Designing Humanity
The Revolutionary Science and Weighty Ethics of Gene-Edited Babies
Exploring the groundbreaking science, controversial applications, and profound ethical implications of gene editing in human reproduction.
Introduction: A World-Changing Announcement
In November 2018, the world of science was shaken to its core. Chinese biophysicist He Jiankui announced he had created something unprecedented in human history—the first gene-edited babies1 4 . Through rewriting DNA in twin girls' embryos, the man who would later be dubbed "China's Frankenstein" claimed he had made them immune to HIV1 .
The scientific community responded with immediate condemnation, labeling the experiment "monstrous" and deeply unethical1 . The backlash was swift and severe, resulting in He Jiankui's imprisonment for three years for violating medical regulations1 4 .
"Move fast and break things has not worked very well for Silicon Valley in health care. When you talk about reproduction, the things you are breaking are babies."
This dramatic event ignited a global firestorm of debate that continues to intensify. As we stand at this revolutionary crossroads, gene editing forces us to confront fundamental questions about what it means to be human, who gets to decide which genetic traits are desirable, and whether we should use powerful technologies to direct our own evolution.
Key Facts
- Announcement Date November 2018
- Scientist He Jiankui
- Subjects Twin Girls (Lulu & Nana)
- Target Gene CCR5
- Sentence 3 Years Prison
The CRISPR Revolution: Rewriting Life's Code
Understanding the Technology
Gene editing technology acts like molecular scissors that can snip DNA at precise locations, allowing scientists to remove, add, or replace specific genetic sections1 . While the first gene editing technologies emerged in the 1970s, a revolutionary new tool called CRISPR-Cas9 burst onto the scene in 2009, earning inventors Emmanuelle Charpentier and Jennifer Doudna the Nobel Prize1 .
This breakthrough technology is simpler, faster, cheaper, and more accurate than previous methods1 . As Australian molecular biologist Merlin Crossley explains: "It's as if you were given a new smartphone and you could never change it. And then suddenly you had a way of installing a new app"1 .
Nobel Prize Winners
Emmanuelle Charpentier
Jennifer Doudna
The Evolving Toolkit
| Technology | Mechanism | Primary Use | Key Advantage |
|---|---|---|---|
| CRISPR-Cas9 | Cuts DNA strands at specific locations | Gene disruption, insertion | High precision, ease of use |
| Base Editors | Chemically converts one DNA base to another | Single nucleotide changes | Doesn't break DNA backbone |
| Prime Editors | Uses reverse transcriptase to write new DNA | Precise DNA rewriting | Versatile, fewer off-target effects |
| CRISPR-Cas13 | Targets RNA instead of DNA | RNA modification, diagnostics | Temporary effects (non-heritable) |
Beyond these tools, researchers are also developing epigenome editing techniques that modify gene expression without changing the underlying DNA sequence6 . The field now encompasses a diverse array of editing tools, including zinc fingers, TALENs, meganucleases, and CAS-CLOVER2 .
The Experiment That Shook the World: He Jiankui's Gene-Edited Twins
Objectives and Methodology
He Jiankui's controversial experiment aimed to make embryos resistant to HIV by targeting the CCR5 gene, which produces a protein that HIV uses to enter cells1 5 . His team worked with couples where the father was HIV-positive, using CRISPR-Cas9 to edit embryos during in vitro fertilization (IVF) procedures1 .
Results and Immediate Consequences
The experiment resulted in the birth of twin girls, given the pseudonyms Lulu and Nana1 . While He Jiankui claimed the editing was successful and the girls were healthy, the announcement was met with universal condemnation from the scientific community.
Major Concerns
Experiment Timeline
2017-2018
Experiment conducted
November 2018
Public announcement
2019
International condemnation
December 2019
Sentenced to 3 years in prison
Inside the Lab: The Science of Editing Human Embryos
Step-by-Step Process
Ovarian Stimulation and Egg Retrieval
The mother receives hormones to stimulate multiple egg production, which are then surgically retrieved5 .
In Vitro Fertilization
Eggs are fertilized with sperm in laboratory culture dishes5 .
CRISPR Component Delivery
At the single-cell or early-division stage, CRISPR-Cas9 machinery is injected into the embryos1 .
Embryo Culture
Edited embryos are cultured for 3-5 days while monitoring development5 .
Genetic Screening
Embryos are tested for successful editing and screened for potential off-target effects5 .
Embryo Transfer
Selected embryos are transferred to the mother's uterus1 .
The Scientist's Toolkit
| Reagent/Tool | Function | Considerations |
|---|---|---|
| CRISPR-Cas9 RNA or Protein | The editing machinery that cuts DNA | Protein form may reduce off-target effects |
| Guide RNA (gRNA) | Directs Cas9 to specific DNA sequences | Must be designed for specificity to target |
| Donor DNA Template | Provides correct gene sequence for repairs | Needed for precise edits rather than simple disruption |
| Microinjection Equipment | Delivers editing components into embryos | Requires specialized skill and equipment |
| Culture Media | Supports embryo development outside body | Composition critical for embryo health |
| Genetic Sequencing Tools | Verifies edits and checks for off-target effects | Whole genome sequencing recommended |
The Global Response: Science Grapples With Ethics
Scientific and Ethical Backlash
The international scientific community reacted with a mixture of shock, anger, and concern to He Jiankui's announcement. Key objections included:
- Safety Unknowns: The potential for off-target mutations and long-term health consequences remained significant1 6
- Heritable Changes: Unlike somatic cell editing, changes to embryos would be passed to future generations5
- Slippery Slope: Many feared this opened the door to non-medical "enhancements" and designer babies1 5
- Regulatory Failure: The experiment circumvented established oversight processes1 4
Regulatory Landscape
In response to the controversy, many countries reinforced bans on heritable human genome editing. In Australia, making heritable changes to a human genome can result in 15 years in prison1 . Leading scientific organizations called for a 10-year moratorium on inheritable gene-editing4 .
Key Figures in the Gene Editing Debate
| Figure | Position | Viewpoint |
|---|---|---|
| Julian Savulescu Australian philosopher |
Supports therapeutic applications | "It has the potential to save trillions of dollars globally and significantly prolong life and reduce suffering"1 |
| Robert Sparrow Philosophy professor |
Concerned about social implications | Fears gene editing could "reinvigorate social Darwinism"—the idea that people are poor because they are genuinely inferior1 |
| Ben Hurlbut Bioethicist |
Advocates caution | "Just because you can do it doesn't mean you should do it"4 |
| Tim Hunt CEO, Alliance for Regenerative Medicine |
Opposes heritable editing | "If you make a mistake, the mistake passes onto all future generations. So that's a pretty big ethical roll of the dice"4 |
The Future Unfolds: Current Developments and Possibilities
Clinical Trials Underway
FDA-Approved CRISPR Therapy
Months for Personalized Treatment
Companies Entering the Space
Clinical Progress in Therapeutic Gene Editing
While heritable embryo editing remains controversial, non-heritable somatic cell gene therapies have been advancing rapidly. As of February 2025, approximately 250 clinical trials are underway involving gene-editing therapeutic candidates2 .
Notable Successes
- CASGEVY: The first FDA-approved CRISPR-based therapy for sickle cell disease and beta thalassemia2 6
- Personalized Therapies: In 2025, researchers reported successfully treating an infant with a rare genetic disease using a bespoke CRISPR therapy7
- Cancer Treatments: CRISPR-edited CAR-T cells are showing promise against various blood cancers2 6
- Liver and Metabolic Diseases: Therapies for conditions like hereditary amyloidosis and hypercholesterolemia are in advanced trials2 8
The "Manhattan Project" and New Commercial Ventures
Despite the controversy, commercial interest in embryo gene editing continues. In 2025, biotech entrepreneur Cathy Tie unveiled the "Manhattan Project"—the first company to publicly announce plans to create gene-edited babies, promising to prevent "thousands of diseases"1 4 .
Commercial Landscape
Tie claims her approach will be more measured and ethical than He Jiankui's, focusing on disease prevention with stringent oversight4 . Other ventures are also entering the space, supported by Silicon Valley investors, futurists, and pronatalists—who fear falling birth rates pose an existential threat to humanity4 .
Ethical Crossroads: Navigating the Uncharted Territory of Human Genetic Engineering
The "Designer Baby" Dilemma
The concept of "designer babies"—children whose genetic makeup has been selected or altered to achieve specific traits—represents perhaps the most controversial application of gene editing technology5 .
Therapeutic vs Enhancement Editing
- Therapeutic Editing: Selecting or editing embryos to prevent serious inherited genetic disorders5
- Enhancement Editing: Altering traits like height, eye color, athletic ability, or intelligence5
While therapeutic applications garner more support, many worry about a "slippery slope" toward enhancement. As philosopher Robert Sparrow warns, gene editing could reinforce elitism, resulting in a two-tiered society where the rich can buy genetic advantages1 .
Equity and Access Concerns
If gene editing technologies become available but remain expensive, they could dramatically widen existing inequalities.
"If these technologies become widespread but remain expensive, only the wealthy may afford to give their children a genetic 'head start,' widening existing inequalities and creating a 'genetic underclass'"5 .
This raises profound questions about whether gene editing should be available only through the market at a high price or should be part of basic health care1 .
Consent and Future Generations
A fundamental ethical challenge is that gene-edited children cannot consent to permanent alterations to their genetic makeup, especially when those changes could affect their health, identity, or could be passed to their own children5 .
Conclusion: The Genome as Our Common Heritage
The creation of the first gene-edited babies marked a watershed moment for humanity—the point at which we gained the ability to directly rewrite our genetic inheritance. This power carries extraordinary potential to alleviate human suffering by eliminating devastating genetic diseases. Yet it also raises alarming possibilities for social division, genetic discrimination, and irreversible changes to the human gene pool.
As we move forward, the challenge will be to establish robust ethical frameworks and inclusive global dialogue that includes not just scientists and policymakers, but also parents, patients, and diverse public voices5 . The question is no longer just "Can we edit human embryos?" but rather "What kind of future do we want to build with this technology?" and "Who should decide?"
The answers will determine whether gene editing becomes a force for healing or a source of division—whether we create a more just and healthy world, or a genetically stratified one. As these technologies continue to advance, society must engage in thoughtful, inclusive deliberation about how to harness their benefits while protecting our fundamental humanity. The future of our species may depend on the choices we make today.