In his book The God Delusion, Dawkins discusses creationism in his chapter "Why There Almost Certainly is No God." Arguing against the ID notion of "irreducible complexity", he casts it as a fallacy in the form of The Argument from Personal Incredulity: If I can't imagine how something came about, then it couldn't have come about naturally and must have been the creation of special design. Dawkins says there are many examples where this isn't true, and cites a reference in support of his argument:
In his book Seven Clues to the Origin of Life, the Scottish chemist A.G. Cairns-Smith makes an additional point, using the analogy of an arch. A free-standing arch of rough-hewn stones and no mortar can be a stable structure, but it is irreducibly complex: it collapses if any one stone is removed. How, then, was it built in the first place? One way is to pile a solid heap of stones, then carefully remove stones one by one. More generally, there are many structures that are irreducible in the sense that they cannot survive the subtraction of any part, but which were build with the aid of scaffolding that was subsequently subtracted and is no longer visible. Once the structure is completed, the scaffolding can be removed safely and the structure remains standing. In evolution, too, the organ or structure you are looking at may have had scaffolding in an ancestor which has since been removed.Does Dawkins realize he just gave a powerful argument for intelligent design? Yes, arches are typically built by piling stones supported by a structure, then removing the structure. This is how the Romans - intelligent agents - did it. Dawkins carefully abstracts from the agent ("one way is to pile a solid heap of stones...") as though describing an intelligent process without the agent somehow magically removes the agent. This isn't the first time I've seen this kind of thing happen (citing an example of intelligent design in support of an evolutionary process); I wonder if Dawkins knows what he is doing or is simply blind to it.