Wednesday, July 27, 2016

DNA Ancestry Limitation

There was a TV show in New Zealand where people were given their ancestral roots through a DNA test and flown to far flung places depending on what the test revealed. I have been wanting to do such a test so was keen to see how it went.

Very quickly it became apparent to me the limitation this test has. I noticed unusual links to obscure races or regions being thrown up and those you might expect not featuring. For example, my ancestry of say three to four generations back is in the majority from England. Many New Zealanders would share that with me, but people weren't being picked up as English. Then I realised that a nation like England - with constant immigration for many centuries - is a melting pot of DNA. I assume there is no English DNA as such!

Another point of which I just found out is that males who submit to a DNA test will be analysed though their father, father's father and so on. Women their mother, mother's mother. In other words as our ancestry widens the further we go back, this testing doesn't. It end up a small DNA sampling is found, then extrapolated to become a percentage of our ancestry. That method may end up being quite misleading.

Now I'm not a geneticist or know much about DNA markers but I do know that if I'm told I have a certain percentage of a given race or region, I want it to be correct. From what I see, the idea of finding your ancestry through DNA is not an exact science, and had thought it was. So due to the limitations of DNA ancestry testing, I will save my money and the trouble it takes.

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