So the very existence of SIVcpz is relatively recent. It has no ancient association with chimpanzees. And now, based on a study published in 2009, part two of the two-part hypothesis has also been cast into doubt. The virus is not so harmless in its chimpanzee host. Evidence from the chimps of Gombe—Jane Goodall’s study population, known and beloved around the world—suggests that SIVcpz causes simian AIDS.
