Monday, June 12, 2017

Mystery DNA Cousin Demystified

A few years ago at 23andMe a close match appeared for my father, his siblings, and their third cousin, Bob, on their shared Cook/Neil line of Morris County, New Jersey.  Common ancestors are Calvin Cook (1826-1889) and Mary Neil (1830-1898).

The amount of shared DNA ranged from 1.66% with my uncle to 3.82% with cousin Bob.

The probable relation would be second to third cousin.  The variance in amount of shared DNA is within normal.  Or the higher amount could indicate that this mystery cousin is closer to Bob.

Either way, the person ignored my requests to connect through the 23andMe website.

Recently, 23andMe required users to not be anonymous.  This person bypassed this non-anonymous requirement and instead blocked sharing requests.

This person won't make or break my family tree, so I moved on.

Then Cousin Bob's cousin contacted me.  They share ancestors Patrick Bernard Brady (1830-18xx) and Elizabeth Duffy (1837-1918) of County Meath, Ireland.  They were the parents of Mary Brady (1870-1942), wife of Francis Asbury Cook (1851-1919).

She wondered how Bob was so closely related to her highest DNA match.  This Mystery DNA Cousin had limited contact with Bob's cousin and revealed Brady ancestors on two separate ancestral lines from two counties in Ireland, Cavan and Donegal.

In this situation, we are not using haplogroups to assign relationships or ancestral lines.
We are using them to confirm that we are dealing with the same elusive DNA tester.

The shared percentage with Bob, as well as the haplogroups, were the same for the Mystery Brady Cousin as for the Mystery Cook/Neil Cousin.

So if the Mystery Cousin is the same for both situations, this explains why Cousin Bob shares more DNA with the Mystery Cousin.  They are related through Cook/Neil ancestors as well as the separate Brady line.  For Bob, these lines merged in his great grandparents, Francis Cook and Mary Brady.

The above diagram is my theory on how the Mystery Cook/Neil Cousin (Mystery Brady Cousin) is related to my branch.  If this person comes forward, we can revise the this diagram if needed.

Sunday, June 11, 2017

Locations of My DNA Family at 23andMe

The genetic testing site 23andMe released a new tool called "Your DNA Family."

Part of this feature displays the locations of the people who share your DNA.

This is a different concept from "ethnicity."  The three major testing companies offer ethnicity estimates with different labels.

23andMe: Ancestry Composition
Family Tree DNA:  My Origins
AncestryDNA:  Genetic Ancestry/Ethnicity Estimate

My Heritage is attempting to join the genetic genealogy market.  It offers Ethnicity Estimate (beta).

AncestryDNA recently offered an additional view on origins called Genetic Communities.

Ethinic estimates will differ from company to company and over time because the reference populations will change based on new information and increased people who test.  For the latest take on my ancestors, see my post about Living DNA's interpretation of me.

Based on my exchanges with DNA matches at 23andMe, they live across the globe, but mainly in the United States.  The other countries I see most often are Canada, Ireland, Australia, New Zealand, Germany, France, and Hungary.

I was not surprised to see that a lot of my DNA relatives live in New Jersey, New York, and Pennsylvania because this area is where my ancestors settled after leaving Europe.  Florida and California are popular destinations for New Jersey natives to relocate.

Next I compared my United States map to my parents.  My father has more relations spread across the United States, while my mother does not.

A list view captures the numbers.

I'm not sure where 23andMe is getting the numbers.  A tester answers (or doesn't) questions about themselves, including their current residence.  With the worldwide totals, hundreds of my DNA relatives are unnacounted for.  Maybe people did not answer this question and are not tallied in this breakdown.

Another important factor is that 23andMe (and direct-to-consumer DNA testing) is not available in every country in the world.  According to its website, 23andMe ships to over fifty countries; health reports are not available in most of them.  So if your DNA relatives live in a country that 23andMe cannot ship to, or does not offer the health information interpretation, you have diminished chances of finding these relatives in your matches.

If 23andMe wanted to be more useful for genealogy, it would bring back the profile pages of participants and allow searching and sharing of genomes with people not on your list of matches, currently called "DNA Relatives."

Thursday, June 8, 2017

Preston DNA Double Match

A new DNA cousin appeared among my matches at

He also matched two known Preston cousins at this site.  He displayed his name, which is unusual, so I was able to identify him as a descendant of Hannah Preston (1888-1935), a sister of my great grandmother, Anna Preston (1890-1921).

Ancestry enables people to link their DNA profile to a person in a family tree.  This DNA match did not do this, but his non-DNA Ancestry profile page offered a link to a small tree.

I started with the one person in the family tree who had a name.  I quickly uncovered that the mother of the only identified person was Jane Pearl (or Pearl Jane) Preston, born around 1903 in Kentucky.  This is not where I expected the match to be.  I followed this line over many generations through Virginia to Philip Preston (1711-1774), who came from Staffordshire, England, according to his Find A Grave page.

I saw no intersection with my Preston line from (County Wicklow?) Ireland to New York and New Jersey.

The family tree of this DNA match can be extended to include Prestons on two separate branches.

We need more research and more DNA comparisons to decide where the shared segment of DNA came from and if these two Preston lines arose from the same ancestor.