‘All domestic animals and plants are genetically modified already’

There is an argument among people who, like yours truly, support (or at least are not in principle against) applications of genetic modification in plant and animal breeding that ‘all domestic animals and plants are genetically modified already’ because of domestication and breeding. See for example Food Evolution or this little video from Sonal Katyal.

This is true in one sense, but it’s not very helpful, for two reasons.

First, it makes it look as if the safety and efficacy of genome editing turns on a definition. I don’t know what the people who pull out this idea in discussion expect that the response will be — that the people who worry about genetic modification as some kind of threat will go ‘oh, that was a clever turn of phrase; I guess it’s no problem then’. Again, I think the honest thing to say is that genetic modification (be it mutagenesis, transgenetics, or genome editing) is a different thing than classic breeding, but that it’s still okay.

Second, I also fear that it promotes the misunderstanding that selective breeding is somehow outdated and unimportant. This video is an example (and I don’t mean to bash on the video; I think what’s said in it is true, but not the whole story). Yes, genome editing allows us to introduce certain genetic changes precisely and independently of the surrounding region. This is as opposed to introducing a certain variant by crossing, when other undesired genetic variants will follow along. However, we need to know what to edit and what to put instead, so until knowledge of causative variants is near perfect (spoiler: never), selection will still play a role.