Biotechnology & Genomics — Bioethics
The Edit We Can't Take Back
In 2018, a scientist in Shenzhen quietly crossed a line that every previous generation of biologists had agreed, without a formal vote, never to cross.
The Idea
There is a distinction in genetics that used to be almost philosophical — the line between somatic edits and germline edits. Somatic changes affect only the person being treated: edit a patient's liver cells to correct a disease, and that change dies with them. Germline edits are different. Change an embryo's DNA and you change every cell in the person who grows from it, including their reproductive cells — meaning the edit propagates forward, invisibly, into descendants who never consented and cannot opt out. For decades, this line held. Not because the technology was unavailable, but because the scientific community understood that germline editing is a fundamentally different kind of act. It is not treatment; it is inheritance. CRISPR-Cas9 made the technical barrier low enough that the ethical barrier became the only real obstacle. And the ethical barrier, it turned out, was not as solid as anyone had assumed. What makes this genuinely hard — not just alarming — is that the case for germline editing is not trivially dismissible. If you could reliably eliminate a heritable disease before a child is born, refusing to do so requires a serious argument, not just instinct. The bioethics debate is not really about whether to feel uncomfortable. It is about where to draw a line in a domain where the consequences of drawing it wrong compound across generations.
In the World
He Jiankui announced the births of Lulu and Nana at a Hong Kong gene-editing summit in November 2018 — two girls whose embryos he had edited using CRISPR to disable a gene called CCR5, which HIV uses to enter cells. His stated goal was to make them resistant to the virus. The scientific community's response was immediate and almost uniformly condemnatory — not because the goal was obviously monstrous, but because the process was reckless. The edit was not proven safe in humans. The girls' father was HIV-positive but the virus was not actually transmissible in the way He implied. CCR5 disruption may increase susceptibility to other viruses, including West Nile. And crucially, alternative protections against HIV infection already exist. He had not solved an unsolvable problem; he had taken an irreversible gamble with two children's genomes — and potentially their children's genomes — to demonstrate a capability, not to cure a disease. He was sentenced to three years in prison by Chinese authorities. Lulu and Nana are now school-age children somewhere in China, carrying an edit whose long-term effects no one fully understands, part of the human germline in a way that has never happened before through deliberate human action. The summit that was meant to discuss the ethics of gene editing became, instead, the place where the world learned the conversation had already been bypassed.
Why It Matters
Most bioethics debates feel abstract until they don't. This one matters now because the technical capability is real, it is spreading, and the regulatory frameworks governing it vary wildly between countries — meaning that a sufficiently motivated researcher in a permissive jurisdiction can effectively make decisions on behalf of all future generations. The discomfort worth sitting with is not just 'should we edit embryos' but something sharper: who gets to decide, and by what process, when the stakes are literally heritable. Democratic institutions move slowly; CRISPR does not. Beyond the headline cases, the same logic applies to subtler edits — not just disease genes but trait-associated variants, where the science is murkier and the temptations are arguably greater. Understanding this territory doesn't require a biology degree. It requires recognising that some technologies change not just what we can do, but what it means to be a generation, and that the ethics need to move as fast as the scissors.
A Question to Ponder
If a heritable genetic edit could guarantee your child would never develop a disease that has run through your family for generations, what would it take for you to feel genuinely confident that accepting the edit was the right choice — and is that confidence achievable?
Get a new one of these every morning.
Start learning with Thinkable