New ancient-DNA checks do not change which paternal family this site prefers

Terms used on this page

The Y chromosome is a piece of DNA that a son normally inherits from his father with very little change. It therefore follows a line of fathers. A mutation is a change in one DNA letter. A rare mutation can be passed from father to son, so it can mark the father-to-son descendants of the man in whom it first appeared. A branch is a group of men who share such mutations because they descend from one father-line ancestor. A read is a short piece of DNA sequence taken from an ancient person, and a base is one DNA letter within it.

Branch names begin with a letter for a very large, old branch of the human Y-chromosome tree, such as E or J. Branch J divides into J1 and J2. The original report compares three proposed branches. They are J-ZS222, E-BY8508 and J-FGC4992/FGC4975. The report and the genetics page also call them CB-01, CB-02 and CB-03. These labels belong to this project and name branches only. They do not identify any historical person. J-Z642 and some Samaritan branches are further comparisons.

What was checked, and how

The analysis took place on 12 October 2026. It used DNA files that other research teams had already made public, and it involved no new laboratory work. For the Akhziv and Iran men it looked at selected positions that separate the branches. It did not download whole genomes or realign the raw sequencing data. For the Sicily and Bakr Awa studies it compared the published branch assignments with the source tables, dates, quality warnings and relationships between branches. It did not recheck those assignments from the underlying DNA.

AI assistants carried out the analysis under Mike Russell’s direction. The important observed letters were then checked separately with samtools, a standard program for reading aligned DNA files, and the letters agreed. For the Iran files, that check rebuilt them from the original alignment records. For Akhziv, it decoded the extracted Y-chromosome file and did not repeat the download. A second AI review of the findings and the draft found no material error and asked for the clarifications included here.

Akhziv: support for a neighbouring branch

Individual I22254 comes from the Akhziv cemetery on the coast of the Levant. His date is uncertain. The available record borrows a site-context interval of about 900 to 400 BC from other men at the same cemetery. It is not his own radiocarbon date. Ringbauer and colleagues published the study in April 2025. It is older evidence that this October check brought back into consideration.

We examined 66 selected positions that distinguish or connect the relevant branches. Eight of them kept a readable letter after the quality checks and after removing observations from the first and last three bases of each fragment. Most positions gave no usable information.

At the mutation called Y15152 (also named Z18297 and FGC20898), one fragment carries the letter A. FamilyTreeDNA, a commercial DNA-testing company, publishes an official mutation reference. It lists T as the earlier letter and A as the changed one. The fragment was placed well and its letter was read with good confidence. The A also survives a stricter check that removes the first and last seven bases of each fragment. However, the official definition of this branch lists four mutations. The panel included two of them. One of the two has a read, the second has none, and the other two were not queried. The evidence therefore rests on one defining change and is less secure than a placement supported by several.

Two fragments keep the earlier T at a mutation called Z2324, and one of them survives the seven-base check. The genetic family-tree records used for the original report and listed in its verification record show that the paths towards J-ZS222 and J-Z642 pass through Z2324, while Y15152 sits beside it. The observations fit a neighbouring branch. They do not add a member of J-ZS222 or J-Z642.

This man helps show that a neighbouring paternal line was present on the coast of the Levant at some time, subject to the uncertain date and sparse evidence. He cannot show when that line first arrived or who founded it.

Iran: broad J2 ancestry, with the narrower branch unresolved

IRN34 was a man buried at Liarsangbon in northern Iran. The burial has an archaeological date of 200 BC to AD 100. That interval describes the burial context. It is not a radiocarbon date for the man himself. Amjadi and colleagues published the study in May 2025.

Five public DNA files belong to this one man. They are not five people, and some contain observations from the same fragment. The final files called Arbor and Twist each give a good-quality letter at a mutation that is consistent with the paper’s broad J2 assignment. J2 is one of the two large, old divisions of branch J. Official mutation references confirm that both letters are the changed state. The paper’s Table 1 reports a PF5096 assignment for the Arbor data, but its Supplementary Table S4 lists that assignment as NA. The two tables disagree, so we do not count them as separate confirmations.

The J-FGC4992/FGC4975 comparison list names 75 mutations. We could check 71 of them. The other four are untested, because the source list did not give their positions in the reference sequence these files use. Of the 71, 67 have no read at all. The remaining four have observations, but none keeps a letter once we require good alignment, good confidence and exclusion of the first and last three or seven bases of each fragment. A missing letter does not mean the man carried the earlier state.

One observation needs separate mention. At the mutation FGC4980, a fragment that appears in more than one of his files carries the earlier letter G at its first base. It passes the quality checks when end removal is not applied. This is weak evidence against carrying the changed state at FGC4980. It cannot securely exclude an ancient relative who lived before all 75 mutations arose. Ordinary ancient-DNA damage does not explain a changed A turning into this G. The limits are that the observation is isolated, that alignment or sequencing error is possible, and that the timing of the mutations is uncertain.

The result for J-FGC4992/FGC4975 is therefore unresolved. The evidence for broad J2 ancestry is useful, but it does not reach the narrower branch. One man’s sparse evidence also says nothing about how common any branch was among men in Iran at that time.

Sicily and Bakr Awa: published assignments compared

We compared the June 2026 Sicily and Bakr Awa studies with the earlier evidence. We did not check their branch assignments against the underlying DNA, so each assignment below is the authors’ published call.

If the published assignments are correct, the branches reported for CDMBN4, GABN9, the three J-PH128 men and A22059 are neighbouring or separate branches, as the table below shows. For QERBN10, the modern age estimate for his reported narrow branch conflicts with his date. Both the published assignment and that age estimate need checking, so he gives no secure evidence. Two points need emphasis. The three Bakr Awa men in J-PH128 belong to one related family, so they are not three independent paternal families and not a series showing a population growing. Three other Bakr Awa men have contamination warnings in the published study, so they give no reliable positive evidence. In Sicily, the sources disagree about the burial rite of CDMBN4, so we do not call him Jewish.

The comparison keeps the earlier evidence for J-ZS222 in I37241, whose published central date is about AD 100 and whose site is withheld. It also keeps the thinner medieval observation from Erfurt, I14846, and the later J-Z642 evidence from I43272, whose central date is about AD 1700 and whose site is withheld. The new studies do not improve those dates or identify the historical founder of any branch.

Findings at a glance

Scroll sideways to read all columns.

What these results mean for the larger question

This search asks four separate questions. Was the family initially present at a place? Did its father-to-son line spread later? Did the line persist? Can it be tied to a named historical source? The new checks do not answer any of them directly.

• Initial presence. These observations cannot test the moment of the arrival this site proposes, in 2903 BC. That date, and the premise that the world was already inhabited, were supplied to the investigation. They are not findings from these DNA files.
• Later spread. A reliable dated match could show that a branch had reached a place by that man’s lifetime. These observations do not show a route between places, because most of them concern other branches and the exact proposed branches have no verified new matches.
• Persistence. Later men can show that a branch still existed. The new work does not extend the securely checked record of the exact proposed branches. Different branches at different dates do not show one family living continuously in one place.
• Historical source. None of these men identifies Noah, Abraham, Jacob, a priestly family or a named migration. Broad ancestry, paternal descent and burial identity are separate questions.

We also compared four ways a paternal family could leave this record. It might survive while staying uncommon. It might expand locally. Its descendants might move between growing populations. Or its father-to-son line might disappear while other descendants survive. None of these assumes a particular number of founders, a reproductive advantage or a rising share of the population.

Each of these histories depends on sons being born and surviving, on the growth of other families, on marriage patterns, on movement, on burial customs and on preservation. Intermarriage can spread a person’s wider ancestry without keeping his father-to-son line. More descendants do not necessarily mean a larger share of the people in a place, and more elapsed time does not necessarily make a line easier to detect.

Later men therefore remain relevant, because a reliable match shows that a branch existed at that time. They are not a count of how common it was. We have not calculated the chance that a proposed family would have been detected in these cemeteries. No site-specific history gives its expected share among the men who could be recovered and tested. We therefore do not treat the missing matches as evidence that the family was absent from the surrounding population. This work does not justify a claim that existing ancient DNA is inadequate, or that new laboratory work is now required.

Sources

• Akhziv. Ringbauer and colleagues, April 2025: the paper; the public DNA record for I22254 (ERR14666629); FamilyTreeDNA’s official reference for the Z18297 mutation.
• Iran. Amjadi and colleagues, May 2025: the paper; the public study record (PRJEB81975). The five files for IRN34 are ERR15001266, ERR15001251, ERR15001280, ERR14964118 and ERR14964117. FamilyTreeDNA’s official reference for the PF5096 mutation.
• Sicily. The 2026 study and its data (PRJNA1400023).
• Bakr Awa. The 2026 study and its data (PRJEB111543).

The earlier men I37241, I14846 and I43272, and the branch definitions, are described in the original report and its verification record.