Personal Genomics and Genetic Genealogy Tidbits

  • There’s a terrific discussion in the comments to “Genetic ancestry testing: people who don’t want to know” about people who refuse to undergo genetic ancestry testing for personal reasons.  I added my own 2 cents at comment 17 trying to explain some of the most common misunderstandings surrounding autosomal DNA testing.

3 Responses

  1. Brad Templeton 14 March 2010 / 9:36 pm

    Well, if you disagree with what I wrote about the use of haplogroups in genealogy, I would appreciate something a bit more concrete, such as what error you find in the numbers I calculate, or some reasoning why the numbers don’t indicate reduced utility for haplogroups in genealogy.

  2. Blaine Bettinger 15 March 2010 / 8:18 am

    Brad – from what I read, I didn’t see anything wrong with your numbers. I do, however, completely disagree with the following sentence from your first post: “As such, the big genealogy web sites are all getting involved, and the Family Tree DNA company, which previously did mostly worthless haplogroup studies, is opening up a paired-chromosome scan service for $250 — half the price of 23andMe’s top-end scan.”

    Rather than “worthless haplogroup studies,” most of FTDNA’s testing is Y-STR testing, which provides extremely valuable information that genetic genealogists use everyday for a wide variety of things (verifying hypotheses or paper records, breaking through brick walls, establishing or refuting relationships etc…). There are literally hundreds of success stories using this type of testing (which I can direct you to if you’re interested). Although you later stated that “[w]hen it comes to the haplotypes, things are much more specific,” I felt like you buried it in your article, which could have been misleading to readers.

    I also wonder if you are glossing over the impact that genetic genealogy results – even haplogroup results – can have on people, especially genealogists. Identifying the ancient origins of a single ancestor (your 1 out of 1024 at 10 generations analogy, a well-worn analogy which genetic genealogist proponents have noted many times is well-known to genealogists) can be an extremely important find for a genealogist. Many genealogists have spent hundreds of hours and dollars researching the roots of just a handful of ancestors, and learning more about one can be exhilarating, even if it’s nothing concrete. I’ve seen this play out many, many times from both personal experience and from reading posts to several mailing lists devoted to genetic genealogy.

    Sometimes you have to look beyond the numbers.

  3. Brad Templeton 16 March 2010 / 5:07 pm

    What I worry about is just this, though. You can learn something about what population one of your many millions of ancestors came from. Haplogroups aren’t telling you anything specific about 10 generations back, it’s hundreds of generations back. We are all very mixed creatures. To be in an ethnic group or race just means there were more of those in your millions of ancestors than others. Almost nobody is “pureblood” except a few people who came from geographic isolation. As such, we all have ancestors of every single haplogroup found in our geographic region.

    There will be the odd surprises due to the geographic isolations — for example not everybody has native american or australian ancestry. So there are some slight odds that if you have such ancestry and it happens to include the maternal line, you will learn about it this way.

    But if you are of European stock, I will advance that every European haplogroup will be found somewhere in your tree of ancestors many times.

    So what is really learned by the knowledge that one of them is your maternal or paternal line ancestors?

    I contend we get excited about the haplogoups not because they are meaningful, but because they are easy to read.

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