It is amusing to watch all this dialog about irreduceable complexity, as if it had suddenly been "discovered" by the Intelligent Design "movement." William Paley (1743-1805) spoke of this very thing in his Natural Theology, showing how ecological interrelationships and interdependences made no sense under evolutionary assumptions; but he did not have the tools then to extend his argument all the way into topics like mitochondrial processes, the intricacies of repair and replication of DNA or RNA etc.
Evolutionists used to reject the teleological argument (design logic) until, they said, someone could show that certain natural assemblages in nature had a machinelike quality. Modern biochemistry has now shone exactly this--over, and over, and over.