That smallpox devastated Indigenous populations after the European arrival has long been inferred from chronicles and demographic collapse, but direct molecular proof from the earliest epidemics was missing. A team led from the Universidad de Chile, working with Trinity College Dublin, has now supplied it. Analysing thirteen bone samples from mummified remains found at Caleta Camarones in Chile's far north, the researchers identified two smallpox infections in young adults, publishing their results in Science at the end of July.
Radiocarbon dating places both individuals between 1492 and 1631, squarely within the early colonial period. The recovered virus belongs to an extinct lineage designated CAM9, and it constitutes the oldest smallpox genome known from the Americas. Its evolutionary position is telling: it sits between medieval European strains and those that gave rise to modern smallpox, consistent with a pathogen carried across the Atlantic rather than one circulating in the Americas beforehand.
External specialists described the finding as demonstrating that smallpox arrived with European colonisation, closing a question historians could never settle from documents alone. The work also opens new ones. Which European population introduced the virus remains undetermined, and its appearance in a region with no previous written record of the disease suggests epidemics travelled along Indigenous networks faster and further than colonial chroniclers ever saw. For ancient-DNA research in South America, it is a landmark result.