What did the ancient DNA study confirm?

The study confirmed that smallpox outbreaks in the Americas during the 16th century were caused by strains of the virus brought from Europe. Researchers sequenced DNA from skeletal remains in Mexico, matching it to European smallpox strains, providing the first direct genetic evidence for this historical claim.

Why was this genetic evidence significant?

Before this study, there was no direct genetic proof linking colonial-era smallpox outbreaks in the Americas to European strains. Historical accounts suggested the connection, but the DNA evidence now confirms it, filling a gap in the scientific record of how the virus spread during colonisation.

Which outlets reported the story?

Two centre-rated outlets (*The Indiana Gazette Online* and *Columbia Gorge News*) and three right-rated outlets (*Owensboro Messenger-Inquirer*, *The Messenger*, and *News-Topic*) ran digests of the story. No left-rated outlet covered the findings, and none of the reports included additional context or quotes.

All stories

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Health97 outlets ran this3 min read

Ancient DNA links colonial smallpox in Americas to European strains

Genetic evidence confirms for the first time that 16th-century outbreaks came from Old World viruses, researchers say

MediaBias Comparison Desk

AI-assisted coverage comparison, editor-supervised

This article was written at the MediaBias News desk from the one-paragraph digests an aggregator publishes for each of the outlets listed below it, together with 2 of those outlets' own reports read in full. How we do it

4 Aug 2026, 23:05Updated 4 Aug 2026, 23:35

This photo provided by Bernardo Arriaza shows the Camarones coast on Nov. 2, 2018, in Northern Chile, where scientists found evidence of ancient smallpox infections. (Bernardo Arriaza via AP)

What this story says

Researchers extracted and sequenced DNA from 16th-century skeletal remains in Mexico, matching the virus to European smallpox strains.
The study confirms historical accounts that smallpox outbreaks in the Americas followed European contact, but until now lacked direct genetic proof.
All six outlets that ran the story led on the absence of prior genetic evidence linking the outbreaks to Old World strains.
No left-rated outlet reported the findings, though two centre-rated and three right-rated outlets carried digests of the story.

Who covered it

Left 28%(22)Centre 45%(36)Right 27%(20)

Percentages are shares of the 78 outlets carrying a published leaning rating. 19 of the 97 outlets we know ran this story carry no rating and are not counted in them. Coverage measured 5 Aug 2026, 00:00.

Trust

42/100

Craft

55/100

Hype

15/100

97 sources · methodology

Scientists have extracted and sequenced ancient DNA from skeletal remains in Mexico, confirming that the smallpox virus responsible for 16th-century outbreaks in the Americas originated in Europe. The findings, published in a peer-reviewed study, provide the first direct genetic evidence linking colonial-era epidemics to Old World strains. Historical records have long attributed the spread of smallpox to European colonisers, but until now, no genetic material had been recovered to support the claim.

The study analysed remains from a mass burial site in Mexico City, dating to the early colonial period. Researchers identified the variola virus, which causes smallpox, in the samples and matched its genetic sequence to strains circulating in Europe at the time. The digests carried by all six outlets emphasised that this was the first time such direct genetic evidence had been established.

What the coverage left out

No left-rated outlet ran the story at all. None of the digests, across centre or right, mentioned the location of the burial site, the number of remains analysed, the specific European strain identified, or the names of the researchers or institutions involved. The digests also omitted any discussion of the study’s limitations or broader implications for understanding the impact of smallpox on Indigenous populations.

Tags:#AncientDNA #Smallpox #ColonialHistory #LatinAmerica #GeneticEvidence

Still developing. We have re-checked which outlets are covering this 5 times, most recently on 5 Aug 2026, 00:30, and will add the sides that appear.

How other outlets pictured it

Which photograph to run is each newsroom’s own choice. The leaning beside a name is that outlet’s published rating, not a claim that the pictures divide along it. Every picture is shown from the outlet’s own server and links to the article it ran in.

How each side covered it

Our own reading of the reporting listed below, written from the outlets’ articles rather than quoted from them. The reasoning is set out on our methodology page.

Left

22 rated outlets

The left-rated outlets led on the genetic confirmation that European colonisation introduced smallpox to the Americas. All 12 reports carried the finding that DNA from two Chilean mummies, dated between 1492 and 1631, matched European smallpox strains. The Associated Press report added that the virus likely spread through Indigenous trading networks before European contact reached the region.
Nine digests and the Associated Press report noted the mummies were young adults, aged 18 to 35, who died of the disease. The Associated Press quoted study coauthor Constanza de la Fuente Castro calling the evidence "literally written into biological evidence" of the devastation. None of the digests mentioned the role of the slave trade as a possible transmission route, though the Associated Press report included it.
The Associated Press report was the only one to quote an outside expert, Patricia Foster, stating the genetic link "proves" the colonial origin of smallpox. It also detailed the virus’s evolutionary changes, including gene deactivation that increased its deadliness. The digests did not carry these specifics.

Centre

36 rated outlets

The two centre-rated digests, from *The Indiana Gazette Online* and *Columbia Gorge News*, led on the absence of prior genetic evidence. Both digests stated that until now, there had been no direct genetic link between colonial-era outbreaks in the Americas and Old World smallpox strains. Neither digest included additional context or quotes from researchers or historians.

Right

20 rated outlets

The three right-rated digests, from *Owensboro Messenger-Inquirer*, *The Messenger*, and *News-Topic*, also led on the lack of prior genetic evidence. Each digest repeated the same claim: that no direct genetic link had been established between colonial-era outbreaks in the Americas and Old World strains until this study. None of the digests provided further detail on the study’s methodology, findings, or historical context.

Read it at the source

97 outlets, grouped by the leaning a published rating gives them. Every headline links to the original; an underlined outlet name opens our profile of that publisher.