Thoughts in understanding ancestry DNA

Above image.  My Global 10 Genetic Map coordinates:  PC1,PC2,PC3,PC4,PC5,PC6,PC7,PC8,PC9,PC10 ,0.019,0.0272,0.0002,-0.0275,-0.0055,0.0242,0.0241,-0.0033,-0.0029,0.0015.  The cross marks my position on a genetic map by David Wesolowski, of the Eurogenes Blog

The above map shows genetic distances between different human populations around the planet.  Look how tightly the Europeans cluster.  Razib Kahn recently blogged on just this subject.  The fact of the matter is that the greatest diversity exists between populations outside of Europe, particularly within Africa, and between African and non-African populations.  However, we obsess over tiny differences within European populations, when in truth, most Western Eurasians are very closely related.  We share ancient ancestry from slightly varied mixes of only three base ancestral groups, with the last layer arriving only 4,300 years ago.  This obsession in the Market drives DNA to the consumer businesses to largely ignore non-European diversity, and to focus too closely on differences that blur into each other.

The above image is from CARTA lecture. 2016. Johannes Krause of the Max Planck Institute. It shows the currently three known founder populations of Europeans and their average percentages.

However, at the same time the new Living DNA service seeks to zoom in closer on British populations, attempting to detect ancestry percentages from such tiny zones as "East Anglia".  They appear to be having a level of success with it as well, although that blurriness, that overlap and closeness of populations in Europe gives problems.  Germans are given false percentages of British, Some Scottish appear as Northern Irish, and the Irish dilute into false British areas.  However, I've seen enough results now to suggest that it is far from genetic astrology.  They get it correct to a certain level, particularly for us with English ancestry.  Ancestry DNA customers expect perfection.  I don't think that we will ever get that from such closely related populations at this resolution, but it does provide a new genealogical tool that can point us into some revealing directions.

Above image.  My Living DNA Map.  Based on my recorded genealogy, I estimate 77% to 85% East Anglian ancestry over the past 250 years or so.  Living DNA at Standard Mode gave me 39%.  I'm impressed by that.  That a DNA test can recognise even at a 50% success, my recent ancestry in such a tiny zone of the planet.  I have doubts though that this sort of test will ever be free of errors, and mistakes.  The safest DNA test for ancestry is still one that is based on more distinct populations, and outside of Africa, that can be as wide as "European".  23andMe for example in their "Standard Mode" (75% confidence), assign me 97.3% European, and 0.3% Unassigned.  That is a pretty safe result.

Autosomal DNA tests for ancestry, particularly for West Eurasian (European and Western Asia) descendants, are not reliable at high resolution.  If you want to get really local, then sure - do it.  However, only use the results as an indication, not as a truth.  Populations in Western Eurasia are closely related, and share recent common descent.  There has been a high degree of mobility and admixture ever since.  Some modern populations tested do not have a high level of deep rooted local ancestry in that region.  They overlap with each other.  Keep researching and meander through different perspectives of what your older pre-recorded ancestry could have been.

Above image by Anthrogenica board member Tolan.  Based on 23andMe AC results.  My results skew away from British, and towards North French.  He generated this map, plotting myself (marked as Norfolk in red), and my Normand Ancestral DNA twin Helge in yellow.  My results fall in the overlap with French.  Helge is Normand but in AC appears more British than myself.  I am East Anglian yet in this test appear more French than he does.