mdsolar writes that a study suggests that tuberculosis first appeared in the New World less than 6,000 years ago and it was brought here by seals. After a remarkable analysis of bacterial DNA from 1,000-year-old mummies, scientists have proposed a new hypothesis for how tuberculosis arose and spread around the world. The disease originated less than 6,000 years ago in Africa, they say, and took a surprising route to reach the New World: it was carried across the Atlantic by seals. The new study, published Wednesday in the journal Nature, has already provoked strong reactions from other scientists. "This is a landmark paper that challenges our previous ideas about the origins of tuberculosis," said Terry Brown, a professor of biomolecular archaeology at the University of Manchester. "At the moment, I'm still in the astonished stage over this."