Any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time.
Explanation:
The theory of natural selection is defined as <em>the process whereby organisms better adapted to their environment tend to survive and produce more offspring</em>. This means that, in this case, people who inherit a trait in their genes that allows them to resist the HIV virus, will be able to survive better and have children.
Unfortunately, there is no record of such a trait existing, and in this case, there is no kind of natural selection that can arise if every human becomes infected.
According to the CDC, on September 14th, 2014 a man traveling from Liberia to Dallas, Texas was the first person to be diagnosed in the U.S. He did not have any symptoms when he left Liberia.
