at the Lincoln Park Zoo in Chicago.

At Gombe Stream National Park in Tanzania researchers collected observational data and, from chimps that had died, tissue samples.

Feces and urine tests pinpointed which living chimps were SIV positive. SIV is spread via bodily fluids, during sexual contact and probably during birth, Lonsdorf said. The virus may also spread through biting and fight wounds, she added—"which will be the topic of further study over the next several years."

At the outset of the study, there was little sense that anything was wrong with the SIV-positive chimps, said Lonsdorf.

Then the researchers began noticing the much higher death rate among the SIV-positive chimpanzees. And infected females, it turned out, were much less likely to give birth. When they did, their babies had a very low chance of survival.


Hope for Fighting AIDS in Humans?

"We can learn a lot about disease mechanisms by studying the same disease in different species''.

imagine if there came a day when there were no chimps or monkeys...