I am aware that genetic DNA testing to predict “ethnic” makeup uses sample populations to match your results to predict your ethnic inheritance. Leaving aside the fact that some of the sample populations used by some companies is very small and hence makes the results they give virtually useless I would still like to understand the methodology a bit more.
I had a test done by ftDNA and it predicted my ethnic inheritance as 67% West and Central Europe and 33% Scandinavian. Apart from being surprised that none was from the British Isles population cluster despite my tree being full of people born in England I was happy with that as a guide.
However I have now used the analysing tools on gedmatch.com and whilst generally they have given results that would support the ftDNA analysis and a bit more detail they have also made me more sceptical of the whole DNA testing scheme for ethnic inheritance. The reason I say this is because one of the tools allows you to analyse your results chromosome by chromosome which shows a totally different picture.
Using the Eurogenes K13 Admixture Proportions my percentages for “North Atlantic” (which I assume correlates roughly to West and Central Europe) ranges from 29% on gene 17 to 65% on gene 14 whilst my percentages for Baltic (ie Scandinavian) varies from nil on gene 18 to 38% on gene 12. Now I understand that they use all your genes to determine your ethnic makeup but when the maximum you have on one gene is still below your overall percentage then it’s a bit dicey to say the least. (I have ignored the weighting that would be necessary because of the different size of individual genes).
So the question; does anyone have a simple layman’s explanation of how they arrive at your ethnic inheritance further to the above ?
To leave on a positive note I used their eye colour predictor tool and it gave a good match to my actual eye colour
