The DNA

Three people in this family have taken the same test, and the results were updated to MyHeritage's v2.5 model this month. Set side by side they do something the registers cannot: they say what is in the body now, rather than what a clerk wrote down.

They also do something the registers never would — they disagree with each other, and with arithmetic. A child is exactly half of each parent. The percentages are not. That is not an error in the test and it is not a surprise in the family; it is what these models do, and this page is mostly about learning to read them honestly.

An ethnicity estimate is not a document. It is a statistical fit of one person's genome against reference panels of living people, expressed to one decimal place because the software can, not because the world is that precise. This archive grades every claim doc, inf or lore. These numbers get a fourth grade of their own — dna — and it ranks below doc, because a register entry names a person and an estimate names a probability.

If these numbers behaved like inheritance, David's column would be the average of his parents'. Here is what happens when you actually take the midpoint.

The total drift is 42.4 percentage points. Every row moves. The largest movements are all in one direction: Balkan is 13 points higher than it should be, and the three British-Isles groups together are ten points lower — 23.3 expected, 13.4 measured.

Three rows land dead on the midpoint — Danish, South Italian and, to a tenth of a point, Breton. Two of Ivan's disappear entirely: his 4.0% Baltic and, from Cheryl, Sardinian and Swedish, all of which fall under the reporting floor once halved.

The reason is that these models do not blend, they assign. A stretch of chromosome is given to whichever reference population fits it best, and a person of mixed descent has long stretches that could plausibly go either way. Where the two sides of a family are far apart genetically — a Kvarner Croat and a woman of the Low Countries and the British Isles — the more sharply defined population tends to win the contested segments. Balkan is a tighter cluster than 'English', which is itself a blend of everything that ever landed there. So Balkan takes segments that a strict accounting would have split, and the British share shrinks.

Germanic goes the other way — 8.6% in David against a 2.6% midpoint, higher than either parent's contribution allows. That is the same effect running in reverse: Germanic sits geographically between his mother's Dutch and his father's East European, and it collects the segments that neither cluster claims outright.

Now the part that matters more than any percentage. Ivan's estimate contains no Italian at all. Not North Italian, not South Italian, not a fraction.

This archive's founding story is that the name came out of Carnia — the Val Degano in Friuli — and reached Istria by about 1679. If that is true, why is there no Italian in the father's DNA?

Because there was never going to be. Autosomal DNA halves every generation, and it halves fast:

The reporting floor on these estimates is around 1%. Read the table again with that in mind: everything older than Giovanni Battista, born 1787, is beneath the floor — and that is on the direct male line, which is the slowest-diluting path a surname takes.

So the Carnian origin is not contradicted by the DNA. It is simply out of range. An ancestor of 1679 contributes about one part in a thousand of a living descendant's genome, twenty times less than the test can see. The Omiš chart's fourteenth-century man contributes a number with four zeros after the decimal point.

This is the single most useful thing on this page. The paper reaches back to 1318. The DNA reaches back about six generations, to roughly 1790. They are not two views of the same distance. Where they overlap — Kvarner, generations 4 to 6 — they agree exactly. Beyond that overlap, the DNA has nothing to say, and an absence of Italian is not evidence against Carnia. It is evidence that the test works as designed.

The coloured continents are deep ancestry. The genetic groups listed beneath them are something else entirely — clusters of living testers who share recent ancestry in one place. They are a record of where a family was two or three generations ago, and they are blunt about it.

David carries four: South Africa #2, South Africa and Zimbabwe, South Africa #3, South Africa (Gauteng and Free State) — and England. His father carries none of them. Every one comes through his mother, whose own list reads South Africa, South Africa and Zimbabwe, and Argentina (Corrientes and Buenos Aires).

That is the maternal family's twentieth century written in genetic shorthand: the Low Countries and the British Isles by descent, southern Africa by residence — Gauteng and the Free State named outright — with a strand running to the Argentine littoral. The direct line's own migration is in the same list from the other side: David was born in Johannesburg, and his father came to it from Senj.

These groups do not date anything and they do not name anybody. What they do is tell you where to write next — and on the maternal side this archive has written almost nothing.

One of those groups now has a person behind it. Cheryl's father — Nuno Fernando, called Larry — was born in South Africa, and his father came from Argentina while his mother came from England. That is a documentary explanation for two things the estimate had only guessed at: the Argentina (Corrientes and Buenos Aires) cluster, and a share of the English. A genetic group is a question; this is the first time a family document has answered one.

Ivan's estimate carries 10.3% Greek and Albanian, a tenth of him, and it survives into David at 2.5%.

In the eastern Adriatic this is not exotic. It is partly the deep Balkan substrate that every population on that coast shares, and partly something more specific: for four centuries the Venetian Stato da Màr moved Greek and Albanian people up and down this sea — the Arbanasi settled outside Zadar in the 1720s, Greek communities held churches in Venice, Trieste and the Dalmatian ports, and Venetian galleys carried crews from every shore they touched.

This archive already has a family out of Crete at Seget. That is a different family and no connection is claimed — but it is worth saying that a Greek-and-Albanian tenth in a Kvarner man is exactly what four hundred years of Venetian sea traffic would leave behind, and the registers on At sea are full of the ships that did it.

The same test offers a list of notable individuals whose ancient DNA has been sequenced, ranked by a Genetic Fit score. The scale runs the wrong way round: lower is closer. Under 1.0 is «very close», 1.0–3.0 «close», 3.0–5.0 «moderate», above 5.0 «distant».

The temptation is obvious. King Béla III of Hungary, Croatia and Dalmatia sits at the top of David's list at 2.196, the best score anyone in this family has, and it is very easy to read that as a line of descent from a medieval king.

It is not one, and the three lists prove it themselves.

If the score were meaningless, the two parents' lists would be interchangeable. They are not, and the differences fall exactly where descent says they should.

Philip Calvert, an English colonial governor of Maryland, appears on David's list and his mother's — and not on his father's. She is the parent with 13.7% English, 14.7% Irish and 18.2% Scottish and Welsh. Jean-Paul Marat appears on hers alone; she is the parent with 5.1% French.

Running the other way, the two Rurikid princes — Gleb Svyatoslavich and Izyaslav Ingvarevich, of the house that ruled Kyiv and Novgorod — appear on David's list and his father's, and not on his mother's. He is the parent with 20.8% East European and 4.0% Baltic. King Ladislaus I appears on his father's alone.

So the method is doing something real at the level of regions. It is only when it is read as a family tree that it collapses.

Read the fourteen names again and notice what is not there. There is no Italian on any of the three lists. No Croatian. No Venetian, no Istrian, no Friulian, nobody from Carnia or Vodnjan or Senj.

The list is Hungarian and Transylvanian nobility, princes of the Rus', a Saxon architect, a Scanian bishop, a German composer, a Bronze Age battlefield in Mecklenburg, an English colonist and a French revolutionary.

That is not a statement about this family. It is a statement about which graves have been opened and paid for. Ancient-DNA projects have concentrated on Hungarian royal tombs, Rurikid burials, and a handful of famous individuals; the medieval dead of the eastern Adriatic have largely not been sequenced. A list of notable individuals is a map of published research, and this family's own coast is a blank on it.

It is the same rule as the rest of this page, in a new dress: an absence in the data is a fact about the data.

One thing is worth keeping, stated for what it is — a resonance, not a relationship.

The name at the top of David's list, Béla III, was king of Hungary, Croatia and Dalmatia. Ladislaus I, on his father's list, is the king who took Croatia in 1091 and founded the bishopric of Zagreb. And John Corvinus, on all three lists, was Ban of Croatia and Dalmatia at the end of the fifteenth century.

Three of the fourteen held the crown or the office that governed the shore this family lived on. Senj, where Ivan Defranceski ended up, was a royal free city of that kingdom; the Vinodol coast below it was held from the same crown.

That is not descent. It is something quieter and, for an archive that keeps a sovereignty chart, more interesting: the population of the Carpathian basin and the Croatian littoral has been one interbreeding world for a thousand years, and a genetic profile from it will land near the people who ruled it — because they came out of it too.