Ancient DNA Links European Colonization to Smallpox in the Americas
WHO:
AP News - Researchers from Trinity College Dublin, including geneticist Shigeki Nakagome and biological anthropologist Constanza de la Fuente Castro.
AP News - Patricia Foster, a biologist at Indiana University, commented on the research.
WHAT:
Phys.org - Researchers recovered and analyzed the first ancient smallpox virus genomes ever identified in the Americas, providing the strongest direct evidence to date that the disease was introduced through European colonization.
ScienceAlert - The virus lineage identified by researchers was named CAM9, which fits neatly between medieval European strains and modern variants.
ScienceAlert - The CAM9 genomes serve as a snapshot of the viral evolution, helping to understand which evolutionary changes occurred before smallpox reached the Americas and which changes occurred later.
AP News - Ancient DNA from Chilean mummies provides evidence that European colonization brought smallpox to the Americas.
AP News - The study identified two smallpox infections in ancient DNA from leg bone fragments of an adult man and woman.
AP News - The two individuals likely died between 1492 and 1631.
AP News - The research suggests that the strains of smallpox in the Americas evolved from European strains.
WHERE:
AP News - The archaeological site at Camarones, in northern Chile, where the bone samples were collected.
WHEN:
AP News - The study was published in the journal Science on a Thursday.
WHY:
ScienceAlert - The study highlights the need for a better balance between resources and funding for science in the Global South and the Global North, advocating for prioritizing capacity building in the region.
AP News - The research aims to confirm the historical link between European colonization and the introduction of smallpox to the Americas.
HOW:
ScienceAlert - The researchers tracked lineages of the virus over time and across continents, revealing that the genetic mutation rate of the virus slowed dramatically in the Americas for a couple of centuries after its introduction.
AP News - Researchers examined 13 bone samples and analyzed the ancient DNA to identify smallpox infections.
AP News - Scientists compared the genes of the smallpox strain found in the mummies to other strains, establishing a genetic link to European versions.
(UPDATED July 31, 2026 10:55 UTC)
Researchers have made a groundbreaking discovery by recovering and analyzing the first ancient smallpox virus genomes ever identified in the Americas, providing strong evidence that the disease was introduced through European colonization. The identified virus lineage, named CAM9, fits between medieval European strains and modern variants, serving as a crucial snapshot of viral evolution that helps clarify changes before and after smallpox reached the continent. This study also emphasizes the importance of balancing resources and funding for science between the Global South and North, advocating for enhanced capacity building in the region.
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(UPDATED July 31, 2026 01:35 UTC)
Researchers from Trinity College Dublin, including geneticist Shigeki Nakagome and biological anthropologist Constanza de la Fuente Castro, have uncovered evidence that European colonization introduced smallpox to the Americas through ancient DNA extracted from Chilean mummies. The study, which analyzed leg bone fragments from an adult man and woman who likely died between 1492 and 1631, identified two smallpox infections and suggests that the strains found in the Americas evolved from European variants. Patricia Foster, a biologist at Indiana University, commented on the research, which was published in the journal Science and aims to confirm the historical connection between colonization and the spread of smallpox.