Well, Scottish wildcats are considered a separate species, but they interbreed with domestic cats [which is kind of a problem]. In point of fact, most small [and not so small] wild cat species can interbreed with domestic cats.
What that says about cat genetics however...
Hemingway cats have a stable form of polydactyly mutation, they breed true [although not dominant with regular cats] They've certainly started to develop functional thumbs, and have crossed the boundary that they could be considered a new species. I suspect that they won't be classified as such though, it would make people uncomfortable.
Re: Yes ...
Well, Scottish wildcats are considered a separate species, but they interbreed with domestic cats [which is kind of a problem]. In point of fact, most small [and not so small] wild cat species can interbreed with domestic cats.
What that says about cat genetics however...
Hemingway cats have a stable form of polydactyly mutation, they breed true [although not dominant with regular cats] They've certainly started to develop functional thumbs, and have crossed the boundary that they could be considered a new species. I suspect that they won't be classified as such though, it would make people uncomfortable.