You: For example, the human appendix lives, respirates and puts out waste just like any other organ of the body does, but it doesn't do much otherwise. Can you say that the appendix was designed and placed in the body for a specific purpose? It seems rather pointless to me.
Aaron: I would not say that a useless organ was designed to be useless any more than I would argue that a broken automobile engine was designed to frustrate your mechanic. Only interaction to produce a useful result proves design. An appendix does not serve any useful purpose and therefore does not fit my criteria for a thing that necessarily proves design.