Yes, I'm using "natural lifespan" here as a placeholder for "the typical lifespan assuming nothing is actively trying to kill you." It's not great language, but I don't think it's obviously tautological.

The shark's "natural" lifespan requires that it eats other creatures. Their "natural" lifespan requires that it does not.

Yes. My question is whether that's a system that works for us.

If you eliminate some species because you think they're mean, you're going to damage a lot more.

I'd just like to point out that (a) "mean" is a very poor descriptor of predation (neither its severity nor its connotations re: motivation do justice to reality), and (b) this use of "damage" relies on the use of "healthy" to describe a population of beings routinely devoured alive well before the end of their natural lifespans. If we "damaged" a previously "healthy" system wherein the same sorts of things were happening to humans, we would almost certainly consider it a good thing.

I like Beyond Meat, but I think the praise for it has been overblown. For example, the Effective Animal Activism link you've provided says:

[Beyond Meat] mimics chicken to such a degree that renowned New York Times food journalist and author Mark Bittman claimed that it "fooled me badly in a blind tasting".

But reading Bittman's piece, the reader will quickly realize that the quote above is taken out of context:

It doesn’t taste much like chicken, but since most white meat chicken doesn’t taste like much anyway, that’s hardly a problem; both are about texture, chew and the ingredients you put on them or combine with them. When you take Brown’s product, cut it up and combine it with, say, chopped tomato and lettuce and mayonnaise with some seasoning in it, and wrap it in a burrito, you won’t know the difference between that and chicken.

I like soy meat alternatives just fine, but vegans and vegetarians are the market. People who enjoy the taste of meat and don't see the ethical problems with it don't want a relatively expensive alternative with a flavor they have to mask. There's demand for in-vitro meat because there's demand for meat. If you can make a product that tastes the same and costs less, people will buy it.

Maybe it's likely impossible to scale vat meat such that it is actually cheaper to produce, long-term, than meat from conventionally-raised livestock. Has this sort of analysis been done? I'd assume from the numbers New Harvest quotes - 45% reduction in energy use, 95% reduction in water use, etc. - that it is actually possible.

If you put vat meat on a styrofoam plate with a label with a big red barn on it and a cheaper price tag than the stuff next to it, people almost certainly will buy it. If consumers were that discerning about how their meat was produced, they wouldn't buy the stuff that came from an animal that spent its entire life knee-deep in its own excrement.

If AMF can add about 30 years of healthy human life for $2000 by averting malaria and a human is worth 40x that of a chicken, then we'd need to pay less than $1.67 to avert a year of suffering for a chicken (assuming averting a year of suffering is the same as adding a year of healthy life, which is a messy assumption).

This might be a minor point, but I don't think it's necessarily a given that one year of healthy, average-quality life offsets one year of factory farm-style confinement. If we were only discussing humans, I don't think anyone would consider a year under those conditions to be offset by a healthy year.

Do you consider young children and very low-intelligence people to be morally-relevant?

(If - in the case of children - you consider potential for later development to be a key factor, we can instead discuss only children who have terminal illnesses.)

We're treading close to terminal values here. I will express some aesthetic preference for nature qua nature.

That strikes me as inconsistent, assuming that preventing suffering/minimizing disutility is also a terminal value. In those terms, nature is bad. Really, really bad.

I also recognize a libertarian attitude that we should allow other individuals to live the lives they choose in the environments they find themselves to the extent reasonably possible.

It seems arbitrary to exclude the environment from the cluster of factors that go into living "the lives they choose." I choose to not live in a hostile environment where things much larger than me are trying to flay me alive, and I don't think it's too much of a stretch to assume that most other conscious beings would choose the same if they knew they had the option.

Absent strong reasons otherwise, "do no harm" and "careful, limited action" should be the default position. The best we can do for animals that don't have several millennia of adaptation to human companionship (i.e. not dogs, cats, and horses) is to leave them alone and not destroy their natural habitat.

Taken with this...

We need to value the species as a whole, not just the individual members; and we need to value their inherent nature as predators and prey.

...it seems like you don't really have a problem with animal suffering, as long as human beings aren't the ones causing it. But the gazelle doesn't really care whether she's being chased down by a bowhunter or a lion, although she might arguably prefer that the human kill her if she knew what was in store for her from the lion.

I still don't know why you think we ought to value predators' "inherent nature" as predators or treat entire species as more important than their constituent individuals. My follow-up questions would be:

(1) If there were a species of animal who fed on the chemicals produced from intense, prolonged suffering and fear, would we be right to value its "inherent nature" as a torturer? Would it not be justifiable to either destroy it or alter it sufficiently that it didn't need to torture other creatures to eat?

(2) What is the value in keeping any given species in existence, assuming that its disappearance would have an immense positive effect on the other conscious beings in its environment? Why is having n species necessarily better than having n-1? Presumably, you wouldn't want to add the torture-predators in the question above to our ecosystem - but if they were already here, would you want them to continue existing? Are worlds in which they exist somehow better than ours?

We have neither the knowledge nor the will to protect individual, non-pet animals.

We certainly know enough to be able to cure their most common ailments, ease their physical pain, and prevent them from dying from the sort of injuries and illnesses that would finish them off in their natural environments. Our knowledge isn't perfect, but it's a stretch to say we don't have "the knowledge to protect" them. I suspect that our will to do so is constrained by the scope of the problem. "Fixing nature" is too big a task to wrap our heads around - for now. That might not always be the case.

When you ask, "Assuming that these environments are (or would be) on the whole substantially better on the measures that matter to the individual living in them, why shouldn't we?" it's not clear to me whether you're referring to why we shouldn't move humans into virtual boxes or why we shouldn't move animals into virtual boxes, or both.

Both.

If you're talking about humans, the answer is because we don't get to make that choice for other humans. I for one have no desire to live my life in Nozick box, and will oppose anyone who tries to put me in one while I'm still capable of living a normal life.

Then that environment wouldn't be better on the measures that matter to you, although I suspect that there is some plausible virtual box sufficiently better on the other measures that you would prefer it to the box you live in now. I have a hard time understanding what is so unappealing about a virtual world versus the "real one."

If you're referring to animals, the argument is similar though more indirect. Ultimately humans should not take it upon themselves to decide how another species lives.

This suggests to me that you haven't really internalized exactly how bad it is to be chased down by something that wants to pin you down and eat parts of you away until you finally die.

The burden of proof rests on those who wish to tamper with nature, not those who wish to leave it alone.

To prove what?

We need to value the species as a whole, not just the individual members; and we need to value their inherent nature as predators and prey.

Why?

While zoos have their place, we should not seek to move all wild creatures into safe, sterile environments with no predators, pain, or danger any more than we would move all humans into isolated, AI-created virtual environments with no true interaction with reality.

Assuming that these environments are (or would be) on the whole substantially better on the measures that matter to the individual living in them, why shouldn't we?

That seems plausible, though PETA already has a million-dollar prize for anyone who can mass-market an in-vitro meat product. Given their annual revenues (~$30 million) and the cost associated with that kind of project, it seems like they're going about it the wrong way.

From a utilitarian perspective, wireheading livestock might be an even better option - though that probably would be perceived by most animal activists (and people in general) as vaguely dystopian.

By the way. One question I always wanted to ask a pro-animal-rights type: would you support a program for the extinction/reductions of the population of predatory animals on the grounds that they cause large amounts of unnecessary suffering to their prey?

I've heard this posed as a "gotcha" question for vegetarians/vegans. The socially acceptable answer is the one that caters to two widespread and largely unexamined assumptions: that extinction is just bad, always, and that nature is just generally good. If the questioned responds in any other way, he or she can be written off right there. Who the hell thinks nature is a bad thing and genocide is a good thing?

But once you get past the idea that nature is somehow inherently good and that ending any particular species is inherently bad, there's not really any way to justify allowing the natural world to exist the way it does if you can do something about it.