An Imperfect World

Deep into DNA
a monthly column by Mike Maglio


Proof:  Evidence establishing a fact or truth of a statement.

Anthropology is the study of humans.  Cultural anthropology is a branch that studies the knowledge, beliefs, art, morals, laws and customs of the world’s people.  I include genealogy, the study of the generations, as a very focused branch of cultural anthropology, the study of your own heritage.


For centuries anthropology relied on the study of languages and the discovery of artifacts to build a model of human history.  Today and for more than a decade, anthropologists have used DNA to support their arguments.  This as a tripod of evidence and adds balance.  Language, artifacts and DNA give anthropology three legs of support.


As genealogists, we rely on oral tradition and historical records.  With DNA for genealogy, we can build our own tripod of evidence.  The difference between anthropology and genealogy is that pottery shards don’t lie.   The stories that grandma told and even great-grandpa’s marriage record, could be full of half-truths or even outright inventions.  While DNA doesn’t lie, it never gives the complete story either.  We need to combine all three techniques to fill the gaps left by the other methods.


Oral tradition is an age-old version of the whispering game or telephone game.  A family story is passed down from generation to generation with errors accumulating in the retellings.  The current tale could be significantly different from the original anecdote.  Genealogists love a good mystery, so we sift through these stories for nuggets of truth.  An often told family story is about having Native American roots.  Grandma knew that it was the truth because when she was a child she saw a photo of her father’s mother dressed in buckskin and feathers.


Using tradition genealogy, we track down the photo and then the photographer.  We might find that the photographer was famous for supplying costumes.  The new facts about the photo may not be enough to prove or disprove Grandma’s story.  Add autosomal DNA testing with an ethnic population comparison and you get a 7% match for Native American.  The autosomal test won’t tell you which one of your ancestors was the Native American.  You have to switch back to historical records and revisit Grandma’s story for more bits of truth.  The old photo gives you a time frame and a location, which leads you to a census record for your gg-grandmother.  The census record has some tantalizing hints, but nothing definitive.  Now if you can find a living descendant in the maternal line, it’s time for a mitochondrial DNA test.


Historical records can have their own problems.  A death certificate is only as good as the informant’s knowledge.  It’s not uncommon to find a marriage record where both parties lied about where they were living or census records with folks lying about their age.  People can show up on the census in multiple places or their information can be completely wrong because it was given by a neighbor.  There is always the probability that the record you need no longer exists or never existed.


To complicate matters even more, there can be non-paternal events.  Non-paternal events include orphans and adoptions, infidelity, illegitimacy, undocumented name changes or any situation where a person doesn’t have the same surname as their biological father.  A conservative estimate is that 1 in 100 people fall into this category.  After I give DNA presentations, nearly everyone shares a story about an adoptee or illegitimate family member in their tree.  These folks have a large gap in their fan charts.  DNA testing can shed light on these gaps.  If you are male, you can take a Y DNA test.  One of the first results you will get is a set of records with matching surnames.  Or, if you have a brick wall with adoption or illegitimacy, you could get a set of records with your real surname.   This doesn’t mean that your problems are solved.  More than likely you won’t immediately find your missing link.  You can get to a common ancestor within the last 3 to 6 generations.  Then you would use traditional genealogy to track forward in time to a point where the families connect.


DNA testing is not enough by itself.  I remember a story from when I first started researching DNA.  Two men, one from Poland and one from India, contacted each other after learning they were an exact 12 marker Y DNA match.  They spent a significant amount of time trying to figure out how they were related.  When it became available, they upgraded their tests to 37 markers.   The additional results showed that they were not closely related and that they would have to go back thousands of years to find a common ancestor.



If we look at the Thomas Jefferson / Sally Hemings case, DNA has proved that the Hemings descendants have Jefferson genes.  It cannot prove that it is Thomas’ genes.  DNA tests can verify a relationship, but not descent.  This is why we need our genealogy tripod of oral tradition, historical records and DNA.  Each type of evidence needs to be used to support and balance the other types of evidence.


Genealogy usually follows a zig zag research line, with plenty of dead ends and steps to be retraced.  Validate the hard work that you have done researching your paternal lines by getting Y DNA tests to link to common surname projects.  After you get your autosomal test done and the cousin matches start rolling in, compare your trees to find your connections.  When you run across discrepancies in family stories or on records, stop and ask yourself why.  What would your ancestors have gained from the deception?  Then figure out what type of DNA test would best help you solve the mystery.


It’s an imperfect world out there.  You need all the evidence you can find.  Combine these three techniques for success.  In my next columns I will go into detail on how to get the most out of your DNA tests.



Mike Maglio is the author of Deep into DNA, a monthly column in The In-Depth Genealogist which focuses on the use of DNA in genealogical research. Mike can be found blogging at OriginHunters.



© Mike Maglio (Origin Hunters) 2012

This article originally appeared in the June issue of The In-Depth Genealogist. Receive The In-Depth Genealogist free by subscribing HERE.