Surprise DNA results and my Mother's complicated family tree

[Tab J Thomas]

Hi All,
I have a complicated family tree involving both my paternal and maternal line, but the focus of this post will be my Mother's family and our DNA test results.
My Mother was adopted immediately after she was born. She knows who her biological Mother is and has spoken to her, but I never met her as we were in two separate countries. She knew about her ancestry on biological Father's side, which is fairly standard Welsh. She has no interest in doing a DNA test, so I did mine.   

I've attached the results in snipped form to this post.
The North Atlantic stuff is obviously standard for a person of English descent. What was a surprise, however, was quite a large percentage of Baltic Heritage, 22 percent, which as far as I know indicates a Grandparent or Great Grandparent. Even discounting the rest with the exception of Western Mediterranean as statistical noise presents quite a different ethnic background than I was expecting.

Part of the difficulty of having almost no information to go on about the Maternal side of my family tree means there's little I can do with these test results. I've researched my Father's parents and their backgrounds extensively, and there's no reason to think the West Med or the Baltic comes from them, as I've traced them back many generations.

I think DNA tests like these are very different to people who come from essentially broken family backgrounds.

What do all of you think?

[KGarrad]

Basically, I'm an old cynic!
I place absolutely no trust in the interpretation of DNA results from any of the companies doing DNA tests.
Their databases are simply too small to be of any use - except to their Marketing Departments.

You should treat all such results as a bit of fun; and shouldn't rely on them being accurate?

[hurworth]

Which of the admixture tests at Gedmatch did you use to get this pie chart please?

Edited - I can see it's Eurogenes K13

I've just run some kits through K13 .  They're all  getting 22-23% Baltic.  Even the one with two Norwegian gtgt-grandparents is getting 22% Baltic, but the others are pretty much all British Isles give or take a gtgt-grandparent. And similar amounts of West Asian, East Med, North Sea etc as you are seeing.

If you go to the pie chart and click on the Spreadsheet button it gives you averages (don't know how they got them) for various places.   English, Irish and Scottish are all getting about 22-24% Baltic.  I don't think your DNA is pointing to a recent Baltic ancestor.

[pharmaT]

I've just checked my DNA admixture.  Mine comes up as 23.21% Baltic.  I was born in the UK as were my parents, grandparents, grt grandparents, grt grt grandparents, 3xgrt grandparents, 4x grandparents and at least 56 of my 5x grt grandparents.

What you have to remember is the science of ethnicity estimates is in it's infancy.  It looks at deep ancestry.  Based on current science the biggest benefit from DNA testing is cousin matches.

[mike175]

Maybe 'ethnicity' results will mean something one day, but for now they are of no real value to the genealogist. The significance of those small percentages is put into perspective when you consider that most people outside Africa have up to 4% of their DNA from Neanderthals who died out more than 30,000 years ago or more than 1,000 generations. As someone pointed out in a recent TV program, that's about the same as having a Neanderthal great great great grandparent!

I have fairly well sourced evidence for all my 3g/grandparents . . . now I just need to work out which one was the Neanderthal 

[miw]

As well as the results of these analysis being a work in progress (as the databases increase they may get more accurate) you also have to remember that most of us English are the result of many invasions and mass immigrations.  I'm wondering if I will ever find out where my 6% Jewish comes from.