"However, this one can be traced back quite far enough to cause any young earth creationist great discomfort."
I don't think so......i'm sure not feeling any discomfort by all this rambling by evolutionary biologists.
Did you know the odds are 10(161) to 1 that not one usable protein would have been produced by chance in ALL THE HISTORY of the earth. Note this is a figure containing 161 zeroes. It might be well to recall that even if one molecule were obtained, it would not help at all in arranging the second protein molecule unless there existed an accurate duplication process. Even if there were such a process, there are many other kinds of proteins needed before there can be a living organism. Did you know that in a minimal cell, the 239 protein molecules required include at least 124 different protein species.
So all your neat little hypotheticals are not based on facts just philosophical meanderings.
The probablility of forming one protein molecule by chance is one 10 to the 243rd power..that is a figure of 1 followed by 243 zeros. A fraction so small that one may say the probability is zero.
Well, perhaps I should have said "any rational young earth creationist."
Please produce a source for your calculations.
Experimentation has actually shown that in a random library of DNA sequences enough will code for functional proteins to make the origin of new functional proteins by random means in early life forms quite plausible.
And it is hypothesized that we start with RNA, not proteins. Perhaps you should go review your cell biology--ribosomal RNAs are the engines behind protein synthesis.
By the way, I'm making a mental note that I have now repeatedly given you plausible mechanisms for the invention of new genes so that I can reproduce the same evidence next time I come across you asking this same question again. . .