“Should I take a DNA test?” We evaluate the reasons for – and against- taking a DNA test.
*This article originally appeared in NGS Magazine, and is reprinted with permission.
The first hurdle a researcher may face as they contemplate engaging with the growing field of genetic genealogy may be the decision of whether or not to take a DNA test in the first place. While DNA testing is increasingly useful for the genealogist, the power of genetic genealogy to reveal surprising or unexpected information, and its current and potential future uses are reasons to pause and consider the options.
From its beginnings in the early 2000s, genetic genealogy has grown as an increasingly pertinent and prominent sub-field of the larger field of genealogical research. While DNA testing for genealogical purposes was initially limited to specific circumstances and was primarily confined to Y-DNA and mitochondrial DNA investigations, the advent of direct-to-consumer autosomal DNA tests has sparked an explosion in genealogical DNA testing. Indeed, the reasons to test are many and varied – so much so that even the non-genealogist may find gems of interest. For those readers who have not yet tested, this article may offer considerations to aid in your decision of whether or not to test. For other readers who have already performed DNA testing, this article might be an aid as you invite your relatives to test with informed consent.
Ethnicity Admixture Reports
One common motivation for performing a DNA test is to obtain an ethnicity admixture report. Indeed, ethnicity reports have been a major marketing point for some of the most successful DNA testing companies. Particularly for individuals who descend from diaspora populations, discovering the percentages of DNA that originate from different areas of the globe can influence perceptions of identity and belonging. While ethnicity estimates are based on solid science, they are still quite broad in their predictions and are continually being refined through improvement of company algorithms and reference databases. Ethnicity estimates can provide broad geographic context for a test taker’s family history, but their meaningful use as part in-depth genealogical investigation is limited. Ethnicity estimates are only the very beginning of what can be discovered using DNA evidence.
Connecting with Additional Biological Relatives
Family history research often grows into a collaborative effort as researchers attempt to compile and locate the traces of their ancestors’ documentary and family legacy. Just as family stories, heirlooms, and information are frequently distributed and dispersed among the descendants of an ancestor, so too is their DNA – their genetic legacy. Genetic testing enables researchers to connect with long lost and unknown relatives from distant branches of their family tree. Sometimes those relatives have additional information on shared ancestors that was lost to a researcher’s own branch of the family. DNA testing can help researchers connect with genetic cousins who may hold the keys to long-standing family mysteries and who may be open to further collaboration and teamwork in uncovering family history stories.
Working to Overcome Brick Walls
Sometimes document research can only take a researcher so far in the investigation of their family story. Record destruction, elusive ancestors, adoptions, cases of unknown or misattributed parentage, and ancestors with common names are just some of the many reasons why research in documentary evidence aimed at extending an ancestral line might come to a standstill. In each case, DNA testing may help break through a brick walled research problem. Alternatively, it might help others who are working through their own brick-wall problems. Brick wall problems are often solved through analysis of the test results of many individuals, exploration of shared matches between individuals, identification of likely relatives of a brick-wall ancestor, perhaps some targeted testing and eventual identification of the right people in the right place at the right time to be parents or close family members of an individual. However, just as DNA testing can help resolve long-standing mysteries in a researcher’s family tree, they can also reveal unexpected and surprising results.
Preserving DNA Evidence for Future Generations
Given the short history of DNA testing for genealogical purposes, it is common to consider DNA testing in terms of what researchers can learn about their own ancestors. However, DNA testing also preserves genetic information for future generations of descendants. 100 years from now, descendants and relatives of test takers will hopefully continue to benefit from the tests that are performed today. Their genetic inheritance and connections to previous and deceased generations will provide strong evidence and reminders of their ancestral heritage and ties.
Confirming Proposed Genealogies and Achieving Genealogical Proof for Biological Relationships
Even for researchers who have successfully extended their own family trees through thorough document research, genetic genealogy testing can help to confirm that genealogies constructed through document evidence are biologically accurate. Some studies estimate historic rates of misattributed parentage to be around 2-5%. However, it is likely that the rate of misattributed parentage is at least, in part, dependent on the population and historical time frame being studied. Even assuming a low rate of misattributed parentage, many if not most individuals will have at least one case of misattributed parentage within the first several generations of their family tree. Even if they do not have a case of misattributed parentage among their own direct ancestors, it is extremely likely that there will be a case of misattributed parentage in at least one of their collateral lines of relationship resulting in the identification of unknown collateral relatives or identification of half-relationships previously assumed to be full relationships. Prior to widespread DNA testing, genealogies based on document evidence were typically assumed to be biologically representative. Now that DNA testing is an option for consideration, however, genealogical standards dictate that differentiation should be made between social and biological genealogies. Genealogies purporting to be biologically accurate must be supported by genetic evidence.
Not to Test:
Just as DNA testing can help resolve long-standing mysteries in a researcher’s family tree, they can also reveal unexpected and surprising results. These surprise discoveries can “evoke strong emotions and [have] the potential to alter [a researcher’s] life and worldview.” Researchers may discover troubling or traumatic information about their heritage or family history including but not limited to:
- the discovery that they were adopted
- the discovery that the man who raised them is not their biological father.
- the discovery that they were conceived by a donor
- the discovery of previously unknown siblings, half-siblings, parents, or descendants.
- the discovery that an ancestor was the victim of rape or incest.
- the discovery that an ancestor adopted multiple identities because of his or her criminal activities.
While researchers might anticipate how they might react to these discoveries, anticipated reactions can differ from real reactions when faced with one of these scenarios.
Current and Future Uses
In addition to genealogical investigation, some DNA testing companies may use or enable use of DNA data for additional purposes. 23andMe, AncestryDNA and MyHeritage all may use or enable use of an individual’s genetic data as part of in-house or third-party research after obtaining informed consent from their customers. These research studies may deal with evolutionary history, medical studies, personalized medicine, pharmaceutical development, human history and other topics. Family Tree DNA and GEDmatch.com permit law enforcement agencies to utilize their databases for investigations involving violent crimes. While Family Tree DNA and GEDmatch currently limit law enforcement use of their databases to violent crimes, it is possible that this could change in the future and may be utilized by international jurisdictions. Meanwhile, 23andMe, AncestryDNA and MyHeritage resist sharing genetic information with law enforcement unless compelled to do so by valid legal processes. Also, while legislation in the United States currently protects individuals against discrimination in health insurance and employment, this law does not prevent other forms of genetic discrimination. Finally, the ways in which genetic evidence is used today might be very different from the potential uses of DNA in the future. Any number of factors including changes in governments, legislation, or regulation could affect the way in which genetic data can or cannot be used.
Anonymity and Privacy
While it is possible to disguise the identity of a particular test-taker through undecipherable usernames, and controlling what data is shared, it is not possible to guarantee complete privacy or anonymity for an individual who agrees to perform DNA testing. Also, because genetic genealogy research relies on collaborative research efforts, it is possible and even likely that test takers will be contacted by family members in relation to their test results either through the company messaging systems or by other means of contact obtained through compiled public records.
Not all DNA tests are offered in all countries and jurisdictions. Before performing a DNA test, researchers should consider whether or not they can legally perform DNA testing in the jurisdiction in which they live.
Usefulness for Research Objectives
In some cases, DNA testing may not be helpful for addressing a specific research question. If an ancestor lived prior to the mid-eighteenth century, autosomal DNA testing may not be as helpful for extending their ancestral line. If a researcher aims to identify the progenitors of more distant ancestors through DNA testing, Y-DNA or mitochondrial DNA testing may need to be pursued. If those testing options are not possible in the context of a case, then it may not be possible to rely on genetic evidence to aid in solving the problem. Nevertheless, DNA tests are constantly changing as more individuals perform testing and though a particular problem may not be solvable today, it may be solvable in the future. By performing DNA testing, users preserve their own genetic signature for future generations.
An Excellent Question
To test or not to test? It is an excellent question and in the end after weighing pertinent considerations and factors, each test taker must make that decision themselves. Before performing a DNA test, a customer should consider the risks, benefits, opportunities and potential concerns associated with genetic testing. Each individual should be aware of how their DNA might be used and come to their own conclusion of whether or not to perform DNA testing.
On one hand, genetic genealogy testing can reveal surprising information; it might be used for medical, pharmaceutical, and law enforcement investigations; its future uses are uncertain and uncharted; anonymity of test results cannot be guaranteed; DNA testing is not legal in some jurisdictions; and it may not be useful for particular research questions. On the other hand, DNA testing can help individuals better understand their ethnic origins and can help in the formation of their identity; they can connect users with biological family members and genealogy collaborator; they can assist in breaking through research brick walls; they can preserve genetic evidence for use by future generations; they can assist users in confirming the biological accuracy of their family trees. Each side of this decision carries valid concerns and important opportunities. Consider the opportunities, consider the options, consider the concerns.
If you’ve taken a DNA test and need help analyzing the results, or if you have a genealogy question you think DNA might be able to help answer, we would love to help! Contact us to discuss your questions and goals, and we’ll help you choose a project option and get started.
1 J.M. Greaff and J.C. Erasmus, “Three hundred years of low non-paternity in a human population,” in Heredity (2015 Nov; 115 (5): 396-404, https://www.ncbi.nlm.nih.gov, accessed July 2019.
2 Leah Larkin, “MPEs, Probabilities, and Why You Need DNA, Even if Your Think You Don’t,” The DNA Geek (blog), 5 October 2017, https://thednageek.com/mpes-probabilities-and-why-you-need-dna-even-if-you-think-you-dont/, accessed July 2019.
3 Board for the Certification of Genealogists, Genealogy Standards. 2nd ed. (Washington D.C.: Ancestry.com, 2019), 32.
4 23andMe, “Terms of Service,” section 5, https://www.23andme.com/about/tos/, accessed July 2019.