Thursday, July 2, 2020

Where Are the "Holes" In My Pedigree Chart? Can DNA Help? - Post 2

I posted Where Are the "Holes" In My Pedigree Chart? Can DNA Help? - Post 1 on 1 July 2020, and said I would try to put the number of DNA Matches from my AncestryDNA ThruLines on my Fan Chart.  A "ThruLine" is a chart with the lines from an identified common ancestor to me and to my DNA match.  The ThruLine is identified based on my Ancestry Member Tree, the DNA Match's Ancestry Member Tree, and the Ancestry Big Tree.

The challenge is to not count a DNA match more than once.  AncestryDNA includes downstream DNA Matches in their ThruLines count for an upstream ancestor.  For example, Ancestry says that I have 14 ThruLines for my great-grandfather Thomas Richman (1848-1917), but that includes the two ThruLines that have his daughter, my grandmother, Alma Bessie Richman (1882-1962).  So Thomas Richman has 12 unique ThruLines that share DNA with me.

I used the FamilySearch Fan Chart that I showed in the earlier post, and added a box for each couple in the fan chart, and put the number of unique ThruLines in the box, in red.

These are not all of my ThruLines since I have unique ThruLines from many of my 5th great-grandparents, but the chart above only goes back to the 4th great-grandparents generation.

I have included all of the ThruLines that AncestryDNA gives me, even though a few of them are, in my humble opinion, wrong.  These include DNA matches down to 6 cM (< 0.1%) in shared DNA.  I could parse the information even more by doing the same chart with DNA matches with, say, more than 15 cM.  For now, the above will have to suffice.

Some more statistics:

1)  There are 238 unique ThruLines on this chart (II have about 400 total ThruLines, and 67,897 AncestryDNA matches):
** 99 for my father's side
** 139 for my mother's side.

2)  By generation:
**  4th great-grandparents generation -- 42 on father's side, 80 on mother's side
**  3rd great-grandparents generation -- 36 on father's side, 51 on mother's side
**  2nd great-grandparents generation -- 7 on father's side, 8 on mother's side
**  1st great-grandparents generation --  12 on father's side, 0 on mother's side
**  Grandparents generation -- 2 on father's side, 0 on mother's side

3)  By Great-grandparent line:
**  Seaver line:  16
**  Hildreth line:  19
**  Richman line:  23
**  White line:  27

**  Carringer line:  54
 ** Smith line:  19
**  Auble line:  26
**  Kemp line:  40

I don't think that this has helped me understand how DNA can help me find more common ancestors of my DNA matches, but it was fun to do.  It will be interesting to see how this changes over time.


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1 comment:

Jim Bartlett: said...

A great post - a one-page summary that let's you know quickly where new ThruLines fit. I use a spreadsheet to list each Match with each ThruLines CA (sometimes the Match appears more than once). I do this to track all ThruLines Matches and to see if there is something to be gleaned from the Clusters (Shared Matches) and the Triangulated Groups for those with that info. Jim Bartlett