DNA as confirmatory evidence

[Pauline]

I've been pondering over the comment in the latest newsletter about DNA providing "confirmatory evidence", in the context of establishing that we have found the right baptism (or whatever).

The more I work through my DNA matches the more it brings home just how complex DNA inheritance is, which makes me wonder just when, and to what extent, we can use DNA to confirm what we have found in the paper trail.

DNA clearly provides a degree of proof (depending on how much DNA is shared) that we are related to our DNA cousins, but exactly how we relate is less certain. It may depend on how many family members have tested, and how many matches we have in a particular line.

I think sometimes - maybe often - DNA can only provide us with further supporting evidence rather than anything more definite.

What do others think?

 

[jorghes]

I have had a couple of experiences of DNA as confirmatory evidence.

I had added a couple of 5th great grandparents to my tree and was decidedly ambivalent about them - I didn't have a lot of documentary proof that they were meant to be there, and they had emigrated to Canada with some of their family while one of their sons (my direct ancestor) had stayed in Scotland. His son had later emigrated as well, but to Australia. It seemed vaguely unlikely, although not impossible, but I admit to thinking that perhaps these people weren't meant to be in my tree.
My first quivering leaf in my DNA results - almost the holy grail in Ancestry hint lists, where they have a matching ancestor in their own tree (private or not) - was to that same set of 5th great grandparents who emigrated to Canada, through a descendant of that emigration. I was so happy to have that confirmed. (later found that same cousin on Lost Cousins, so doubly confirmed!)

Also, when I first discovered my Jewish ancestry - before that I thought my entire ancestry was limited to England, Scotland and Wales - I found it difficult to believe, especially when I found a complete tree. I added it all, since I was fairly sure it was correct, but there's always that element of doubt. However, once I input my DNA results and more particularly, those of my father, we so far have 9 "hints" in regards to relatives on that side: from 3rd cousins (2), at least 5 4th cousins and 6th, 7th and 8th cousins, all confirmed by DNA.

I got a fresh confirmation link this morning to my father's ancestry this morning for another side that I was fairly sure was correct - paper trailed to this particularly ancestor's second marriage, but now confirmed with DNA.

I don't think that DNA can take the place of searching through the paper trail, since you might not know where the link it is if you haven't done the searching first. But I think it definitely can confirm that you have found the right people once they're there! Ancestry's linking system can make the confirmation easier, since it looks for links for you, but again, without the research done on both sides for the most part, it doesn't matter as without the matching information it won't work.

 

[Pauline]

I have had a couple of experiences of DNA as confirmatory evidence.

I guess my thinking is that it very much depends on the circumstances.

For example, I have a recent ancestor for whom there had always been a slight question mark as to who the mother was. Since I have a fair few DNA matches on both the paternal and maternal side of this "slightly in doubt" mother, I feel I can now be pretty confident in removing the question mark.

But there are other circumstances where things are much less certain, such as with my Wiltshire ancestry. Although I have to go back to the 16th century to find any confirmed pedigree collapse in my own ancestry, now that the Wiltshire parish registers are online I have been able to discover all kinds of much more recent connections between my different ancestral lines there, with a sibling of one ancestor marrying the sibling of another and so on.

So some of my Wiltshire DNA matches are related to me in several different lines, and even where Ancestry have highlighted a shared ancestor in our trees, I cannot be sure that our shared DNA comes from that particular ancestor.

 

[peter]

I guess my thinking is that it very much depends on the circumstances.

Absolutely - you have to consider all the possible scenarios that could have led to the DNA match, just as Sherlock Holmes would have done.

But don't assume that just because you are related to someone through more than one line you cannot make use of the match - sometimes you can identify a segment of DNA as having come from a specific ancestor. The more cousins who have tested, the more likely this will be.

 

[Pauline]

But don't assume that just because you are related to someone through more than one line you cannot make use of the match

No, I’m not assuming that.

The more cousins who have tested, the more likely this will be.

Yes, and I guess it would help if I had more close family members I could ask to do a test. With more distant cousins, although I can suggest doing a test, and outline the potential benefits, I just have to wait and hope! I do make good use of the “shared matches” feature.

 

[peter]

I guess it would help if I had more close family members I could ask to do a test

Actually it's distant cousins who are most likely to help, because close family members share so many different lines with you.

 

[Pauline]

Actually it's distant cousins who are most likely to help, because close family members share so many different lines with you.

Mostly, yes, though close kin can be helpful when you don't know whereabouts in your tree a connection might be.

 

[peter]

close kin can be helpful when you don't know whereabouts in your tree a connection might be

Agreed, but that's not what this particular discussion is about, and I didn't someone new to DNA to be confused.

 

[Pauline]

that's not what this particular discussion is about

That occurred to me after I posted - though too late to edit it!