Hi thanks for your reply. Let me try to clarify my question. You said: I am not sure how you are defining "natural environment."
My understanding is that if you find a species in an environment, you call it the "habitat" or "natural environment" of that species. If you then take members of that species into a new environment, their behavior (for example) will often be maladaptive with respect to the new environment. We explain the maladapted behavior by saying that, "Well they're not in their natural environment." However, given enough time, behavior and other phenotypes should approach near-optimality for the new conditions. At this point, the new environment has become "natural". My question is, how many generations (say) does this take? Or do you just have to take it on a case-by-case basis?