In some sense all life has been genetically engineered by the process of vicariance, or speciation. All species have always had the potential to be more efficient, but they were not sentient, like us, and therefore unable to do anything but breed normally. For instance, the insects have had some 400 million years to gain sentience and they have not yet achieved it. If one species of insect became self aware, then they may have attempted modifying other species to be better workers, for example. The mammals are the only group with species that can claim sentience and we did it in less than 200 million years. One of the problems with sentience is that there is a tendency to eliminate competition. So if the insects did what we did, they would probably not be as diverse as they are now.
As for eating engineered food, I'm all for it. The most important thing we need is corrosive and poisonous (oxygen) and few complain about that. The air we breath is far more modified than the food we eat, I would argue. If the process of genetically engineering food had the tendency to add certain elements like mercury or europium, then a public outrage would be called for. But if they want to add mouse parts to cows or eel parts to salmon, I don't give a damn.
I would guess that evolution will one day cease to exist in the traditional sense. It's not difficult for me to picture a future where every animal did not arise by speciation. With one exception, of course. Us. An end to human existence that few people consider is one in which another kingdom gains sentience. So, it would be in our interest to carefully control what other species do, such as genetically engineering them. It's a far-fetched threat, but we know that sentience is possible.
