I don't think it's really accurate to describe selective breeding as restricting how you can modify the underlying data. I'd rather say that the executable itse

I don't think it's really accurate to describe selective breeding as restricting how you can modify the underlying data. I'd rather say that the executable itself contains layer upon layer of consistency checks so if you modify it too much it will just refuse to "boot up." In fact selective breeding relies heavily on this mechanism since it can create hundreds or even millions of nonviable organisms for every viable organism. If the consistency checks in the natural genome don't stop you, pretty much by definition whatever you're doing could happen through an unlikely coincidence of selective breeding (especially if you involve a wild virus to take the place of the lab virus.)