The Pineo X segment is a conventional term I use for a segment of my maternal grandmother’s X chromosome which can be traced unusually far back, and confirms some of my colonial ancestry. I used this name because my initial matches were through the Pineo family, although the DNA has since been traced beyond that, and of course some matches are closer. I’ve thought of calling it the Mayflower X segment due to the evidence that at least a big chunk of it came over on that ship in 1620, or the Samson X segment, since more lines converge there.
The X is not passed from father to son, allowing for more narrowing down of possible relations, and is passed unchanged (excepting occasional mutation) from father to daughter, so that it can be preserved for more generations.
My mother and maternal aunt have both had DNA tests, and their maternal copy of the X will be a mix of what my maternal grandmother got from her father and her mother, where the latter is where the Pineo X came down through.
My mother’s portion of the segment is from nucleotide 1 to about 30.3 million, while my aunt’s is at least from about 19.1m to 44.4m, and possibly also includes the first 19m. Together, thus, these provide coverage of over the first 44 million bases on this copy of the X. Large coverage is helpful of course because many relatives will only have a small piece of the Pineo X.
I appear to have inherited none of this segment, instead having gotten that bit of X from my maternal grandfather, or at least my segment is too small to show up in matches.
My aunt’s first 19m bases are found in some of these relatives but not others. If segment matching were perfect, this would be impossible, but in practice there are any number of explanations. Most importantly, my mother and aunt tested on different chips (v4 vs. v5), so the SNP coverage is different, and it may be that, due to insufficient overlap, some segments that in fact were related failed to meet the threshold to be matched by 23andMe.
I have numerous X matches to descendants from Nova Scotia, clearly through my great-grandfather Robert Huntington. Such segments could not have come from his father, and so were from his mother Emily F. Gesner, and thus in turn from one (or both) of her parents Gibbs and Eliza Gesner. The evidence will show that it came through Emily’s father Gibbs, and thus in turn from his mother Sarah Pineo (wife of Henry Gesner). Sarah could’ve gotten it from either of her parents, but it turns out it was from her father David Pineo, and thus his mother Elizabeth Sampson.
Here are some descents of relations to get us to the Pineo family:
| David Pineo & Rebecca West | ||||
| Sarah Pineo | Rebecca Pineo | |||
| Gibbs Gesner | John Henry Gesner | Elizabeth Newcomb | ||
| Emily F. Gesner | Jane Gesner | Elizabeth C. Gesner | Annie North | |
| Robert Huntington | Ida L. Rockwell | Sophia R. Bentley | Lottie E. Bishop | |
| my grandmother | G. Rockwell | Harold Eaton | R. A. | |
| ⋮ | MF 17–44 | Edith Eaton | Lucile Eaton | KC 0–33 |
| GE 23–44 | J. F. | |||
| SF 23–44 | ||||
At the bottom are my living matches, with the range of the X segment that they match (in millions of bases). To illustrate the logic, Elizabeth Newcomb might have gotten the segment in whole or part from her father, but Gibbs and John Gesner could only get the segment from their mother Sarah Pineo.
Here are a few more distant matches, where David Pineo is as above:
| Alexander Standish & Sarah Alden | |||
| Mercy Standish | Lydia Standish | ||
| David Samson | Caleb Samson | Peleg Samson | |
| Elizabeth Sampson | Bethiah Samson | Mercy Sampson | |
| David Pineo | Ruby Pineo | Silence Ford | Deborah Weston |
| ⋮ | Nathan Woodworth | Abigail Carr | Isaac Whittemore |
| Ruth Woodworth | Augustus Ayer | Polly Whittemore | |
| Susan Cox | Mary Ayer | Benjamin Green | |
| Ralph Griffin | Lovina Ingalls | Lola Green | |
| Etta Griffin | M. Johnson | G. Corson | |
| E. B. | NK 0–20 | SS 0–20 | |
| PB 19–41 | |||
The logic of X descent continues to guide us. Although David and Caleb are sons of Caleb Samson, and Peleg the son of Isaac Samson, the segment must have come from their mothers, that is, the Standish family.
It is unlikely that Mercy and Lydia Standish independently got the same mix of X from their two parents, so almost certainly they both got at least the 1–20m segment entirely from one parent.
Sarah Alden’s parents John and Priscilla immigrated on the Mayflower, as did Alexander Standish’s father Myles (who could not be the source of the X). However, Alexander’s mother Barbara immigrated on the Anne in 1623. I had another match that got me to the Alden family and thus the Mayflower, but I lost my notes for it (oops…).
There are many generations here, leaving the possibility that there is another line of descent that takes me to a different X ancestor. To that I can only say that the evidence each match provides is cumulative, and also Mayflower descendants are well-documented, so it is less likely something was overlooked.
This provides corroboration for portions of other important descents that go through some of these generations. For example, it adds DNA support to my descent from Henry Samson, and thus, through him, much of my medieval ancestry.