Wait! As in...humans?!
Totally.
I'm writing a story in which humans have actually avoided most genetic mutations we have today and therefore:They get sick less often, and live longer!
Yes, foreign concept, I know.I thought another thing that might interest you is that these humans live approximately three hundred years. (Numenor, anyone?)
Further notable: The entire "known" world of men, dwarves, and elves (goblins are debatable human but not generally included in lists of humanoids), are contained within the area of a medium sized country! (Again, Numenor?) There are limited populations out side of this area but they are, again, limited, and never interact with each other.