Very interesting.

How did Humans first contracted the virus from monkeys?

Does this findings mean that if we cannot find the cure for HIV, ultimately our system will grow immune or resistant to it? If so how long would it be before Humans can get to that point? 100, 200, 500 years?

I'm assume that a human contracted it while slaughtering a monkey for food. Perhaps some of the monkey's blood splashed into the person's eye? Perhaps many humans contracted the virus in a similar manner?

Or just by eating said infected monkey.

This is completely irrelevant, but said infected monkey would be an excellent name for a rock band.

What kind of proof would you find acceptable?

Purified virus, the proof that it can be transmitted between human and lead to AIDS alone