The Basics for Solving Unknown Parentage Cases using DNA
KITTY MUNSON COOPER
These slides can be found at
Why does testing your DNA help?
You get half your DNA from each parent, about a quarter from each grandparent and so forth ....so if enough biological relatives are tested you can figure this out
You can see from this chart that you will share alot of DNA with your closer relatives but beyond 2nd cousins there is less and less
Chart from the ISOGG wiki (courtesy Dimario, Wikimedia Commons)
The "G" trick
The cousin level = the number of "G"s for the shared ancestor.
If you are in different generations take the shorter path and the other is removed by the generation difference
Step 1: TEST your DNA:
at Ancestry and 23andme then transfer to the other sites
also test any close biological relatives that will help
Step 2: Upload the Ancestry DNA results to other sites for free to get more matches:
- Family Tree DNA *
- LivingDNA (primarily British, not many matches yet)
* pay a little $ to unlock tools
If your roots are deeply American, you may only need to test at Ancestry
Any of these matches may resolve the case quickly for you but proceed carefully
Enter the cMs and get probable relationships https://dnapainter.com/tools/sharedcmv4
This online calculator that gives you the probable relationships is an invaluable aid
The DNA Adoption has much help, with very close matches, save all the information you can see then initiate contact ... review the advice here:
Then read step 10: https://dnaadoption.org/first-timers/step-10/
With less close DNA matches, the basic methodology to resolve unknown parentage involves analyzing and building the trees of your best matches ...
Look through the family trees of 2nd, 3rd, and 4th cousin DNA matches for common ancestral couples ("pedigree triangulation")
Use Ancestry.com to build private, unsearchable family trees down from each common couple to find where they intersect and produce someone in the right place at the right time.
This may only get to the grandparents or great grandparents
Once you have a candidate parent build their pedigree tree back to at least 1800
Make sure this tree is private and unsearchable initially but once you are ready to try it out, you make it searchable so that ThruLines can use it for you
Add a fake child to that parent and then connect your DNA to that fake person
Ancestry will use auto complete in the name field
Select the pedigree tree you created and link your DNA test to the fake child
Now wait ... it often only takes a day or two to get common ancestor hints ... see if they are consistent with your hypothesis
Click on each Common ancestor in your match page to view the relationship. Consistent with your theory?
Check the cMs of each match and compare them to the charts
Do they fit your theory?
Clicking on a person's name in the list of matches takes you to the DNA match page
Does this fit your theory?
Next click on the shared ancestor's name in the left hand column box called "Common Ancestors" to get to this view which shows the relationship
You might try using the "What Are The Odds" tool at DNApainter to check your theory - https://dnapainter.com/tools/probability
Read this to learn more https://blog.familyhistoryfanatics.com/2019/08/what-are-the-odds-dna.html
If you can make a GEDCOM of the descendants of the common ancestors, you can upload that to WATO …
An unknown father case named B had a 779 cM match to a person some 35 years younger and also a 324 cM match to the daughter of the match
normally that might be enough if the match responds and helps but no such luck
So we checked the possibilities at my favorite online calculator
There were many many more 2nd-3rd cousin level matches descending from his paternal great great grandfather
So we used WATO to combine the chances
We also tried the new relationship calculator at GEDmatch to see if it shed any more light on this
the match did have a small but adequate tree
To combine the probabilities of all the DNA matches to descendants of Caleb Browning b 1832 we made this WATO tree
N.B. The father of the good match is the same age as our B
Underneath the diagram, the possibilities are explained in more detail.
It is 9 times more likely that Son A is the unknown father than those two of his brothers who were in the right place at the right time also ...
So the next step is to get descendants of each possible other brother to test
Let's look at how this was done for an actual solved case.
Tessa was looking for her unknown father. All she knew his surname was Padilla and that it was an encounter in a town in California in a specific year
It's very helpful when one parent or a half sibling is tested
Because you can separate out the matches and ethnicity of the unknown parent
What does this ethnic mix tell us?
Hispanic, Mexico or New Mexico
People with endogamous roots do best to wait for close matches, 2nd cousins (or better) ... Tessa had three good paternal matches, one at each site.
The surnames of many of the paternal matches looked New Mexican to me (endogamous!)
When I lived in Albuquerque, I learned a great deal about the early Spanish settlers of that area so I was happy to help Tessa find her unknown Dad
The 23andme match was the grandchild of (Jose) Pasqual PADILLA sharing 5.1%
or 368 cMs.
Based on other matches and their ages, the 23andme match was confident that he was the half 1st cousin of the Padilla father we were looking for; that Tessa's grandad was a son of the 2nd wife of Pasqual Padilla,
thus a half first cousin once removed - Half1C1R to Tessa
The Ancestry and MyHeritage matches shared common ancestors: surname MARTINEZ
The Ancestry match - 287 cM - had a tree with just parents. Building that tree in our research tree we found common ancestors with the My Heritage match of 282 cM
Eugenio and Maria Martinez
but they were the great great grandparents of the Ancestry match. Jose, the son of that couple who was the Ancestry match's grandad had several wives and many children - so perhaps another half 1st1R?
Obituaries are a great source for finding the names and parents of the living. This one for Trinidad Martinez from the Albuquerque Journal found the Martinez-Padilla pairing we were looking for
Next task was to see if we could find a daughter of (Jose) Trinidad Martinez married to a son of (Jose) Pasqual Padilla
So did Pasqual have a son named Luis?
Yes Pasqual's son Luis married Teresa Martinez! the daughter of (Jose) Trinidad Martinez
So which of those 9 sons was in California at the right time?
Only 2 of them
Meanwhile Julie, a daughter of one of the possible half brothers, tested independantly at 23andme and shared 774cM (about 10%)
Now Tessa showed off her sleuthing skills, she called the librarian of the small town that most of these Padillas were from and got copies of their obituaries and lots of information. Neither possible father was still alive but she tracked down a son of each one of them and talked them into testing
So Julie is either a half niece or a 1C1R
image from Blaine Bettinger's chart 2017
Here are the tests results that came in
for her possible half brothers at Ancestry
Tessa was welcomed into her father's family; here she is with her half brother and half niece
BioAncestry can often help greatly with unknown parentage. Adoptee Amelia was told that her mother was Italian and her father a Hungarian musician and that they died in a car crash
As you can see, one parent was actually Jewish and the other Italian.
It helped to go through her matches and star all the jewish side
Many automated tools can work with just the "favorites" aka starred
On Ancestry, there were enough close relatives on the Jewish side to find her late father's family but very few Italian matches. MyHeritage is often better for Europeans....
MyHeritage is currently the only company that lets you sort by bioancestry and/or location,
but again, there were not very many closely related Italians
We are still working on finding Amelia's mother
We found a few candidates in the list of NYC births,
none have panned out yet
She has sent for her original birth certificate,
(these are now available from many states)
The DNA methodology does not work as well when very few people from the extended family have done testing
There are many automated tools to help with the process of finding unknown parentage
My favorites are:
GWorks from DNAgedcom.com
DNA2tree (iPad and iPhone only)
There are also many techniques to help with the process of finding unknown parentage
My favorites are:
The Leeds Method
Building the trees of your matches is always the most important technique
Copying family groups from Ancestry Trees to my research tree
In order to upload a GEDCOM to Ancestry you need to create one
Pedigree Thief can create an Ahnentafel from a pedigree on some sites:
- A pedigree view on MyHeritage.com
- An ancestor list on GENI.com
- NO LONGER ALLOWED at Ancestry.com
Then you can use my tool to turn an ahnentafel into a GEDCOM
Another technique is to copy over family groups from the trees of your matches into your research tree at Ancestry
Start by clicking a person to copy and going to their profile
On the Tools menu, top right,
click on Save to Tree
Click on Add a new person, once this person is added, click your browser's back button twice to go back to the oriiginal tree and add this person again with the whole family group
to bring up this box
Now click the checkbox next to each family member you want to copy over and then Save to your tree
Another approach when the person is already in your tree is to use the trees on the Hints page
I check the checkbox for the trees with the most sources that have him and his parents
Then Review selected tree hints gets us the page where we can copy over each family member
You can keep repeating that as you build the tree up, go to his father's page and click on Ancestry Family Trees under Sources
A box comes up, click the View individual member trees
If the tree you copied him from has his parents then just click his name to go to his profile in that tree and use the Tools then Save to Tree to copy him with his family group from that tree
GWorks from DNAgedcom.com is my go to tool for building a database of the ancestors of your matches
The numbers of trees each ancestor appears in scream out ENDOGAMY
Earlier, I glossed over how I had the surnames for Tessa's paternal match ancestors, in fact I used GWorks
Jane had a third cousin match at Ancestry with a good tree
Can GWorks can identify which line from the second cousin match is the one they are related on?
Top ten ancestors in GWorks
Can you find any GWorks listed names in the far right of the pedigree?
Three of them have DNA tested descendants, check the abbreviated McGuire diagram for clues
Surname frequency from GWorks can help you decide which children's trees to build down in an unknown parentage case
So the next step was to look for the surname of Pratt B's wife and then for child D's spouse
Child D's spouse's surname is in the database many times, now to get a child of D, a possible parent to test
Clustering is a powerful way to group your related matches together in a visual diagram, this one is from DNAgedcom
Each box in this diagram represents a grandparent line, you can change the low and high cM numbers to cluster. This one used 60-300 to get the nice boxes
This cluster diagram is from GEDmatch
This cluster diagram is from GEDmatch
This is the AuoTree Analysis
The next item is a list of results in a table with icons when something could be generated
Cluster 2 is my Munson grandad
lets look at the autokinship by clicking on that icon
which brings up a new html page
Since so many of my MUNSON cousins are tested ... what would autokinship came up with for that cluster 2 green box?
Lauritz + Josephine Monsen
Pretty accurate. I have identified which child of my great great grandparents each match is descended from. Only the last one is not correct, he is actually descended from a sister of Josephine's
A closer look at my cousins with the one generational correction
Ancestry has disallowed GENETIC AFFAIRS tool to cluster your DNA matches there
but they have the ability to color code your matches into 24 groups plus star your "favorites"
On an iPhone or iPad find the DNA2Tree app and download it
DNA2tree is only on iPhones and iPads via a paid subscription but it is a real game changer for unknown parentage searches
I decided to try DNA2tree for an Australian unknown father case that had only 4th cousin matches to see what it could do
clicking on Load Some Matches gets these options
Favorites = starred
Next click on Find Common Ancestors
Here is a sample set of Common Ancestors
Note the repeating usernames (privatized)
See what happens when you Merge Common Ancestors
Now there are only three lines, with no duplication of user names
Details of the Bugden matches
Click on Graph to see an image
It did not all fit on the screen !
Thomas BUGDEN in our research tree at Ancestry with all his children added by me
Thomas BUGDEN in our research tree at Ancestry with all his children added by me
At this point I recruited an Australian search angel to build the tree down, looking for a descendant who married a Chinese person
BUGDEN pedigree for father's mother, full story here: https://blog.kittycooper.com/2019/12/can-ethnicity-help-with-unknown-parentage/
Another important tool is the ability to check if your parents are related, if they are this can make it harder to figure out the pedigree triangulation
This is a free tool at GEDmatch.com
What About Y- DNA Testing?
Y 37 STR marker results for an Ashkenzi Jewish man
If you are from a population group who only took surnames in the last 100-200 years, a Y test is unlikely to give you a surname
more about Y testing: dna-explained.com/2020/01/02/y-dna-part-1-overview/
2. Are there any close matches (1st cousins or closer), figure it out from there
3. Are there several second cousins who are not matches for each other? Build their trees
4. If you have DNA2tree, use it to find common ancestors and build a research tree or two
5. Still puzzled? Run GWorks on DNAgedcom and add trees collected elsewhere
6. Might a Y DNA test help?
My CURRENT APPROACH
1. Use the "Are your parents related" (AYPR) tool at GEDmatch on the adoptee
To learn more take a class at DNAadoption.com
Or join Cece Moore's FaceBook group for adoptees
Or read my blog
all images either screenshots or used by permission, note that the relationship images are from Blaine Bettinger's chart 2017
All my presentation slides are online at https://slides.com/kittycooper
Unknown Parentage Searches with DNA,2022
By Kitty Cooper