At least thirty-three of my DNA matches at AncestryDNA are related to me through Augusta Newman who died in White County, Indiana, in 1864 and his wife Melinda (Sledd) Newman who died in Linn County, Iowa. In looking at the shared centimorgans I had with some of those descendants, I noticed amounts that seemed a little high for the distance of our paper genealogical connection. In reviewing those thirty-three descendants of Augusta and Melinda, I noticed that six of those Newman cousins were also cousins on another family line. The amounts of shared DNA were compared with averages from Blaine Bettinger’s “Shared cM Project.”
- Thomas T. Newman. Two descendants.
- 5th paper cousin (also a 5th cousin through a separate Tinsley connection)—shared 29cM–two segments. The shared cM Project (Version 3.0) suggests an average shared cM of 25 cM (range 0-94). Not suggestive of a duplicate relationship.
- 5th paper cousin (also a 5th cousin through a separate Tinsley connection)–shared 16cM–two segments. The shared cM Project (Version 3.0) suggests an average shared cM of 25 cM (range 0-94). Not suggestive of a duplicate relationship.
- Edward Tinsley Newman. One descendant.
- 5th paper cousin through Augusta Newman (also a 4th cousin through a separate Rampley connection) —shared 26 cM–two segments. The shared cM Project (Version 3.0) suggests an average shared cM of 25 cM (range 0-94) for 5th cousins–not unusually high or suggestive of a duplicate relationship.
- William Newman descendants-including me–Three other descendants.
- 3rd paper cousin (also a 3rd cousin through a separate Neill connection) — shared 169 cM across 7 segments. The shared cM Project (Version 3.0) suggests an average shared cM of 74 cM for this relationship. While 169 is in the range (0-217), the shared amount seems high.
- 3rd paper cousin once removed (also a 4th cousin through a separate Janssen connection and a 5th cousin once removed through a Post connection)— shared 111 cM across 4 segments. The shared cM Project (Version 3.0) suggests an average shared cM of 74 cM for this relationship. The shared amount is higher than average and is even higher than the average amount of shared cM for a 4th cousin (35 cM) and a 5th cousin (25 cM).
- 3rd paper cousin (also a 5th cousin through a separate Rampley connection)— shared 109 cM across 5 segments. The shared cM Project (Version 3.0) suggests an average shared cM of 74 cM for this relationship.
Having a double or triple connection does not guarantee that the amount of shared DNA will be doubled or tripled. While I received half of my DNA from my father and my mother, it is not likely that I have exactly 1/4 of my DNA from each of my grandparents.
One thing worth noting: a possible reason why the double cousins I have through Thomas T. Newman do not share any more DNA than usual is that the double connection we share runs through one great-great-grandparent for both of us (Newman men married Tinsley sisters). The other shared paper genealogical connections are more spread through my ancestry–and that would seem to increase the probability that there’s more shared DNA. Maybe.
The averages are only averages.
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