Thomas W.M. Nuhfer | July 2, 2025

Content warning : This article contains potentially disturbing descriptions of eugenics history, including sterilization, medical abuse, and death. It involves discussion of scientific racism, ableism, classism, antisemistism, and transphobia, including some direct quotations of eugenicist speech. It also addresses the events of the Holocaust and Nazi eugenics. Readers are advised to please take care.

“Nothing in biology makes sense except in the light of evolution.” On the first day of my first college biology course, my professor wrote this on the blackboard. It comes from a famous 1973 essay of the same title by Theodosius Dobzhansky (Fig. 1), an evolutionary biologist whose work shaped modern evolutionary theory. In the decade since that class, I’ve run into Dobzhansky’s work over and over again. It’s not an overstatement to say that Dobzhansky is a household name for biologists. And yet, it took almost ten years of encountering that name before I learned about his role in the modern eugenics movement. Why did it take so long?

Fig. 1 – Theodosius Dobzhansky in 1943. (Source: Public domain.) 

Before we get to that question, let’s step back. What is eugenics? What does it have to do with evolutionary biology? The eugenics movement emerged in full in the early 1900s, especially in the USA, Britain and Germany [1]. It was influenced by Victorian interest in heredity and socio-biology, as well as by Mendelian genetics [2]. Eugenics describes the effort to manipulate the genetics of the human population, or to “improve” human genetics towards social ends. Eugenics ideology claims that undesirable social traits in the human population are inherited genetically and seeks to remove those who are considered “unfit”. 

In the early 20th century, eugenics was supported by a broad range of scientists, who published in eugenics journals, spoke at conferences, and advised policy makers and medical practitioners (Fig. 2). In these contexts, geneticists, evolutionary biologists, and agricultural scientists advocated for and implemented forced sterilization, limits on immigration, non-consensual experimentation, lethal medical neglect, and euthanasia (murder) of infants, children, and adults.

Fig. 2. – the logo of a 1921 eugenics conference held at the American Museum of Natural History in New York. (Source: Public domain.)

 The targets of this campaign were largely immigrants, Black, Latino, and Indigenous people, poor people, disabled people (in particular schizophrenic, autistic, and cognitively disabled people), Jewish people, and gay people. The tools and beliefs of the American eugenics movement directly informed and inspired genocide in Nazi Germany. American scientists actively promoted eugenics sterilization to German scientists, and American foundations donated money to eugenics institutions in Germany prior to and during the Holocaust. [3] After World War II, public excitement for eugenics waned, however, American eugenics continued. In the 1950s, the US government funded and enacted forced sterilization of Puerto Rican women, coercively sterilizing more than 34% of mothers in under 15 years [4]. In the 1927 landmark case Buck v. Bell, the US Supreme Court upheld sterilization on the basis of disability (Fig. 3) [5].

Fig. 3– Carrie Buck, the plaintiff of Buck v. Bell, a young disabled woman who was forcibly sterilized. (Source: Public domain.)

Dobzhansky was among a group of scientists in the mid twentieth century who sought to reform eugenics and its reputation. In contrast to earlier eugenicists, Dobzhansky argued against the concept of biological race and did not believe that race was related to genetic fitness. He even advocated that genetic diversity increased fitness and argued that eugenics was a method of promoting racial and economic equality by giving everyone a better “genetic endowment”. Reform eugenicists like Dobzhansky instead focused their efforts on disability, also a socially constructed category. In 1962, he wrote: “The only solution open is replacement of natural with artificial selection. Persons known to carry serious hereditary defects ought to be educated to realize the significance of this fact if they are likely to be persuaded to refrain from reproducing their kind. Or, if they are not mentally competent to reach a decision, their segregation or sterilization is justified.” [6] To this day, the Buck v. Bell Supreme Court case used to legally justify sterilizing so-called “feebleminded” individuals has not been overturned [5].

So, why don’t we talk about it? I came into my career as a biologist familiar with eugenics based on my experience as a scientific historian, a disabled person, and a disability activist. But I encountered a thick professional silence around this topic. Many scientists don’t ever receive the training which could give them necessary social context to help them recognize or understand eugenics [7]. And that lack of practice leads some scientists to avoid the topic intentionally due to discomfort. I remember being shut down in a graduate evolution course while discussing Dobzhansky’s work by a professor who said firmly “I don’t want to talk about eugenics.” 

It is hard to talk about. But as evolutionary biologists, it’s time to bring this topic into the light. It’s important to understand and communicate that evolutionary fitness – the quantified ability of an organism to pass on genes – is not a social or moral imperative. No one needs to somehow genetically earn the right to be valued, loved, to have a family, or to be included in human society. Genetics do not ever determine human worth. Right now, the eugenics movement is rearing its ugly head. For example, current US Secretary of Health and Human Services Robert F. Kennedy endorsed eugenics when he suggested creating a registry of autistic people and said: “…these are kids who will never pay taxes, they’ll never hold a job, they’ll never play baseball, they’ll never write a poem, they’ll never go out on a date. Many of them will never use a toilet unassisted.” [8]. Transgender people are frequently required to undergo medical sterilization in order to be legally recognized [9]. Growing white natalist movements encourage white births and immigration restrictions in response to demographic change [10]. Given the long history of our fields’ endorsement and development of eugenics, it’s time for evolutionary biologists to start talking about it. We must recognize, and help others recognize eugenicist ideologies, and confidently speak up against eugenics in our work and society. 

References:

1. Allen, Garland E. “The Social and Economic Origins of Genetic Determinism: A Case History of the American Eugenics Movement, 1900–1940 and Its Lessons for Today.” Genetica 99, no. 2 (June 1, 1997): 77–88. https://doi.org/10.1007/BF02259511.
2. Farber, Steven A. “U.S. Scientists’ Role in the Eugenics Movement (1907–1939): A Contemporary Biologist’s Perspective.” Zebrafish 5, no. 4 (December 2008): 243–45. https://doi.org/10.1089/zeb.2008.0576.
3. Black, Edwin. “The Horrifying American Roots of Nazi Eugenics”. History News Network (September 2003). http://historynewsnetwork.org/article/the-horrifying-american-roots-of-nazi-eugenics.
4. Gutiérrez, Elena R., and Liza Fuentes. “Population control by sterilization: the cases of Puerto Rican and Mexican-Origin women in the United States.” Latino (a) Research Review 7, no. 3 (2009): 85-100.
5. Antonios, Nathalie, and Christina Raup. “Buck v. Bell (1927).” Arizona State University. School of Life Sciences. Center for Biology and Society. Embryo Project Encyclopedia.|Arizona Board of Regents, January 1, 2012. https://keep.lib.asu.edu/items/173656.
6. Dobzhansky, Theodosius Grigorievich. Mankind Evolving; the Evolution of the Human Species. New Haven, Yale University Press, 1962. http://archive.org/details/mankindevolvinge00dobzrich.
7. Costello, Robin A., Abby E. Beatty, Ryan D. P. Dunk, Sharday N. Ewell, Jenna E. Pruett, and Cissy J. Ballen. “Re-Envisioning Biology Curricula to Include Ideological Awareness.” Research in Science Education 54, no. 1 (February 1, 2024): 13–26. https://doi.org/10.1007/s11165-023-10101-0.
8. PBS News. “Fact-Checking Robert F. Kennedy Jr.’s Statements on Autism,” April 23, 2025. https://www.pbs.org/newshour/politics/fact-checking-robert-f-kennedy-jr-s-statements-on-autism.
9. Lowik, A. J. “Reproducing Eugenics, Reproducing While Trans: The State Sterilization of Trans People.” Journal of GLBT Family Studies 14, no. 5 (October 20, 2018): 425–45. https://doi.org/10.1080/1550428X.2017.1393361.
10. Rasmussen, Claire. “Fertile Ground: The Biopolitics of Natalist Populism.” ACME: An International Journal for Critical Geographies / ACME : Revue Internationale de Géographie Critique / ACME: Revista Internacional de Geografía Crítica 22, no. 3 (2023): 1069–92. https://doi.org/10.7202/1102113ar.