Ancient Mummy DNA Provides Evidence That Colonization Brought Smallpox to Americas

Ancient DNA recovered from mummies in Chile has provided strong evidence that European colonization introduced smallpox to the Americas. Smallpox, a highly lethal disease, had killed roughly one-third of those it infected and left survivors with deep, disfiguring scars. Outbreaks had occurred in Asia and Europe, eventually reaching the Americas.

However, genetic analysis of Chilean mummies from Camarones in northern Chile offers the strongest genetic link yet to the virus as it existed outside of the Americas, providing insight into its spread through colonization. Geneticist Shigeki Nakagome and colleagues examined 13 bone samples, finding evidence of two smallpox infections in an adult male and female, likely having died between 1492 and 1631.

The genetic analysis places the strain of smallpox in the Americas between European medieval strains and later versions, suggesting the virus evolved from Europe first. The exact source of the initial infection in the Americas remains unclear, but it could have been brought by European settlers arriving in different waves or via the slave trade.

The study also sheds light on the devastating impact of the disease, as the two infected individuals were aged 18 to 35, and the disease likely caused their deaths.