"Evolutionary common sense would suggest that this leopard — an island inhabitant, after all — might well be a species all its own, distinct from its mainland relatives."
In the above sentence. what does "after all" mean? The meaning of "after all" is frequently used, but in this case, it seems the conventional definition doesn't work well. In other words, what's the function of this phrase to connect the rest of the sentence? Many thanks.
After all in this case emphasizes that we need to consider something.
In this case it is telling us to consider that this leopard is an island inhabitant.