Definitive Genetic Evidence From Chilean Mummies
Published: August 2, 16:00
For the first time, an international research team from Ireland and Chile has produced conclusive genetic proof that European colonizers introduced smallpox to the Americas. The study, published in Science, identified variola virus DNA in two naturally mummified bodies from northern Chile, dated between 1492 and 1631. Because the recovered viral genomes are nearly identical, the two individuals were likely infected at the same time.
The CAM9 Viral Lineage
Scientists named the newly identified lineage CAM9. It serves as a bridge between medieval European smallpox variants and twentieth-century strains. Historical estimates suggest that European-introduced smallpox killed roughly 4 million Indigenous people in the Americas. After spreading rapidly, CAM9's evolution slowed for about two centuries, then accelerated again in the 1800s, a shift researchers link to the start of mass vaccination campaigns.
Shigeki Nakagome, a genomicist at Trinity College Dublin, said that 'the CAM9 genomes offer a revealing snapshot of the virus's evolutionary path.'
Constanza de la Fuente Castro, an anthropologist at the University of Chile, stressed that 'this discovery illustrates both the scientific promise of the region and the need to support research capacity in Global South countries.'
These findings matter not only for understanding the history of epidemics but also for recognizing the devastating impact of colonization on Indigenous American populations. Tracing genetic connections among viruses can aid future research into viral evolution and its social effects, potentially informing better responses to infectious disease today. The work also underscores why scientific investigation should be strengthened in countries that are often sidelined from global research efforts. Smallpox remains one of the most significant infectious diseases in human history, and this study adds a crucial piece to its complex global story.
Understanding the historical impact of diseases is crucial, especially in light of recent findings about how viruses can spread. For instance, a study has revealed that dead cells may facilitate the transmission of viruses, highlighting the complex interactions between pathogens and their hosts. This emphasizes the need for ongoing research into the mechanisms of viral spread and the implications for public health.