As Jeff has already described, I advised him that his father taking an autosomal DNA test now might actually shed some light on the mystery of his maternal grandfather, since I have had many success stories with other friends and colleagues. As currently Ancestry.com has the most people in their database, along with the easiest way to search through surnames and trees, I recommended his dad test with them first, before exploring other options. Fortunately, we did not need to try again!
As the DNA is specific to Jeff’s father Jack, I’ll now be describing the results for Jack. When I saw his results arrive I looked at the top six results, all predicted to be between first and second cousins. One was a close relative to Jack’s father (Record), two were close relatives to Jack’s maternal grandmother (Young), and the other three were not related to anyone in Jack’s known ancestry (mystery). These “unknown” three were not related to the other “known” three results, and all the “unknown” three were “shared matches” with each other. They also all had family trees that showed how they related to each other! As this involves living people, and not all contact has been established, I will be describing these matches with aliases and then referring to the common ancestors with very generic identifications.
The summary of possible kinships below is from data available on https://isogg.org/wiki/Autosomal_DNA_statistics. The closest match was a male we will call “Michael Ford,” who matched Jack at 354 centimorgans across 17 segments. This match was predicted by Ancestry to be between a first and a second cousin. Other possible kinships ranged from half first cousin to first cousin twice removed.
The next match, a female, we will call “Annabelle Harris”; she matched Jack at 280 centimorgans across 15 segments. This match was predicted by Ancestry to be a second cousin. Other possible kinships ranged from half first cousin to first cousin three times removed.
The third match, a male, we will call “Jason Mitchell,” and he matched Jack at 210 centimorgans across 14 segments. This match was predicted by Ancestry to be a second cousin. Other possible kinships ranged from half first cousin to second cousin twice removed.
There are additional possible kinship assignments for more immediate remote kinships: for instance, Michael and Jack could be great-great-nephew/uncle, etc. As I determined how all three matches related to each other, and that all three related through Jack’s maternal grandfather, several of those other kinships are not generationally or chronologically possible.
The good news was that all three of these people had trees on Ancestry and they were all related to each other through the “Jackson” family (not the real surname) of a nearby state. The below chart demonstrates how these three matches related (all names changed), women in red, men in blue:
J. Martin Jackson (Martin) was born in the 1880s in a state bordering Kansas, but hundreds of miles away from El Dorado, Kansas, where Jack’s grandmother was living in 1913 and 1914. However, I discovered from Martin’s World War 1 Draft Registration Card that he was living in El Dorado in 1918! Following this trail back, I find him there in the 1915 state census of Kansas. Newspapers.com had several papers for El Dorado at the time, which highlighted Martin’s entire stay there – from 1911 to 1918 – in between his first and second marriages. He met and married Ella Shaw there in 1917 and by 1920 Martin and his second wife were living back in his home state.
There wasn’t anyone alive in Martin’s family besides him that fit the criteria for being Jack’s grandfather. Martin’s father died a few years after his sister Jennifer’s birth and the mother Ellen remarried. She had three sons living with her the 1910 census, which indicated she was the mother of five children, five living, which were Martin, his full sister Jennifer, and their three half-brothers. This trio was too young biologically to father a child in 1914, and they were living hundreds of miles away in another state. (As half-brothers, they also had less genetic overlap and would not account for the additional matches behind Martin's father.) Martin was the only one and he was right in the same town! He was about a decade older than Jack’s grandmother. He was divorced, and had not yet married his second wife.
To go back to the kinships above, and how they work out with J. Martin Jackson as Jack’s grandfather: the chart below (only the names of Jack, his mother, and grandmother are real) now has Martin followed by his three sequential relationships:
Jack and Michael Ford are half first cousins, an average kinship of 425 centimorgans, which can range from 137 to 856. Jack and Michael have 354.
Jack and Annabelle Harris are half first cousins once removed, an average kinship of 212.50 centimorgans, which can range from 57 to 530. Jack and Annabelle have 280.
Jack and Jason Mitchell are second cousins, an average kinship of 212.50 centimorgans, and this can range from 46 to 515. Jack and Jason have 210.
Based on the large amount of shared DNA, the lack of any other male members of the family that fit the genealogical, chronological, or geographical criteria, and Martin’s presence in the same town in 1914, I feel very confident that Martin is Jack’s grandfather. This was only possible because so many people have decided to take tests, and in this case, the closest people alive tested! Plus they had trees, so that helped too!