Go Fish!

I don't know about you, but until recently, the whole DNA thing has been pretty disappointing.  I feel like we are constantly playing our own version of the old "Go Fish" game when we contact our DNA matches:

"Do you have a William Green in your family?"

And the game goes on, because the likelihood that you and your genetic match have both identified your common ancestor is not terribly high.  Your actual DNA connection is probably two generations before your earliest known ancestor, or even more likely, hidden behind women who all have different surnames than their father.

Not only that, but getting information from your matches can be like pulling teeth.  FtDNA has the best tools for comparing DNA, but not many of their customers post family trees, so it is hard to have any sense of where in the world your potential match comes from.  While Ancestry is all about family trees, the company takes the paternal approach and tells you that you are related.  The lack of tools for users to compare and contrast the data for themselves just means you are relying on the accuracy of the posted family trees; you will miss the matches who either have it wrong or don't post at all!

I have been reading the DNA blogs for some time, and have been fascinated with the work of Roberta Estes, Blaine Bettinger, CeCe Moore and others.  This is an entirely new way of recording our ancestors -- even to the point of some day recreating ancestral DNA -- and it finally reached a critical mass for me just before I went to RootsTech.

I actually had a problem to solve.  A DNA cousin contacted me with new information and we needed to find other relatives so we could prove or disprove a hypothesis.  All you need to make it interesting is to have people who share a common segment of DNA and some kind of information about the potential ancestor.  By creating a spreadsheet with all the various permutations of who matches whom and on which chromosome, you can gradually begin to identify particular DNA segments as belonging to ancestral individuals.  

Kitty Cooper put it succinctly:  "The way to prove the common ancestor is to see if A and B match each other in the same place that they match you. This is what we call triangulation."1   In this particular case, it was no dice.  The problem that spurred me to tackle DNA research on a practical level fizzled out with no solution, since the third person did not match on the same segment where the second person matched my mother and uncle.  But now that I see the possibilities, I have been combing my match lists for people I know for a fact are cousins and recording their data on a spreadsheet.  

This is a section of the spreadsheet I created to show five different individuals who match my uncle on Chromosome 5.   My uncle, mother, and one of these matches are all known descendants of Reuben Hill, a Revolutionary War soldier from Rutherford Co, NC.  The others are matches on FtDNA who share roughly the same segment of DNA. Most importantly, all of these people also match each other.

Now of course I can't say (yet) that this area on Chromosome 5 belongs to Reuben Hill (or his wife Margaret Brien).  It's just that sharing this particular segment -- together with the traditional genealogical research I've done on this line -- really narrows down the field, and gives me something to talk about when I contact the other matches.  

I am no longer playing "Go Fish."
1. Cooper, Kitty. "Triangulation -- Proving a Common Ancestor." Web Blog Post, "Kitty Cooper's Blog."  www.kittycooper.com, 26 Feb 2015, accessed 27 Feb 2015.

Some great reading:

DNAeXplained -- Genetic Genealogy (Roberta Estes):

Triangulation for Autosomal DNA
Chromosome Mapping -- AKA Ancestor Mapping
Chromosome Browser War
Demystifying Autosomal DNA Matching
How Phasing Works and Determining IBD Versus IBS Matches
A Study Utilizing Small Segment Matching
Getting the Most Out of AncestryDNA

The Genetic Genealogist (Blaine Bettinger): 

Your Genetic Genealogist (CeCe Moore):

The Folly of Using Small Segments as Proof in Genealogical Research, Pt. 1

Kitty Cooper's blog:

Triangulation -- Proving a Common Ancestor

International Society of Genetic Genealogy (ISOGG)