I suggest reading the entire article.
Is Intelligent Design Testable?
FALSIFIABILITY: Is intelligent design falsifiable? Is Darwinism falsifiable? Yes to the first question, no to the second. Intelligent design is eminently falsifiable. Specified complexity in general and irreducible complexity in biology are within the theory of intelligent design the key markers of intelligent agency. If it could be shown that biological systems like the bacterial flagellum that are wonderfully complex, elegant, and integrated could have been formed by a gradual Darwinian process (which by definition is non-telic), then intelligent design would be falsified on the general grounds that one doesn’t invoke intelligent causes when purely natural causes will do. In that case Occam’s razor finishes off intelligent design quite nicely.
On the other hand, falsifying Darwinism seems effectively impossible. To do so one must show that no conceivable Darwinian pathway could have led to a given biological structure. What’s more, Darwinists are apt to retreat into the murk of historical contingency to shore up their theory. For instance, Allen Orr in his critique of Behe’s work shortly after
Darwin’s Black Box appeared remarked, “We have no guarantee that we can reconstruct the history of a biochemical pathway.” What he conceded with one hand, however, he was quick to retract with the other. He added, “But even if we can’t, its irreducible complexity cannot count against its gradual evolution.”
The fact is that for complex systems like the bacterial flagellum no biologist has or is anywhere close to reconstructing its history in Darwinian terms. Is Darwinian theory therefore falsified? Hardly. I have yet to witness one committed Darwinist concede that any feature of nature might even in principle provide countervailing evidence to Darwinism. In place of such a concession one is instead always treated to an admission of ignorance. Thus it’s not that Darwinism has been falsified or disconfirmed, but that we simply don’t know enough about the biological system in question and its historical context to determine how the Darwinian mechanism might have produced it.
For instance, to neutralize the challenge that the irreducible complexity of the bacterial flagellum raises against Darwinism, Ken Miller employs the following argument from ignorance. Like the rest of the biological community, Miller doesn’t know how the bacterial flagellum originated. The biological community’s ignorance about the flagellum, however, doesn’t end with its origin but extends to its very functioning. For instance, according to David DeRosier, “The mechanism of the flagellar motor remains a mystery.” Miller takes this admission of ignorance by DeRosier and uses it to advantage. In
Finding Darwin’s God he writes: “Before [Darwinian] evolution is excoriated for failing to explain the evolution of the flagellum, I’d request that the scientific community at least be allowed to figure out how its various parts work.” But in the article by DeRosier that Miller cites,** Miller conveniently omits the following quote: “More so than other motors, the flagellum resembles a machine designed by a human.” **
So apparently we know enough about the bacterial flagellum to know that it is designed or at least design-like. Indeed, we know what most of its individual parts do. Moreover, we know that the flagellum is irreducibly complex. Far from being a weakness of irreducible complexity as Miller suggests, it is a strength of the concept that one can determine whether a system is irreducibly complex without knowing the precise role that each part in the system plays (one need only knock out individual parts and see if function is preserved; knowing what exactly the individual parts do is not necessary). Miller’s appeal to ignorance obscures just how much we know about the flagellum, how compelling the case is for its design, and how unfalsifiable Darwinism is when Darwinists proclaim that the Darwinian selection mechanism can account for it despite the absence of any identifiable biochemical pathway.
