At the moment, when we genetically modify something we do it lots of times and pick the ones with the results we were looking for (and without results we really don’t want).
We’re also not 100% sure every gene only does one thing (in fact we know some of them do lots of things).
So if you’re working with plants or microbes, you can do this and just discard the “bad” ones, but obviously we don’t want to do that with humans.
Latest Answers