Sometimes a headline gives you practically the entire story. Take this one: "Gene-Editing Unintentionally Adds Bovine DNA, Goat DNA, and Bacterial DNA, Mouse Researchers Find." The writer details how this happens, of course. And, there is an important subtext. The problem is chalked up by scientists and regulators to incompetence on the part of the company doing alterations to create cattle without horns.
But the real news is this according the author: "[F]oreign DNA from surprising sources can routinely find its way into the genome of edited animals. This genetic material is not DNA that was put there on purpose, but rather, is a contaminant of standard editing procedures." [My emphasis.]
At the risk of sounding like a broken record (remember records?), as Garrett Hardin, the author of the first law of ecology, reminds us, "we can never merely do one thing." Why is this truism so hard to accept, so hard that I feel compelled to refer to it in consecutive posts? The simple answer is that as long as there is profit in ignoring it and as long as it is possible to pass the bad consequences on to others, people will act as if Hardin's first law was never spoken.