Some people eat, sleep and chew gum, I do genealogy and write...

Wednesday, April 13, 2016

Beginning My Intensive Exploration of DNA and Genealogy

After many years of flirting with the topic of DNA and Genealogy, I decided it was time to seriously consider whether or not any of the specific questions I had in my own lines could be reasonably answered through involvement with DNA testing. Since I "inherited" a vast pedigree supposedly extending back many generations, it has taken me years to document enough of what was already there to make judgements about the missing parts of this extensive pedigree. To date, I have not seen any particular use for DNA testing. The only particular instance where it appeared to useful was with a Great-grandfather who was persistently reported as "adopted." Since my parents are 2nd cousins related through this particular grandparent, it is possible that DNA testing could confirm or deny the possibility of adoption and thereby confirm or deny the 2nd cousin relationship of my own parents.

Another major obstacle to my use of DNA testing was the fact that I have little or no contact with the members of the particular families that might confirm or deny the relationship. In addition, there seems to be some long-standing animosity in the family concerning that particular issue. In other words, I might be stepping off into a family feud. 

As far as just obtaining a DNA test on a fishing expedition, I am still not convinced that finding out what percentage of my ancestry comes from what part of Europe on a percentage basis is supposed to help me at all, since I have researched, documented, confirmed lines to England, Scotland, Wales, Ireland and Denmark. Lately, I have been thinking about another issue. That is my Jewish heritage. My Great-great-grandfather came from England and when he migrated to the Southwestern part of the United States he married my Great-great-grandmother and took her name. His original name was De Friez and when he married he took the name Jarvis. He later had his name changed officially in the Arizona Court. The De Friez surname is commonly found on lists of Jewish surnames in England.
See for example, “Sourcebook for Jewish Genealogies and Family Histories.” Accessed April 13, 2016.

 Currently, on the FamilySearch Family Tree, the De Friez line is shown to extend back from England to the Netherlands where it clearly becomes involved with Jewish families. Lately, I have been considering a DNA test to either give me an incentive to begin confirming this supposed connection or not. 

Let me emphasize, I am not starting out on this investigation as a beginner. As I have mentioned before in posts, DNA testing issues have been around for a long time in the legal profession. As a trial attorney, I was always aware of the arguments pro and con to DNA testing and the limits of its use in a trial situation, although as a commercial litigator, I had little use for that type of evidence. See “Paternity FAQ | Arizona Department of Economic Security.” Accessed April 13, 2016. Here is a sample list of articles concerning the validity of DNA testing in courts. You might note that many of these articles are quite dated. The use of DNA testing in many instances is no longer a major issue.
The real issue with DNA testing per se, is the serious issue of unintended consequences. Confirming or denying close family relationships can have serious emotional and other consequences. Likewise, although the DNA type testing done for genealogical purposes does not usually end up with medical issues, genetic testing for gene deficiencies can also have serious and long-lasting family consequences. These aspects of gene testing and certainly downplayed by the proponents of DNA testing for genealogical purposes. 

My own observation is that without a specific, researched and documented objective, DNA testing may be motivating or thought provoking but mostly just interesting. Even is this context, finding out that your family line has a significant component of a particular racial or ethnic composition may also have some undesirable consequences. 

Considering my own family lines, I am still not certain that DNA testing would give me any solid, useful information that would not still have to be obtained and confirmed through careful, documented research. My method of approaching these issues has always been to read and study everything written on the subject until the additional information I find becomes repetitious. 

What I certainly do not need is another biologically related, detailed explanation of X and Y chromosomes. What is more helpful to me is the standard court analysis of this type of information. Here is a quote from the  National Center for Biotechnology Information cited above,
Among the issues raised is the validity of the assumptions that (1) except for identical twins, each person's DNA is unique, (2) the technique used allows one to determine whether two DNA samples show the same patterns at particular loci, and (3) the statistical methods used and the available population databanks allow one to assess the probability that two DNA samples from different persons would by chance have the same patterns at the loci studied. Even if those assumptions are accepted, there is the important question of whether (4) the laboratory's procedures and analyses in the case in question were performed in accordance with accepted standards and provide reliable estimates of the probability of a match.
I suspect that very, very few genealogists who send off for a mail-order DNA test, have considered these issues with regard to the testing procedure. How do you know that your DNA sample has not been contaminated? I am not challenging the professionalism of the DNA testing companies, I am merely pointing out valid and very important concerns that I would have before I spent my money and subsequent research time based on a DNA test.

Stay tuned, I will probably have more to say on this subject.


  1. Since a DNA test for you is probably going to show some fraction Danish and the rest from England/Wales/Ireland/Scotland, the most interesting bit, as you note, would be whether it does show anything about the Defriez line. I say: go for it! Or in the words of the immortal H.L. Mencken: "I believe that it is better to know than be ignorant." : )

  2. James, if you can point me to relevant De Friez profiles on FamilySearch, I may be able to help. I found an Isaac baptized on Aug 31, 1695, in the Noorderkerk in Amsterdam, for whom a source exists on film on-line. The Noorderkerk was a Protestant church at the time, so I don't know whether he was Jewish or not. He may have been baptized, because other religions were suppressed. I'm not that good with that part of history, so this is just guessing.

  3. The Isaac I'm referring to is and the source is on (5th entry in the right column).

    1. Sure, here is the entry for Charles Godfrey De Friez Jarvis KWCK-XQG. Unfortunately, the Isaac De Friez you refer to, 2T54-DG7 has had no sources added. It helps us all when we add sources to the entries in the Family Tree. It certainly looks like this is the entry used to give the christening date shown. Thank you.