DNA, since its inception, has been a bastion of the biological sciences. In a world full of confusion, a world where memories can be faulty and bodies can vary wildly from person to person and sibling to sibling… DNA had been it. The one truth, the answer, that everyone had been waiting for without even realizing it.

And then, as with most things scientific, it got embraced by the general population as a pseudoscience rather than as what it is: a way to identify people and their relations to others.

Originally called “nuclein” back in 1878 by Albrecht Kossel (Jones, 1953), DNA had been a purely scientific thing. It had nucleic bases, it had form – discovered in 1953 by scientists (Crick & Watson, 1953). In 1984, it had real purpose for the first time ever rather than the stuff of examining under microscopes in dimly lit labs: it was used to identify people and those who are close relations to them. (Jeffreys, 2013)

The keyword there is “close relations to them.”

DNA testing company after DNA testing company, DNA evaluating company after DNA evaluating company, all make the grand claim of being able to tell their users, their clients, exactly what their ethnicity makeup is. For example, as of July 2024, Ancestry boldly claims to their clients who are DNA tested: < client name >’s <number> ancestral regions.

What is so interesting about this is that, despite sounding so definitive to the their clients, in their 2023 whitepaper, Ancestry waffles; they call it “ethnicity estimation” instead. (Adrion et al., 2023) This begs the question: which is it? Are these percentages set-in-stone for what a given person is, or are they the result of some finagling?

Science changes all the time. We can watch it live thanks to the internet. But in truth, the science behind ethnicity estimates isn’t changing drastically every year. Why then does Ancestry keep updating their ethnicity estimates every year?

A change in reference panels.

That’s right: every year, presumably more people are added to these reference panels by Ancestry that then expands their results. Fine tunes it, the company may argue. But, well… science is science, and ethnicity estimates are not exactly a science. That might change at some point in the future, but for now, it’s not.

It could be argued that it is not a pseudo-science because it uses complex formulae and algorithms to determine ethnicity estimates. For those individuals who want to argue such, I encourage, implore even, that you take a moment to research – of all things – modern Western astrology. It also uses formulae to determine the exact position of the heavenly bodies in the sky if the earth was the center of the universe. Modern humans know better, the earth is not the center of the universe, but operating literally on this statement rather than metaphorically resulted in an entire field of study that was treated as reality for a long time. And for many folks, it still is.

Reference panels can change and shift. The accuracy of these algorithms changes and shifts, too. The result is not a precise science you can cozy up with in textbook form once, read through and study, and learn like the back of your hand. It is a slow slog that is constantly being updated and changing.

References

Adrion, J., Lang, J., Noto, K., Olpin, R., Sedghifar, A., Wang, Y., & Wolf, A. (2023). Ethnicity estimate 2023 white paper. Ancestry. Retrieved June 28, 2025. https://www.ancestrycdn.com/support/us/2023/09/Ethnicity2023whitepaper.pdf

Auton, A., Do, C. B., Durand, E. Y., Macpherson, J. M., Mountain, J. L., Poznik, G. D., & Wilton, P. R. (2014, October 17). A scalable pipeline for local ancestry inference using tens of thousands of reference haplotypes. 23andMe. Retrieved June 29, 2025. https://permalinks.23andme.com/pdf/23-16_ancestry_composition.pdf

Crick, F. H. C. & Watson, J. D. (1953). Molecular structure of nucleic acids. NATURE.

Ding, Y., Hou, K., Xu, Z., Pimplaskar, A., Petter, E., Boulier, K., Privé, F., Vilhjálmsson, B. J., Olde Loohuis, L. M., & Pasaniuc, B. (2023). Polygenic scoring accuracy varies across the genetic ancestry continuum. Nature: International Weekly Journal of Science, 618(7966), 774–781. https://doi.org/10.1038/s41586-023-06079-4

Jeffreys, A. J. (2013). The man behind the DNA fingerprints: an interview with Professor Sir Alec Jeffreys. Investigative genetics, 4(1), 21. https://doi.org/10.1186/2041-2223-4-21

Jones, M. E. (1953). Albrecht Kossel, a biographical sketch. The Yale journal of biology and medicine, 26(1), 80–97.

Jorde, L. B., & Bamshad, M. J. (2020). Genetic ancestry testing: what is it and why is it important?. JAMA, 323(11), 1089–1090. https://doi.org/10.1001/jama.2020.0517

Lovell, D. (2021, April 15). Biology professor breaks down science behind ancestry, heritage tests. Syracuse University. Retrieved June 29, 2025. https://news.syr.edu/blog/2021/02/15/biology-professor-breaks-down-science-behind-ancestry-heritage-tests/

Lupi, A. S., Vazquez, A. I., & de los Campos, G. (2024). Mapping the relative accuracy of cross-ancestry prediction. Nature Communications, 15(1). https://doi.org/10.1038/s41467-024-54727-8

Regalado, A. (2019, February 11). More than 26 million people have taken an at-home ancestry test. MIT Technology Review. Retrieved June 20, 2025. https://www.technologyreview.com/2019/02/11/103446/more-than-26-million-people-have-taken-an-at-home-ancestry-test/