Sep. 19, 2010 An ancestor of HIV that infects monkeys is
thousands of years older than previously thought, suggesting
that HIV, which causes AIDS, is not likely to stop killing
humans anytime soon, finds a study by University of Arizona and
Tulane University researchers. The simian immunodeficiency
virus, or SIV, is at least 32,000 to 75,000 years old, and
likely much older, according to a genetic analysis of unique SIV
strains found in monkeys on Bioko Island, a former peninsula
that separated from mainland Africa after the Ice Age more than
10,000 years ago. The research, which appears in the Sept. 17
issue of the journal Science, calls into question previous DNA
sequencing data that estimated the virus' age at only a few
hundred years. The study results have implications for HIV. SIV,
unlike HIV, does not cause AIDS in most of its primate hosts. If
it took thousands of years for SIV to evolve into a primarily
non-lethal state, it would likely take a very long time for HIV
to naturally follow the same traje