Your Guide To DNA Ancestry Testing
Humans have a natural desire to know who they are and where they come from, and advances in genetic biology are allowing people to explore their ancestry in a whole new way. DNA testing is now very accessible and affordable for the consumer. You simply find a company online, they send you a package containing cheek swabs which you send back to them to be analyzed. However, there are a lot of companies out there offering different tests, addressing different needs and concerns among consumers and the scientific community, and it can be difficult to find what you're looking for, especially for those with a poor understanding of genetics. This guide attempts to give a comparison of the 2 main types of tests offered and to comment on the usefulness of each.
Introduction
In the half century since James Watson and Francis Crick created the first accurate model of DNA, which opened the modern era of genetics, we have completely mapped the human genome, and are able to provide new scientific insights into ethnic development and geneology.
Along the way, geneticists have discovered "heredity markers" in human DNA that tell their unique story as passed down by their ancestors, and some of these markers are unique to certain population groups. Things such as the colour of your skin, your resistance to malaria, what kind of eyelids you have, the air intake your nose is suited for etc are all traits that have been developed in different degrees and durations of isolation among all the distinctive ethnic groups of the world.
Now, there are several different tests you can take, offered by a handful of companies that have their own patented testing methods and databases, but there are basically only 2 methods used: Analyzing Parental or Mitochondrial DNA (mtDNA) and Autosomal (unrelated to sex) DNA.
mtDNA Tests
The largest ancestry test that is being offered right now is The Genographic Project through National Geographic and IBM. I have personally seen the results from this test and this is basically what you receive:
X belongs to: Haplogroup I (M170)
If you look at the map highlighting you ancestor's route, you will see that members of haplogroup I carry the following y-chromosome markers:
m168 (Not African) > m89 (Not Asian) > m170 (European) *comments in brackets added by author
Your most recent common ancestor, the man who gave rise to marker m170, was born about 20,000 years ago and was heir to this heritage. He was probably born in one of the isolated refuge areas people were forced to occupy during the last blast of the ice age, possibly in the Balkans.
It's possible that the Vikings descended from this line. The Viking raids on the British isles might explain why the lineage can be found in population in southern France and among some Celtic populations.
This is where your genetic trails as we know it today, ends.
...not what I was looking for, either. That's because the purpose of this test is to provide research information into early human migration, and only offers clues into deep ancestry. All tests that analyze mtDNA have the same limitations.
Mitochondrial DNA (technically "Y-chromosome" info for males and plain "mtDNA" for females) is supposed to be copied exactly from father to son or mother to daughter, with only minor (and invisible) mutations among populations occuring over periods of thousands of years, slower depending on birth rates and which are subject to natural selection. To use an extreme example, let's say 10 generations ago, your Swedish great grandfather left his home country and bred with a Japanese woman. Even if their male descendents throughout the next 9 generations bred exclusively with Japanese women, it is still extremely unlikely that your Y-chromosonal information would differ from your Swedish great grandfather. The same goes for women, only the vehicle is mtDNA instead of the Y-chromosome DNA. If you're a male and took this test it would tell you that you are European, even though you would be overwhelmingly Japanese.
There are only 38 major haplogroups (mtDNA mutations that have survived and are present in groups of significant size) in the world after all, and only 9 major ones making up the entire white population. The only real data that the test gives the customer is an arbitrary dot on a map. Genetic markers of diversity are completely ignored.
Theoretically, the mtDNA test could offer an advantage if you are concerned with "purity", but with outrageous exceptions as I will explain. If you are a Scotsman, but your haplogroup turns out to be one typically present in a completely different part of Europe, it only means that one of your ancestors, as far back as even tens of thousands of years, wasn't from your part of the world. Your fellow Scotsman have just as much chance of deviation as you do, as several haplogroups are often widely present in effectively homogenous populations.
Now, if you turned up with a sub-saharan african haplogroup, that means that your lineage would be a rare exception to the majority of your neighbors, and given the timelines of meetings between Northern Europeans and Blacks, odds are that you had a black male ancestor in sometime in the last 500 years or so. On the other hand, say you find the typically European haplogroup result you were hoping for, but in reality your great grandmother was black? It would not affect your Y-chromosone results although of course it would be a contributing factor to your genetic makeup. You could have your sisters tested as well, but what if your dad's mom was black? That information would not be submitted to you or your sisters, again even though the genes from that relative are still very much a part of all of you. Basically, it's an ineffective method of confirming or disconfirming an already absurd concept.
At least the test is cheap. For only $100 you get your little certificate and a whole lifetime of conversation starters.
Autosomal DNA Tests
Sometimes called BGA (Bio Geographical Ancestry) testing, Autosomal DNA expands the range of examination to include unique characteristics common in reasonably well defined population groups, that are of course manifested by DNA. The most credible company doing these tests (they have been used by US forensics agencies) is AncestrybyDNA. This testing method claims to give an approximate percentage breakdown of the different ethnic groups you may be comprised of in the results (there is of course a margin of error, which may increase with more disparate admixture). The data analyzed in this test is quantitative because there has been testing done on native inhabitants all over the world to form a reference database. This has been cross-checked with anthropological data (undoubtably enhanced by the recent mtDNA findings) on human groups to produce an estimate of your unique ethnic blueprint.
AncestrybyDNA's basic test splits you into percentage European, Sub-Saharan African, East Asian and Native American (here is a table of average results organized by nation), and it currently costs about $200. From there you can upgrade to the EurasianDNA 1.0 test for another $200, which splits you into percentages of the following broad categories:
- Northern European
- Mediterranean
- Middle Eastern
- South Asian
There's also a EuropeanDNA 2.0 test available for those who want an even more in depth look. It chops you into:
- Southeastern Europe (SEE - Armenian, Jewish, Italian and Greek)
- Iberian (IB -Spanish, Portuguese)
- Basque (BAS - Spanish/French Pyrenees border),
- Continental European (CE - German, Irish, English, Netherlands, French, Swiss and some Italian)
- North Eastern European (NEE - Polish, Baltic, Swedish, Norwegian, Finnish, Russian) ancestry.
However, the more in depth European test is currently a $550 upgrade! $800 is probably more than most people are willing to pay.
Conclusion
Now you might say, "How is this useful? All my parents and grandparents have all been eskimo, I don't need a test to tell me that I'm eskimo." or even "Well, my dad is French/German, and my mom is Nigerian, what does it matter one way or another what percentage I am of which?"
Well, that's pretty much what it comes down to. The test is an elaborate way of confirming data that is easy enough to gather using traditional methods like geneological research, looking at family photos, talking with family about your heritage, even just looking at yourself in the mirror. Learning about the different ethnic groups is useful too, the literature is out there, and you must always consider travel and interacting with different cultures if you haven't already. Listen to your body and take note of your behavior. Remember, race is a spiritual concept as well as a biological one, and tests like these by themselves could never bring you that kind of satisfaction.
If you have serious doubts about your background, or want to apply for minority status, these tests could have some really practical value, assuming the more efficient methods like parental DNA tests aren't an option.
The large scale implications of genetic testing are intriguing. The fact that they are able to stimulate interest in race in societies where these concepts are actively discouraged is a hopeful sign for change. Now that these tests are available to the public in the open marketplace, consumer interest can help keep scientific findings on differences in peoples from being buried under moral political pressure (corporate ownership is more of an impedance rather than a danger). The Human Genome Diversity Project's rebirth (the HGDP can be considered the pilot project of the current National Geographic project) from it's demise over ethical issues is a very encouraging sign that ethnic and cultural awareness is still alive in our society, and can perhaps overcome the forces against it.
As the technology develops, the sample pool expanded, and perhaps most importantly, if there is enough public interest to neutralize the taboos surrounding these issues, we can expect this process to become more and more refined as/if time goes on.
If you can afford them, DNA ancestry tests provide a fun way of exploring your background, and can provide important clues in your journey of self discovery.
by Mathew Eugene
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