Dr. Abby Hafer is a zoologist and anatomist. She (figuratively) took a jackhammer to “intelligent design,” focusing on five aspects of human anatomy. In each case she showed not only how the design is not optimal, but how better design would be perfectly possible and in fact is seen in other animals.
TESTICLES – They have to hang outside the body because the body’s temperature is too high for sperm production. Putting such a valuable organ in such a vulnerable position is bad design. Cold blooded animals don’t have this problem; their testicles are tucked safely inside.
Dr. Hafer explained that good enough is the design standard in evolution by natural selection. That is, the design need only be good enough to get the animal to reproduce. Testicles meet this unambitious criterion – most men don’t lose their balls before using them. In contrast, the design standard for an intelligent (indeed, infallible) designer should be far higher (especially, one might add, if this particular designed creature is in his image.) But maybe he flunked Design School.
BABY CROWNING – A human baby has to realllllly squeeze through the birth canal. This often kills the baby, the mother, or both. Why are we built like this? Because walking upright favors narrow hips, while being smart favors big heads. Women’s hips are just barely wide enough to enable birthing big-headed babies. Usually. Good enough. Barely.
Might a better design solution have been possible? Sure – kangaroos! They have it easy. The Creator must have liked them better than humans.
CHOKING: Our air passages and food passages interconnect with sometimes fatal results. Other animals have separate passages and cannot choke to death on food.
A lot of good, actually. Dr. Hafer showed many examples of creatures with much more primitive light-sensitive organs which still provide them with survival advantages.
Meantime, the human eye is not so great after all. That screw-up designer of ours inexplicably put the wiring in front of the light-sensitive parts, blocking some of the light, and also bunched the optic nerve fibers to cause a blind spot. The result is that we can’t see well in dim light, and our brains must do a lot of “photoshop” type work to collate and make sense of the images, with resulting loss of information. Animals like squids have much better eye design. (And wouldn’t an intelligent design include a third eye in back of our heads?)
THE APPENDIX: The killer argument. And the killer organ – literally. The appendix has no function – and sometimes kills its bearer. It once had a function (in rabbits it’s useful for digesting wood; as evidenced in my home’s woodwork, from when my daughter had rabbits) – and it remains as a vestigial organ because evolution hasn’t had enough time to get rid of it. If you were designing a human being from scratch, you certainly would not include an appendix. This is really bad design.
The stock answer to all this, the last redoubt of the “intelligent design” adherent, is to say, “Well, that’s the way God wants it.” If you want to believe that, fine. But it’s not science!