Imagine a world where the very definition of life, humanity, and even our own bodies is being rewritten, not by philosophers or poets, but by scientists in sterile labs. This isn’t the plot of a new science fiction blockbuster; it’s the astonishing reality unfolding in the groundbreaking work of Jacob Hanna. Last May, when the Palestinian stem-cell scientist found himself in a familiar back office at a US airport, being questioned by customs agents, the scrutiny wasn’t just about his keffiyeh or outspoken views on Gaza. This time, the agents had a new keyword: “embryos.”
Hanna, an Arab Christian, an LGBTQ-rights advocate, and a brilliant mind at Israel’s prestigious Weizmann Institute of Science, was on the vanguard of something truly revolutionary. He wasn’t carrying biological samples in his luggage, but if he had been, even he might have struggled to define them. His lab specializes in creating synthetic embryo models — structures that resemble real embryos but miraculously don’t involve sperm, eggs, or fertilization. It’s a feat that’s opening up the earliest phases of development to scientific scrutiny, and simultaneously, raising some of the most profound ethical questions of our time.
Beyond the Billion-Year Recipe: Crafting Life from Stem Cells
For eons, the recipe for creating a body has been remarkably consistent: sperm meets egg, fertilization occurs, and a new organism begins its journey. Jacob Hanna’s work is challenging this fundamental blueprint. Instead of relying on nature’s ancient method, he’s coaxing the very beginnings of animal and even human bodies directly from stem cells.
Picture this: you bring together specific stem cells in just the right way, and they spontaneously begin to organize, attempting to form an embryo. It’s a testament to the inherent potential within these cells, a natural urge to collaborate and build. In 2022, Hanna’s team achieved a significant milestone with mice, producing synthetic embryos complete with beating hearts and neural folds, all growing inside small jars acting as a rudimentary artificial womb. The next year, he repeated the trick with human cells, creating incredibly realistic mimics of a two-week-old human embryo, even including cells destined to form the placenta.
To call this “astonishing” feels like an understatement. As French biologist Denis Duboule noted, Hanna’s creations are both “entirely astonishing and very disturbing.” The line between a natural embryo and one conjured from stem cells is blurring rapidly, making it increasingly difficult to distinguish between the two, especially when legal protections kick in.
Hanna isn’t alone in this pursuit. Researchers at institutions like Caltech, the University of Cambridge, and Rockefeller are joining the chase, alongside a growing number of startups with commercial ambitions. Hanna cofounded Renewal Bio, which envisions growing synthetic embryos as a “bioprinter” – a source of youthful replacement cells, be it bits of liver, or even eggs. This isn’t just about understanding biology; it’s about potentially remaking medicine, and perhaps, even ourselves.
Navigating the Ethical Labyrinth: Boundaries, “Bodyoids,” and Brains
Such profound scientific advancements inevitably lead to profound ethical dilemmas. How far is too far? This is where the world of Jacob Hanna’s lab collides with the global scientific community and bioethics. The International Society for Stem Cell Research (ISSCR), a self-governance organization, has historically tried to draw clear lines, labelling these stem-cell creations as mere “models,” not “synthetic” nor “embryos,” and insisting they “cannot and will not develop to the equivalent of postnatal stage human.”
Hanna, however, believes these structures will become more realistic and develop further. He’s not alone in that conviction. The very language used by ISSCR has been described by some as “brainwashing,” an attempt to control narrative rather than acknowledge accelerating scientific capabilities. The discussions around this research quickly veer into uncharted territory, leading to concepts like “bodyoids” – a proposal from Stanford scientists for an “unlimited source” of nonsentient human bodies for drug research or organ donation.
The 14-Day Rule and Headless Entities
One of the most pressing issues is the glaring lack of legal and policy frameworks to govern synthetic embryos. Existing laws, like the US Fetus Farming Prohibition Act, reference “human pregnancy” and a “uterus,” neither of which are present in lab-grown models. Even the widely accepted “14-day rule,” which prohibits growing natural embryos in the lab beyond two weeks, doesn’t apply here, because these structures aren’t legally defined as “embryos.” Universities, like Cambridge, have described the situation as a “grey area,” leaving scientists uncertain and, in some cases, genuinely “scared” by what they see under their microscopes.
Hanna’s proposed solution to the ethical conundrum is as audacious as his science: if his models advance to later stages, he plans to block the formation of the head, brain, or heart through genetic modification. His reasoning? No brain, no awareness, no person, no foul. Just a “clump of organs.” This idea of “disenhancement,” or creating “life that is not life,” is a concept explored in other biotech fields and has chilling literary parallels, like the Bokanovsky’s Process in Aldous Huxley’s Brave New World.
However, bioethicists like O. Carter Snead from the University of Notre Dame fundamentally challenge this standard of humanity. To them, it’s a dangerous slippery slope, arbitrarily deciding “who’s in and who’s out” of the boundaries of human dignity. The discussion isn’t just academic; it’s about the very essence of what we consider human, and the profound consequences of those definitions.
The Promise and Peril: What These Models Could Unlock
Despite the ethical storm, the potential benefits of Hanna’s work are immense. For the first time, scientists could gain an unprecedented view into the unfolding of early human development. The womb has always been a “black box,” but synthetic models, created in thousands, can be observed, prodded, and studied in real-time, offering insights into birth defects, disease origins, and fundamental biological processes that were previously impossible to access.
Beyond understanding, there’s the promise of medical applications. Hanna’s startup, Renewal Bio, aims to use these “bioprinters” to produce medically valuable cells that traditional stem-cell methods have struggled to create. Imagine a cancer patient needing a bone marrow transplant who can’t find a match. Could blood-forming cells be harvested from hundreds of embryo-stage clones of that person, providing perfectly matched, “youthful, genetically identical everything” tissue? Hanna believes the potential to save lives outweighs the moral risk of growing embryo models for a month, the time it takes for key blood cells to form, arguing that “there is still no personification of the embryo” at that stage.
Ambition and Adversity
Of course, the journey is fraught with challenges. The process is inefficient — only one or two out of a hundred attempts result in a viable synthetic embryo, with the rest being “disorganized blobs,” as one former student put it. Technical limitations, like the lack of a blood supply in current artificial wombs, mean these entities starve once they grow too large. And the geopolitical realities of Hanna’s location, with war impacting his team and institute, add another layer of complexity to an already high-stakes endeavor.
Yet, Hanna’s ambition is undeniable. His former student, Alejandro Aguilera Castrejón, now leading his own lab in Virginia, attests to Hanna’s drive: “Jacob wants to make it as realistic as possible and go as far as possible—that is his aim.” This ambition, coupled with Israel’s relatively permissive environment and the nuanced interpretations of early life in Jewish thought, positions Hanna at the forefront of this biological revolution.
His work has captured the imagination of venture capitalists and tech futurists, with some cofounders already flashing photos of pregnancy tests turning positive for synthetic embryos. The sci-fi aspirations are palpable, with talk of longevity medicine and even more radical ideas like head transplants onto younger cloned bodies emerging in whispered circles.
Jacob Hanna is not just a scientist; he’s a figure at the vortex of science, ethics, religion, and politics. He engages with religious scholars, bioethicists, and experts, even as he faces political scrutiny and personal threats. As bioethicist O. Carter Snead observes, Hanna’s willingness to “ask these hard questions” is admirable, even if one might cynically wonder if it’s also a “branding exercise” for a “green, sustainable alternative to embryos.”
The Future is Now: Defining Humanity’s Next Chapter
The astonishing embryo models of Jacob Hanna force us to confront uncomfortable questions about the very essence of life, individuality, and humanity. While a full-term baby from a bottle remains science fiction, the capability to grow sophisticated, human-like structures for weeks or months is very real, and it’s happening now. The boundaries are blurred, the laws are lagging, and the ethical implications are monumental.
As these models become more realistic, we, as a society, must decide where to draw the line. Is it at the appearance of a beating heart, the development of a neural fold, or the emergence of recognizable human features? Or, as Hanna proposes, is it a matter of deliberately preventing consciousness? This isn’t just about scientific curiosity; it’s about shaping our future, the definition of personhood, and the values we choose to uphold. The conversation isn’t just urgent; it’s overdue. Jacob Hanna’s work, from his airport encounters to his groundbreaking lab, serves as a powerful, unsettling, and ultimately vital catalyst for this necessary dialogue.
