Can 83 cM Last for 7 Generations?

Recently, I came across a DNA match at Ancestry. This match was on my mother’s side. Here is how the match showed at AncestryDNA:

Nigel at Ancestry

The match, Nigel, showed as a predicted 4th cousin. However, the range stated he was possibly a 4th to 6th cousin to my mother (and my sister). Further, the matching surnames looked familiar based on my mother’s ancestry. However, the Ellis on Nigel’s side was a female from the early 1700’s. Any possible Ellis connection would be before the Nicholson/Staniforth connection.

Shared Surnames

The Common Ancestors

I wrote to Nigel and mentioned that it looked like we were related on at least one line. I had a bit of trouble figuring out exactly how we were related as did Nigel. It helped me to map it out – especially as Nigel has 4 Johns in a row in his ancestry.

moms-nicholson-ancestry

It turns out that Nigel was not just a 4th cousin as predicted by AncestryDNA, but a 4th cousin, 2 times removed to my mom. Our common ancestor based on the chart above is John Nicholson baptized 1765. That is where the 7 generations comes in. John Nicholson is 7 generations before Nigel and 5 generations before my mom. However, my sister Heidi and Nigel have the same DNA as my mom and Nigel and Heidi is 6 generations away from the probable common ancestors of John Nicholson and Sarah Stanisforth.

Nigel at Gedmatch

I mentioned my Nicholson webpage to Nigel which he enjoyed. Nigel was willing to upload his DNA to Gedmatch for my research. Here is how his match looks like with my mother:

Mom to Nigel Gedmatch

Here is where the 83.8 cM comes in. Hence the title of the Blog: “Can 83 cM Last for 7 Generations?”

A chromosome 1 map

Here is a map of my Chromosome 1 kindly produced by M MacNeill – prairielad_genealogy@hotmail.com. The top portion of this map was based on raw data DNA. It shows how my 2 sisters and I inherited our DNA from our 4 grandparents.

chr-1-and-nigel

The four light blue bars at the bottom of the above image show the DNA matches that Nigel has to my mom, my sister Heidi, myself and my sister Sharon near the beginning of Chromosome 1. Nigel is related on my mother’s mother’s side. Notice how Nigel’s light blue matches below correspond to the DNA mapped to my mother’s mother’s light blue regions above. Heidi inherited a large maternal grandmother segment in this area of Chromosome 1 from our mom that had the large match to Nigel. The entire segment mapped to my maternal grandmother’s side appears to make up the match I have with Nigel.

A Nicholson Triangulation Group

My mother forms a Triangulation Group (TG) with her 2nd cousin Carol and 4th cousin, twice removed, Nigel. The TG is on Chromosome 3. To show the TG, I have to take the Gedmatch threshold down a little.

My mom’s match to Nigel

mom-nigel-tg

Likewise, the threshold was reduced to show the match between Nigel and Carol.

Nigels’s Match to Carol

nigel-carol

No threshold change was needed for the match between my mother and her second cousin Carol.

Mom’s match to carol

mom-and-carol

Here is what the TG looks like with the likely common ancestors of Nicholson and Staniforth:

tg-mom-nigel-carol

Are There Other Possibilities?

83.3 cM is way off the charts for 4th cousin or 4th cousin, 2 times removed. I brought the question to the ISOGG Facebook Group. The prevailing wisdom there is to check for other closer relatives (which makes sense). If there are missing ancestors on either side of the match (my family or Nigel’s), that may leave room for other more recent common ancestors.

my ancestry

First, the match is on my mother’s side. So that narrows things down. Secondly, my mom is 1/4 English. Therefor, I am only looking at 1/8 of my ancestry and 1/4 of my mom’s.

Mom's ancestry

Above, I have circled in yellow the one out of 4 grandparents of my mother that could match Nigel as Nigel has not shown any German ancestry. Annie Nicholson is 2 generations back from my mom (my mom’s grandmother).

Here is an enlargement of Ann Nicholson’s ancestors:

Ann Nicholson Ancestors

This shows that in the 5th generation from my mom where the assumed common ancestors of our match is found, most of the ancestors are identified. Mary doesn’t have a last name and I’m missing parents for Charles Ellis. So even if the new common ancestors were in this generation, they would be in the same generation of our currently assumed common ancestors. But what if Nigel has an unidentified ancestor in his 6th generation that matches someone in my mom’s 4th generation? That would be a closer match. So let’s look at Nigel’s tree.

Nigel’s tree

Nigel’s father’s side appears to be from Scotland. His mother’s side is from England. Nigel’s maternal grandmother is from the Derbyshire area and his maternal grandfather is from the Sheffield area. So that narrows things down to 1/4 for Nigel. My mom’s only English ancestors were from the Sheffield area, so we will concentrate on Nigel’s maternal grandfather’s side.

Here are Nigel’s maternal grandfather’s Sheffield ancestors:

Nigel's Maternal Grandfather's Line

The tentative common ancestors between Nigel and my family is one generation off this chart. The John Nicholson married to Martha Jow had as parents another John Nicholson who married Sarah Stanisforth. The ancestry above shows that Nigel has 6 out of 16 Sheffield ancestors 6 generations away. Is this a problem?

Nigel’s missing ancestors

Above, I had said that if Nigel had missing ancestors in generation 6 that matched with my mom’s generation 4 ancestors, then there could be a closer match. I’ll look at thee various possibilities and we will decide if they pose a problem.

  1. A problem that I hadn’t considered previously would be if Nigel’s unknown 6th generation matched with my mom’s 2 unknown ancestors in her 5th generation. Those unknowns are the parents of Charles Ellis born 1795. I don’t think that scenario is very likely. First, it would not likely be on the Ellis side. Charles Ellis’ father would also be an Ellis and Nigel doesn’t have any Ellis’s in his known generation 5 ancestors. But what about Nigel’s unknown female ancestors in generation 5? They were already married and having the children that are known in Nigel’s generation 4. So any unknown common ancestor there would have to be in Nigel’s generation 7 which is back where we started.
  2. Another scenario would have a missing female ancestor of Nigel remarrying. However, usually in this case, there would only be a 1/2 match and thuse 1/2 the DNA coming down to Nigel and my family. I would rule this scenario out based on the very large DNA match between my family and Nigel.
  3. When I look at other scenarios the reasoning seems to be similar as what I mention in #1 above. The options appear to bring us back to Nigel’s generation 7 again. That means that we either have an additional set of common ancestors in addition to the one that we have identified or we don’t. It makes sense to me to go with the ancestors that we do have rather than worry about missing ones we may have. Put another way, I’m gambling on the possibility that there were not additional common ancestors in Nigel’s generation 7 and my mom’s generation 5.
ON the other hand: Our non-conformist ancestors

One thing that Nigel and my family’s Sheffield ancestors had in common were that they were non-conformists. This means that they attended a church that was not the official Church of England. In their case it was the  Congregational Church. Perhaps there were other types of churches that they attended during the family history. What I don’t know is if people in these these groups married cousins to keep within the faith, or if there were enough of these non-conformists around that this wasn’t necessary.

So, Where Are We?

  1. The prevailing wisdom is that if there are missing ancestors, then the matches could be in a closer generation in those missing spots.
  2. I would like to push back the prevailing wisdom a bit. Even if we are missing some ancestors, there are things that can be deduced about those missing ancestors based on known ancestors in the next more recent generation.
  3. In genealogy research and DNA matching, things are not usually known 100 percent. I believe that there is a high probability that John Nicholson and Sarah Stanisforth are the common ancestors between Nigel and my family represented by a relatively large amount of DNA that made it down through both of our lines from the 1700’s.

Kitty Cooper’s Chromosome Maps

Above I have shown the genealogy and a Triangulation Group for the Nicholsons. I have also shown that the match between Nigel and my family is through my correct grandparent’s (mother’s mother’s) DNA. Now that I have convinced myself that John Nicholson and Sarah Stanisforth produced the matching DNA between Nigel and my family I will add that couple to my Kitty Cooper generated Chromosome Map:

joel-new-chromosome-map-kitty

The Nicholson/Staniforth connection on my map above is shown on Chromosomes 1 and 3. Note that this is not the oldest DNA that I have and that the matches are in line with 2 other ancestors (Frazer in Green and Rathfelder in purple) from around the same time period.

Of course, I can’t leave it at that. Now I need to show my mom’s updated Chromosome map:

moms-chormosome-map

Note the following:

  • My mom’s segments are larger than my corresponding maternal segments as she is one generation back from me
  • My mom’s Nicholson/Stanisforth DNA is shown in purple.
  • My mom does not show DNA from that couple at Chromosome 3. That is because her match came in at 6.9 cM which is just under the 7.0 Gedmatch threshold. If I wanted to be more accurate, I would have added that match also – especially as that is the match that resulted in the triangulation group.

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