If you can only get AIDS from someone who already has it...?

Then how did patient zero (the first person diagnosed with what eventually became to be known as AIDS) get the virus?

The most widely accepted theory in the medical and research fields is that SIVcpz, Simian Immunodeficiency Virus found in chimpanzees was passed to humans through the butchering and consumption of the animals.

mutation of the virus from something similar.

there are a few theories... some involve contamination from monkeys

From being with someone else, or from a blood transfusion from someone else.

It is believed that it was passed from a monkey to a human, and that the disease mutated so that it "worked" in the human body.

However, the first person diagnosed was probably not the first person who had it.

The virus would have mutated somehow. It might have made the jump from another species to humans or it's possible it was a virus that mutated and was then able to infact humans. Bottom line is that it'd have involved a mutation at some point.

I've heard from other people that the first person got AIDS from some sort of dirty act with animals, but those people were 12.

Personally, I think it originated in a lab. Experiment gone wrong.

And the people above me have the movies 12 Monkeys and Outbreak in mind.

The very first AIDS virus came from a monkey.

The story goes it was from eating raw monkey, since it was a primate disease before it was a human infection. (I don't know how true that story is, or if it's urban legend)

HIV probably mutated from another less harmful virus. Viruses are mutating all the time and causing slightly different symptoms.

The hypothesis is that it was a zoonotic transfer. That is, it crossed the species barrier. This is a big deal in the fact the way that a virus identifies the cell it is programmed to invade.

Probably from an animal and the animal got it from eating spoiled food? Just a thought.

It has never been proved that I know of. There was one theory that AIDS began from people eating meat of the 'blue' monkey.

HIV

Just as with anything, there is no definitive answer but millions of things started somewhere so AIDS is no different.

It evolved from a monkey virus or was developed in a lab. Originally it was thought that because no virus kills 100% of it's hosts it had to have been developed artificially to control the African/homosexual/and black American populations from the beginning of the Regan administration.

Don't know. I've hear all the reasons mentioned so far. I've also heard the theory that it started from anal sex. All kinds of disease can come from feces. Some have thought, a ripping of the delicate tissue would have allowed fecal material into the blood stream.