I imagine it might be much tougher to design a full animal without a brain. You'd always be on the line between it not being able to stay alive due to loss of functionality, or, in the other direction, possibly having some degree of thinking/consciousness. This on top of the fact that we'd need a far better understanding of brains and genetics to ever hope to engineer such a thing.
If it did exist, I think it'd not only be more ethical to kill it but that it'd be (hypothetically) completely ethical. I don't think it would be an animal. It gets a little weird, though, because one would have to also accept that you could hypothetically use a similar process to create brainless humans and that it'd be fine to kill and eat them if you wanted to. Or do whatever else you wanted to them. That human also wouldn't be an animal.
Modifying an existing organism might be much easier, and removing higher functions might be enough, depending on what we know now or later about the brain.
Is what makes eating an animal and a plant different for most people what constitutes their mass, or how we perceive them to think and feel? Making them not think and feel (and at the organism level, not the removal of that potential in an individual after birth) may be a path forward.
As a hypothetical, to bring it back to humans, and divorce it from reproduction which might have emotional baggage in many peoples reasoning, imagine a person with a tuberous growth that was removed, but we can cause it to continue to grow outside the body. If it's confirmed safe to consume, are there ethical problems with that person eating their own cells? What about other people?
I don't see why there would be. I think there'd just be psychological (perhaps biologically/socially-ingrained) "disgust" problems. It's not unethical to eat your own skin tags or to eat other people's skin tags, but most people won't find the idea appetizing (unless they're on the brink of starvation, perhaps).
>Modifying an existing organism might be much easier, and removing higher functions might be enough, depending on what we know now or later about the brain.
It still sees like it'd be very hard to know for sure, though. Obviously I'm no expert, and perhaps no one, including experts, can say such a thing with confidence, but I suspect that consciousness is integrated way too deeply in animal brains to the point that you can just remove some of the more modern/advanced parts and get rid of all of it.
For example, if you lobotomize a human (i.e. sever many/most connections between the prefrontal cortex and the rest of the brain), you remove most of the higher functioning capability, but they're probably still conscious.
I think you'd either have to change so much of the brain in so many ways such that it'd be very easy to mess something up and prevent it from staying alive for long, or you'd have to risk that you're just making dumber/less sensitive and reactive yet still possibly conscious beings.
I'm way more optimistic about the dead tissue growth idea (unfertilized eggs, tumors, etc.), or perhaps some other route entirely that hasn't been discovered yet. Maybe in a few centuries they'll devise a way to make humans fully autotrophic, with some layer of cells injected into the skin + some mechanism to use photons and air molecules as fuel to generate needed compounds, so you'd just need an hour of sunlight exposure per day to get all the energy and nutrients you need.
“You mean this animal actually wants us to eat it?” whispered Trillian to Ford.
“Me?” said Ford, with a glazed look in his eyes, “I don't mean anything.”
“That's absolutely horrible,” exclaimed Arthur, “the most revolting thing I've ever heard.”
“What's the problem Earthman?” said Zaphod, now transferring his attention to the animal's enormous rump.
“I just don't want to eat an animal that's standing here inviting me to,” said Arthur, “it's heartless.”
“Better than eating an animal that doesn't want to be eaten,” said Zaphod.
“That's not the point,” Arthur protested. Then he thought about it for a moment. “Alright,” he said, ``maybe it is the point. I don't care, I'm not going to think about it now. I'll just ... er ...”
But let's say we map all the pain receptors and pain-like receptors(like loneliness) and engineer a chicken without those or with them blocked ?
It's a doable thing with today's tech,similar things are already been done to lab mice. hopefully that chicken lives.
Would it be ethical to kill such a chicken?
Ultimately, with an approach like this it might be best bit to think of it as "modified cow/chicken/pig" but instead survey different animals to find some that already have fast and/or efficient growth phases that might already have some benefits.
I understand this is a hard sell for a lot of people, even if you just look at swapping out staple meats which this might require. Ultimately, we're probably served better by a bunch of different options than one giant monoculture of meat production, so there may be a place for everything.
So something like bamboo rhizome constantly growing an meat trunk, using either photosynthesis & minerals (plant-based) or plant mush (fungus-based) as source materials.