top of page

DNA: a PSA

In a way, everything I've written for 52 Ancestors in 52 weeks has been about DNA, or at least about genetic genealogy and using DNA to better identify relatives. Although I've been interested in genealogy for a long time (and took all the genealogy DNA tests as they became available, and made my brother do the same, because... Science), I didn't attempt any genetic genealogy - using DNA testing and analysis to uncover family relationships, ancestral origins, and genetic traits - until about a year ago. DNA definitely made a difference. This fan chart was generated by the wonderful free tools at DNAPainter.com based on my family tree BEFORE DNA:

Dark blue is people born in the US, orange = Germany, red = Canada

Here's what I think I know today, AFTER DNA:



Genetic Genealogy companies sell a lot of DNA test kits to promote "ethnicity" testing, i.e. "I thought I was Scottish, but I traded my kilt for liederhosen!" In reality, DNA testing can provide information about where the genes you ended up with lived at some point or another, but it's an evolving science and every company approaches it differently. Still, I was always puzzled about why ethnicity reports didn't have more liederhosen... it turns out 3 great-grandparents who I believed were German immigrants were different people altogether, with English and Colonial roots, something I only learned through DNA research. For me, researching with DNA is another dimension to the puzzle, and I do love a good mystery. I'm sure there are more surprises in store and I am looking forward to stumbling upon them. However, genetic genealogy should be used with care. If you're considering looking into using DNA for genealogy, be sure you've thought about these things:

1. Don't take a DNA test unless you have thought through what it could tell you. Every day, people check their results for their kilt vs. liederhosen designation and instead find out that their father is not biologically related to them, or that they suddenly have a half-sister they've never heard of. Depending on the test, you may also learn about health risks of which you were unaware. I thought I went into this with eyes wide open but learning that my great-grandfather was not the man married to my great-grandmother really shook me for a bit, even though all the parties involved had been dead for half a century by then.

1A: DNA test results have to be interpreted and there's a definite learning curve with that. It's not uncommon to encounter someone with a despairing story about how they just found out they are adopted because their parents' names didn't come up as DNA matches... but it was because their parent hadn't ever taken a DNA test (or they did but it's in a different database - law enforcement or military or just a different company)! In order for a match to occur, the person must have tested with the same company, and must have said it was okay for their matches to see their user ID. Or a person thinks they are adopted because they expected their matches to all share their same surname. Of your 32 great-grandparents, only one shared your surname at birth!

1B: DNA won't create a family tree for you. It can only identify relatives who have also taken a DNA test and share DNA segments with you. The rest of your family tree still requires traditional genealogical research to piece together. So many people have their DNA done and then abandon their research because their matches are all relatively distant and they don't know any of them. That's kind of the whole point of DNA - to find relatives you didn't already know about! So you take the match and then work to figure out how they fit into your tree.


1C: There are only two relationships that can be absolutely confirmed by DNA -- Parent/child and full siblings. Right now, ALL other relationships are "best guess" estimates, based on the amount of shared DNA. So people get their results and it says their Aunt is their half-sister and they either freak out or decide that "DNA is WRONG!" DNA is not right or wrong; it simply is. How it is interpreted can change over time. The amount of shared DNA between Aunt and niece or nephew is the same amount shared between half-siblings, or between a niece and Aunt or Uncle... Each company tries to give a prediction but people tend to read that as fact when it is just the company's best guess.

2. DNA testing companies have different privacy policies, and it is important to read and understand them before taking a test. Some companies may share your genetic data with third parties, such as law enforcement agencies, without your explicit consent. Personally, I'm all for that (sorry/not sorry to all my criminal relatives, whoever you may be!) but I do try to stay on top of the ability of insurance companies to access health data to make coverage or rate decisions.

3. There are different types of DNA tests available and different companies with whom you can test. The drug store paternity tests are pretty much useless for anything. Ancestry.com has by far the biggest DNA database and you can link your DNA research to your "paper" research on your online family tree. 23andme focuses more on health data; although they give you better DNA segment analysis capability than Ancestry, there are no research databases and the "tree" capability is a limited exercise in total frustration. With Ancestry and 23andme, you have to buy their test to check for matches in their databases. With many other companies and tools, you can upload the data from your Ancestry or 23andme test, often for free. Why more companies? To try to find more matches, of course... and to use the unique tools that each company offers. Also, if your ancestors are relatively recent immigrants, other companies may have more matches for you based on how they have focused their marketing. 23andme and Ancestry both have frequent sales on their tests and there are also some hacks for spending less on the incredibly expensive Ancestry.com research subscriptions, so avoid the impulse buy and plan your purchases.


4. Just as every individual has unique DNA, everyone's matches will be different. Some people will have hundreds of "close family" matches -- that may seem like a windfall but can actually signal that your family tree is a tangled web. Others, like me, won't have many at all. Whether that matters to your research depends on your goals. In my case, having matches who only shared greats or great-greats was just peachy because those were exactly the ancestors I was trying to identify. A lot of adoptees lose hope when a DNA test doesn't come up with a match that says "father" or "mother." However, by identifying the shared common ancestor with more distant matches, it's possible to trace forward in time to identify likely candidates. On the other hand, if someone is searching for a child, unfortunately, the only way to identify them is if that particular individual tests.


Genetic genealogy is so much fun. I'd love to help you get started if you're at all interested. I'm no expert, but I do have a solid grounding in "mistakes you don't need to make because I already did." Who knows... maybe *we* are related!



Comments


bottom of page