A species is not some kind of treasured unique token. It's not a thing. It's a process. It only seems like a thing because humans like to find patterns and give them names.
Outside of practical considerations wrt. biodiversity, why should we care? I mean, if you don't think individual members of a species are entitled to a good life, or at least life free of needless cruelty - then why would you care about their species? Conversely, if you think the species should be saved for reasons other than entertainment or practicality, then I think it only makes sense if you think individuals of that species deserve better conditions.
This is philosophical BS. A species is a species. Is a technical term [more or less] well defined that is the basis of all live sciences. Is also the product of millions years of evolution so when lost, is irreplaceable.
> Why should we care
This is exactly the problem, that animalist evangelists don't care. They do it just for the dopamine rush and the sweet money while avoiding carefully to notice the negative consequences of their acts.
Animalists have a tunnel vision focused in individuals and about not activating a particular random type of receptors (that evolved as a life-saving mechanism). They are blind or cynical about everything else. When we scratch the surface there is a lot of cargo cult ideas, tons of magical thinking and very outdated XVII century scientific knowledge. With luck we can see a thin and unstable crust of real knowledge on life sciences at most.
You've not actually answered the relevant question: Why care about species, but not about individual suffering?
There is no sensible answer, because your emotional attachment to the consumption of dead animals, and the very understandable resistance to the idea that you may have supported (and continue to support) needless cruelty of immense proportions has made you blind to "the negative consequences of [your] acts".
On the practical side, since you supposedly care so much about species: Have you ever put any thought to the idea that all the ecological destruction we cause, just to feed the 7 billion animals of a handful of species, has destroyed far far far more species than it has "saved"?
> This is philosophical BS. A species is a species. Is a technical term [more or less] well defined that is the basis of all live sciences.
On the contrary, most of philosophical BS starts from a mistaken belief that categories are a thing. They're not. They're just fuzzy selectors. A "species" is a technical term, and so is a "chair" or a "rivet". Good enough, as long as you don't zoom in on it too closely. If you do, you'll find the boundary of the category is fuzzy (and if you ask another person to zoom in with you, you'll discover your fuzzy boundaries don't fully overlap).
The "basis of life sciences" you refer to is a historical artifact. People like to categorize and give names to things. They did so according to their practical needs and tools they had. We have better tools now - particularly ones that let us see how life ticks. Genetics is pretty much upending the old taxonomy "that is the basis of all live sciences", because up until ~100 years ago, we had no first clue what's actually going on.
And if you look at what the modern life sciences discover, you'll see that organisms indeed break the usual definition of "species" in every possible way.
In a way, species not being a thing is also fundamental to evolution - after all, how would one species evolve into another, if not through intermediary forms that are kinda both, and kinda neither?
> Is also the product of millions years of evolution so when lost, is irreplaceable.
Well, yes. But that doesn't immediately make it valuable. Random googling says the estimate is of about 8 million different species of plants and animals on Earth, with barely a million classified so far. That's a lot of diversity, but losing any one of them hardly matters. Something else will take its place. It may not be exactly the same, but similar enough.
If you disagree, then ask yourself why. Why value "the product of millions years of evolution"? Could it be a practical reason (e.g. it may have evolutionary adaptations or genetic patterns useful for us)? Could it be aesthetic reasons (it's pretty)? Something else? It's good to name it.
(Personally, I mostly care about biodiversity for practical reasons - primarily ecosystem stability, and secondarily medical and biotech research applications.)
Outside of practical considerations wrt. biodiversity, why should we care? I mean, if you don't think individual members of a species are entitled to a good life, or at least life free of needless cruelty - then why would you care about their species? Conversely, if you think the species should be saved for reasons other than entertainment or practicality, then I think it only makes sense if you think individuals of that species deserve better conditions.