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

Tuesday, June 25, 2013

Thoughts on DNA Testing

I got a comment recently that I thought was worth commenting on:
You said "We are not talking about science here. I can't conduct an independent experiment and validate your findings." 
Two years ago this argument may have been mostly true. 
Today, genealogists do have the ability to scientifically verify the results of their paper "proofs". DNA does not lie. Autosomal DNA testing and the tools developed for working with this data is available now. It allows us to scientifically prove the validity of our methodology findings.

It is not cheap ($100 to $200 range depending on current sales), but it is getting there very fast. It is already less then the cost of traveling to a distant repository.

It does require the participation of other descendants, but social networking and on-line trees make them easier to find then ever. 
It does require time and does not replace paper based proofs, but it certainly is science and it can produce your "proof".
Hmm. You may or may not have noticed that I stay well away from certain topics. The reasons for this are complex. For example, I am an active and participating member of The Church of Jesus Christ of Latter-day Saints and a Church Service Missionary at the Mesa FamilySearch Library, but I do not usually comment in this Blog on either Church doctrine or Church procedures. It is not they do not impact my beliefs and practices, but I have chosen to address the larger genealogical community as such from the standpoint of genealogy. In this position, I mirror the attitude of the FamilySearch Centers around the world. Normally and if things are operating properly, anyone should be able to utilize the FamilySearch Centers and Libraries without concern that they will be "proselytized" by the Mormon missionaries. I feel the same way about this Blog.

In the proper context, I am very much involved in all the religious aspects of my beliefs about genealogy. There is a time and a place for everything. Likewise, I refrain from expressing political viewpoints unless they relate directly to genealogy. However, I am very opinionated and vocal about the impact of law and legal matters on genealogy.

Now, about DNA. Does DNA testing allow us to "scientifically prove the validity of our methodology findings?" I think that this statement is a little too conclusive for my part. What people believe about the efficacy of DNA and what DNA testing actually establishes are sometimes two entirely different things.  It is true that DNA is "scientific" in the sense that it takes a fair amount of specialized knowledge and semi-medical procedures to establish relationships, but the results, without a sizable database sample, can be pretty tentative. Quoting from Wikipedia: Genealogical_DNA_test about each of the three different types of genealogical DNA testing:

SNP based testing: "The reliability of this type of test is dependent on comparative population size, the number of markers tested, the ancestry informative value of the SNPs tested, and the degree of admixture in the person tested." 
STR tests: "As most STR analysis examines markers chosen for their high intra-group variation, the utility of these particular STR markers to access inter-group relationships may be greatly diminished." 
Biorgeographical ancestry: "As studies from more populations are included, the accuracy of results should improve, leading to a more informative picture of one's ancestry."

Now, some people are overwhelmed with the results of their DNA testing and firm believers in its efficacy. Others, with less useful results are skeptical of the usefulness of the procedures."

As discussed and used by various DNA service providers, there are some things they do well and other things they do not do well. I strongly suggest that if you are interested in DNA testing, you become adequately educated as to the procedures, types of testing and validity of the results. 

As for me, I think that although it may be a scientific procedure and has been used for years in both criminal and civil actions, I am not personally convinced that it can provide generally useful genealogical evidence except in some very limited cases. For that reason and others, I have stayed away from getting involved either for or against the use of DNA in genealogy. For a fairly good analysis of the problems and challenges from a legal standpoint, see DNA Evidence

So I guess I would agree with the last statement made by the commentator above, DNA does not replace paper proofs.


  1. Your words are so wise! I look forward to seeing you this weekend in Sacramento.

  2. DNA should help your case of your suspicions in your research. Sometimes I do not have the paper proof but I do have a suspicion, usually I am correct....

  3. Agreed. I suspect it's pretty good at confirming or disproving paternity or close relationships, but most genealogists are interested in relationships with further distance.

    Even at it's best DNA might be able to prove that you are somehow a cousin of the individual you thought you were a cousin of, but it won't 'prove' that the connection you found through research is the correct one. It won't prove dates of birth or death. It won't prove any facts uncovered through research about your ancestor's lives.

    That said, DNA tests can help you find those distant cousins who might be conducting research along similar ancestral paths.

  4. It can be a great tool for genealogy testing as well, as you noted, but it can't answer everything.