Devasting diseases have occured in indigenous populations of north and south America once they came in contact with Europeans. One disease, however, can no longer be attributed to this collection: tuberculosis.

In a Nature paper (doi:10.1038/nature13591) this week Bos, Harkins and colleagues demonstrate Mycobacterium tuberculosis isolates in Peruvian human skeletons from 1000 years ago i.e. 400 years before Columbus traveled to the Westindian islands. These mycobacteria do not ressemble the actual strains in Europe and America but are more closely related to those found in seals and sea lions proposing that human diseases could have spread via sea mammals before man themselves actually came in close contact.