I’ve long thought that the defeat of intelligent design theory lay not in complicated scientific proofs, but simply in forcing people to actually look at the design that their creator supposedly gave us.
A quick look at the human body shows not a miracle, but rather a kludgey system that barely keeps running at the best of times and breaks down spectacularly at the worst of times. Heck, even kludge is too nice a term for some aspects of the human body. A Rube Goldberg device might be a better analogy in some cases.
Take, for example, the human eye, which is often touted as being so complex that it must be made by an intelligent designer. As I’ve noted previously, our eyes are actually installed upside down, backwards, and with a blind spot! Which is the sort of design one might expect if you let me do it, but…
Someone (I wish I could remember who) once pointed out to me that the maxillary sinus cavity is another terrible bit of design. It has to drain upward against gravity, which it frequently fails to do, leaving tons of people (including one I might be related to ::waves::) with constant infections that are difficult to treat and nearly impossible to eradicate.
Menstruation is another ridiculous idea. I mean, besides the discomfort and need to sop up bodily fluids for 5-7 days every month (which is bad enough), a woman’s body spends 30-40 years wasting resources on preparing the body for pregnancy every single month.
That’s calories and iron stores that could be going toward keeping her body healthy, but are instead flushed out of the body. Surely an intelligent designer could have come up with something cleverer than that.
On a related topic, there’s the well-known problem of pregnancy. (Which is just one giant Rube Goldberg process on a good day.) Specifically, there’s a teensy tiny flaw in human childbirth, which is that if the baby stayed inside the mother as long as it needed to properly grow, its head would be too big to fit through the birth canal. So even what we call “full-term” babies are really born several months too early.
The problem is that humans got too smart and our heads got too big. If humans had been designed, why wouldn’t we have been designed so that a baby could stay inside through what’s often called the “fourth trimester”?
And heck, I haven’t even touched on disease. Cancer? Impossibly bad design! Heart disease? Ugh. Birth defects? Don’t even try and justify those, please, because I don’t want to hear it.
What I’m getting at is that if you insist that your deity designed human beings, you should fire him or her immediately, because they clearly are amazingly incompetent.
Alternatively, if I was a deity being accused of designing the human body, I would immediately (if not sooner) smite my followers for the grave insult.
p.s. I recommend this article at io9 for some great explanations of some other examples of unfortunate elements of the human body (like our backs). I’ve only scratched the surface of the idiocy.