Ancient Retrovirus Is Resurrected

Tue, 27 Feb 2007 10:00 AM EST

... Retroviruses have been around longer than humanity itself. In fact, the best-known family member, HIV, is a relative youngster, with its first known human infections occurring sometime in the mid-20th century. But although many retroviruses went extinct hundreds of thousands or millions of years ago, researchers studying the pathogens don't use the traditional tools of paleontologists: They need look only as far as our own DNA. ...