How DNA Testing Provides Proof of Relationships

Autosomal DNA is a mixture of non-sex determining chromosomes that mix or recombine also known as admixture DNA according to the International Society of Genetic Genealogists (ISOGG). Testing companies include but are not limited to 23andMe, Ancestry, and Family Tree DNA.


A new collaborative health study administered by the University of Michigan’s department of Biostatistics called Genes for Good offers another option.


If interested in testing for genetic ancestry and disease in your family, check out Genes for Good, Frequently Asked Questions for information on receiving a free DNA test kit. The Genes for Good study requires your continued participation via online surveys while permitting your DNA to be used in genetic research on disease. The raw DNA file, however, is yours to use as you wish. This is your DNA and not the property of the University of Michigan. It can be downloaded and used by you for genealogical research on free sites such as A site operated by users, volunteers, and researchers. Read the GedMatch Site Policy before uploading any data.



Likewise, those testing at Ancestry may upload their raw DNA to Family Tree DNA for a small fee. However, Ancestry does not accept raw uploads at this time from any other testing companies. Researchers hoping to upload raw DNA results across platforms to maximize the number of potential matches for their profile could purchase an Ancestry DNA test kit. After receiving your matches from Ancestry, download the raw DNA file to Family Tree DNA and GedMatch. This practice is called autosomal DNA transfer.


Why transfer to Family Tree DNA if you tested with Ancestry and uploaded it to GedMatch?


Surname and Geographical Projects housed at Family Tree DNA consist of males tested to confirm patriarchal lineage. If you are a female descendant, you may want to compare your autosomal results with other known male descendants of your line. The female descendant may also have the father or grandfather test. Certain projects only accept Y-DNA tests. It is common to see a female administrator of her father's Y-DNA test. Other projects on FTDNA will accept both Y-DNA and atDNA to reinforce proof of relationships. 

Genetic Triangulation. International Society of Genetic Genealogists. ISOGG Wiki. William Hurst.
Genetic Triangulation. International Society of Genetic Genealogists. ISOGG Wiki. William Hurst.

How Does DNA Complement GPS?


Recall in DNA, GPS, AND YOU, the Genealogical Proof Standard consists of five steps professional researchers use to ensure your family tree is accurate. Every professional genealogist is also a Genetic Genealogist as DNA becomes the proving ground for your supporting documentation.


Genetic Triangulation employs the DNA tests in question and documented proof of association to confirm two testers relate genealogically and genetically. See also Jim Bartlett's blog on Segmentology for a review on Genetic Triangulation in atDNA testing.


Q: Can you genealogically match a person with whom you share no genetic match?

A:  Yes and No.


YES. This is called the ‘non-parental event’. A person adopted into the family will share your paper trail but their genetics match the adoptee’s birth parents.  



 NO. There is no record of adoption or other event tying the two testers together. Paperwork errors could be to blame. If the tester is not a genetic match, the paper trail of your family line is confused with another line. Compare notes and determine where the error occurred. Record the error so both testers can move forward.

The Case of the Invisible Coal Miner

Which Test Is Right For You?



A Y-DNA test confirms your male ancestor and validates surname research. Remember Charles CLARK?  Separating your patriarchs and gathering descendants is integral to family surname research. You can review the Clark(e) Surname Project at FTDNA for males only. Is there a study for your surname? You can perform a search here. This CLARK study began in 2001 to determine if all Clark(e) families from Virginia were the same. Why would anyone find it necessary to confirm the CLARK families who came out of Virginia were all related? Most of those Virginia families told their grandchildren they were relatives of William CLARK who traveled with Meriwether LEWIS (LEWIS & CLARK Expedition).


In Kentucky, being a CLARK may also tie you to another noted William CLARK. The William CLARK who was allowed to lease some land from his two Churchhill uncles because he loved horse racing. The administrators of the CLARK(e) Surname Project extend membership now to all Clark(e) males. The CLARK(E) Y-DNA Colorized Chart shows why a researcher cannot assume a shared surname equals shared blood.



This test confirms your maternal ancestry. The field is relatively new. Ongoing research is changing how we approach mtDNA or mitochondrial DNA testing. I recommend Steve Handy's blog for a great tutorial on mtDNA called DNA Genealogical Experiences and Tutorials.



Researchers call the autosomal test the “cousin finder.” Fairly accurate to the fifth generation from every line, it is used by genealogists to break through brick walls. It is also the leading test for female researchers. A man receiving few matches with a Y-DNA test may take an atDNA test to find female descendants of his male lines. A good choice if your family seems to produce more daughters than sons, like mine.


Genetic Triangulation is the method used to determine if people share a most recent common ancestor (MRCA). The bases for genetic triangulation varies based on the type of DNA testing. Please refer to the ISOGG Wiki for more information.


There are many reasons to test your DNA. To find your roots, to find your cousins, or find medical answers. What kinds of testing your family pursues depends on your research goals. However, DNA is not a substitute for documented research. DNA confirms research. DNA is NEVER an alternative to documented research.


Do you have a DNA match?


Does the paperwork lead both testers to the MRCA

      (most recent common ancestor)?


Testing answers questions. It also produces questions.

Rushing to judgment or failing to properly research results in faulty analysis.

Take your time. This is not a sprint. It is a marathon.


I recommend those testing have an established private family tree stored offline. Testing your DNA prior to compiling a paper trail will confuse a researcher. Matches have little meaning without a documented family line for comparison to others. DNA always tells the truth. Failing to perform a reasonably exhaustive search or a faulty analysis though can pin the tail on the wrong donkey.


You may make changes as you research so best to leave the family tree offline until you have confirmation. With the advances in Genetic Genealogy come the pitfalls of online genealogies filled with errors – attached to DNA profiles. In Blaine Bettinger's March 2017 post on his blog, The Genetic Genealogist, he asks Can A Genealogist Refuse to Use DNA Evidence?


Nothing online goes away. Information stored online has eternal life. The moment you think it is deleted once for all, take hold. You may witness a resurrection.


Most Ancestry users copy from other user trees. If the original tree is wrong then multiply the errors by the number of users who copied this information to their trees. There is a shared image on Ancestry containing the supposed family hierarchy of a famous man. The chart is wrong. To date, 343 users copied the error-laden image to their Ancestry user tree. Multiple credible resources in libraries and online prove this information is false. Yesterday, more users copied the image. Errors circle like sharks. If you are unsure, refrain from posting your family information.



Adding insult to injury, the blogosphere attempts to correct the record with faulty analysis. One genealogy blogger, changed an entire family line when he misinterpreted a letter (one type of credible document) on a family tragedy. Another researcher brought this error to the person’s attention. They amended their analysis but the horse was out of the barn. The bad information is still making laps. No one returned to the site for the amendment. Those researchers who copied the bad data will not remove it from their online trees. This may never get fixed. Let the buyer beware. Even with credible documents, faulty analysis creates fairytales and leaves the facts behind.

The Y and MtDNA Trees at the National Genographic Project attempt to tell the human story.

The National Geographic DNA testing kit, Geno 2.0 Next Generation Kit is an additional option in atDNA testing.


How DNA Can Help Your Family Research

by Maurice Gleeson

Presented at Back to Our Past (13th Oct 2012), Royal Dublin Society, Dublin, Ireland

Please take time to watch all four parts of Gleeson's talk in 2012.

It is one of the best explanations of how DNA can help your research found online.


I hope researchers and members of the Trimble County Historical Society benefited from this discussion on DNA as it relates to the Genealogical Proof Standard (GPS). A member poll earlier this week expressed interest in forming a closed and confidential group for Trimble County DNA.  A notice will appear on our Facebook group page, Historical Trimble County when the group is ready for participants.  Please direct any questions to

The Trimble County Historical Society meets the third Saturday of the month from April to November.

All meetings are open to the public.




Trimble County Public Library, Conference Room

October 21, 2017 at 10:30 a.m. to 12:00 p.m.

Light Snack Provided


Tina Mitchell Boutall

Research Committee

Trimble County Historical Society