If that group of the species is the only one in its area, as per your model of divergence, then the species will be overrun by the natives, who are already apt to the area, though they may have been fed upon for a number of generations by the invader. The original species, still unevolved, has varied a little over those generations, but is comfortable in its habitat.
I'm having a moment of joy that you're even less capable than I am of defending your position, even though we're still arguing on your grounds. I should probably apologise, since that's not a good thing; I ought be more aware. No offense intended, but I'm still waiting for anything that you might have to try and convince me, originally the sideliner, of your position - once I'm convinced, you can begin trying to convince Eleison, and, if that happens, we can accept that physicalism has won in this conflict of theories.
Edit: I'm not throwing out evolutionary theory, I'm throwing out the supposed evidence that you've given in support of it (and even one of the theoretical processes). So far, there's nothing at all to convince me that evolutionary theory is correct, and a great deal to convince me that Tradition has it right as to the origin of species. I was more convinced of evolution at the start of this, I must admit, but it's definitely swung the other way - I suppose I should thank you for helping me grasp this aspect of Tradition.