Tuesday, May 13, 2014

DNA News of the Week: What is really Provable?

The names in red  represent lines I've had DNA matches on. I've had a Forgey matches out past  my paper trail.

An important statement recently regarding DNA standards and ethics, which was recently drafted, was brought up at  last week's NGS conference. You can read more about it here at The Legal Genealogist's blog. It raises questions about how test results should be used and interpreted. I was aware of the possibility of NPE's back in 2011 when I started DNA testing relatives. I didn't have to deal with any of these events until recently. The possibility of uncovering long forgotten family secrets is a bomb shell issue, and not my favorite part of the process. So we are all trying to navigate this booby trapped maze. Advice on handling our results is appreciated.

Another very interesting bit of information coming out of the NGS conference regards ancestral predictions at AncestryDNA. AncestryDNA had been using megabase matches to predict relationship degree. Fall 2013 they switched to using centimorgans. Anyone testing earlier than that still has results based on megabases. Another hint coming out of the conference was that Ancestry does intend to offer more tools to better analyse your results. Doesn't sound like a chromosome browser? We'll have to wait and see how useful they are? You can read more about what was gleaned regarding AncestryDNA at NGS from CeCe Moore's "You Genetic Genealogist" blog.
It was confirmed in the past week that Family Tree DNA did give a couple of customers the wrong DNA results due to samples becoming switched. I think the error rate is generally low, from what I hear. It is probably best to confirm your results with a second company if your results don't make sense. 

Since myOrigins came out last week I've done more reading about the admixture results the DNA companies provide. As everyone agrees the sample populations are still too small to base any definite conclusions. Also as the Genographic project puts it if you are very mixed ethnically, the results can become very complicated. 

A very interesting blog post about the new myOrigins utility was posted at the DNAeXplained-Genetic Genealogy blog. I borrowed Roberta Estes' idea, and chart, to see if I could infer my father's likely results. I came out with a 30% difference, meaning I didn't inherit this DNA from my mother. It was an interesting exercise, the differences became very apparent when I charted them. All of this is really speculation at this point. We'll see how much more unambiguous the results can become?

I borrowed Roberta Estes' chart to compare our results. Undetermined was 30. 

So what can we definitely prove with DNA without question? 
  1. With Y DNA we can prove a definite relationship between two men. We can only estimate when that relationship occurred. 
  2. With mtDNA we can also prove two people are related, and estimate when.
  3. atDNA can prove relationships in the past few generations, and we can speculate on possible relationships beyond that. This test requires a family tree going back at least 5 generations and preferably 11. 
  4. As far as admixture results we can only predict European, African, Asian and Native American ancestry with a high degree of accuracy. We can't reliably predict any more precisely than those broad areas. 
  5. Y DNA is more reliable in giving us more precise ancestral locations. SNP's provide us with the possibility of finding a very specific ancestral locations.
  6. Solid DNA matches can prove our paper trail. DNA without a paper trail proves nothing, and a paper trail without DNA confirmation doesn't prove a blood relationship. 
My DNA goals:
  1. After attempting to reconstruct possible results for my father I've decided I need to find a stand in for him. I will try to get one of his 4 sisters to test.
  2. We need more Forgey/Forgy & Forgie men to take the Y DNA test. We need at least one confirmed haplo for each line. We can also use more atDNA testers
  3. I would love to find more Owens DNA matches. So far I do have one moderate match at AncestryDNA. We may need to recruit more Owens relations for DNA testing.
  4. I don't have any matches on Urmey, Brower, or Hicks. Since AncestryDNA's surname search doesn't work reliably (meaning it doesn't bring up every instance of the name you are searching for) I need to page through all my matches looking for these names
  5. I am also attempting to breakdown my Sarah Campbell brickwall. I found a couple of moderate DNA matches at AncestryDNA which may lead to a breakthrough. 
So what have I proven to date using DNA? I now know that my Forgey family was Scottish. We used SNP DNA testing to prove this. We also know that the most common Haplogroup for the Forgeys is I-L126. We know Andrew Forgey of Maury County, Tennessee, Andrew Forgey of Hawkins County, TN and Samuel Forgey of North Carolina are definitely related. These men were also related to a Forgie family of Co. Down , Ireland. The surname did derive from Ferguson and our group has close matches with the surname Ferguson. My Forgey family, along with the others have had no NPE's since around 1600. I've confirmed my blood relationship to a number of my lines (see pedigree charts). I've discovered Native American, and African ancestry. 

Still waiting on a YDNA result at FTDNA. This test is taking much longer than usual. I'm hoping they don't have to rerun it? I was thrilled to learn I may be able to breakdown a brickwall on my Thurman line when a descendant in my line takes a Y 37 marker test. Hoping his test comes back sooner than our last test! 

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