Recently while visiting family in South Texas, I was jogging through an old neighborhood and noticed something very interesting. Along this particular street, there was a track on one side and a row of homes on the other side. To my surprise, the curb along the track was interrupted every hundred feet or so by concrete structures that appeared to be driveways. But unlike the driveways on the other side of the street that terminate at garages and carports, these driveways terminated just beyond a chain-link fence (see picture).
Let’s think about this: driveways are designed to allow vehicular access from the street, but fences are designed to keep traffic out. So what kind of intelligent designer would put short driveways under a fence that terminate at grass? The question is obviously rhetorical since there never was a deliberate plan to create such features. In other words, nobody woke up one day and said, “I think it would be neat to put partial driveways along a field and block them with a fence.” In fact, that side of the street was once lined with houses just like the other side. The school across the field annexed the land next to it, leveled the houses, built a track, and put a fence around it. Since reworking the curb and concrete ramps for cosmetic purposes would have consumed valuable resources, the school simply left the vestigial driveway pieces in place. Mystery solved.
But what if somebody wanted to believe instead that the street, the house, the track, the chain-link fence, and the useless driveways were all designed and built just as they are today? In other words, what if these useless driveway-like structures were the result of deliberate planning rather than circumstance? For the history denier, there must be a valid reason to build driveways that terminate in grass under fences. Perhaps when it rains, the water drains off the field faster because these structures act like culverts? Heck, it’s possible that engineers even considered this benefit when the decision was made to leave the old driveways in place. But regardless of their newly adapted function, nobody in their right mind would argue that these vestigial driveways were optimized for drainage. In fact, when we do find structures specifically designed for drainage, they look different than this. So despite the obvious fact that our vestigial driveways are nearly identical to the functional driveways across the street, the history denier must still claim that these relics of neighborhood evolution are culverts designed specifically to facilitate drainage.
If loss of personal credibility were the only consequence of denying history, there would be little harm in it. But what if the school decided to put a baseball diamond on the field such that the dugout is situated along the fence by the vestigial driveways? If the history deniers are in charge of the construction, somebody might get hurt. Why? Because if they proceed as though a designer built everything we see just as it is, and they assume the vestigial driveways were designed for drainage, then there is no reason to expect that utilities might be buried on that side of the street. Should they encounter any utilities while digging, the history deniers must shrug their shoulders and say, “I guess the designer put those there for some odd reason.” On the other hand, if these vestigial driveways once belonged to houses, then we should expect to find water mains, sewage pipes, electrical conduit, and natural gas lines.
Our bodies are similarly littered with sub-optimized relics of the past. The tortuous path of the recurrent laryngeal nerve, which exits the skull and loops around the aorta before innervating the voice box, makes absolutely no sense apart from the developmental pathway we inherited from fish. The "wisdom" teeth that don't seem to fit our stubby faces are also difficult explain if anatomically modern humans appeared on earth with no evolutionary precursors. In fact, nothing about human physiology and anatomy makes much sense apart from the evolutionary history we share with the rest of God's creatures. Deniers of this apparent history are not only forced to offer convoluted explanations of these vestiges, but they unwittingly undermine the life and earth sciences by destroying one of their most important organizing principles: history.
While the obfuscation of successful scientific paradigms might be an unintended consequence of the Intelligent Design movement, notice how design still played an important role in solving our driveway mystery. In fact, we concluded that our driveway-like structures were originally designed as driveways because they were clearly notoptimized for drainage. We also compared our mysterious curb with other curbs optimized for use along fields and other culverts optimized specifically for drainage. In some sense, design helped us figure out the evolutionary history of the neighborhood!
In biology, the fact that structures show evidence of design, or optimization, is no secret. You can watch any episode of Wild Kingdom and hear the narrator referring to how the cheetah is designed for speed and his teeth areoptimized for tearing flesh, etc. But sadly, when employed by the Intelligent Design movement, design becomes a polemic to reject natural history rather than a tool to discover it.