> Simian AIDS was discovered after human AIDS. How do they know the jump didn't occur in reverse?
I'm not sure we (that is, humans) realized that SIV was a thing until HIV prompted us to look in those places. It's the classic example of not knowing what to look for until you've found it.
I agree, the time of discovery proves nothing. But I asked how they can tell either way since there is no data from earlier. However, I would think captive animals were monitored more closely for strange diseases than people in rural mid-1900s Africa.
You'd probably be wrong about that. Even today in most of these places, a captive animal that dies is just 'sick' and disposed of. Or often sold off as food if the death symptoms aren't obviously apparent, as would be the case with HIV. There is no functioning FDA in central africa.
I'm not sure we (that is, humans) realized that SIV was a thing until HIV prompted us to look in those places. It's the classic example of not knowing what to look for until you've found it.