What is a Family-Specific match list?

Our DNA match lists reveal people amongst the various testing companies who have identical segments of DNA to us, such that we can infer that we have a common ancestor. The higher the cM amount, the closer the relationship, at least up until 2nd cousins. Thereafter the randomness of inheritance means that we WILL NOT match some of our 3rd-higher cousins and associated removed cousins. A 'removed' relationship means that we are not on the same generational line as our match or known cousin (if not talking DNA). Once removed can mean EITHER an earlier generation = ideal for answering DNA questions, or a later generation such as your cousin's child who is your 1C1R. Your cousin's grandchild is your 1C2R. The 'earlier removed' have much more DNA from any common ancestor compared to 'later removeds'. In the beginning I was extremely lucky to have access to the DNA match list of my father's 1C (since he had already died.) Pat is my 1C1R, but she is an 'earlier removed'. This generation is the closest to the people I am investigating.

How can DNA answer genealogical questions?

Experience with DNA results has allowed us to reliably identify amounts of shared DNA reflecting specific relationships. Ancestry and the Shared DNA Project have developed these guides. In all cases of DNA matching, the amount of DNA reflects distance from the common ancestor. But from 3rd cousin and higher (ie more distant) there is more variability in interpreting cM amounts. 

Due to a run of Roberts, I'll refer from now on to Robert1 (son of George and Jean born 1813), Robert2 (son of Robert and Janet McRae born c1834) and Robert3 (son of Robert2 and Margaret Bain born 1863).

If my aim was to identify the parents of Robert2, born c1834 who emigrated to Australia, I would need to gather as much of HIS DNA from his descendants as possible. Robert2's DNA signature contains a random mix of his father's DNA and his mother's DNA, ie 50% from his father Robert1 Buchan, and 50% from his mother Janet McRae. Pat is the great grand-daughter of Robert2. However, Pat only got about a eighth of that DNA signature. Robert2 gave half of it to his son Robert3 (Pat's grandfather) who gave half of that to his daughter Alice (Pat's mother), who gave about half to Pat. Robert2's other children received different Buchan DNA, but all of it can only reflect the DNA signature that Robert2 himself carried. All Robert2's descendants carry some proportion of that same DNA, diluted down each generation. 

Robert2's DNA, no matter how much we have of it, can not tell us which family in Scotland he came from, until we try to match other people.

Robert2 might have had siblings in Scotland, as we had never found any in Australia. If there were no siblings, his father Robert1 might have had siblings. Not only did Robert2 have 8 half-siblings in Scotland, his father Robert1 had 7 siblings. Initially it was Robert1's siblings who led me back to George and Jean. Those siblings carried a different mix of DNA from their parents compared to Robert1, but each had 50% Buchan DNA and 50% Johnston DNA. Although always a random mix of their parent's DNA, some of the DNA signature in Robert2's descendants would be identical to parts of the DNA signature of the descendants of his father's siblings. That is how we match each other. Some of their descendants had taken a DNA test, and by matching them I was able find the paternal family of Robert2.

Removing the DNA of Roberts2's wife

In order to match the Buchan-Johnston descendants, I first had to 'purify' Pat's results to reveal only Buchan DNA. When chasing ancestors, gathering as many descendants from different descendant lines increases the chance of capturing a DNA segment that another more distant descendant might have also  inherited. In truth I was very lucky and did not need any other DNA than Pat's to match to other Buchan descendants. But gathering more DNA was going to be crucial to ask who were Janet McRae's parents [another post, and only of relevance to Australian born Buchans]. I have gone on to collate DNA match lists from 8 Australian Buchans, who collectively have matched about 200 people overseas.

Gathering DNA match lists (based on DNA signatures, or identical DNA segments) from Buchans born overseas will allow me a much greater chance of finding the families of origin of George Buchan and Jean Johnston. I hope that more DNA signatures will broaden the pool through which we might find descendants of the siblings of George and Jean, just as I found the siblings of Robert1.

Creating a Surname Specific Cluster of Matches

It is critical to understand WHO is represented in any group of matches we define. Robert2's DNA contains the DNA of his parents [Buchan and McRae], and all 4 of his grandparents [Buchan, Johnston, McRae and ?], and backwards in time for a few more generations. DNA is not sexist, it equally includes the DNA of the father McRae and the mother McRae [whose maiden name is unknown]. In terms of Robert2, the names of his paternal grandparents are known - George Buchan and Jean Johnston, but neither of their father's first names or mother's full names. I feel I am back where I started knowing the names of Robert2's parents but not WHO they were.

The graphic below shows how I (1) created a Buchan Network and (2) split off the Bain Network and is drawn from the perspective of my first test taker, Pat G. Robert2 and his wife Margaret Bain had 6 children who had families, none of which has yet died out. Overall there were three great-grandchildren who have taken a DNA test, and who are the closest generation to Robert2 - Pat, Kerry and Kathryn - they are all 2C to each other. Descendants of Alice's first cousins have also taken tests, meaning that we have DNA tests from all lines of descent from Robert2.

I then gathered all the shared matches to this total of 12 Australian born Buchan descendants to create the Buchan Network. In my first iteration this was about 50 people, some of whom were not born in Australia.  The Australian born people however carry both Buchan DNA and Bain DNA. The Bain DNA needs to be removed as they are in the Buchan Network by matching solely on their Bain DNA. I don't want to be wasting time trying to find a Buchan connection when none could ever exist. [I was also very lucky that Robert2 and Margaret came from opposite ends of Scotland - lowland Edinburgh and highland Rosshire. Or else there might have been more confusing DNA connections - a tricky situation called Endogamy.]

To identify solely Bain matches, I needed to find descendants of Margaret Bain's siblings. Fortunately Margaret was joined by 4 of her siblings in Australia, who had families. The fortune came from recognising Bain descendants as I had already collected them in my family history research. These family names are seldom printed on a Match List. Indeed I have only found one definite Buchan descendant actually named Buchan amongst the current Match List of over 300 people.  Two women named Buchan might be Buchan born, or they might be a female descendant who married some-one named Buchan [though I hope they are Buchan born].

I was able to find 3 DNA matches, MikeD, RegA and BruceM who had no Buchan DNA. I then examined their match lists to find people who were solely Bain, and I remove them. This task is not possible without building family trees for all these Bain families. It is not wasted time, for there will certainly come a time when I want to ask a Bain-DNA question. 

It was sometimes impossible to identify a small cM match as soley Bain. If in doubt they were removed from the Network. The remaining people who I call Buchan Descendants have both Buchan and Bain DNA, but I will want them to be matching people on Buchan DNA segments. The reality that they also contain Bain DNA segments becomes irrelevant. We all carry DNA segments from dozens of lines.

Interpreting a Match list

The first task once I had gathered a Buchan Network was to identify as many people as possible. Supremely easy with siblings, first and often second cousins, based on the family history research I had already done, it then became harder. If I recognise someone and where they sit on my family tree, then they are called a Known Match. If an unknown match was located in Australia, I made an almost universally correct decision to consider them Australian born and look locally. In this way I found about another 20 people who I had originally not recognised.

The second task was to look at my highest Unknown Match likely to be in the 3C range, because this is where Scottish relatives would sit if they were descended from siblings of Robert2. The cM range for 3C is between 40-70cM. I was drawn to HelenB as a match for obvious reasons as you'll see, however Pat's match with HelenB was actually the highest match in this range - at 44cM. I looked at any match who provided a tree, hoping for signs of a Buchan or Edinburgh. With Helen there was a triple jackpot! She had an ancestor named Robert Buchan in Edinburgh. The rest of that story is in the post about Robert1. I added her shared match list to the Network.

I then looked at other Unknown Matches and their trees. Without trees the task is impossible. The aim is identify where the trees of matches intersect, or in other words how matches are related to each other. I easily found the trees of Mikeoduns [Paul Hedderwick] and HazelWaters48. The common name in their trees was Isabella Inglis born c1805 who married Daniel Inglis. Both extended their trees back to George and Jean Johnston. Sandra McKenzie had only 4 people in her tree but her paternal grandmother was Georgia Inglis. I then built that tree backwards using traditional genealogical methods to where she connected into this Buchan family. At the same time I found Andrew Buchan, the only direct male Buchan descendant I have ever found. A little more digging found that his ancestor George Buchan was Isabella's brother. Death certificates confirmed that Isabella and George had a brother named Robert. Further confirmation that Robert1 was their brother came from Pat's good sized matches to the descendants of Robert1 and Margaret Ireland. I have since confirmed that several overseas descendants [HelenB, PaulH, MarkP and WilliamA] also match these same people.

I was lucky again that several Scottish family historians had created large documented trees for this family [particularly IainKerr3 and markandjoannepearce1]. Mark is now a contributor to this DNA study. I was very confident that I had found the family of Robert1.

The following graphic was another early attempt to explain whose DNA can be found in our match list. Though hard to display, the light purple and light orange areas cover the entire tree, all descendants carry some of the DNA of either George Buchan or Jean Johnston (or else they would not make it onto a DNA Family Tree). However the purple and orange areas are petering out by the generation at the bottom. This highlights the extreme value of people at the generational level of Pat, Mikeoduns and Sandra Mackenzie.

Whose DNA is carried in whom?

If the match, and their grandparents, were born overseas, and especially if they had any Scottish and Midlothian connections, I tried very hard to locate them on the family trees of Robert1's siblings. By concentrating on the shared matches of anyone whom I could link together, and building back their family trees till they reached George and Jean, it was possible to create the current DNA family tree below. Though illegible, it does show the current extent of the DNA Buchan Tree.

Buchan DNA tree July 2022

Members of this Private Blog who would like this tree should contact me so that I can email it to them.

Not on this tree are the other 52 Australian born Buchans. It may be that we are an inquisitive lot, looking for our roots back home, but I believe that only local knowledge has enabled me to identify this many matches as descendants of Robert2 and Margaret Bain. It is my hope that others reading this blog will be able to look at their own trees to find more matches hidden away. And then please let me know. 

After converting Unknown Matches to Known Matches [ie placing them in the tree], a remarkable thing emerges. There are many people in our match lists who are NOT descendants of George Buchan and Jean Johnston. They are descendants of George's siblings and Jean's siblings. They might even be descendants of George's aunts and uncles, or Jean's aunts and uncles, but the DNA is petering out and the documentary record is often absent by 1750. But I live in hope. For the Australians, the match list also includes descendants of Janet McRae's siblings, or aunts and uncles.

How we try to identify these people uses a technique called Bottoms Up by Diahan Southard, and will be the subject of another post.