For decades, we’ve understood our increasing ability to genetically engineer our offspring through a sci-fi lens. Technology promised a future of pure human excellence — peak intelligence, strength and beauty without any defect, or so we heard in film and literature. From this, we derived a great fear of our own ingenuity; if we can design the best of humanity, what terrible fate awaits those who are less than perfect? Yet for all the fictionalized notions of eugenic horror, the science behind assisted reproduction technology (ART) such as in-vitro fertilization (IVF) may suggest a dysgenic future, one no less concerning than that portrayed by movies like Gattaca — and it could already be out of our control. Far from perfecting humanity, what if we’re IVFing ourselves out of existence?

Last November, Science girl — one of the more interesting content farms on X — posted a video of a nanobot guiding a low-motility sperm toward an egg, I was surprised to see an inversion of the usual debate around ART. Most of the replies didn’t reflect Gattaca-style fears of genetic elitism, but rather something closer to natural selection fundamentalism — including Pirate Wires’ own Mike Solana:

The skepticism was a funny inversion of the usual dynamic in the debate over genetic engineering. Most criticism of ART, particularly in vitro fertilization (IVF), involves the idea that it allows us to play God by choosing which embryos to implant, freeze or destroy, mirroring the bioethical debate around abortion. The Vatican rather neatly summarized the most dominant anti-ART position in 1987, stating that embryo freezing, selection, and destruction make it so that “life and death are subjected to the decision of man, who thus sets himself up as the giver of life and death by decree. . . and can lead to a system of radical eugenics.”

Still, here we all are on X dot com, confronted with a form of ART that is, if anything, the opposite of eugenic. It’s hard to accuse the scientist who guides an arguably defective sperm along its merry way of wanting to create a master race of Übermenschen — and yet, this distinctly anti-eugenic side of ART is somehow morally controversial, too. So if ART concerns aren’t just about implanting designer babies and selectively destroying imperfect embryos, perhaps they’re about something deeper and even more uncomfortable to discuss?

“The eugenics argument doesn’t really make sense to me,” said Noor Siddiqui, founder of Orchid, a fertility startup which provides parents with whole genome embryo reports. “The reason why people are repulsed by eugenics, myself included, is that it’s about forced sterilization and it’s about the government choosing who can and cannot reproduce. Versus what Orchid is doing is the exact opposite of that: it’s saying that regardless of what genetic disease you or your partner carry, or even if you’re infertile, we want to help you have babies.”

ART has changed the makeup of those who are able to reproduce, and how they reproduce, which means that many people who might have not reproduced in the absence of modern technology are, for the first time in human history, able to pass on their genes. Put differently, ART, over a long enough timeline, might have evolutionary implications for the entire human race. And yet, almost nothing has been written on the topic, save for a few articles by Norwegian gynecologist Dr. Hans Ivar Hanevik.

When I spoke with Dr. Hanevik, who Zoomed in from what appeared to be an examination room, I showed him Solana’s tweet (he laughed) and asked him if I’d just gotten my search terms wrong, if there was some body of research I’d been missing — but he told me he had the exact same experience when he began researching the subject himself. “This is quite new,” he said with a hint of reticence (Norwegians, he mentioned, are a humble people, and he didn’t like to explicitly credit himself). “Nobody had put this into a scientific framework before.”

Essentially, evolution assumes that the traits being selected over generations confer some sort of genetic advantage, be that in terms of reproductive fitness or survival. The question then, with respect to ART and evolution, is whether we’re beginning to see entirely new technological selection pressures?

The first IVF baby was born fairly recently (England, 1978), so it’s too early to know the full extent of these new selection pressures. However, the numbers are looking strong: 10 million people around the world have been conceived via IVF, including 2 out of every 100 American babies as of 2024. Moreover, IVF technology is only getting better: per an Australian report, the live birth rate increased by 18 percent between 2010 and 2019, with even greater increases reported for older women. It’s also growing more common: the ART market is projected to grow at a 6.3 percent compounded annual rate between 2023 and 2030. It’s not crazy to imagine at least some of these ART babies reproducing with each other.

Even if it’s too early to know exactly what this will look like, we can form some educated guesses. For instance, IVF selects for different sperm than sexual reproduction does. A systematic review from 2019 found that while traditional ART technologies “provide highly motile sperm populations,” they do not “...[replicate] the complex selection processes seen in nature.” As Dr. Hanevik explained, “We choose sprinters, whereas nature chooses the marathon types that have the stamina to go all the way up into the fallopian tubes.”

This is somewhat intuitive: unlike in the act of sexual intercourse, sperm in the IVF process only have to travel the short distance of a petri dish. This is even more pronounced in the intracytoplasmic sperm injection (ICSI) process, where a sperm is injected — or more recently, driven (remember the nanobot?) — directly into an egg. Conversely, during sexual intercourse, the sperm has to travel the full length of the uterus and fallopian tube. The small petri dish can’t replicate the unique conditions of the female body, with all its secretions and movements that influence the movement of sperm during and after intercourse.

Now, if ART is being used for male-factor infertility, we might expect the sons of men who use ICSI to have lower sperm quality or motility than their male peers conceived via sexual reproduction. So far, there is little data to answer this question satisfactorily, but a 2019 study suggests that ICSI-conceived men may have impaired sperm production. In the long term, this might mean that those men will be dependent on ICSI themselves to reproduce… and their sons, and their sons, and so on. Of course, male-factor infertility can also be associated with a host of other genetic and disease markers, compounding various evolutionary traits. Over enough time, ART could become the rule rather than the exception — and look far more distinct.

In fact, we can already see some changes taking shape. As Dr. Hanevik noted, IVF enables delayed reproduction, meaning it can influence more than just our biological evolution, but our cultural evolution as well. Many companies in the US and abroad offer egg-freezing and ART as employee benefits, and as the age of first-time motherhood continues to rise, ART might make it even more psychologically palatable, biologically feasible, and culturally normative for younger women to push off reproduction until their late 30s or 40s.

Again, this may also reinforce ART as the new norm. Consider: a woman graduates college, freezes her eggs for maximal optionality, marries a nice man, and elects IVF at a young-ish age despite being fertile, solely because she happens to have frozen eggs. A culture of ART intended to help those struggling with infertility could make ART a first preference, as opposed to a last resort, even for those without infertility concerns.

There’s also the fact that the existence of genetic testing poses questions to parents that didn’t exist before: Siddiqui, for instance, believes that in the future, genetic testing will become the norm. “There’s this romantic idea that you would have your baby via sex, but if it’s 10,000 times safer to have genetically normal babies via IVF screening, people are going to choose that whenever they can.”

Here, we start to see the possibility of an evolutionary fork in the road. Although it’s disproportionately available in developed countries, ART still isn’t cheap, even in the West. There is a great deal of fear that it will create inequality, with the wealthy being able to genetically engineer superchildren for themselves, while everyone else remains subject to nature. But perhaps instead of becoming superhuman, the well-off citizens of the world may simply find themselves and their progeny on a divergent evolutionary path — for better, or for worse. Still, the primary distinction may just be a greater dependence on ART.

As Dr. Hanevik noted in a co-authored study, by selecting for different traits than nature would, “IVF sets the evolutionary stage for a human species increasingly reliant on, and adapted to, technological means of reproduction.” If this idea — that ART might make us more dependent on ART — is so important, with so many implications for all of humanity, why, I asked Dr. Hanevik, is basically no one touching it?

Well, maybe because it’s touchy. About a decade ago, he recalled giving a public presentation on this topic only to have his research inaccurately represented by British tabloids, with one calling him a “controversial doctor” and implying that he called IVF babies “genetically flawed”—this, despite the fact that he supports IVF. But the touchiness among researchers goes beyond fear of yellow headlines. “I think one of the reasons people turn to becoming ‘sperm eugenicists’ is that although we do not like to think about it, evolution has this side to it that is actually a competition,” he said. “So it’s either me or it’s you. And we can say, well, we’re all in this together and we’re all humans… But when we come to this point of reproduction, sometimes I sense that people get very egoistic.”

For all the fear of omnipotent ART, there is still much we cannot control about the reproductive process — and really, the future of the human species — even if we were to genetically pre-screen every single embryo.

Indeed, reproduction, precisely because it goes hand in hand with evolution, is ultimately about who passes down his or her genetics and who doesn’t. On a broader level, our individual choices add up to determine which traits survive and which traits don’t, which characteristics survive and which characteristics don’t — which peoples and civilizations survive and which peoples and civilizations don’t.

If eugenic ART is controversial because it allows us to play God, perhaps non-eugenic ART is controversial because we sense that it might make us dependent on a god of our own making — that is, ART itself. Perhaps there is something psychologically destabilizing about latex gloves and pipettes coming into what has been, throughout human history, an intimate act, to plan what was, until recently, largely unplanned, and which has ripple effects throughout the human species that we still don’t understand.

And yet, on some level, most concerns around IVF are almost entirely theoretical. Who’s really going to look at the couple struggling with fertility, the child born of IVF, and tell them they didn’t deserve to become parents, that their child shouldn’t exist because his or her conception maybe, possibly, might have concerning evolutionary repercussions? In our modern world, any serious debate — insofar as one exists in the first place — will likely fizzle out before it begins.

As with most technologies, there’s no going back. Yet equally inescapable is our fear and anxiety, an all too human reaction to a species-shaping force that is as unpredictable as it is irreversible. We may technologically surpass nature, but we can’t escape our own.

— Neeraja Deshpande