What are the study's limits?

The sample is small and comes from a single cemetery, so the data don't prove that intermarriage never happened in colonial Quebec.

Martin-Moya flagged the caveat directly: "Our sample is small and comes from a single cemetery, so this does not show that such unions never happened. It is, however, consistent with genealogical and genetic studies suggesting that Indigenous ancestry among present-day French Canadians is very limited."

The 45 people analyzed may also skew toward lower-class French colonists. Archival records show that clergy and wealthier residents buried inside the church were more likely to be exhumed and moved later, while poorer residents were buried outside and then entombed beneath the expanding city.

Reburials and urban development also disturbed or destroyed earlier graves, narrowing who could end up in the sample.

Raquel Fleskes, a molecular anthropologist at Dartmouth College who was not involved in the research, told Live Science that the apparent lack of genetic mixing "provides a perspective on population relationships during the colonial period, one where perhaps nongenetic interactions were present but no biological relationships were found."

Were Indigenous or African people buried in colonial Montreal?

Archival records show that some Indigenous people were buried in Catholic cemeteries in Montreal as early as the 17th century, Martin-Moya said. Over time, though, "Indigenous communities were increasingly separated from the colonial town through land dispossession and the relocation of missions away from urban centers."

"Their dead would most likely have been buried in those communities," she added. Enslaved Indigenous and African people were often buried on their enslaver's property or in cemeteries for the poor.

The DNA also revealed several genetic lineages spanning multiple generations. But the graves were scattered across multiple sections of the cemetery rather than grouped into family plots, suggesting that 17th-century Montrealers buried their dead without strict biological kinship ties, Fleskes said.

What does the study not prove?

The findings do not mean Québécois have no Indigenous ancestors today, Martin-Moya said, nor that relations between French settlers and Indigenous peoples were only hostile. Those ties included alliances, trade, conflict, and sometimes family bonds.

"What our results suggest is that when such ancestry exists, it needs to be put in context," she said. "A single ancestor who lived more than 300 years ago does not say the same thing about a person today as being raised within an Indigenous family, community or nation."

Martin-Moya added: "Biological ancestry cannot by itself establish Indigenous belonging, as it is rooted in kinship, community and relationships with land, not in blood or DNA."

The study is titled "Ancient DNA challenges to admixture narratives: Insights from Notre-Dame cemetery (1683-1796) in colonial Montreal, Canada." Its DOI is 10.1073/pnas.2523026123.