@ Romilly
I did not reply immediately as I thought it best to let others comment if they wished. I will now comment and what I say is my personal opinion and reflects what I have said in several threads on here.
Autosomal DNA does have its uses and they are primarily for helping you trace near kin and this is soundly scientifically based. Unfortunately some DNA companies market the test primarily on finding your ‘ethnic identity’ and are thereby duping the public. These tests do not have sufficient scientific input to make the predictions that they do. These tests use pseudo-science based on assumptions and in some cases very small comparison population samples to make predictions. This is all they are predictions, they are not scientific fact and to hammer the point home the companies do from time to time reclassify their assumptions and you suddenly find you have gone from being say one third Scandinavian to a mere 5 per cent Scandinavian – that would not happen if the tests were scientifically based and robust. Another problem is that different company’s use different sample populations and so testing with different companies can give you different ‘ethnic identities’.
Turning to the rests recently received. They are as good as any other as they are only guesses or predictions. They know nothing of the donors ancestry and have made comparisons with the sample populations they have, but who is to say they are accurate? Even on a well-researched tree few people go back before 1700 which in genealogical terms is very recent and there could be significant events that happened before that which still have an impact on your results. Also trying to break down your identity into Scottish, English, Irish etc. is not as easy as some people say as we are a very mixed up and inter bred nation with a lot of people not really knowing much more about their ancestry than a generation or two back. Ok they learn more by researching it but what about all those brick walls that stop research and errors we all make at some time, they all affect our ability to say what our ethnic ancestry is i.e. we may say it’s one thing but the (imperfect) autosomal test may indicate something else – who is right? When Ancestry started doing the autosomal tests there were a fair few posting on here saying the tests were overestimating Scandinavian inheritance and under estimating Irish inheritance. Ancestry did take notice of this and refigured their tests to play down Scandinavian influence and increase Irish influence. OK that might have been a shrewd move as their market is largely in America (with its large and influential Irish immigrant population) but it is not scientifically based so really what use are their test results if they can be so easily manipulated?
I myself tested with ftDNA. Last year they recalculated their ethnic identity algorithms and my results then showed a marked difference to my father’s which they had not done before so to say the least I was less than impressed. However when I use the analysis tools on Gedmatch mine and my father’s results are much more in sync, should this difference between two companies using the same data really occur if they were scientifically and robustly based? (Oh and my father is definitely my father!)
In conclusion what I would say is remember the results are only guesses and should be treated as a bit of fun. If you want to do further analyses on the results you have received upload them to Gedmatch and use the different analysis tools they have to get several more analyses. However, at the end of the day the companies do reclassify their results and the ethnic identities from time to time so what you are today will not necessarily be what these same companies using the same data say you are in the future.
