Discussion
| These CORBINs have dozens of full matches at 12 markers, a few full
matches at 25 markers, and even some near matches at 37 and 67 markers
(all in other surnames). However, they have no full matches at 37
markers, so their haplotypes remain unique at 37 or more markers. |
| The purple and deep orange of some cells in the SNP column indicate
the two groups created for our CORBINs in the Haplogroup
I1-Z138Y Project, one for those who are A16956 and the other for those
who are one SNP downstream at A16959. Please note how this SNP difference
jibes with the STR branch marker (purple cells) and with their paper genealogy.
Notice that #621421 is also positive for A16958, but the others are not,
which means the mutation happened either in him or his father (A16958 was
named in 2017, but FTDNA still sees it as unnamed variant 12116526).
It cannot have happened in their grandfather or they would all be positive
for it. To make these SNP results easier to visualize, I've created
a
pedigree table with just the SNP values. |
| One individual included above has been tested at SMGF (Sorenson Molecular
Genealogy Foundation). There has never been a way to contact individuals
tested with them; so, if you are that person, please contact me. Update:
Ancestry.com bought SMGF and took their database offline — a real loss
to researchers as this was an early database containing individuals who
are no longer with us and cannot be tested again. |
| #274210 (bottom row) has a paper descent from this family's progenitor,
but he is not a genetic match with other descendants, which means he has
an NPE
in his patrilineal line. (He is Haplogroup R1b-M269, which means
he cannot have had a common ancestor with the Haplogroup I1 Northern Neck
CORBINs for thousands of years.) The testing of more cousins would
determine in which generation the NPE occurred. He does not, in fact,
have a match with anyone at any level, so we do not yet have a clue to
the identity of his actual patrilineal ancestor. Or, the paper
genealogy may be wrong. He may be from a CORBIN family not otherwise
tested, so far. |
| We are extraordinarily fortunate with regard to this family in that
their paper generalogy is relatively well known, thanks in part to the
publication of Kenneth Corbin's book, The Leaves of the Corbin Tree_(see
thread
at GenForum). Based on both paper genealogy and Y-DNA test results,
the Northern Neck CORBINs descend from John CORBIN of Richmond Co.,
VA. The author has this John as son of John CORBIN, 1652 immigrant,
but that paper connection is disputed. |
| For a detailed explanation as to how I use color to graphically represent
genetic relationships in a family, please see my discussion of "Signature
Markers." |
|
Summary
of Current Results
| 1. In the data table above, cells highlighted in light blue are
modal_for
Haplogroup I1-M253, meaning these are the most common values to have, so
possessing them is unremarkable.
2. Table cells highlighted in dusky orange are the signature
markers for the family. No other family has this particular pattern
of consistent differences from the Hg I1-M253 modal haplotype, and we would
expect anyone closely related to this family to have all or most of them.
3. So far, we have discovered four sets of branching markers
in the family. These are, as the name implies, mutations shared by
only a branch of the family, not the entire family. The mutation
is relatively recent, downstream of the family's progenitor, and its location
(the person in whom it occurred) can sooner or later be determined by testing
cousins.
-
One of the branches is identified by the mutation from 37 to 36 at CDYb,
the bright green table cells. In the lineages (please scroll to the
far right in the table), we see that this mutation had to have been present
in David Sr and may have been present in Jeremiah. To determine which,
we need to find and test a patrilineal line descendant of David Sr's brother,
Martin. Within this group, we have another branch, shown in a paler
green where DYS393 mutated from 13 to 14. We don't know whether the
mutation occurred in Van Buren or William; a test on a brother of Van Buren
would tell us, but some work on their paper genealogy will be needed to
determine just who Van Buren's brothers are — and Y-DNA STR testing could
help identify them.
-
Another branching marker is the mutation from 20 to 19 at DYS448, the magenta
table cells. This mutation had to have been present in James and
may have been present upstream in Rawley II or Thomas. Testing patrilineal
descendants of the brothers of James, Rawley II, and/or Thomas can determine
in which generaiton the mutation occurred.
-
Another branching marker, the mutation from 28 to 27 at DYS389ii highlighted
in purple, unites four descendants of James Madison. This STR branch
is further confirmed by SNP testing. While the family as a whole
appears to be A16956+ and A16957+, just the four descendants of James Madison
are A16959+, and of those, just one is A16958+. These results
beautifully demonstrate the usefulness of NGS (next generation sequencing)
technology applied to SNP testing of the male Y-chromosome, as with FTDNA's
BigY-500 test.
4. The table cells colored bright yellow represent private
markers. These are recent mutations present, so far, only in that
one line. As more cousins are tested, some of the private mutations
may become branching markers.
5. Based on paper genealogy, the two table cells in bright cyan
(DYS385a = 13) do not appear to be branching markers, but rather back mutations,
that is, independent returns to the Haplogroup I1-M253 modal value.
Either that, or we have a serious error in paper genealogy.
6. There are two ways to account for the two table cells in red
(DYS641 = 10). One is that each individual had an independent back
mutation to the marker's Haplogroup I1-M253 modal value, so these are private
mutations, not branching markers. The other is that the mutation
from 11 to 10 at DYS641 happened only once, after the mutation from 20
to 19 at DYS488, so represents a branching marker, but that #335257 subsequently
had a back mutation at DYS488 (from 19 back to 20). The former is
much more likely than the latter.
7. Marker DYS712 (boldface red column label in Panel 5), is the
most volatile of all the standard markers. Most mutations at this
marker are going to be private and can happen more than once in the same
family (i.e., the mutations will be coincidental and not genealogically
significant). In this family, only four individuals hold the modal
value of 27, while five individuals do not share it, quite unlike the pattern
of other markers in this panel where most values are modal and only one
or two are not, all of which means to not place too much significance in
the value of this marker. |
| The more family members who take the
BigY-500 test, the more family lines we can prove genetically, which is
a powerful check on the accuracy of our paper genealogy — and a powerful
aid for those with paper connections still to be made. Please take
the BigY-500. FTDNA will have a sale during the winter holiday season
beginning in mid to late November and ending December 31st. |
|
