Assume we make contact to a tribe we did not know existed.
We understand the value of genetic diversity for our species. And as we had no contact for a long time, we can assume that the tribe adds to the total genetic diversity.
That's true without any biological interaction, just as an abstract set operation.
Based on the new contact, we can
- stay biologically separated, interacting culturally to some degree, if at all.
- welcome them in our society, preserving their culture to some degree.
- be in contact with the tribe, with some members leaving the tribe.
What do these variants mean for the overall genetic diversity as a species?
As an example, the tribe may be immune against an illness present in animals in their region, while nobody else is immune. Let's assume we know that.
In the first case, we know there are immune humans, and if the worst possible pandemic would occur, the tribe would save our species from extinction.
But what happens in the second case? Do we know something about who, if anyone, is immune, after many generations?
And in the third case, is combining both more advantageous than any one of them?