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What Do Ancestry DNA Tests Reveal?

17/05/2017 17:13 BST | Updated 17/05/2017 17:13 BST
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Taking an ethnic DNA test is never innocent. Once you have opened the box and all the genes have been analysed, you are left with more questions than answers.

I took an AncestryDNA test with the view of finding out if there was any true in the fact that my paternal great grand parents originated from Germany, traces or Teutonic genes would have sufficed to convince me. Because all in all, except for that one set of great-grand-parents, I was pretty certain of where I came from.

Here is the scientific bit: Each individual inherits about 25% from each grandparent, 12.5% from each great-grandparent and approximately half the previous amount for each subsequent generation. The particular combination we each inherit from a set of parents, makes each one of us unique. When buying a test it's important to get an Autosomal DNA test which tests both paternal and maternal lines.

Who did I think I was? My father's father's family originated from the small village of Pollet in the Departement de l'Ain, France. The first inhabitants settled in the territory of today's Ain about 15000 BC. Trawling cemeteries is a good way to identify ancestors, in Pollet nearly all the gravestones bare our family name. Therefore, I was expecting the results to show 50% Western European.

My mum's side was always going to be slightly more volatile. My mother was born in France of the union of two Moroccan Jews. So throw in the mix a good dose of North African, a little Spanish as along the route, one may have dilly-dallied, some Middle-Eastern blood on account of the family Jewishness and Bob 'z your uncle. But, is he....?

The test results taught me that it's really impossible to predict what your DNA profile will look like. I would go as far as saying, "predictions, forget it! In the long run, predicting your genetic ancestry without proof will only make you look plain stupid".

My 50% French turned out to be non-existent. Vanished, disparus. It would appear that I have less than 1% of Western-European DNA. To everyone who refers to me as The French Woman, ethnically, I ain't. Mind you, I am not much more Moroccan either, I have only 3% of North African DNA.

But I am BRITISH! And that, I can't explain, nor can my mum! 15% of British genes is a large percentage. Baring in mind that a native Brit will have 60% British DNA maximum. My 15% makes me a quarter British, I could flatter myself and claim that I am the perfect immigrant, I even stole the locals' DNA but, I found an altogether more scientific explanation.

"Testing companies will often assign national labels to genetic clusters, whereas gene variant frequencies tend to change smoothly across borders". states an UCL article before continuing, "Thus, French people may be assigned a large percentage of "British" ancestry. Normandy and Kent are genetically similar, as you would expect from history and geography, so it is not easy to distinguish English from French based on DNA alone."

And here comes the really interesting bit, "Given high quality genomic databases it would be possible to assign an individual to a region of origin with a reasonable degree of accuracy (human provenancing), but this is beyond what genetic testing companies currently have available both in terms of having enough genetic markers in large and well-annotated databases."

How does population and DNA matching work? In other words, what is the baseline for the DNA tests? Here is what Ancestry DNA says, "Your ethnicity estimate shows where your ancestors came from hundreds to thousands of years ago. We calculate it by comparing your DNA to the DNA of a reference panel of people with deep roots to specific places around the world. To read more about population and DNA matching click here

The results left me puzzled about my origins but I have always been a bit of a travelling chameleon, feeling an integral part of the population of humans around me, even when xenophobia raises its ugly head and tries hard to exclude me. So puzzling as they are the results have not disturbed me. I belong as always to where my home and the people I love are.

In many ways, the test results enthrall and puzzle me in equal measure and even though I can't easily disentangle my ethnic DNA from my passports or my beliefs, where I come from matters less now than it did when I first agreed to take the test.

But for me, the most important result fact revealed by the test was that we all are of mixed origins and to whoever says, "Not me, gov! I know where my ancestors came from", I dare them to take the test.

A version of this article was originally published on personal blog