25 October 2016

Who I am: DNA testing and ethnicity

This is one in a series of posts on the search for my biological family.

The last decade has seen the proliferation of DNA testing. In addition to becoming more sophisticated, it has also become less expensive. Although I did not expect that DNA testing would be the answer to the question of who I am, I thought it might help. And it turns out, it has.

The first DNA test that I did was an autosomal DNA test via Ancestry.com. This is as simple as spitting some saliva in a small tube and sending it back. The Ancestry DNA test would tell me two things of some significance: first, an ethnicity estimate. Ancestry estimates your genetic ethnicity by comparing your DNA to the DNA of other people who are native to a region. The AncestryDNA reference panel (version 2.0) contains 3,000 DNA samples from people in 26 global regions. Second, the results will show me other people (Ancestry.com members) that I am related to, with some measure of how closely related. I'll cover DNA relatives in the next post.

Keep in mind that most people have some idea where they are from, from their parents (incidentally, even if you think you know where you're from, you might be surprised by the results you get--so consider it!). I had no idea. Here's what Ancestry told me about my ethnicity:

Keep in mind here that these are genetic regions. "Ireland" here is not just the country of Ireland, but also includes Scotland and Wales (and is distinct from "Great Britain"), primarily because the Scottish and Irish intermingled quite a bit. Either way, the big takeaway from this test it is estimated that I am about half Scottish/Irish.

One of the cool things about the Ancestry.com DNA test (and of most such tests) is that you can download the raw results and upload them to other genealogy sites. In this way, you can compare your results against different samples and match other users who might not be on Ancestry.com. Here is my ethnicity estimate from FamilyTreeDNA:

You can see here that this comparison shows a much stronger link to the British Isles (and when you drill down, specifically Ireland).

Finally, there is a very cool site called GEDmatch.com. This site also allows you to upload raw DNA test results and match them against other profiles (as well as many other cool tools which I will address in later posts). Specifically, GEDmatch has a series of tools called "Admixture" which are  similar to the ethnicity estimates. Here are the results of my DNA test against the Eurogenes project:

Although this project uses different labels, you can see it seems largely consistent with the other results. Still, there are some interesting variations. Specifically, 3% South Asian and 1% American Indian definitely stood out for me. It's difficult to know much of this is a matter of estimates. Nonetheless, it's interesting to say the least.

So, now I know that I'm largely Scottish/Irish, with perhaps some very interesting small bits from here and there. Shit, I'm downright cosmopolitan.

In my next post, I'll talk about DNA testing and relatedness to other people.
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