Will ancestry DNA tests tell me my family origins?

I have taken several DNA tests for ancestry, including those provided by the FT-DNA, 23andMe, and Living DNA companies.  Unusual for a tester, I am actually of a single population, very local, well documented ancestry here in East Anglia, South-East England.  I'm not someone in the Americas or Australia, that might have very little clue what parts of the world that their ancestors lived in, previous to immigration.  I know my roots, I'm lucky.  I live them.  You might ask, why did I feel the need to test DNA for ancestry?  The answer is, curiosity, to test the documented evidence, fill the gaps, look for surprises, and in particular, to understand the longer term, to reach further back into my ancestry.

I have though, become a bit of a skeptic, even a critic, of autosomal DNA (auDNA) tests for ancestry.  They are the tests presented by the businesses in results called something like Ancestry, Family Ancestry, Origins, Family, Composition, etc.  Instead of testing the haplogroups on either the direct paternal (Y-DNA), or direct maternal (mtDNA), these tests scan the autosomal and X chromosomes.  That's good, because that is where all of the real business is, what makes you an individual.  However, it is subject to a phenomena that we call genetic recombination (the X chromosome is a little more complicated).  This means that every generation circa 50% of both parents DNA is randomly inherited from each parent.  I said randomly.  Each generation, that randomness chops up the inherited segments smaller, and moves them around.  After about seven or eight generations, the chances of inheriting any DNA from any particular ancestral line quickly diminishes.  It becomes washed out by genetic recombination.

Therefore, not only are the autosomes subject to a randomness, and genetic recombination - they are only useful for assessing family admixture only over the past three hundred years or so.  There is arguably, DNA that has been shared between populations much further back, that we call background population admixture.  It survived, because it entered many lines, for many families, following for example, a major ancient migration event.  If this phenomena is accepted - it can only cause more problems and confusion, because it can fool results into suggesting more recent family admixture - e.g. that a great grandparent in an American family must have been Scandinavian, when in fact many Scandinavians may have settled another part of Europe, and admixed with that ancestral population, more than one thousand years ago.

DNA businesses compare segments of auDNA, against those in a number of modern day reference populations or data sets from around the world.  They look for what segments are similar to these World populations, and then try to project, what percentages of your DNA is shared or similar to these other populations.  Therefore:

  1. Your results will depend on the quality and choice of geographic boundary, allocated to any reference population data set.  A number of distinct populations of different ancestry and ethnicity may exist with in them, and cross the boundaries into other data sets.  How well are the samples chosen? Do they include urban people (that tend to have more admixture and mobility than many rural people).  Do they include descendants of migrants that merely claim a certain ancestry previous to migration?What was the criteria for sample selection?
  2. Your results might be confused by background population admixture.
  3. You are testing against modern day populations, not those of your ancestors 300 - 500 years ago.  People may well have moved around since then.  In some parts of the World, they certainly have!

It is far truer to say that your auDNA test results reflect shared DNA with modern population data sets, rather than to claim descent from them.  For example, 10% Finnish simply means that you appear to share similar DNA with a number of people that were hopefully sampled in Finland (and hopefully not just claim Finnish ancestry) - not that 10% of your ancestors came from Finland.  That is, for the above reasons, presumptuous.  It might indeed suggest some Finnish ancestry, but this is where many people go wrong, it does not prove ancestry from anywhere.

Truth

This is my main quibble.  So many testers take their autosomal (for Family/Ancestry) DNA test results to be infallible truths.  They are NOT.  White papers do not make a test and analysis system perfect and proven as accurate.  Regarding something as Science does not make it unquestionable - quite the opposite.  The fact of the matter is, if you test with different companies, different siblings, add phasing, you receive different ancestry results.  Therefore which result is true and unquestionable?

A Tool for further investigation

So what use is DNA testing for ancestry?  Actually, I would say, lots of use.  If you take the results with a pinch of salt, test with different companies, then it can help point you in a direction.  Never however take autosomal results as infallible.  Critical is to test with companies with well thought out, high quality reference data sets.  Also to test with companies that intend to progress and improve their analysis and your results.

For DNA relative matching, then sure, the companies with the best matching system, the largest match (contactable customer) databases, and with custom in the regions of the world that you hope to match with. There is also, GEDmatch.  Personally, I find it thrilling when I match through DNA, but in truth, I had more genealogical success back in the days when genealogists posted their surname interests in printed magazines and directories. 

The results of each ancestry test should be taken as a clue.  Look at the results of testers with more proven documented and known genealogies.  Learn to recognise what might be population background, as opposed to recent admixture in a family.  Investigate haplogroup DNA - it has a relative truth, although over a much longer time, and wider area.  Just be aware that your haplogroup/s represent only one or two lines of descent - your ancestry over the past few thousand years may not be well represented by a haplogroup.  Investigate everything.  Enjoy the journey.  Explore World History.

Living DNA - my early results are in!

After a four month wait, my initial results have arrived today from Living DNA.  The wait has, I feel been understandable for a launch company.  The results are still limited to standard mode only.

Living DNA Standard mode

100% European
Regional:
74% Great Britain & Ireland
10% Europe (South)
7% Europe (North and West)
10% Europe (unassigned).

Sub-regional:

39% East Anglia
8% South Central England
5% South East England
5% Lincolnshire

2.5% Cornwall
2.4% North Yorkshire
2% South England
1.9% Devon
1.6% Central England
1.5% North West England
1.3% South Yorkshire
1.2% Northumbria

3.5% unassigned Great Britain & Ireland

10% Tuscany (Europe South)
5% Scandinavia (Europe North and West)
2% Germanic (Europe North and West)
9.7% Europe unassigned.

My initial response?  Enthralled and highly impressed.  A little disappointed that the East Anglia percentage was not higher.  I suggest 77% based on my documentary record.  Living DNA gave it 39%.  I still find that a very good result.

However... let's get this into perspective to 23andMe and FT-DNA tests.  Documentary evidence suggests that I am 100% British over the past 300 years.  23andMe said 32%.  FT-DNA said 36%.  Living DNA gets it so much closer at 74%!  That is a whole lot more accurate.

What about the remaining 26% on regional level, where do Living DNA say that comes from? All European.  It suggests 9.7% unassigned European, 9.6% Tuscan (Southern European), 4.6% Scandinavian, and 2% "Germanic".  The Tuscan is interesting, but I'm not convinced yet that it is not ancient and population based.  The Scandinavian is also most likely ancient - in my opinion.

Two things please and impress me about my results on the sub regional level:

1) Based on documentary research, I estimate that 250 years ago, 77% of my ancestors were in East Anglia.  Living DNA indeed, sees it as by far my largest sub regional percentage.  At 39%, a little low, but very impressive.  They correctly identified me as East Anglian.

My next main region, in my Family Tree, I have circa 12% ancestors from "South Central England".  Living DNA saw this, and it is indeed, my second  largest percentage at sub regional level.  I get South Central England with 7.5% - incredible.  The small "South England" would also tied to this line.

Then I get 5.4% South-East England.  It could be over spill from the East Anglia ancestry, but I do have one 3xgreat grandfather Shawers In London, that I do not know the origins of.  I wonder now?

Then it's "Lincolnshire" with 4.8%.  Brilliant!  I had a 3xgreat grandfather from the southern parts of Living DNA's Lincolnshire sub region.  That fills my documentary record almost perfect.  The small "Central England" percentage would also tie to this line.

Then follows a number of low percentages from all over Southern and Eastern England.  They might tell a story, or might not.  Surprisingly Cornwall and Devon show up in low percentages, as does Yorkshire.  Did my Shawers line actually come from one of those regions?  I have seen Shawers in Devon, Cornwall, Shores in Yorkshire, and Shawers in Lancashire.

2) What is excluded can also demonstrate the accuracy of such a test.  No Welsh, Northumbrian, French, Normand, Irish, Scottish, or Iberian ancestry suggested.  Not that I'd have any objection against descent from any of these, or anywhere - but that this test successfully sees that I am NOT descended from these close regions, is to my mind, a great success, and a vast improvement on any past autosomal DNA tests for ancestry by other businesses.  The truth is, that the English are so like these other populations!

On mtDNA they get my haplogroup down to H6a1a.

They have not yet completed my Y-DNA analysis.  I guess L in an English tester might have thrown them a bit.

No other DNA test has ever existed quite like this.  My initial response is - an amazing test.  The future of autosomal testing for Ancestry.