Journals of a Time Traveller

I have new DNA cousin "matches".  This is a very important avenue of DNA testing for genealogy and ancestry that I have simply missed until recently.  Up to now, I've concentrated on DNA testing for general ancestry (or ethnicity as some businesses will call it).  The problem was that I first tested with 23andme, and simply, using their heavy USA customer base, and user unfriendly "experiences", I couldn't find any DNA relatives that actually had paper trails that could correlate to my own.

One of the problems is I feel, is that an awful lot of Eastern English migration to the Atlantic Coast of North America, occurred very early - late 16th to early 18th centuries AD.  As a result, although some generous matching systems (such as 23andme's) suggests much more recent shared ancestry, in reality, our links to our distant USA cousins are so old, that all they do is reflect that my distant cousins have Puritan, New England, and Virginian ancestry from Eastern England.  Even for those that do claim to trace ancestry to those pilgrim fathers - I can't.  Certainly not for the thousands of my direct ancestors for Generations 11 - 14.  I don't think any of us can.  Chuck in a bit of genetic folding, and all that these distant relationships is really telling us is, that we both have some ancestry from south east England between 300 and 600 years ago.

Then I tested with Ancestry.com, Ancestry.co.uk, AncestryDNA or whatever you want to call that genealogy mega-business.  Their matching system is dumbed down to the frustrating level.  No chromosome locations or chromosome browsers for painting.  Instead however, they have the fattest database of testers and customers - some of whom, will like myself, be subscription slaves to their family tree and documentary genealogical services.  Their matching systems may cut out chromosome data - but on the flip side, you can browse trees, surnames, ancestral locations, of your DNA matches.  As a consequence, I've found 14 matches that share DNA, with predicted relationships - that correlate to a paper trail relationship.

In addition I am now scouring GEDmatch, 23andme, and FT-DNA Family Finder for more relative DNA matches.  I'm recording everything (including chromosome locations when available) onto a spreadsheet.  The image at the top of this page demonstrates my DNA matches where they share ancestry so far.  The darker the shade, the stronger the verification.

I'm starting to see how this is a better tool to understanding, or verifying ancestry, than any stupid ethnicity / ancestry composition by DNA.  Family isn't always biological.  However, finding a genetic correlation is the ultimate evidence to strengthen a tree.  It's fascinating to see actual paper research turning up as segments of inherited DNA on matches.

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.