DNA of Chilean Mummy Reveals Traces of Smallpox Brought by European Colonization to America

Illustration of ancient mummies and colonial ships. Mummy DNA from Chile provides genetic evidence that European colonization brought smallpox to the Americas. Illustration created by AI.

DNA of ancient mummies from Chile provides the strongest scientific evidence to date that European colonization brought smallpox to the Americas. The findings reinforce the historical record of the plague that killed millions and hit indigenous populations.

Kyodo News, quoted Sunday, August 3, reported that the evidence was found from the analysis of mummies from the Camarones archaeological site, northern Chile. The research involved geneticist Shigeki Nakagome from Trinity College Dublin and a number of colleagues.

Smallpox was once one of the deadliest diseases in human history before it was eradicated in 1980 through vaccination. For centuries, the virus killed about a third of those infected.

Many survivors of smallpox also have deep scars. Some have wounds that damage their appearance.

The smallpox epidemic first attacked Asia and Europe. The disease then spread to the Americas. Colonial records, administrative documents, and missionary reports record how smallpox killed millions of people and destroyed indigenous communities who had never been exposed to the virus.

Now, the historical record has been strengthened by ancient DNA.

Nakagome said the analysis of the Chilean mummy provided the strongest genetic link to date with the smallpox virus previously present outside the Americas. These findings also provide a clearer picture of how smallpox reached remote populations through colonization.

In the study, the researchers examined 13 bone samples from the Camarones site. They found evidence of two smallpox infections in the ancient DNA from the fragments of the legs of an adult male and an adult female.

Based on the dating of the bodies and gene examinations, the two people are estimated to have died between 1492 and 1631.

The scientists then compared the smallpox virus genes with other versions. The result, the smallpox strain from America is between the medieval European strain and the later emerging version.

Strains are groups of viruses that have certain genetic characteristics. Comparison of strains is important to track the origin and changes of viruses over time.

The results are important molecular evidence. That is, the virus traces are read from genetic material, not just from historical records.

The evidence suggests that the smallpox strain that infected people in the Americas first evolved from Europe.

"No one will question that smallpox came to this hemisphere through colonization, but this finding proves it," said Patricia Foster, an Indiana University biologist.

Foster was not involved in the research published Thursday in the journal Science.

Even so, the study's authors say it is not clear which population first brought smallpox from the Old World to the Americas.

European settlers came in waves after Christopher Columbus' explorations of the Caribbean in 1492 and Amerigo Vespucci's explorations of the South American coast about a decade later.

Researchers also opened the possibility that the disease passed through Africa, as slave trade entered and spread.

Kyodo News said that the South American smallpox infection was found in an area that had previously had no record of the disease. The finding opens new questions about how the virus can move so far south.

One possibility is that smallpox spread through the networks of indigenous trade that existed long before the arrival of Europeans.

By studying the various strains, scientists can see how the virus changes over time, including how some genes become inactive and affect the virus's ability to cause infection.

This research not only strengthens the history of the spread of smallpox. The findings also show the human victims behind the outbreak.

The two individuals studied were aged between 18 and 35 years. Smallpox was likely the cause of their death.

One of the study's authors, Constanza de la Fuente Castro, a biological anthropologist from the University of Chile, said the findings showed the extent of the impact of smallpox across the Americas. The disease wiped out many populations and made them more vulnerable to European conquest.

"This is not just a matter of culture or demographics. It is really written in biological evidence that we can still recover and read today," de la Fuente Castro said.