Category: DNA Testing Info

When you receive your Y-DNA results from Family Tree DNA, you will see this on your main screen.  Click on “Matches” and you will see a list of men who share Y-DNA with you.

When you click on “Matches”, a screen like this comes up with a large list of men who share your Y-DNA.  On the left is the “Genetic Distance”, followed by the name of the person who tested.  Earliest known ancestor is based on the tester’s research on their male line.  Keep in mind, our trees are based on paper and our DNA is based on genetics.  It is very common to see a mixture of names here.  Different names could be due to name changes many hundreds of years ago, or a non-paternal event.   Why are my Y-DNA Surnames Different? 

The orange “Tip” box will give you an idea of how many generations ago you shared a common ancestor with this person.  For example, a person with a genetic distance of 2 has a 100% probability that you shared a common ancestor 24 years ago and a 99% probability that ancestor was within the past 12 years.  Obviously, the smaller the number, the closer the common ancestor was.

With genetic distance, I think in terms of steps on a ladder.  My father tested at the 67 level.  Currently, Family Tree DNA offers this test at 37, 67, 111, and 500 levels.  The cost varies from $169- $649.  So what do these levels mean?  If your DNA were steps on a ladder and the ladder had 500 steps, you would only have them sequence the first 37, 67, 111, etc. steps.  By looking at the image above, my father’s closest match is at a genetic distance of 2.  If we test at a higher level, this person will still be a genetic distance of 2.  If the person was a 0 genetic distance, I would be interested to see if this held true at a higher level of testing.   The only motivation for me to test my father at a higher level would be to determine information I have obtained from the projects I have joined.  I have touched on these “projects” in two previous posts and it is a topic requiring further discussion another time.  Family Tree DNA, Why are my Y-DNA Surnames Different?

Below is an illustration to help with understanding genetic distance.

For example, if the red line indicated 67 DNA markers and the steps above go up to 111 markers, because I only tested to the 67th step, I only know how closely our 67 steps match.  In this case they are exactly the same which would indicate a genetic distance of 0.  However, our DNA does not match higher up.  I would only know this if I tested at a higher level.  Although I have a genetic distance of 0 at 67 levels, I might have a genetic distance of 2 at 111 level of testing.

There are many companies providing DNA autosomal testing services.  Regardless of which company you use, your DNA results on their site are only compared to others who tested with the same company.  Gedmatch allows users to add DNA results from most companies to a central location.  This allows users to compare their DNA to users who have tested with other companies.  Gedmatch has many excellent tools.  Some are free and others are low cost.  If you are looking for DNA matches and want to “fish in a bigger pond,” Gedmatch is for you.  They offer details on how to upload your DNA, specific to the company you tested with.  To learn more go to:  Gedmatch

Family Tree DNA offers many different DNA testing options.  If you have autosomal DNA from another agency, you can upload your results to FTDNA for free.  After you upload your results, you can access their Family Finder database for only $19.00.  This will give you information on your autosomal matches.  My preference has been to test with Ancestry and then upload results to FTDNA for autosomal DNA.  This allows you to “fish in another pond” while searching for DNA matches for an insignificant fee.

Family Tree DNA is a great site for ordering Y-DNA.  Remember, this gene is passed down from father to son so the donor must be a male.  This tool is very helpful for determining the origin of the surname.  Unfortunately, if you are like me, your surname might not be what you think it is.  This might be due to a name change in the past or, as in my case, a non-paternal event.

If you plan on ordering the Y-DNA test,  you will have to decide what level  you want to test at.  I recommend testing at the 67 level to begin with, unless you want to spend the higher amount to do the “Big-Y” test.  FTDNA allows you to retest at different levels without having to resubmit a saliva sample.

When your results are in, go in and look at the various surnames associated with your DNA.  In my case, O’Byrne was the common name.  I joined the O’Byrne surname project (see below) and confirmed that I descend from the O’Byrne Clan out of Leinster, Ireland.

FTDNA offers many “projects.”  You can submit DNA to one of the projects and your DNA is compared to other members in the project.  Most surname projects track the origin of the surnames.  For instance, there were many men with the last name Curtis who came to America from various places.  By placing DNA in the Curtis Surname Project on FTDNA, it is possible to learn which Curtis a particular person from.  These projects are not limited to surnames.  They have many options to choose from such as: Ashkenazi Jews, inhabitants of various regions at various times, descendants from a particular area, etc.

If you are considering DNA testing and are unsure which company to test with or which test to take, it will be helpful for you to identify the purpose of your testing.

Y-DNA:  If you are male or you wish to know more about your family surname, you might be interested in Y-DNA.  Unfortunately, only a man (father or son) carries the y-chromosome.  If you are woman and are interested, ask a brother or uncle  if they are interested in learning more about their origin.

mtDNA:  This type of DNA is passed down to both male and female children from their mother.  It contains DNA information about the female relatives, above the mother.  (The mother, her mother, her mother’s mother etc.)

Autosomal DNA:  This type of DNA is what most ancestry websites use to help individuals discover cousins.  It includes matches on both the maternal and paternal sides of the family and will show relatives dating back five to eight generations.