Answer my question. What reason do you have for thinking this isn't just a case of water running downhill and finding the path of least resistance.
The experiment was designed to provide one very narrow and specific environmental challenge. It was also designed to create a winner in a competition.
When you provide a narrow criterion for success, you get the same results from any stochastic process.
I'm not asserting this has to be the case here. I'm just saying there isn't any reason to believe it isn't.
I answered your question.
Now a few for you.
How many base pairs in the target gene?
What is the mutation rate per generation?
How many bases were impervious to mutation?
Question authority js. :-}