Genetic Evidence Shows Europeans Brought Smallpox to the Americas

Genetic analysis of ancient mummified remains in Chile has provided the most definitive proof to date that smallpox, a disease that ravaged the Americas, originated in Europe and was introduced during the colonial period. The findings offer the first molecular evidence that the disease was brought to the continent during this era.

A research team from Ireland, Chile, and Japan analyzed the first colonial-era smallpox genomes recovered from the Americas. They studied two mummified bodies of indigenous individuals buried in northern Chile between the late 15th and early 17th centuries. This research supports previous assumptions about the spread of the infectious disease.

Smallpox, caused by the Variola virus, was a major factor in the catastrophic decline of indigenous populations following the arrival of Europeans. The study indicates that the virus spread in waves, causing an estimated three to four million deaths in the Americas, and potentially more, particularly among indigenous groups with no prior immunity.

Previously, direct genetic evidence linking colonial-era outbreaks in the Americas to strains circulating in the Old World was lacking. The study, published in the journal *Science*, reveals that the viruses belong to an extinct lineage of the smallpox virus. This lineage is evolutionarily positioned between medieval European strains and those that circulated in later centuries, solidifying the European origin and transmission route.

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This discovery provides the first molecular evidence that smallpox was introduced during the colonial period.