DNA’s Limitations: Its Statistical Basis & the Need for an Hypothesis about Who You’re Looking For
Editor’s Note: I observed that Joe had acquired a real mastery of these tests while chasing his ancestral mysteries, and asked how the technology brought him to enlightenment he could not have reached otherwise. Joe first cautions that DNA adds a layer of complexity to the fascination and frustration of Irish genealogy: everything comes couched in statistical terms — the chances that you are related to this person or that. His first hypothesis was simple: are Jimmy Harte and I related? He warns that people who get a test kit as a Christmas gift, without a base of traditional research or a question to test, will find the results largely meaningless.
Transcript
Speakers: WJB — William J. Bowe; JH — Joseph Hart. Transcribed from the recording; punctuation added and obvious mis-hearings corrected.
WJB: Here, what you’ve just explained — you along the way acquired a mastery of this complex set of tests and what they do, and you got your education in this while pursuing, of course, these ancestral mysteries. So explain how it is that you got with this technology to enlightenment that you wouldn’t have gotten to otherwise.
JH: Okay. I’ll preface this by saying that I mentioned that I find Irish genealogy fascinating and frustrating, and the use of DNA has tended to just add a layer of complexity to the fascination and frustration. Again, anything to do with DNA and genealogy — use of DNA testing is a statistical endeavor. And that’s the one thing that I found to be most unsatisfying about DNA testing, is everything is couched in statistical terms, meaning what are the chances that you’re related to this person or that person?
So anyway, I got to the point where, okay, I’ve been digging in the paper trail for a number of years. I’m not making much headway. Jimmy suggests we try DNA, and so that started the whole focus on using DNA as a tool to gain more clues, to see if I’m on the right track, basically. So it started out that the strategy for using DNA was, are Jimmy Harte and I related? And Y chromosome testing is going to tell us that.
So I found that if I go into any kind of DNA research, it helps to have a hypothesis that you want to test. A lot of people nowadays get a DNA test kit as a gift at Christmas, or you give one to your mother on Mother’s Day. And people haven’t been doing their homework by starting out in traditional genealogy and building kind of a base of information that they can relate their DNA test results to, or come up with questions. Say, the basic question is, am I related to this other person? And if we’re related, where is our common ancestor in the past? So that’s what I kind of started out with. I can see that somebody else who gets the test kit as a gift, takes the test, and gets these results, it’s going to be kind of meaningless. Most of it, or a lot of it, is going to be meaningless to them. Or if they’re an orphan, an adoptee who is attempting to find their biological roots, they’re going to have a difficult time unless they’re extremely —
