PHOENIX, ARIZONA—Professor Anne Stone of Arizona State University may have provided an answer to one of science’s great debates—the origins of tuberculosis in the New World. Stone’s new research shows that tuberculosis likely spread from humans in Africa to seals and sea lions that brought the infection to South America, where it was eventually transmitted to the native population. For their work, researchers collected ancient DNA samples and tested them for the presence of TB. Three of the samples taken from sites in Peru dating to between A.D. 750 and 1350 showed evidence of TB infection and the genome could be mapped and studied. The researchers discovered that the ancient strains of TB were most closely related to strains present in pinnipeds. “What we found was really surprising. The ancient strains are distinct from any known human-adapted tuberculosis strain,” Stone told the ASU News. To read more about tuberculosis in the ancient Andes, see ARCHAEOLOGY’S “Diagnosis of Ancient Illness.”