Tuesday, March 15, 2011

More About DNA

I was recently put in touch with Dan from the Pittman Family DNA site, and he was a tremendous help in understanding some of the things that can be interpolated from my DNA results.

Below are selections from the things that he said in the course of several emails.

In comparing your results (Ancestry) with those in the Pittman DNA Project (through Family Tree DNA),
we can only compare on 34 markers out of the 46.  You match exactly on 32 markers with 18 different men who have submitted saliva samples.  Three of these men have good records (and the family was in the right place at the right time / family  traditions are strong) that lead conclusively back to (Capt.) Thomas Pitman (bc 1614) of Surrey / Isle of Wight Co. VA.

One marker - DYS442 - had a value of 5 lower thatn what is posted in our Project.  Another marker - Y-GATA-H4 - you is a value of one lower.  The other markers are apples and oranges.  (I have some experience checking with FTDNA when someone wants to compare Ancestry or Relative Genetics results with a group of people in my Project.

All in all - with an exact match of 32 markers - plus knowing that direct blood line descendants of (Capt.) Thomas did move to Robeson Co., it is a safe bet that both of you [sic. a cousin and myself] are descended from Thomas.  I am also related, but like you, have not discovered the missing link or 2 that would time me directly into his line.

Both Ancestry and FTDNA test many similar markers but they also test markers
that are unique to their own program.  Also, FTDNA has a person's saliva sample tested by the
Univ. of Arizona and Ancestry, I'm sure, uses some other group.  I have found in some instances,
even when testing the same marker, such as DYS442, they interpret the results differently.

And finally:

There are people in the Project who are connected to Thomas' line by a genetic distance of '1' and '2'.  I can go back far enough in there lines to know they probably are related but somewhere in England and perhaps descend from an uncle or great uncle of Thomas.  But that is really stretching my limits of understanding this DNA stuff.

As an example we have a family with a strong tradition that they came from Lancashire, England and migrated to the American colonies in 1765-1766.  Yet they are a perfect match with Thomas' descendants.

The tradition / common story  in my line is that I probably descend from Samuel Pitman Sr. who shows up in 1766 Granville Co. NC and the 1790 SC Federal Census.  My proven ancestors were living in the same
area of SC in 1805 (Tygerville Baptist Church Minutes).  But the common thought is that Samuel was born in England about 1740.

Thomas came over about 1650 as a bonded person to Robert Hutcinson.  Approximately that same time, a
Joseph Pitman came over and settled in Accomac Co. VA.  I have proven descendants of both in the Project.  Descendants of both migrated to NC about the same time.  But there is no indication that they knew each other.  Yet, at the Y-37 level, all markers match exactly.  That's enough to know that they relate by blood very, very closely.  Brothers? Cousins?  We don't know.
One of the things that makes it hard is that in England - before about 1837 - you almost have to know the parish / church that the family attended in order to get earlier information.  that's the problem I'm having researching UK records.

So thanks so much for the edification Dan.  Surely, one day we'll find what we are looking for.

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