Every one you can!
There are always a lot of reader questions about what DNA test to take and who to test for the best results for genealogy.
The Legal Genealogist‘s standard answer is: test everyone you can afford to test, with every test that might provide the answer you’re for.
But in case that by itself isn’t helpful, let’s look at specific reader questions and why specific tests might provide solutions to their problems.
Q. Test the older generation?
Reader Walker Hall had a question many people ask: “Since my parents are still around and interested in genealogy, should I skip straight to testing them if they are receptive, rather than waste money on myself? I would assume that as long as they are truly my parents (haha), then my dna results would be of little genealogical value compared to the combination of my parents’ individual results.”
The same question, with a twist, came from reader Diana Bowen: “is it better to go with the older generations in the family when testing? I can get my mom, mother in law, paternal aunt and then my husband’s paternal aunt. Does it make more sense to do this or just to test my husband and me?”
A. Oh, yeah.
This is an easy one. One of the most useful tests for genealogy is the autosomal DNA test — the test for the kind of DNA we all inherit from both of our parents1 in a mix that changes, in a random pattern, from generation to generation in a process called recombination.2 It’s really useful for finding cousins who share some portion of DNA with us with whom we can then share research efforts.3
Because of that recombination in every generation, some DNA that our parents might have inherited isn’t going to be passed on to us. Of necessity, when each parent passes that DNA to us, 50% of what that parent has gets dropped out of the mix. So for autosomal DNA testing, we always want to test any available representative of an older generation: a parent is better than our generation, a grandparent better than a parent.
So Walker should definitely test his parents, and testing both of them will give him all of the possible cousins he might match on either his maternal or paternal side. There isn’t anything Walker can get from testing himself that he won’t get by testing both of his parents.
For Diana, she definitely wants to get testing done by all four of the older generation relatives — but in her case, there is a benefit in testing herself and her husband as well. That’s because, in each of their cases, the older generation candidate on the paternal side is the father’s sister, rather than the father.
Remember that recombination is purely random and it happens not just in every generation but every single time a child is conceived. In Diana’s situation, each father could well have inherited some fairly substantial chunks of DNA that his sister — the aunt — did not inherit. And each father could have passed some or all of those chunks down to his child — Diana or her husband.
As a result, Diana could have cousin matches in the DNA testing databases that her aunt won’t have and her husband may have some that his aunt won’t have. And, of course, the reverse is also true: each of the aunts will match some cousins that their niece and nephew won’t match.
You remember that part about testing “everyone you can afford to test, with every test that might provide the answer”? Yup. I really mean it.
Q. On beyond autosomal?
Diana had another part to her question: “is there any reason to also consider a ydna test anymore (as an extra)?” And reader MC, who’s thinking of getting her whole family tested (including her parents and her brother), was wondering too: “Should I get any of my family members to take the paternal or maternal line tests? What additional data could I expect from those?”
A. Oh, yeah.
This is also an easy one, and again: my answer is yes, do it, and you may learn a lot. Because as wonderful, as exciting, as innovative as autosomal DNA testing is and can be, it often can’t give us a clear-cut answer to the one question we most want to have a clear-cut answer to:
Am I descended from — or at least related to — that one man or that one woman?
For the first question, the answer can come from a YDNA test. YDNA is the kind of DNA found in the male gender-determinative Y chromosome that only men have.4 It gets passed from a man only to his sons and from his sons only to his grandsons and from his grandsons only to his great grandsons, with few changes down the generations.5
For the second question, the answer can come from testing mitochondrial DNA — mtDNA — the kind of DNA we all have that serve as energy producers for the cells in our bodies.6 It gets passed from a mother to all of her children — male and female — but only her daughters can pass it on to her grandchildren.7
I wrote about this back in August in a post called The value of the tests that emphasizes one key fact: those “old tests” are not so “old hat”!8 Being able to nail down a male line or surname or a specific female line of descent can be a powerful addition to genealogical testing, and you can only get this by doing these additional tests.
Bottom line: test everyone you can afford to test, with every test that might provide the answer you’re for.
SOURCES
- ISOGG Wiki (http://www.isogg.org/wiki), “Autosomal DNA,” rev. 14 Nov 2014. ↩
- ISOGG Wiki (http://www.isogg.org/wiki), “Recombination,” rev. 1 Sep 2014. ↩
- See Judy G. Russell, “Autosomal DNA testing,” National Genealogical Society Magazine, October-December 2011, 38-43. ↩
- ISOGG Wiki (http://www.isogg.org/wiki), “Y chromosome,” rev. 23 Apr 2014. ↩
- Ibid., “Y chromosome DNA tests,” rev. 27 Nov 2014. ↩
- “What is mitochondrial DNA?,” Genetics Home Reference Handbook, National Library of Medicine, US Department of Health (http://ghr.nlm.nih.gov/handbook : accessed 29 Nov 2014). ↩
- ISOGG Wiki (http://www.isogg.org/wiki), “Mitochondrial DNA tests,” rev. 9 July 2014. ↩
- Judy G. Russell, “The value of the tests,” The Legal Genealogist, posted date (https://www.legalgenealogist.com/blog : accessed 6 Dec 2014). ↩
Judy,
You did make me laugh with this one. “test everyone you can AFFORD to test” with the emphasis as I placed it. Fixed income priorities are a matter of weighted values! And unfortunately we still need to eat. In my case the decision is made easier as no one left in my parent’s generation and very few untested first cousins that I can convince and at second cousins I can afford to wait for them rather than pay out of my own pocket……LOL
What is this “eat” of which you speak? 🙂 Yeah, sigh, this business of not being independently wealthy can be a real bummer. Not only do I not descend from generations of people who left wonderful records, I also do not descend from people who left any money…
I just want to clarify that it probably is not worthwhile (unless you are a testing junkie and have a lot of spare cash) to test multiple individuals who are closely related and shared direct line ancestors with direct-line tests (Y and mt) unless there is reason to suspect that there is mis-attributed paternity somewhere.
With autosomal tests, it is probably wise to test as many as you can, as soon as you can, but target those older generations that may not be with us much longer first :).
Good clarification, Angie: if the father has been YDNA tested, there’s no fundamental reason to YDNA test the son, a brother, a male cousin, etc. If the mother has been mtDNA tested, there’s no fundamental reason to mtDNA test her children, her sisters, etc. Unless of course you are independently wealthy and are doing it all just for fun…
In reply to Angie and Judy a question I need an answer to: I have tested my second cousin once removed (mtDNA – full sequence)to test against my own to verify that we share the great and 2nd great grandmother w/FTDNA. I happened to have Debbie Parker Wayne here to speak for our fall seminar when I received my results and freaked out when I saw I was a distance of 1 from my cousin. Debbie told me to check the FTDNA website that she thought this was a heteroplasmy and I need not panic.
What I found was that I had one coding region difference – an extra box at the end labeled G15326R (RSRS) and where my difference from the rCRS reads 15326R hers reads 15326G. She has 4 mutations that are the same as mine – there is that one difference. So that mutation happened somewhere in the last 4 generations on my side. My mother was the only daughter in her family and she is gone – no other subjects in this line. Would there be any reason to test my brother or sister to see if the mutation occurred in the passage to me (oldest) and not to one of them? We are the only direct line descendants in my direct female line and there are only a few in the other direct line – all the other lines were boys.
Is it worthwhile even trying to pinpoint when the mutation occurred with only my siblings available to test? If I understand the brief description on FTDNA correctly this would be position 73. Or I am trying to solve an unsolvable question with the few subjects available and would be better off testing more cousins?
Thanks
Carolyn, I’m a long way from being an expert in mtDNA heteroplasmies, but my own sense is, while it may be interesting to see where the heteroplasmy occurred, this isn’t going to be particularly useful. In my own family results, both my maternal first cousin and I have a heteroplasmy, but we each have a different one. So we are reported as a genetic distance of 2 from each other, even though our mothers are sisters and all of our other DNA results clearly show there’s no chance at all of error in that relationship. Clearly, one of those heteroplasmies — or both of them — would have to be very recent, since we don’t both share both of them.
We are — out of sheer curiosity — going to do her mother’s mtDNA (my mother has passed on but my cousin’s mother, my youngest aunt, is still living). I could test my sisters to see if they share the heteroplasmy that I have. But, realistically, to what end? It’s a single digit mutation out of more than 16,000 markers, and unless I needed it to prove a specific parental line, I don’t think I’d bother (except, as noted, because it’s an interesting curiosity).
Thanks. Probably best to test more cousins and try to determine which DNA matches come from where.
I do find it interesting because it has to be fairly recent. And a woman who lists her oldest known ancestor as living in Russia (though with a German name), matches my cousin with 0 distance and me with a distance of 1. Possibly a descendant of one of the daughters who ended up in Russia – maybe a German from Russia.
trying to find my maternal grandfather’s father…we only have one direct line male left, through his father and myself, through my mother…what test would be best for finding my great grandfather ????
great grandfather unknown deceased
grandfather….known but deceased
uncle…known but deceased
male 1st cousin, grandson, living
daughter of grandfather, my mother…known but deceased
myself….grand daughter, living
who do I test and which test and how many marker to be most accurate to grandfather
thank you
Nancy J
Test your cousin, both YDNA (and as many markers as you can afford but not fewer than 37 markers) and autosomal DNA, and test yourself for autosomal DNA.
OK I’ve just taken my first DNA test and am awaiting the results. I also bought a couple other boxes from Ancestry because of their sale. My question is this, what do you do when you test older generations? The process seems to require an ancestry account for the DNA owner but the people I plan to ask to take the test don’t use the computer. Or can I activate any number of kits within my own account (which would imply that I am accepting the privacy etc policies on their behalf)?
I have a proven ancestry back to William Kerr and Margaret Jane Miller both of whom passed away in Lafayette Township, Owen County, Indiana. William passed on 05 Mar 1850. His wife passed on 27 May 1850.
Try as we might, we cannot VERIFY the parents of William. Some suggest that he is a descendant of Walter Ker of Freehold New Jersey.
Other report suggest that his a a descendant of a John Kerr. If I were to take a DNA test, would I be able to find the branch from which my William descended or would it simply report that he is of Scottish decent. A fact we already have established.
If you are a direct male line descendant (no females in your line of descent but males only) or if you are in contact with a cousin who’s a direct male line descendant of William, AND if descendants of John and Walter have both tested, THEN a YDNA test could help you identify which of those Ker lines (if either of them) you belong to.