Most people know that animal breeding has a long history. At least since the Neolithic revolution, and probably in some fashion earlier if you consider that dog-human interaction/co-evolution dates to the Pleistocene. In some ways this is not always a good thing, when you consider flourishing from the perspective of the animal. It is a well known fact that when you keep selecting on one particular trait of an organism, there tend to be “correlated responses.” That’s because traits are interrelated, sometimes in a direct structural sense, and sometimes due to common genes. In nature these correlated responses often prevent excessive deviation from optimal fitness. E.g., if you make mice too big they can’t breed.
But outside of natural circumstances all sorts of things can happen under human tutelage. That’s how we get grotesquely large chickens with breasts so unwieldy that they can’t walk. And, it’s how we get “cute” cats like the Persian breed who are well known to have issues with conventional mastication. The point is that conventional quantitative genetic breeding methods can lead to “monsters,” because there are plenty of mutations floating around in natural populations. There’s nothing exotic, and even before understanding the genetic basis of inheritance humans were engaging in this sort of activity for thousands of years.
All this is something you have to keep in mind when reading articles such as this in The New York Times, Open Season Is Seen in Gene Editing of Animals. Basically, probably triggered by the FDA approval of genetically modified salmon, there is now a lot of discussion around genetically modified organisms of the animal kind. The New York Times piece opens with an interesting twist:
Other than the few small luxuries afforded them, like private access to a large patch of grass, there was nothing to mark the two hornless dairy calves born last spring at a breeding facility here as early specimens in a new era of humanity’s dominion over nature.
But unlike a vast majority of their dairy brethren, these calves, both bulls, will never sprout horns. That means they will not need to undergo dehorning, routinely performed by farmers to prevent injuries and a procedure that the American Veterinary Medical Association says is “considered to be quite painful.”
If you read the whole article thought it is clear that what the new techniques are doing is supercharging the aims and methods of conventional breeding. In many cases there isn’t even going to be any transgene that moves between species. Rather, researchers may want to create specialized knock-outs, which lack gene function.
Bioethicists and animal rights organizations may suggest there are new ethical questions which are confronting us, but there really aren’t. Using traditional breeding techniques humans are already producing animals whose faces barely close in (many flat-faced cats basically have a hair-lip), or which need caesarian section to give birth. We’ve been confronting these questions for a while now, and better genetic modification techniques just amplify them, or, with greater precision allow ways to ameliorate some of the unfortunate side effects by offering more options.