Genetic Genealogy

Genetic genealogy, more often called genetic ancestry testing, is an option available for people interested to learn more about their family history and explore potential unknown relatives. It is estimated that more than 26 million consumers have undergone genetic ancestry testing, and had their DNA added to health databases (Regalado, 2019). Consumers get these tests for about fifty-nine dollars, which offers entertainment, clues of ancestry, and a chance of discovering a family secret that has been burdened throughout the ages.

But what is ancestry? Ancestry refers to a person’s genetic lineage, including close familial relatives, or maybe even remote ancestors from thousands of years ago. Scientists study how these relations occurred, and where those ancestors may have come from, in turn providing information about a person’s ancestry (Bardill & Garrison, 2015). Researchers employ different types of genetic markers to compare and contrast between a consumer’s DNA and genetic databases from diverse populations. By learning genetic variation in different countries, It may finally help in understanding the mechanisms of evolutionary change and facilitate the identification of complex disease genes (Royal et al., 2010).

Ancestry genetic testing has been done using different methods, including mitochondrial, Y-chromosome, and autosomal tests. A specific DNA marker known as a single nucleotide polymorphism (SNP) is used as the critical point of comparison in an ancestry test most of the time as a result of being commonplace for genetic variation (Bardill & Garrison, 2015). These variations work as markers, as it may be unique to a specific individual, or a group of people like in this case, ancestors.

One of the methods of genetic testing is sequencing the Y-chromosome in males as a father’s son inherits the Y chromosomes intact. This chromosome is utilized to trace the paternal genetic lineage as it is constant in the family lineage. The SNPs in the nonrecombining bulk of the chromosome is analysed usually by chromatography to infer ancestry. (Smart, Bolnick, & Tutton, 2017) Consequently, the Y chromosome is traced to find the biological father’s lineage line far back into time.

Moreover, Mitochondrial genetic tests are one of the other standard tests, as mitochondrion is an organelle that is responsible for cellular respiration, producing ATP. These organelles have their own DNA called mtDNA. (Reece et al., 2015) mtDNA is inherited from mother to her offspring, where it doesn’t rearrange itself after reproduction. This is ideal for ancestry testing as it can be used as a tracking point for generations passing from mother to child. However, an mtDNA test is only used as supporting evidence to make sure that someone is related to the other as it is limited in tracking.

In addition, autosomal testing is a vital tool for researchers; this type of testing utilizes the 44 individual autosomal chromosomes every human is born with. Autosomal genes are almost identical in every ancestor of a human being. Therefore, genealogists can detect autosomal chromosomes found in the DNA and compare it to their database to reveal ancestry. Autosomal DNA testing is considered to be the most useful of these tests; it can find ancestors from up to 1000 years ago, it is also more information-rich than other tests as it can show someone’s relations to others and their ethnicity.

When doing a genetic ancestry test, a rather common question pops up, “Does this mean that I’m destined to this identity?” Yes and no. Consumers tend to be told that they are a various percentage of different nationalities. These tests are somewhat flawed as a consequence of not having a complete database of the world’s DNA. Therefore, these tests shouldn’t be considered for a human’s ethnic identity. For example, a study says that “Most individuals who have less than 28% African ancestry identify as European American, rather than as African American” (Bryc, Durand, Macpherson, Reich, & Mountain, 2015) However, this does not mean that these tests are always wrong, but that they should be considered with caution.

Furthermore, scientists try to connect between the cultural heritage and the genetic ancestry of humans. Genetic ancestry is the biological heritage that is responsible for different traits like curly or straight hair. On the other hand, cultural heritage comes from the people who have raised us and our environment as a growing child. Since a person’s identity comes from his ethics, and his/her behavior, therefore, this depends on the cultural heritage and not being an ancestor of a person who had excellent behavior. In conclusion, genetic ancestry is an activity used for entertainment more than for a scientific test.

References

Bardill, J., & Garrison, N. A. (2015). Genetic Ancestry Testing. In International Encyclopedia of the Social & Behavioral Sciences: Second Edition (Second Edi, Vol. 9). https://doi.org/10.1016/B978-0-08-097086-8.82075-9

Bryc, K., Durand, E. Y., Macpherson, J. M., Reich, D., & Mountain, J. L. (2015). The genetic ancestry of african americans, latinos, and european Americans across the United States. American Journal of Human Genetics, 96(1), 37–53. https://doi.org/10.1016/j.ajhg.2014.11.010

Reece, J., Urry, L. A., Meyers, N., Cain, M. L., Wasserman, S. A., Minorsky, P. V., … Cooke, B. N. (2015). Campbell Biology: 10th. In Campbell Biology.

Regalado, A. (2019). More than 26 million people have taken an at-home ancestry test — MIT Technology Review. Retrieved February 21, 2020, from MIT Technology Review website: https://www.technologyreview.com/s/612880/more-than-26-million-people-have-taken-an-at-home-ancestry-test/

Royal, C. D., Novembre, J., Fullerton, S. M., Goldstein, D. B., Long, J. C., Bamshad, M. J., & Clark, A. G. (2010). Inferring Genetic Ancestry: Opportunities, Challenges, and Implications. American Journal of Human Genetics, 86(5), 661–673. https://doi.org/10.1016/j.ajhg.2010.03.011

Smart, A., Bolnick, D. A., & Tutton, R. (2017). Health and genetic ancestry testing: Time to bridge the gap. BMC Medical Genomics, 10(1), 1–9. https://doi.org/10.1186/s12920-016-0240-3