Does the fact that many non-human animals have pituitary disprove Cartesian Dualism?

[FlatAssembler]

There's some nuance to the debate.  Some would contend that's not pain.  Just about every living thing responds to stimuli.  Pain is on top of that.  That's why we look for analog structure.  The closer to us, either by lineage or structure, the more credible the supposition of pain.  Personally, I take the most cautious position.  If you're wondering whether or not it could feel pain, treat it like it can.

Take a look at slaughterhouse bmps over the past few decades.  Quick kills, screens, noise suppression.  None of it to make us feel better about it, they still have to rotate people through the positions.  The cattle might not be aware anymore but we are.  It's done because the product is better, end of.  If just watching an animal in pain didn't suffice...that there are physical differences in the end product between an animal cruelly killed and an animal humanely slaughtered is proof enough for me that at least some animals are just as awash in chemicals and neural activity as we are under similar circumstances.

I'm particularly careful with fish...all my redneckbros laugh at my gear.  I actually think there's something to the objection of whatever they're feeling as pain, as we understand pain - but it doesn't hurt to be nice - you've already got em hooked.  They're fragile and not meant to be handled anyway.  Whether you're trying to get them back in the water or onto a plate, handle like a carton of eggs and you'll achieve best results.  I've got a customer that can spot bruised fish at a glance.  It wouldn't surprise me if he had ethical objections to the mistreatment of livestock..but I also suspect that, like the slaughterhouse above, even if he didn't he'd still reject a bad ice pack.

The moderator of the Philosophical Vegan forum, brimstoneSalad, thinks similarly to you. He thinks that the philosophy of mind and neuroscience is mostly irrelevant to ethics, short of a proof beyond reasonable doubt that some animal doesn't feel pain (which he thinks is proven for bivalves, but not for naked mole rats). He thinks that the reason human beings have rights is not because we are absolutely certain they are sentient, because we cannot be absolutely certain of that, as science can't prove solipsism wrong. So he thinks animals have rights as long as we cannot be reasonably certain they don't feel pain. And he thinks it hasn't been proven beyond reasonable doubt that fish or insects don't feel pain, so they should also have rights.