This article is talking about mutation. Two of them in fact. The E Coli adapted to a reduced food supply by mutations that allowed for additional food stuffs to be consumed. New food stuffs that were before unusable. At the same time it retained the ability to continue obtaining sustenence as it always had. It's absolutely fascinating. And even moreso that the same 2 mutations occured in 2 seperate colonies.
What evidence do they have that this is a mutation at all and not just an expression of a rare recessive trait that multiplied when the food supply was reduced? I'm guessing that they didn't test the entire population for the gene in question. Just because they haven't seen in before doesn't mean it wasn't there. It would be impossible to recognize until the dominant ones were removed.
Mapping DNA is pretty common nowadays, it should be fairly easy to tell if this was genetic "mutation" or "recessive gene" that was already present before the experiment started.
"Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence". John Adams
"A dishonest man can always be trusted to be dishonest". Captain Jack Sparrow
