Defender's Guide to Science and Creationism

Mark Vuletic

Assertion

The perfection of structures like the human eye is proof of creation.

The short response

Everything in the biological world is imperfect, the human eye included, so the premise is false.

The long response

Although workable to a degree that is consistent with evolution, the human eye is imperfect. As is the case with all vertebrate eyes, the retina of the human eye is inverted, with the photoreceptors (the cells that detect light) face away from the iris and their wiring (so to speak) points into the center of the eye. While this inversion may have some advantages, it necessitates a hole in the retina through which the wiring attaches to the optic nerve, creating a blind spot in the visual field of each eye. Although normally not noticeable, there are circumstances under which these blind spots can cause us to fail to see something.

The normal blind spots are, of course, not the only imperfections of the human eye, or even the most obvious ones: our eyes suffer from all of the normal afflictions of the human body, including vulnerability to trauma, to disease, to aging, and to wear and tear. These are normal things to expect from the products of unguided natural processes, but not what one consider the perfect engineering of a creator god. Remember that when people talk about a creator god, they are talking about a being whose power supposedly is unlimited, unconstrained even by the laws of nature themselves; had such a being wished to make our eyes out of some invulnerable quintessence (with no blind spots), there would have been nothing to stop him. One might hold that the eye originally was perfect, and that God later introduced deficiences into it when he banished Adam and Eve; however, this would still undermine the claim under analysis, since the claim is about the eyes that we have now.

Imperfect engineering is apparent in far more than the human eye, and extends beyond the normal vulnerabilities of flesh. Useless or inefficient structures that appear to be relics of distant ancestors abound in the natural world; for instance, there are the hollow bones of flightless birds, the clumsy thumb of the giant Panda, and the vestigial pelvis of pythons and whales (Futuyma 1983:198-200). Nothing in the natural world is perfect.

I discuss elsewhere the claim that the eye could not have evolved gradually, and the claim that Darwin himself thought that the eye could not have evolved.

References

Futuyma DJ. 1983. Science on Trial: The Case for Evolution. New York: Pantheon.

Last updated: 18 Mar 2017

Comment
Pleased? Angered? Confused? Have something else you would like
me to write about? Please send in your questions and comments!