It started with men’s underwear, but eventually led me to a very strange place.
From “The underwear elves of 2012” (here):
Why mention the functional fly? Because these days many briefs etc. are made with false flies — made to look like old-fashioned men’s Y-fronts (a bit of stylist retro), but without an opening that might ruin the line of the garment. The FIZX brief and trunk offer an actual convenience to the wearer (the jockstrap is of course flyless).
First, a look at the way briefs and similar underwear have developed, to yield the current situation, in which you can’t always tell from just looking at a garment whether it has a functional fly or not. That leads to the notion of vestigial design element and to repurposing of design elements. And that takes us to features of living things, in particular functional vs. non-functional (vestigial) organs, and also to the recruitment of older structures for new purposes. There’s an analogy here between evolutionary development and the history of design elements, but it’s only a loose analogy, and I believe that evolutionary biologists and historians of design are quite clear that although there are suggestive parallels between the two, the underlying mechanisms are significantly different.
But then the Intelligent Design people enter the picture, and things fall apart into remarkably confused thinking, a mess that I’m at a loss to make sense of.