Okay so I thought the "Vulcans are cats!" thing was just fun silly Tumblr headcanon being Tumblr headcanon, like how it's very popular here to draw Trek species with tails. But I am realizing slowly that people here really do actually think Vulcans evolved from cats in Star Trek canon.
I saw a reply thread in which people were talking about "Vulcans" while actually describing the background and legal situation of the Caitians and Kzinti. That's how I realized you all were serious. I can kinda understand this confusion. There's parallels to the Vulcan-Romulan split in that these are two species who uh... split. They're both psionic species who have violent pasts. But they're not related to Vulcans.
As far as I know, the only source on Vulcan evolution is Spock's World, and their ancestors are described as hominids indistinguishable from our own primate evolutionary ancestors aside from their green blood. There are entire chapters in Spock's World revolving around them being semi-arboreal hominids. Their most catlike feature (double eyelids) isn't a natural part of their normal evolution, but is the result of strategic eugenics projects after they reached their modern form during their early Bronze Age. Ancient Vulcans fought wars to arrange bondings to get them. There are also several chapters in Spock's World about this.
Vulcans being evolutionary quite similar to Humans is thematically important. This is why we freak out the Vulcans and Romulans so badly. This is like... the entire point of 'The Chase' and the Progenitors. The other option we are given in canon is a connection to the Arettans / Arettians, also not cats, who resemble both Vulcanoids and Deltans.
If there's a different novel or episode that discusses Vulcans' evolutionary history and says they are cats, please let me know. I have literally never seen anyone insist on this until I joined Tumblr and you're all saying it as if it's fact, so I'm really interested to learn where it's from.
