[VadeRetro]

How do you know that HIV never "hit the human population" before?

For one thing, the people with the resistance aren't the ones who've been living there in the last 100,000 years.

[CobaltBlue]

For one thing, the people with the resistance aren't the ones who've been living there in the last 100,000 years. "There"? I don't think they've figured out where HIV has been during the past 100,000 years. Given the ease with which it recombines, not sure they ever will.