What’s the model for them decide when to say a new species has been found, rather than just a variant of a known species?
Or more generally, whats the generation of a species? It can’t be just whether they can produce offspring together because some different species has been shown to produce viable offspring.
Like a lot of biology, it’s complicated and often you need multiple forms of evidence to support a species classification if the viable offspring (biological species concept) doesn’t suit.
So there are lots of different models for different types of organisms. And some reproduce asexually so reproductive compatibility would never be enough.
Or more generally, whats the generation of a species? It can’t be just whether they can produce offspring together because some different species has been shown to produce viable offspring.