If we and nature are the products of "intelligent design", then why are so many of our features so poorly put together? For example, the human appendix serves no useful function. Every now and then, someone's appendix becomes inflamed and has to be removed. If it bursts, the infection can be so bad that the patient could die. If we're the product of intelligent design, why do we have a useless organ that can kill us? For that matter, why don't we have better eyesight, better hearing, and better designed knees?

Humans aren't the only creatures with faulty design features. I read an article years ago on this topic that used the panda's thumb as an example of poor design to show that evolution was a more likely answer for that particular feature.