Few fictional creatures are as iconic or as synonymous with their franchise as the giant apex predators of the desert world of Arrakis in the classic novel Dune. Author Frank Herbert imagined the sandworms’ life cycle in incredible detail, and the desert where these behemoths live and hunt continues to be a relevant allegory for our own world and our struggles with sustainability. Within this setting, large-scale climate effects unfold over decades and generations, but individual motives are often influenced by immediate threats and short-term goals. While the sandworms, wastelands and geopolitics of Arrakis have endured as triumphs of fiction, however, one important aspect of Herbert’s universe has remained unexamined: the biology, sociology and ethics of reproduction as depicted in the novel. With a new silver-screen adaption coming to theaters this fall, now is the time redress that oversight.

Predicting Reproductive Biology: Cryptic Female Choice

The main plot starts with the leader of the Bene Gesserit, a pseudoreligious, all-female eugenics organization, assessing the heir to a planetary dukedom. The child, Paul Atreides, is the son of another Bene Gesserit, who was ordered to produce a daughter but willfully chose to have a son instead, throwing the plan into potential disarray. The invocation of eugenics raises immediate ethical questions, but first let us focus on the reproductive biology described here.

Despite the interstellar setting, the human characters in the novel appear to be just that, human in all psychological and physical regards. Bene Gesserit women are human as well but have enhanced control over their physiology and metabolism. They are able to quickly break down toxins, consciously modulate their heart rates, and detect if others are lying in speech. Additionally, it is possible for Bene Gesserit women to determine the sex (i.e., the biological markers such as genital morphology upon which social categories are conferred) of their children with no external intervention. In contrast to the elucidation Herbert gives some Bene Gesserit abilities (the ability to detect deception relies on subtle changes in the tone of the liar’s voice), he provides no explanation of how the sex of a fetus is controlled.

This reproductive ability is not only critical to the plot but is also a magnificent piece of speculative science. What Herbert described in 1965 would come to be known, in 1983, as “cryptic female choice” and was elaborated upon in a monograph on “female control” of reproduction in 1996, which met with resistance to its recognition and acceptance in the scientific community. Specifically, the theory of cryptic female choice posits that female individuals can influence reproductive outcomes after mating has occurred. At the time of Dune’s release, and for more than a decade afterward, almost all of the scientific interest in reproduction was focused exclusively on the male perspective. For example, research in the 1970s was dominated by the idea of “sperm competition”—that outcomes of reproductive success or failure could best be understood as proxy contests between male individuals in a passive female reproductive tract. When, finally, the scientific community entertained the idea that had occurred to Herbert decades earlier, that female individuals could influence the processes occurring in their body, it became apparent that cryptic female choice is a widespread phenomenon.

Abundant examples across the animal and plant kingdoms demonstrate that manipulation of fertilization is a reproductive reality and advantage for many species. Indeed, even animals as familiar as honeybees have the ability to control the sex of their offspring. The queen can directly control the numbers of daughters and sons in the colony by laying either fertilized or unfertilized eggs, respectively. In an even more striking example, in some comb jellyfish, the female egg nucleus appears to visit and evaluate several sperm that have reached the egg before choosing to fuse with one to create an embryo. Although evidence, so far, is sparse in humans, a recent study has found evidence that mature human oocytes can give off chemical signals that are more attractive to the sperm of certain individuals.

Given the other feats of the Bene Gesserit, it seems plausible these women may have developed a mechanism to choose specific sperm to determine offspring sex in the universe of Dune. Thus, contained within the immense universe of a science fiction novel remembered for deserts and sandworms is, to our knowledge, the first conception of a reproductive phenomenon that scientists have only recently begun to acknowledge, much less understand.

The Sociology of Female Choice and the Ethics of Reproductive Control

Although finding a groundbreaking theory for reproduction hidden within a science fiction novel is exhilarating, it has to be contextualized within the eugenics program for which it was imagined. The Bene Gesserit plan was to produce a messiah with enhanced mental capabilities through selective breeding of members of noble families. The universe of Dune is, like so many fictional worlds of its time, a firmly patriarchal society with a male emperor and control of noble houses passing from father to son. In such a society, women can hold little formal power and instead must pursue their goals through secrecy and manipulation. The Bene Gesserit are the ultimate personification of this ethos. Thus, cryptic female choice becomes a tool to regain reproductive control in a setting in which open dialogue and consensus between male leaders and their wives and concubines is absent; and it is notable that because of cultural biases about passive women, female reproductive strategies and even physiology continue to be understudied even today, decades after Herbert imagined this powerful sect.

This power imbalance between the Bene Gesserit and the Arrakian patriarchy contributes to the implicit impetus for a secretive eugenics plan. Yet the concept of eugenics is left largely unexamined, especially in a book that has much to explicitly say about the morality of politics, religion and the intersection of the two. A modern reader will likely see the use of eugenics for the depravity it is, promoting the idea that “desirable” people should give birth and that “undesirable” people should not. In practice, denial of reproductive autonomy is often deployed against people of color, especially Indigenous people, and disabled people. Indeed, at the time of Dune’s publication, programs were in place to target birth control, and sometimes sterilization, to low-income, typically nonwhite Americans.

Within this real-world context, the invocation of eugenics in the novel was likely less a signifier of anathema at the time than it seems today. Still, the unfolding of events in Herbert’s story offers an example of one of the inescapable failings of eugenics: the conceptualization and pursuit of perfection by imperfect people is inherently flawed. The birth of Paul Atreides deviates from the Bene Gesserit breeding plan to produce their messiah. This child born the “wrong” sex and a generation too early turns out to be the fulfillment of that desire, but outside their control. In other words, the fictional eugenicists, like their real-world counterparts, deceive themselves by thinking they understand and can control the myriad genetic and environmental factors that influence the development of a human life. And as expected, this accidental messiah has a predictably deep enmity towards the Bene Gesserit who conspired to produce and control him, rendering their whole plan moot. So, whether intended or not, the course of events offers an indirect rebuke to the practices of eugenics by revealing their inherent flaws.

Lessons from the Reproductive Biologist’s Read of Dune

Dune is remembered for its unique ecological setting and lends itself easily to readings that focus on how humans interact with the environment and shape the climate in which they live. Beyond the setting, the political and religious dynamics on display make obvious targets for analysis of extant human societies. Through the lens of a reproductive biologist, however, seemingly minor aspects of the plot and their implications for both cultural attitudes and scientific research come into focus. In the Bene Gesserit, Herbert predicted cryptic female choice and offered a tenuous criticism of eugenics. These points, which went largely unnoticed for decades, only come into focus when placed next to modern ethical and scientific consensus. With the upcoming film and the return of Dune to the popular discourse, we offer a reminder that speculative fiction can be fertile ground for the exploration of scientific ideas and that evaluations and interpretations change as research catches up with imagination.