Drill (<I>Mandrillus leucophaeus</I>) (IMAGE) University of Arizona Caption Island-specific strains of the simian immunodeficiency virus (SIV), which infects monkeys such as the Bioko Drill, revealed the virus has been around thousands of years longer than previously thought. Credit Preston Marx, Tulane University Usage Restrictions Usage only granted in conjunction with reporting/posting of the news release, License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.