Molecular Proof From 400-Year-Old Remains
DNA extracted from 400-year-old mummies discovered in northern Chile provides the first direct molecular evidence that European colonizers introduced smallpox to the Americas. Viral fragments recovered from the archaeological site confirm historical accounts of devastating epidemics that reshaped indigenous populations following European contact.
Screening Bone Samples From Northern Chile
The research team analyzed bone samples originally exhumed in 1957 from a site where 41 mummified bodies were found wrapped in blankets with funerary offerings.
According to Shigeki Nakagome, a professor of medicine at the University of Dublin, the initial goal was to study human DNA. However, investigators also screened the remains for ancient pathogens.
Reconstructing 16th and 17th-Century Genomes
Laboratory analysis identified fragments of the smallpox virus dating back to the 16th or 17th centuries. By reconstructing the viral genomes and comparing them against ancient and modern strains, the research team determined that the samples belonged to a lineage containing European strains from the Middle Ages and the early modern period.
Mortality Rates and The Toll on Indigenous Peoples
For centuries, smallpox was recognized as a major human pathogen until its global eradication in the 1980s via vaccination campaigns. Severe strains historically carried mortality rates exceeding 30 percent. Survivors frequently sustained permanent scarring from pustules.
When introduced to populations in the Americas and Australia that lacked natural immunity, the virus proved catastrophic.
Matthew Ward, a historian at the University of Dundee, notes that epidemic waves may have killed up to 95 percent of the indigenous population on the American continent.
Balancing Fragile Material With Scientific Inquiry
The extraction process required meticulous handling due to the disturbed nature of the original burials and the fragile state of the biological material.
Historians and geneticists now aim to examine broader questions regarding the spread of infectious disease during the colonial era, utilizing molecular data to complement written archives that often lack records for localized outbreaks.
Related reading