Bradley are quick to point out that they did not intend to imply that the insects' tracheal system is the result of the work of a designer. "We are using design there as a shorthand for an awful lot of ideas, such as that the system has been shaped by selection pressures to have a certain functional consequence," says Bradley.

Similarly, Shubin notes: "I'm talking about the three-dimensional relations among structures of a bone. I'm saying that it's organized in such a way that it allows certain functions to happen. That doesn't mean that it was designed from a blueprint."

But some scientists feel they ought to be more careful, in the wake of the publication of a New York Times op-ed by Michael Behe of the Discovery Institute[3] – the most visible arm of the intelligent design movement – in which he supports his thesis by using comments by National Academy of Sciences president Bruce Alberts in the journal Cell.[4] "The entire cell can be viewed as a factory with an elaborate network of interlocking assembly lines, each of which is composed of a set of large protein machines," Alberts wrote in 1998; Behe misrepresented this quote, according to a letter by Alberts published in the New York Times on Feb. 12, 2005.[5]

"I would be worried about being misquoted," says Bradley. "However, my guess is that creationists would find plenty of things to misquote anyway." Bradley concedes that in his paper the word design is subject to misinterpretation, and he says that "there is no reason for sloppy language."

Other scientists refuse to self-censor. "I wouldn't like to have to be aware that the enemies are looking over our shoulder, and to have to choose our words carefully," says Miller. "The language in Hetz's paper makes perfect sense to any scientist who reads it. But yes, the enemies could take that and say: 'See? Biologists recognize design."' Miller, who is also the coauthor of a widely used biology textbook, wouldn't use the word design with his students. "They are going to take the language too literally, and it will cause a misunderstanding."

Michael Ruse of Florida State University says scientists should feel free to use metaphors. "Scientists wouldn't even ask questions about function if it weren't for the design metaphor that they've got," says Ruse. He says the use of "design" in recent papers proves the point he has been making for years: "We all think in terms of design, although not in terms of a hands-on designer."