Blog
Case studies and methods
Each post takes one question people bring to this site and works it through against the evidence — archives, published genetics, and the medieval Jewish genomes from Tàrrega.
"My haplogroup has no Jewish matches, so I'm not Jewish" — why that's wrong
Two men murdered in the 1348 massacre of Tàrrega's Jews carry Y-lines with no modern Jewish matches. An empty match list is not a negative result.
There is no Jewish haplogroup — but there are Jewish branches
'Is J a Jewish haplogroup?' is the wrong question. The right one is which SNP — and how recently your branch meets a Jewish one.
Why your "Sephardic %" is probably wrong
Consumer tests detect Ashkenazi ancestry very well and Sephardic ancestry badly. Below about 2%, the number is noise.
Pedrarias Dávila, or: why the documented conversos are the ones who failed
The founder of Panama City was the grandson of a Jewish boy named Isaque. We know only because the Inquisition put his dead grandparents on trial.
Two men who came back: Bordeaux, 1719
In 1719 a fifty-year-old and a forty-four-year-old arrived in Bordeaux from Spain and were circumcised — four years before French law allowed them to be Jews.
Columbus: the claim everyone repeats, and the document nobody mentions
The 2024 Columbus DNA claim is unpublished. The converso money behind the first voyage is in a printed letter of 1493.
Why the endogamous families show it and everyone else doesn't
Old 'Spanish' families of Antioquia, Nuevo León and Costa Rica aren't more Jewish than their neighbours. Their family structure kept a 500-year-old signal readable.
The Avar, the Priest, and the Levite: Why Your Y-DNA and Your Ancestry Can Tell Different Stories
An eighth-century man buried near Vienna was entirely European by ancestry and carried a Y-line from a clade that is today overwhelmingly Jewish.