Y-DNA results, Aug. 2018


John Sloan (R-U198 Project) has completed SNP analysis of the four Y-500 samples that we have so far. The locations of the earliest ancestors as best we know are shown on the map of NE Scotland.  The results show that all four men share the same common ancestor, born about 550 years / about 15 generations back;  four ancient lines within one genetic family (i.e., the JFS0275 haplogroup). My interpretation of these results as a family tree is shown below, followed by details.

Click on images to enlarge


  1. Earliest known ancestor of each DNA donor is shown; from there down we have written documentation of the descendants.
  2. All four of us are related to the same common ancestor within the JFS0275 haplogroup, going back about 550 years/ 15 generations.
  3. We do not know if this person is the original patriarch of the family; we may find lines that link him to an even earlier ancestor within our haplogroup.
  4. The connections may be as precise as four sons of that man, but could be loosely spread over as many as 3 generations — the precision is limited by how often there is a change in one of the SNPs, which on average is once every 3 generations. If every generation had four sons who married and had four sons, the common ancestor would have 4 sons + 16 grandsons + 64 great grandsons, so the connections of the four lines to this ancestor could be through any of upwards of 80 descendants.
  5. It’s also possible that two of these lines do connect more recently but in an ancestor who had no SNP variations from the common ancestor of all four men.
  6. The estimate of the birth date of the Most Recent Common Ancestor is based on the number of new SNPs in the group — those being the changes that have occurred since the origin of the family. Our numbers are bit below average: for the approximately 15 generations since the ancestor, on average we would each have 5 SNPs that had changed state, or a total of 20 for the 4 of us, but we have only 15.  This calculation may change as other people are added, depending on their SNP mutation rates.
  7. It is noteworthy that #2 has 0 new SNPs — no changes over those 15 generations – and #1 has only 2.  (#4 has 8 and #5 has 5.) But that’s averages for you, and John says he has seen similar results before.
  8. The birthplace of the earliest known ancestor of #4 is shown as Forres on the map, but this is uncertain, and it is even possible that he was from Inverness. We will have a better idea when we have a sample from a man with an ancestor certainly from Inverness.
  9. We can expect to see connections to these 4 lines as we add more people, but we may also find more lines connecting into the same common ancestor.
  10. DNA cannot give us names or places, so we don’t know where this ancestor lived.

The new data also allowed FTDNA to identify a new “cousin” haplogroup, R-Y136618, but keep in mind that the link between this group and ours in R-JFS0266 is very old indeed.


Revised R-U198 tree, Sep. 2018. Source diagram (active site) at http://meekdna.com/U198dna/P7_DF89.html


Page created 23 Aug. 2018 by Christopher S. Lobban, revised 7 Sep. 2018