DNA Heritage

The largest specifically assigned population. This tracks directly to the paternal side of the family: the Long line, the Sullivans, the Daleys, the McNamaras, the Collins family, and the Haggertys—Irish immigrant families who settled in Fall River, Massachusetts in the nineteenth century.

Combined with the Broadly British & Irish category (4.9%), total Irish and British heritage accounts for at least 58.3% of the genome—consistent with the documented paper trail.

The British & Irish (29.8%) and English (1.2%) categories together form the single largest block in the composition. This is the maternal side speaking: the Coffin and Folger families, who arrived from Devon and Norfolk in the early seventeenth century; the Mayflower passengers; and the Norman-era gentry lines that trace back to 1066.

That the archive documents roughly equal depth on both sides of the Atlantic— Irish immigrant lines and English colonial lines—and the DNA splits almost evenly between the two, is not a coincidence. The paper trail and the genome agree.

A small but precise signal, and the archive knows exactly where it comes from: the Pelletier/Harpin line, French-Canadian settlers who arrived in New France in the seventeenth century. The Pelletiers were among the founding families of the colony. At 0.5%, the DNA registers what the documents record—a single ancestral thread woven into an otherwise British and Irish genome.

Combined from Portuguese & Galician (0.4%) and Spanish & Portuguese (0.4%). No Iberian ancestor has been identified in the documented lines, but the geography suggests a plausible origin: the Nantucket and New Bedford whaling industries drew heavily from the Azores and Cape Verde islands in the eighteenth and nineteenth centuries.

Azorean Portuguese sailors were a fixture of the southeastern Massachusetts coast for two centuries. Whether this 0.8% represents a documented ancestor not yet identified or admixture within a known line, the whaling connection is the most likely vector. This is an open question the archive is still investigating.

The largest single category, and also the least specific. At the 50% confidence threshold, 23andMe assigns DNA to “Broadly European” when it cannot distinguish between sub-regions with sufficient certainty. This is not missing data—it is honest data. The genome is European; the algorithm simply can’t narrow it further at this confidence level.

At the 90% confidence threshold, much of the specifically assigned British, Irish, and French DNA would collapse into this category. At lower thresholds, some of this 33.7% would redistribute into the named populations. The 50% threshold represents a middle ground between precision and recall.