>>122715
>how and why
I have put entirely too much thought into those questions but I cannot come up with anything satisfactory. I, too, want to pull on the thread, but for story purposes the best I can come up with is that they're just there, so go with it.
I was able to come up with a few different in-universe explanations but when I try to put myself in the place of the reader they take me out of the story.
In a fantasy setting you can say "a wizard did it." Or "one of the Gods did it." No further explanation is needed. But outside of a high-fantasy setting I can't come up with much and none of it is satisfactory.
If we're talking about a setting that isn't fantasy, if anthros exist, either they evolved or they were created. Did they evolve on Earth? That seems implausible. Our ancestors killed the Neanderthals and, in at least some instances, ate them. It doesn't look like one planet has room for more than one tool-using sophont species. Ultimately they're all competitors for the same spaces and the same resources, and it's going to be a no-mercy, no-quarter, total war to extinction. If it's science fiction you can do some authorial handwaving about how they come from a parallel Earth where evolution took some very different turns during the Miocene and the dominant tool-using species is bipedal raccoons. The Procyonidae are a plausible choice here because while they don't, technically, have opposable thumbs, they do have very dextrous paws that allow them to pick up and manipulate objects in ways most animals can't, in combination with uncommon cleverness. But how'd they get here? Did they do some kind of technomagical bullshit and open portals? For what purpose? Historically, when a culture looks up and sees that people from very far away have come to pay a visit by high-tech means they never imagined, it tends to end very badly for them. The logical reason, in other words, for the Raccoon People to show up on present-day Earth is conquest. If interuniversal travel were easy we'd be doing it already. If interuniversal travel is hard, then whoever's doing it needs to recoup the investment, and historically that means with slaves and loot.
Obviously I'm glossing over some details. I read a 1990s HMOFA-ish story that is still well regarded by "the furry fandom" in which super-advanced aliens in the distant past visited Earth and used genetic samples of various species to terraform lots of habitable-ish worlds in this part of the galaxy, and also to create, via genetic engineering, lots of bipedal tool-using sophont species, which they then scattered around all over this part of the Orion Arm and abandoned. In other words, "a wizard did it." Genetically engineered anthro fobgses visit Earth, etc., and the years of effort analyzing broadcast emissions to learn a few different human languages are glossed over in favor of having a human hook up with one of them, because it's that kind of story. It's still "anthros are essentially aliens who have put enormous resources into visiting Earth, but don't question why they'd have done such a thing. Pizarro who?"
The last alternative isn't any better. Let us posit that humans, for whatever reason, created anthros. Let us posit a world where biochemistry and genetic engineering went a lot further and a lot faster and that starting in the early 1980s, at a time when IRL they were just learning how to splice genes together, someone was making full-on animal people, Dr. Moreau with a Spielberg budget, growing them in big glass vats. Mysteriously, between then and now no one used this l33t sooper-dooper science to create and use something much more plausible, like ethnically selective bioweapons, that would have completely changed history between then and now and possibly brought about the Apocalypse. Let's say maybe someone (*cough* US government *cough*) wanted expendable vat-grown half-man half-bear half-pig supersoldiers, legally not human and legally government property, to be expended for this or that objective so that during the press briefing the public affairs liaison can say "no US service members were involved and there have been no casualties among the US armed forces" That's just depressing. It doesn't get us waifus, either. You could, I guess, say that circa 1981 Monsanto patented multiple processes that allowed them by Christmas of 1982 to have mail-order furry brides on sale at JC Penney and Sears, who are legally not human, legally your property, programmed and conditioned to obey, and so on. In broad outlines this is the most plausible way in which fuzzy waifu might appear in our world. And it is too depressing to think about for long.
So, the path from here to a world where you might go to Costco on a Saturday morning to pick up some groceries and see anthro girls skateboarding in the parking lot is not clear. https://www.youtube.com/watch?v=y1mUN8gyqxU Here, have a mental palate cleanser.
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