The problem with this, of course, is that these "gaps" often continue to shrink over time, and as our understanding of the world around us expand and improve. The ancient civilization used to think that the moving clouds, the eclipses, the ebb and flow of ocean tides, etc., were all due to some act of gods, because they didn't have any knowledge of what caused them. Now, we know better and these events are no longer mysterious or mystical.
And that's where we come back to the ID crowd. More often than not, they lack the necessary scientific evidence to strengthen their arguments. And when they try, the only people they could convince are people who really are not well-equipped to actually decipher the science. This appears to be the case of the latest book titled "Darwin's Doubt" written by Stephen Meyer, who runs the Discovery Institute. He's a non-biologist, who is trying to argue that the rapid explosion of animal phylia in the Cambrian period cannot be explained via the slow and tedious process of evolution, and thus, via invoking the god-of-the-gaps, points to evidence of an intelligent designer.
Whenever someone brings up a scientific point, it must be countered with equivalent scientific point. And this is exactly what has been done in this case. A review of this book written by UC Berkeley's Charles Marshall in this week's issue of Science (Science, v.341, p.1344 (2013)) did just that. In this review, Marshall pointed out several flaws in the biological/scientific points presented in Meyer's book.
However, my hope soon dissipated into disappointment. His case against current scientific explanations of the relatively rapid appearance of the animal phyla rests on the claim that the origin of new animal body plans requires vast amounts of novel genetic information coupled with the unsubstantiated assertion that this new genetic information must include many new protein folds. In fact, our present understanding of morphogenesis indicates that new phyla were not made by new genes but largely emerged through the rewiring of the gene regulatory networks (GRNs) of already existing genes (1). Now Meyer does touch on this: He notes that manipulation of such networks is typically lethal, thus dismissing their role in explaining the Cambrian explosion. But today's GRNs have been overlain with half a billion years of evolutionary innovation (which accounts for their resistance to modification), whereas GRNs at the time of the emergence of the phyla were not so encumbered. The reason for Meyer's idiosyncratic fixation with new protein folds is that one of his Discovery Institute colleagues has claimed that those are mathematically impossibly hard to evolve on the timescale of the Cambrian explosion.
In other words, this scientific argument doesn't hold water.
Unfortunately, and I can see this happening often, the counter argument to this book will not reach those who should be aware of it. The same with the perpetual argument that evolution violates the 2nd law of Thermodynamics, those who belief in ID will use this as the scientific argument against the evolution of life on Earth, without being aware of the holes in Meyer's book.
But at least now, you know that there is a scientific counter argument to what Meyer has brought up, and you can point to this Science review article.