yDNA TESTING
A Valuable Genealogy Research Tool
By Douglas Clare Purcell
Family Tree DNA was the first company to make DNA testing available for genealogical research in
April 2000, and has been setting standards for innovation and service ever since. Today, the Houstonbased company’s unequaled breadth and depth of services, plus the largest DNA-genealogy database in the
world, enhance its continued status as the acknowledged leader in this exciting new frontier for genealogy.
Family Tree DNA was founded by an amateur genealogist, Bennett Greenspan, who has been
researching his own family history since 1964. This explains its commitment to science and dedication to
genealogical research, making it the largest and most trusted name in this field. In addition to having the
widest number of DNA Projects – over 4,400 Surname and Geographic - company members have access to
the largest databases of Y-DNA and mtDNA available today. On October 10, 2011, Family Tree DNA’s
database exceeded 349,081 individual test records (roughly 215,979 Y-DNA and 133,102 mtDNA tests).
The Purcell DNA Project was established in January of 2005, with 12 members and now (October 2011)
has 36.
The company has the widest range of tests of any genetic genealogy company today. In addition to
setting industry standards when it first introduced 12, 25, 37 and 67-marker Y-DNA tests, Family Tree
DNA now offers a 111 marker yDNA test – the most comprehensive in the industry.
Five years ago the Purcell Family of America Genealogical Association (PFA) endorsed the use of
DNA testing as a component of family history research. Since that time, several PFA members, officers and
board members have had a yDNA test to help establish their relationship with other Purcell family
researchers who have also participated in this scientific approach to genealogy. As previously mentioned,
there are 36 individuals who are involved with the Purcell Group Project administered by Family Tree
DNA of Houston, Texas at http://www.familytreedna.com
A y-chromosome DNA test is initiated by using a swab on the inside of your cheek. This process is painless
and quick. DNA testing companies examine junk or non-coding DNA which provides no useful
information on unique traits or health issues. Non-coding DNA makes up an estimated 95% of our DNA
and has no known purpose as it doesn’t code for proteins. However, it acts as a “silent recorder” storing
marker information plus the occasional mutation thus saving the genetic history of your family. Family
Tree DNA, or other DNA testing companies, will provide a swab testing kit with instructions once you
commit to have the test done. Tests offered are for 12, 25, 37, 67 or 111 markers and vary in price. As an
example the cost (effective October 2011) for a 37 marker test is $169, the 67 marker test is $268, and the
111 marker test costs $359. Look for special prices on these tests around Christmas each year. The 37
marker test is recommended for those just getting started in this process. Test results are usually available
within five to six weeks after the DNA swabs are received by the testing company but, in some cases, could
take longer.
Participants are encouraged to compare yDNA test results to see if they share a most recent common
ancestor. The information gained from yDNA tests has little value unless it is compared with others to see
if there is a match or a near match. If you match with someone on 64 of 67 markers tested, you have a
genetic distance of three which indicates that there is a very close relationship. Of course, a perfect match is
an almost sure indicator that you and another test participant descend from the same person. But the only
way you can really know is to compare notes based on your “paper trail” or the research that you have done
on your family. Incidentally, the yDNA of a living male is almost identical to that of his earliest ancestor
except for the occasional mutation. And since the surname of men rarely changes (except for spelling
variations) yDNA testing is the ideal way to make contact with others, of the same surname, who may be
researching your exact line.\Still another benefit of yDNA testing is the elimination of some Purcell family
lines from your research by comparing your yDNA test results with findings from other tests. For some
time I thought a man named Jacob Purcell (1773-1859) of North Carolina had a good chance to connect
with my own Purcell family. However, a descendant of Jacob Purcell had his yDNA tested and it was very
different from my results. Therefore, we did not have a close connection so I concluded my research on this
man and turned to other possible family line connections.
Within a few months of launching the Purcell Family yDNA test, several board members, officers and
members of the PFA got some surprising news. The first president of PFA, the late Todd Purcell, found that
he had a genetic distance of one on a 67 marker test with the current president, J. F. Purcell. Their paper
trail tracked back to Thomas Purcell and Mary Van Hook of Loundon County, Virginia. Soon Tony
Marostica, another PFA past president, Bill Purcell and William L. Purcell also determined that they had a
connection through this same Purcell family in Loundon County, Virginia.
With great anticipation, I finally received the results of my yDNA test and they did not match any other
Purcell family member in the Family Tree DNA data base. But soon, I received an e-mail notice that I had
matched on 64 of 67 markers with another test participant. But his surname, Maloy, was obviously different
from mine. Family Tree DNA also compares test results with other surname projects, which is how I
learned about the Maloy family connection. So I immediately began to check my genealogical records to
see if I could make a connection with the Maloy family. And, I did in North Carolina during the early
nineteenth century. However, in comparing notes with the Maloy (Malloy) family researcher I could not
find a most recent common ancestor. Still, I knew there was a connection.
According to Family Tree DNA the likelihood that we shared a common ancestor (as a result of the 67
marker test) is 65.39% with eight generations but that number increases to 89.34% with twelve generations.
16 generations is 97.33% ; 20 generations is 99.41%; and 24 generations is 99.88%. A generation varies
from family to family but is usually about 25 years. So the Purcell/Maloy family connection probably took
place within the last 200-300 years which is pretty close genetically speaking. And that puts the Maloy and
Purcell families in the time frame of late 18 th century to early 19th century North Carolina. Both families
can be absolutely certain of a most recent common ancestor within 24 generations or about 600 years.
However, in spite of my best efforts, a most recent common ancestor with the Purcell and Maloy families
can not be found. What is the possible answer to this puzzle?
Despite the known linkage of the Purcell and Maloy families in Cumberland County, North Carolina, a
common ancestor has not yet emerged. However, our two yDNA test results show that we probably had a
common ancestor preceding the adoption of surnames. The adoption of hereditary surnames took place in
England about the year 1300. This interesting fact applies to the Purcell and Maloy surnames as well other
surnames. Of course the spelling of surnames has evolved over time. Other possible explanations for our
inability to find a common ancestor include adoption, an extramarital event, a change of name, the use of
an alias, an orphan who was given a randomly selected surname or finally convergence. Convergence is
where, over time, mutations lead to two different surnames having a matching yDNA result today. But the
most likely scenario is simply that my Purcell family and the Maloy family member had a common
ancestor prior to the establishment of hereditary surnames.
More recently, I have established a yDNA relationship with a gentleman named Robert (Bob) McGregor
Purcell of Edmonton, Canada. We matched on 63 of 67 markers which means that Robert Purcell and I are
cousins. He tracks his lineage back to a John Purcell of Campbeltown which is on the Kintyre Peninsula in
the Argyll region of Scotland. This family emigrated to Canada in 1872, almost exactly 100 years after my
Purcell family emigrated from the same area to Cumberland County, North Carolina in 1770. Through
deductive reasoning and, perhaps, some dumb luck my research efforts had been focused on this area of
Scotland. In fact my sister and I went on a genealogy research trip to the Argyll area of Scotland in 2000.
The most important thing gained from this yDNA match was the connection of my Purcell family to the
Kintyre Peninsula of Scotland. Why? I had evidence which allowed me to cross the “pond” with my
research. Interestingly, his emigrant ancestor came to Canada as a MacSporran before changing it to
Purcell. The MacSporran/Purcells were the keepers of the purse for the McDonald Clan. Bob’s Scottish
ancestor was a Purcell before changing his surname to MacSporran. Later, as we have seen, it was changed
back to Purcell c 1872 in Canada.
I continue to look for that elusive Purcell/Maloy common ancestor but realize that the search may,
ultimately, be futile. I am also focused on the MacSporran/Purcell family in Scotland. However, it has been
a learning experience for me which has deepened my understanding of yDNA tests and their relationship to
the traditional genealogical research that most of us are accustomed to doing. And I keep waiting for
another e-mail from Family Tree DNA that shows a yDNA test match with a person who shares my
surname—or a close spelling variant.
PFA members are encouraged to share their own yDNA test results with other members of the
organization through short articles which focus on their success stories. And we suggest that other
Purcell family members consider having yDNA testing done—before it is too late. Some Purcell lines
may now have only one known surviving male descendant. That person should have a yDNA test
done sooner rather than later—if he is interesting in learning more about his family history.
Two great resource publications on DNA testing include: Trace Your Roots with DNA: Using
Genetic Tests to Explore Your Family Tree (Rodale, Inc. 2004; ISBN 1-59486-006-8) by Megan
Smolenyak and Ann Turner
Family History in the Genes: Trace Your DNA and Grow Your Family Tree (The National Archives,
United Kingdom 2007; ISBN 978-1-905615-12-4) by Chris Pomery.
Both books are excellent primers on DNA testing and are easy to read and understand.
Editor’s Note: A new book has just been published in the United Kingdom called Surnames, DNA,
& Family History, (Oxford University Press 2011; ISBN 978-0-19-958264-8) by George Redmonds, Turi
King and David Hey. This book demonstrates the impact that DNA testing has on the study of family
history.