Using DNA Matches
to Break Down Brick Walls:
Update No. 2

June 2012

The last time I wrote an update on this subject ( DNA matches and brick walls - see Update 1 ), we were awaiting two sets of test results: a y-DNA test from the Australian member of the B family, from Family Tree DNA, and an autosomal (Relative Finder) test from my maternal aunt, from 23andMe.

(For background information about the y-dna test, see Y-Chromosome DNA Testing;

for background information regarding the autosomal DNA test, see Tracing Family Trees with Family Finder and Relative Finder Tests.)

The Y-DNA Test Results

The y-DNA test results from Family Tree DNA seemed to take quite some time to arrive – and all of us (this Canadian, and a couple of Australians) were none too patient to see them! (You know the old expression, "a watched pot never boils" ...)

In the meantime, we had all gone on the assumption that the test was just a cursory matter, which would confirm what we had already suspected, that we were related. We all worked steadily on a family tree, which grew rapidly and developed many extensive branches.

I hesitated at first to even start on the tree until a relationship was confirmed, as I have enough other things to occupy my time, but in the end, I felt that the circumstantial evidence in favour of a relationship was sufficient to outweigh any qualms I might have, and I sailed right in.

Hmm … bad assumption! When the y-DNA results arrived, we all were quite stunned to learn that there was no DNA match between the Australian’s results and my family’s results. It took a couple of days for it to really sink in.

At first, we thought that there might have been an illegitimacy (euphemistically called a ‘non-parental event’ in the genetic genealogy world) in his line, or that the results might have been mixed up with someone else’s. There were no DNA matches to the B surname at all!

However, Family Tree DNA assured him that the results were valid and were his, and indicated that it was likely that he was the first with his surname and that y-DNA combination to be tested.

Ah, well – a lesson well learned. However, the experience was not without its positives. One British fellow with whom I was corresponding before I found the Australian branch of the family was working on a book about the different members of a national sports team on which one of the family members had played in his youth, back in the mid-1800s.

I provided him with a copy of documents which another Australian family member, on business in the UK for an extended time period, was able to obtain from a local library. The book has just recently been published, and just this week, the British sports writer e-mailed to say he would be sending me a copy!

Another positive was the joy of working with others, cheering one another on, bouncing ideas off one another, and keeping one another focussed, with each one looking at a slightly different aspect, and all obtaining additional documentation and resources related to the family. That’s so much better - and faster - than working alone on a research project!

So, what’s the upshot of all this? I’ve switched gears, and am relying more on my aunt’s and my DNA test results from 23andMe to assist in determining who my grandfather’s relatives are.

My Aunt's Autosomal (23andMe) Results

My maternal aunt’s results arrived in early February. She started with just under 800 DNA matches, compared to my 580 or so after eight months on the site.

Before they came, it was very difficult to determine which branch of the family my DNA matches were on.

Of my four grandparents, I have substantial information on the ancestral lines of three of them. The fourth – my maternal grandfather’s line – is virtually unknown, so even if I found a relatively close DNA match (pun fully intended!), it would take me a while to determine whose line it matched on.

Once my aunt’s results were in, things became much easier. One fellow had DNA matches to me on 4 segments, and to my aunt on 11. The DNA match therefore was on the maternal line. It took only a short time to determine where the common ancestor was – although, as I said to him, it seemed that there was quite a bit of matching DNA for a second cousin twice removed to my aunt, and a third cousin once removed to me.

By way of comparison, a third cousin once removed on my father’s side (who has been doing genealogy for more than 30 years, has contributed to my website, and is often in touch), who recently tested with 23andMe, has DNA matches with me on 2 segments of our respective chromosomes, which amounts to 0.36% of my DNA.

Her brother, on the other hand – also a third cousin once removed – has DNA matches on only one segment with me, amounting to 0.16% of my DNA.

For the third cousin once removed on my mother’s side, therefore, sharing 1.14% of my DNA on 4 segments was a rather large percentage of DNA matches – unless we were related on more than one line.

When I took a closer look at the family tree, I discovered that he, my aunt and I were related on at least three lines, with a fourth a definite possibility. That explained the ‘excessive’ amount of shared DNA with him, given his somewhat distant relationship to us: we have at least three common ancestors!

The GEDMatch website

There is also a website called GEDMatch, which is a database to which people can upload their DNA test results, from both 23andMe and Family Tree DNA.

Various comparisons can be done, between two different persons' results, or between one’s own results and all DNA matches with people in the rest of the database. There are also a number of utilities available.

Everything on this website is available free of charge.

I uploaded both my results and those of my aunt, and again, having her results as well as mine tended to narrow the field considerably, when attempting to find DNA matches with my maternal grandfather’s side of the family.

My aunt matched with a fellow who indicated that his parentage was neatly split down the middle, with Swedish on one side of the family, and Welsh on the other.

I pounced on that one, as my grandfather’s mother reportedly was Welsh. I have been attempting to ‘flesh out’ what is in his family tree, adding in siblings and their spouses, etc., but have been somewhat hampered by a lack of Welsh records on the various databases.

It also is not easy to sort out which couple named John and Jane Morgan, for example, is the right one, as the majority of Welsh surnames are based on masculine first names!

Nevertheless, I have a number of individuals now who have DNA matches with my aunt and are of Welsh heritage, and sooner or later, I will find that elusive link to my grandfather’s Welsh mother, and everything will fall into place! At least I now have a general idea of the names involved in her family tree!

One of the utilities available on the GEDMatch site tells you the likelihood that your parents were related to each other. It is based on the premise that, where there are segments of DNA in a person’s chromosomes in which the two halves are completely identical, the only possible explanation is that the two segments were passed down to each of that person's parents from a common ancestor, and the person inherited the same segment from each parent.

When I ran my own data through this utility, it indicated that my parents were not likely to have been related. No surprise there.

I then ran my aunt’s results through the same utility, and it came back with several matching segments. The algorhythm indicated that my maternal grandparents most likely shared a common ancestor five or six generations back! Now, THAT was a shocker!

New Genealogy Tools at 23andMe

The next development was within 23andMe itself. They have been developing some additional tools to assist those interested in genealogy. One of them results in the ability to compare and group individuals that I match with, by finding other individuals that they match with. That is, if several people that I match with all match an additional person, chances are great that that group of people are all related along the same branch of the family tree.

I was a little skeptical at first as to just how useful this would be, but the more I work at this, the more it becomes apparent which individuals belong together. Mind you, it doesn’t help that some of them appear to be related on more than one line!

Take the paternal third cousin once removed that I spoke of above, who is also into genealogy, for example; we knew of the relationship on my father’s side before she tested with 23andMe.

I was thinking that, once her results were in, I would have one test result on my mother’s side (my maternal aunt), and one on my father’s side (although a little distant), to help to distinguish which side of the family a particular match was on

Just out of curiosity, I checked her results against my maternal aunt’s … and discovered a DNA match!! The only possible explanation is that she is related on my maternal line, as well!

She has confirmed that her paternal grandmother was of Scottish extraction, with some in that line from the same area of Scotland that some of my maternal ancestors were from.

We have yet to find the common ancestor on that one; but in terms of determining which line different DNA matches are on, the double (or triple) relationships muddy the waters somewhat, and make life … rather interesting!

Another revelation from the DNA results: The more I work at figuring out who is connected to whom among my DNA matches, the clearer it becomes that I have some Irish ancestry – quite a surprise, as this was previously unknown in our family.

I have one grouping, on my mother’s side, in which all signs point to Ireland (by which I mean, the entire island, prior to partition). All of the family trees I have seen in this group lead to Ireland, but, frustratingly, most stop at the person who immigrated from Ireland to Canada.

As all other family lines in my tree are well documented, it seems this has to be on my grandfather’s line. As his mother was Welsh – and there appear to be a number of people of Welsh heritage who match to my aunt and/or me – that leaves only my grandfather’s father as the one with the Irish matches!


So, the search continues. With DNA matches, both from y-DNA testing and from 23andMe, I have been able to determine a likely surname for my grandfather’s father, and to determine that he most likely came from Ireland. I also know that, six or seven generations back, there is likely a common ancestor between him and my grandmother.

Some results are beginning to come – some quite surprising, and others quite predictable. The twists and turns continue, but hopefully, I’m on the right road, which will lead to my grandfather’s family, and the breaking down of that monumental brick wall!

Go from "DNA Matches & Brick Walls - Update 2" to "Update 1"

Go to 'DNA & Brick Walls'

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