We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged. (Discovery Institute 2004)
Since scientists are trained to examine evidence and to be skeptical of everything, even ardent evolutionists could sign such a statement. Indeed, it is well known that random mutation and natural selection are not the only mechanisms contributing to the complexity of life; other mechanisms such as genetic drift and symbiosis are important, too.
Most of the signators to the DI's list (about 80%) are not biologists; some are not even scientists. Generally speaking, mathematicians, electrical engineers, philosophers, and so forth are only marginally more qualified to comment on the validity of evolution than the average person on the street.
The National Center for Science Education has compiled, as a parody of lists such as that from the Discovery Institute, a list of more than 500 scientists all named Steve, or with variants of that name, who support evolutionThe statement signed by the scientists of "Project Steve" is more more specific:
Evolution is a vital, well-supported, unifying principle of the biological sciences, and the scientific evidence is overwhelmingly in favor of the idea that all living things share a common ancestry. Although there are legitimate debates about the patterns and processes of evolution, there is no serious scientific doubt that evolution occurred or that natural selection is a major mechanism in its occurrence. It is scientifically inappropriate and pedagogically irresponsible for creationist pseudoscience, including but not limited to "intelligent design," to be introduced into the science curricula of our nation's public schools. (NCSE 2003)