Monday, November 2, 2009

Finding Potential Y-DNA Matches - Post 1: GeneTree

I received my 43-marker Y-DNA test results from GeneTree last week - as reported in Obtaining my 43-Marker Y-DNA Test Results.

My earlier 20-marker Y-DNA test results were disappointing - I found no close matches in the DNA Ancestry or YSearch databases, but there were no apparent descendants of Robert Seaver, the 1634 immigrant to New England, in any of the databases.

When I clicked the "Find others that match your DNA" link on my GeneTree Marker page, I saw this page:

There are two tabs on that page - "Y-DNA Match Search" and "Surname Match Search." On the "Y-DNA Match Search" page, I could choose between Exact, 85% or 70% Matches, so I chose 85%, and clicked on "Search." There were 166 entries in the GeneTree database that matched 85% or more of my markers. Here are the first two pages:

Well, that's encouraging, to say the least! Even some "Exact" matches, but they are limited to no more than 13 markers in common. And none of them are named Seaver.

But on the second page above, there are two entries with 43-marker tests with the Seaver surname, and one matches 41 of my 43 (95% strength), and the other matches 40 of my 43 markers (93% strength). That's two more persons with the Seaver surname with a possible match than I found earlier this year with my 20-marker test results.

I went back to check the "Surname Match Search" results, and saw:

There are only the two "Seaver" entries, but there are some on the list with fairly close spelling or pronunciation - like "Severe" and "Sevy" - but only the two "Seaver" matches have better than an 81% match.

On the results page, there are three links in the right-hand column for each potential match - "View Pedigree," "View TMRCA" and "Invite to GeneTree. For the first Seaver match, the one with 41 out of 43 matches (a strength of 95%), I clicked on "View Pedigree" and this five generation chart appeared:

I have the Charles Edward Seaver, that married Mary Main, in my Seaver database - he is a 5th great-grandson of Robert Seaver (1608-1683) and a 3rd great-grandson of Joseph Seaver (1672-1754). The #1 on the pedigree chart above is an 8th great-grandson of Robert and a 6th great-grandson of Joseph. My guess is that #1 on the chart is the father or grandfather of the person who submitted his DNA for testing.

It so happens that I am a 10th great-grandson of Robert Seaver (1608-1683) and an 8th great-grandson of Joseph Seaver (1672-1754). This means that my MRCA (Most Recent Common Ancestor) with the 41 of 43 matches Y-DNA tester is Joseph Seaver, who is 9 generations back from myself.

When I click on the "View TMRCA" link for the other tester, it says "11 generations estimated to your most recent common ancestor."

I checked the tester with 40 out of 43 matches, and his pedigree in my database goes back to Robert Seaver (1608-1683) as the most recent common ancestor. The "View TMRCA" for this test says 17 generations to MRCA.

There was a third Seaver surname person on the list, with 23 out of 43 matches, a strength of 53%, and a TMRCA of 50 generations. The tested persons pedigree chart shows descent from a Seaver in colonial Virginia that I know does not descend from my Robert Seaver.

There is another link on the Matches page - to "Invite to GeneTree." When I click on that link I get a popup box that says "Invite a protected SMGF participant to connect with you on GeneTree." I can send a message to the other tested person. Apparently, both of the Seaver persons have not signed up for GeneTree to see their Y-DNA results yet.

I'm ecstatic to find some other descendants of Robert Seaver (1608-1683) have been tested and the TMRCA is approximately correct for the genealogy results. This has tremendous implications for all of three of the Seaver testers - it means that we probably do not have a NPE (non-paternity event) in our genealogy, at least back to Robert Seaver!

But wait - what about the matches at the top of the first page, with up to 13 out of 13 markers (100% strength, TMRCA of 0 generations)? Well, there is no way to compare the tested markers in GeneTree, so I can't see which ones matched up. Perhaps those persons will be in one of the other DNA services that compares Y-DNA markers between persons. I have looked at their pedigree charts on GeneTree and see no geographic match. My guess is that we match on markers that are fairly common for descendants of the British Isles.

1 comment:

DustyR said...

I am glad you found some quality matches at GeneTree. I did notice you were hoping for a way to visually compare your results against others in the database. We are working on that feature. Thank you for the post.