The oldest known genome of a bacterium associated with syphilis and related treponemal diseases has been recovered from 5,500-year-old human remains from Colombia. This skeleton revealed an ancient strain of bacteria that doesn't fit neatly into modern categories. This suggests the existence of a forgotten form that separated early in the evolution of this pathogen. The discovery pushes back the history of treponemal diseases in the Americas by millennia. Diseases diversified long before written records.