The inoperative Vitamin C gene in humans and apes is "junk". Since the last common ancestor to humans and apes lost the ability to fabricate Vitamin C (primates having a high Vitamin C diet, so the gene was not necessary for survival), that gene has acquired more DNA trash over the ages. Study of that specific gene sequence, and the number of mutations it has acquired away from a functional gene, can be used to map the evolution of primate species, and provide evidence for dating.
Evolution theory would predict that these mutations would map according to other morphological changes in primates, and the dates of the divergence. And indeed the changes do map the earlier conclusions. The predictive power of Evolution theory was demonstrated once again.
It's too bad that the ID hypothesis gives no predictions. It would be cool to know what the Designer of the universe had in mind, or perhaps what techniques we could deduce, and perhaps copy, from the Designer. Unfortunately that road is barren.
The amount of inoperative structural genes is extremely modest compared to the regulatory genes that MAKE them inoperative. Regulatory genes: that's the ticket.