Studying, even measuring the capabilities of an animal is science.
Justifying a soul is the purview of spirituality, not science. (Nothing against spirituality, I have a spiritual life, I just don’t confuse it with science).
Yeah, it's hard to quantify and isolate and experiment on, but that just speaks to either current limitations of human science, or possibly to limitations that cannot be surpassed. Given how much mileage certain philosophical movements have gotten out the common intuition that emerged during the Elightenment that everything is scientifically tractable, I understand the resistance to accepting these limitations and opening the door to all of the philosophical consequences of that intuition failing. But sorry, reality doesn't care about your philosophical attachments.
You really think that we’re a special case, that a difference in degree has become a difference in kind?
I personally experience a feeling that I’m conscious subjectively, but I have no evidence that I’m any more or less motivated by pleasure or pain or community than a dolphin is.
Where do we draw the line? What’s the acid test for “yup now we’re dealing with consciousness”?
Descartes was a genius, but he was no Alan Turing, and Alan-fucking-Turing got it wrong on the most famous thing named after him (among the lay population at least). The Turing Test was a great idea, but it’s now trivially useless.
Humans are special to (mostly) themselves and (substantially) other humans.
They are not special to the universe. We’ve had this argument, it was called the “Inquisition” at least once, and we eventually cleared up once and for all what celestial body rotates around the bigger one.