AncestryDNA matches recently helped me confirm a set of 3X great-grandparents: Abner Davis (1786–1855) and his wife Catherine. Through traditional research—including a FamilySearch probate record—I was also able to quickly identify the nine siblings of my 2X great-grandmother, Mahala Davis Stahl.

While reviewing an AncestryDNA ThruLines page for Abner and Catherine, one set of numbers immediately caught my eye.

As shown in the banner image, ThruLines suggested a cluster of potential fourth cousins—descendants of Abner and Catherine’s grandchildren. Most of these matches shared expected amounts of DNA: 11 cM, 15 cM, 13 cM, 14 cM, and 17 cM.

But one match stood out dramatically: 124 cM.

A 124 cM match is far too high for a standard fourth-cousin relationship. This match—whom I’ll call “AB”—was the sole outlier on this entire branch of the tree. I suspected this outlier was caused by intermarriage resulting in more than one shared ancestral line. Because AB hasn’t been active on Ancestry in over a year, reaching out directly wasn’t a practical option.



Down the proverbial rabbit hole I went. An hour or so later, I’d extended both my maternal and paternal family trees until they intersected. To help visualize complex relationships like these, I often rely on a custom Cousin Chart (shown in the thumbnail). On my paternal line through Abner Davis, AB and I are very distant cousins.

But on my maternal side, AB and I are much closer: second cousins, once removed. (My mother and AB’s grandfather were first cousins. Easy to compute the relationship without a chart.)

This double connection explains why our shared DNA jumped to 124 cM—the closer maternal relationship was doing most of the heavy lifting!