25 Marker Matches

Many researchers are unsure what to do with their matches - being especially puzzled by which are relevant.  Matches at 12 and 25 markers are particularly problematic - as they really aren't at a high enough resolution.  Here's a real world correspondence from an admin I support (wiith identifying info removed):

Hi _____,

Your 12/12 matches are only exclusionary (if the individuals didn't match at this level then they couldn't be related; if they do match 12/12 it still doesn't mean a genealogically significant [within the last 1,000 years] relationship occurred.

The seven matches at the 25-marker level with a Genetic Distance (GD) of 1 may (emphasis on may) be related.  Especially if they share your surname (which your 7 matches don't).  But you may want to email/contact them with the news and offer a 5-gen. mini-pedigree of your direct paternal line.  Here's an example:

1. Jim T____ (1953- 2009)
2.  Frank T____ (1920-1980)
3.  Michael T____ (1898-1972)
4. Francois "Frank" T____ (1846-1906) md. R_____
5. Jean-Baptiste T____ (1819-1879) md. L_____

The second step to take is to post your results at the free yDNA sites like ySearch, yBase and Gentree.  Use care and be exact.

Thirdly, you will want to post your pedigree at ______ .  Two of us already have posted ours.  It may facilitate a connection.

Fourth, since you're the first male T______ to participate (congrats on that) you're now in the position of many of us... waiting.


And - here's my comment to the admin - offering him another avenue:

His seven 25 marker matches at GD=1 are all tested at either 37 or 67 markers.  In order to determine which are more relevant, he can upgrade to 37 and get a better comparison to every one of them or upgrade to 67 markers and get the full comparison with 5 of them.  Note: comparsions should always be made at the highest level possible.

There is not a strict correlation between number of mutations and number of generations to most recent common ancestor, but he can be confident that a GD=2 or less at 37 markers and a GD=3 or less at 67 markers will be genealogically relevant.  (Other matches reported by FTDNA at 37 and 67 markers these levels will also be relevant - but some may be too distant for him to ever define.


So bottom line for you - as a researcher -- Increase your testing level to the highest one where you can still get comparisons to the men you are matching.  i.e. - if they are all at 37 and you are at 25, upgrading to 37 gives you the best possible info, but upgrading to 67 would give no additional insights.  But - in the example above, 5 of 7 are already tested at 67 markers - so the best approach is to upgrade to 67 and get the maximun information possible.

Hope this is helpful, Terry

LAuderdale Family

Is there is a Lauderdale Family DNA Project? If so, I would like to have that information.