First, I started a thread on information for you and tried to answer your question.
Second, would your little nylon-eating organisms survive in the wild? No. However, I will say that it is an incredible example of the ability to vary that God put into those little suckers! They would die out in the wild with that competition and, probably, no man-made nylon, but the fact that they had what it took to produce that sort of variation is truly amazing.
My friend did not mix up anything, either. When the degrading of an ability is all that evolutionists can come up with to support evolution, they have a major problem on their hands, for the thrust of the evolutionary argument is that complexity arose with time and chance and natural selection. The loss of that complexity is not an issue at all! It not only is not what evolutionists need to support their argument, it is not even a matter of dispute! We know functions and pieces can get lost. There is no mystery there! Trying to use is as part of a reasonable argument for evolution is simply silly. You are using something no one is arguing about as 'evidence' for something which is its opposite!
Now, what would prove evolution to me? Something past the limits of simple variation within a kind. Something which would cause a biologist to say, "Now this is something new. This can no longer be considered to be in the taxonomic family of XXXX" Get me a change past species and genus. The reason I keep bringing up E.coli is that this change has not occurred even with all the encouragement we can give, in over a hundred years, or over 2.5 million generations. So I doubt sincerely that if we cannot get a simple prokaryote to change with that much encouragement over than many generations that you will be able to get anything else to change.
But that is what evolution is all about, and that is what would prove it. Keep in mind that NO ONE is arguing variation within a kind. Yet that is all evolution can come up with.
You will complain that you need time. Take it. How many generations do you want? Take the simplest form of life you can (that is why I referred to E.coli) and get the sucker to mutate away from kind and survive and reproduce.
THEN I will take evolution seriously.
Don't forget that I used to believe in evolution and, what is more, teach it. I'm not a babe in the woods here.
Good luck!