In 'The Greatest Show on Earth' (which pete refuses to read because he might learn something) Dawkins devotes a chapter to intelligent design vs evolution. He shows that many anatomical structures in mammals, and other phyla, are often based on earlier structures and often involve compromises that a truly 'intelligent designer' wouldn't even contemplate - a truly 'intelligent designer' would have started again!

His examples include (among others) the nerves in a giraffe's neck and the structure (as it happens!) of the human male genitalia.