Another Questionable Article About Genetic Genealogy

I honestly don’t know what to do with this next article. Meredith F. Small Ph.D., an anthropologist at Cornell University, wrote a brief article at LiveScience entitled “DNA Kits: Secrets of Your Past or Scientific Scam?” Dr. Small’s article is largely a comment on the article that appeared earlier this fall in Science, “The Science and Business of Genetic Ancestry Testing” (I provided an analysis of the article here at TGG).

According to Dr. Small:

“[The quest for identity] also leads unwary seekers of the past right into the hands of scam artists who claim they can trace anyone’s DNA back to its source.”

The sentence is extremely misleading:

First – a scam artist is by definition a person who engages in a “fraudulent business scheme.” Although genetic genealogy can be controversial, I’ve never heard a single customer accuse a company of running a scam. To the best of my knowledge, these testing companies are using the best science available to test DNA and compare results to their databases. Are physicians running a scam if they use open-heart surgery to fix a heart, rather than a simple pill that will be invented in 5 years? All technology is based on the best developed science right now. A company might have a limited database or only test a limited number of markers, but this does not qualify them as running a “scam.”

Second – The sentence also implies that genetic genealogy companies promise too much, and that genetic genealogists are unable to decipher the limitations themselves. As my readers might remember I discussed this assumption here. Most genetic genealogists understand and embrace the limitations of genetic genealogy, and also work to help others understand that difference. More can be done, and many are working to make that happen.

Similar sentences include “claims that this analysis will tell you much about where you came from are downright fraudulent, anthropologist Deborah Bolnick of the University of Texas at Austin and 14 co-authors recently reported,” and “Instead of tracing our genetic past, what we get is a scientific scam”

I think one of the major problems of this article is that the author or the editor doesn’t seem to the understand the underlying science. There is a MAJOR difference between autosomal testing and mtDNA or Y-DNA testing. This includes the science behind the test, and the science behind the interpretation of results. For instance, the article includes the following sentence:

“But, [anthropologist Jonathan] Marks points out, these companies are preying on the public because they simply don”t have enough comparative information to pinpoint a gene on a world map.”

For all you genetic genealogy newbies out there, there isn’t a test on the market that attempts to “pinpoint a gene.” Dr. Small fails to establish any line between autosomal testing and mtDNA or Y-DNA testing:

Some autosomal testing does attempt to identify the approximate predominate location of certain DNA markers (SNPs), but genetic genealogy companies do not sequences genes (other than in the full mtDNA test). And contrary to the implication of the article, these companies attempt to give very broad locations, such as “Northern Europe”, or “Asia”, not a specific town or county. Autosomal analysis is based on peer-reviewed science, the best we currently have available. It is true that there will be MUCH better data in 5 years or 10 years, but that doesn’t mean that using today’s science is a “scam.”

As for Y-DNA or mtDNA tests, the results are most often used to place the tested individual’s haplotype into a specific haplogroup. The approximate origin of all haplogroups has been established by peer-reviewed science. There are a few companies that use that haplotype data to identify a potential source of the mtDNA, for example. Again, that identification is based on peer-reviewed science and proprietary databases. Additionally, most genetic genealogists are aware of the limitations.

Perpetuating the mistaken scientific understanding, along comes the most egregious statement in the entire article:

“More insidious, these companies pretend to trace your unique ancestry through mitochondrial DNA, but that’s simply not possible. A few hundred years, a few generations, and every person’s history is a genetic mishmash. One little gene isn’t going to inform anybody about anything.”

It is obvious that Dr. Small either does not understand the underlying science, or is completely glossing over it. For the newbies, mtDNA is passed on almost always completely unchanged from mother to child. Every once in a great great while, that mtDNA changes in a very small way (that is, it gains a mutation). It does not “mishmash” with other mtDNA.

The mtDNA I inherited from my mother was inherited through an unbroken line of women until it ended with me. Employing genetic genealogy, I can trace my “unique ancestry through mitochondrial DNA.” I belong to Haplogroup A, which means that my maternal line crossed the Bering Strait thousands of years ago and settled in Central America. This is not conjecture, and I was not “scammed.” I used peer-reviewed science to come to that conclusion.

Now I confess that the mtDNA test only told me about a TINY percentage of my genetic heritage, but it was an exponential growth of information compared to what I had previously, which was nothing. And note, of course, that assignment of mtDNA into a specific haplogroup is based on single nucleotide markers, NOT on the sequencing of a gene.

The same holds true for Y-DNA testing. Although the markers used for comparative analysis appear to mutate somewhat more rapidly than mtDNA, Y-DNA is still passed largely unchanged from father to son.

And I felt that the concluding paragraph was dismissive:

“If you want to know who you are, look in the mirror. Written on your face is countless generations that have survived to reproduce, and the only thing you can realistically do at this point is thank them and then move forward.”

Genetic genealogy is a valuable part of my life. Although it doesn’t define who I am, it is a part of my identity. Attempting to learn more about myself and my ancestors through my genetic makeup has been a valid and rewarding endeavor. And the current field of genetic genealogy is only at the tip of the iceberg – so far we’ve been looking at a few random SNPs in our genome. Wait until science gets ahold of my entire genome.

P.S. -I will be sure to email Dr. Small about this post, so that she can respond to my criticisms.

9 Responses

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  2. Lee Anders 6 January 2008 / 9:41 pm

    The concluding paragraph appears to not only dismiss genetic genealogy but genealogy as a whole. Not quite sure what to make of that…

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