The virus progenitor of HIV may be millions of years old, which could…

Simian Immunodeficiency Virus, the non-lethal ape predecessor to HIV, might just be much older than current estimates, which peg it at only a few hundred years old. Research published in this week's Science shows the virus is at least 32,000 years old, and may even have been around for a million years. By analyzing… » 9/16/10 3:00pm 9/16/10 3:00pm