In the 20th century. thirteen distinct human immunodeficiency viruses emerged following independent cross-species transmission events involving simian immunodeficiency viruses (SIV) from African primates. In the late 1900s. pathogenic SIV strains also emerged in the United Sates among captive Asian macaque species following their unintentional infection with SIV from African sooty man... https://www.roneverhart.com/Corvette-Radiator-Supports-1997-2004-C5-Z06/