The next revolution in biology is not reading the code of life, but writing it
The next revolution in biology is not reading the code of life, but writing it
By Andrew Hessel | Published: 2025-10-20 18:55:00 | Source: Life – Big Think
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For most of human history, we could only imagine what made us who we are. Then, just over two decades ago, the Human Genome Project—the international scientific effort to decipher the three billion letters of human DNA—changed everything.
Critics at the time described it as too expensive, too ambitious, and too abstract. And they were not wrong. This was the largest biology project ever proposed, and scientists had not even been able to sequence the smallest bacterial genome yet. But the organizers knew that big plans – lunar projects – inspire people and attract funding.
Today, almost every advance in modern medicine rests on its foundation. The project transformed biology into information science, generating strain testing, virus tracing, precision cancer treatments, the first personalized medicines, and more.
Now, a new generation of scientists wants to take the next step: not only that reading A symbol of life, however writing He – she. This is the mission behind the Human Genome Writing Project (HGP-write) and SynHG, the Synthetic Human Genome Initiative.
HGP-write, a non-profit organization I co-founded in 2016, works to build the technological, ethical, and social infrastructure for genome writing at scale. SynHG, a UK-led academic consortium announced in 2025, focuses on engineering and developing the pipelines and tools needed to build chromosomes from scratch. Although the teams are different, they share the same bold goal: to one day build a complete, functional human genome. Together they are helping to launch the next great revolution in biology, one that I believe will go far beyond the impact of the original Human Genome Project (which I will call HGP-read from now on).
Sequence Let us read the Book of Life, our instruction manual. Synthesis will allow us to write new chapters, if not entirely new books.
Why do we write the human genome?
When the HGP readout ended in 2003, it had taken 13 years and more than $3 billion to sequence a single human genome (or sequence about 92% of a single genome, since the technology to fill in all the gaps didn’t exist at the time — the entire genome wouldn’t come until April 2022). Today, sequencing a person’s DNA costs a few hundred dollars and takes a few hours. Few technologies have become so cheap and powerful so quickly.
Advances in sequencing technology have made Moore’s Law — the idea that computer processing power doubles while costs fall about every two years — seem like a slow crawl. This incredible reduction in price and time has created entire industries, millions of jobs, and hundreds of billions in economic value. But the fact that serialization has not yet become a consumer technology, in every home, like televisions and telephones, indicates that we are still far from the financial or technological bottom yet.
DNA writing holds a greater promise: the possibility of treating any disease. DNA synthesis already supports the engineering of new proteins, vaccines, and CRISPR-based therapeutics in the clinic. Writing the entire human genome could enable the correction of any genetic condition, no matter how complex. Writing small genomes could lead to a Neocambrian explosion of new creatures of all shapes and sizes.
Synthetic genomics is not new. In fact, the first synthetic genome was built more than two decades ago. In 2002, scientists at Stony Brook University in New York, led by Eckard Wimmer, constructed the entire poliovirus genome from digital sequence data. In 2010, the J. Craig Venter The first artificial cell – an organism whose DNA contains hidden “watermarks”, including quotes from James Joyce and physicist Richard Feynman, a web address, and the researchers’ own names. By 2019, Jason Chen’s group at the MRC Laboratory of Molecular Biology had re-engineered… Escherichia coli With a completely synthetic genome of four million bases. In 2025, Jeff Buckey and his international consortium of yeast scientists completed the ten-mega yeast genome, a major milestone on the road to writing larger, more complex genomes like ours.
Whole genome synthesis is not speculative science; It’s a branch of genetic engineering that has been quietly simmering under the radar, and has become cheaper and more advanced in recent years.
As with AI systems before GPTs arrived in late 2022, most people are still completely unaware that DNA can be written at all, let alone that thousands of labs and companies around the world use it.
While efforts to write the human genome won’t lead to designer babies or super-soldiers any time soon, they are forcing society to confront an undeniable fact: like amateur gods, we’ve begun to write living beings. We’re not good at that yet. The genomes we have written are small, uncomplicated, and often only slightly modified versions of what nature produced.
The bigger question is whether we will proactively organize as a species to do this engineering responsibly or wait on the sidelines until commercial, military, or geopolitical forces force us to face reality and establish some rules of the road.
Writing drives creativity, understanding and security
Both HGP-write and SynHG aim to make genome-scale synthesis possible, affordable, and, most importantly, safe. This is the big challenge. Going from short segments of DNA to whole chromosomes or genomes requires new tools, enzymes, software and standards – an entirely new “synthetic biological stack.” It also requires the creation of effective biosecurity systems, as some of the smaller genomes that are engineered, such as virus genomes, are potentially the most dangerous.
All of this won’t be cheap to develop, but it will pay off long before the human genome is written.
Each incremental advance in writing technology will accelerate progress across the entire spectrum of life sciences, from agriculture to pharmaceuticals, from materials science to planetary defense; DNA synthesis, after all, is the essential tool for biological engineering and biomanufacturing. At the same time, improved biodetection and biodefense technologies, accelerated by genome writing efforts, will strengthen global health while better protecting us from the next outbreak or pandemic.
Typing whole genomes is powerful. Editing existing DNA allows us to modify the code, but changes must be verified by whole genome sequencing, keeping in mind that off-target changes are common. Building the genome from scratch means that software tools similar to word processors can be used to easily search for and replace strings of letters, or cut and paste blocks of code. Genetic engineering has become a lot like software engineering. It enables scientists to explore transformative questions such as, “What happens if we remove ancient viral remnants from human DNA?” Or “Can we program this cell to not age?”
Increasingly, it will be AI-based tools that do this encryption, just as we see in computer programs. This is already happening. Almost all protein engineering is now done using artificial intelligence tools. Recently, the California-based Arc Institute combined its Evo AI tools with genome synthesis to manufacture dozens of new PhiX174 bacteriophages, viruses that infect bacteria. The success of this experiment suggests that in the near future, defeating a supernaturally deadly bacteria could be as simple as sending a document to an inkjet printer.
When megabase-scale synthesis becomes available—a starting point for the gigabase synthesis needed to synthesize the human genome—we will be able to design almost any single-celled organism from scratch. The entire science of microbiology becomes as much engineering as science. These “designer” microbes could transform biomanufacturing and the production of medicines, fuels, and materials with unprecedented efficiency.
Just as the transistor sparked the digital revolution, rapid, inexpensive, and scalable genome design and synthesis would spark a biological revolution. Life becomes a technological platform, a programmable means of solving the world’s most challenging problems.
The scientific gains here will be profound. Cellular genomes are spaghetti code, with overlapping functions scattered across chromosomes without rational organization, and the only candidate is that it works. Building complete artificial organisms is the only way to untangle all the different evolutionary functions mixed together over billions of years. Starting anew, scientists will be able to shed light on the secrets of metabolism, evolution, and perhaps even consciousness in ways that gene editing cannot. As physicist Richard Feynman famously pointed out, you can’t truly understand what you can’t create.
The world needs another biological jumpstart
But any project that aims to create life must face serious ethical questions: What kinds of genomes should we build? Are there any off limits? Who decides? How do we prevent the development of biological weapons?
Both HGP-write and SynHG recognize that the same tools that can cure or create life can also be abused to cause suffering and death. For this reason, transparency, open science and public dialogue are central to their missions. They want to ensure that decisions regarding the Code of Life are a shared global responsibility, and not the purview of any single company or country.
In this sense, genome writing is as much about governance as it is about genetics. It’s about learning how to safely collaborate on planet-wide technology that has the potential to change the planet. In the short term, if history is any guide, a little friendly rivalry between teams will only accelerate progress. The US effort started early, but the UK has quietly taken the lead thanks to steady, sustained progress – and a “full diligence” mandate that values responsibility as much as speed. But this is a race, like a sequence, no matter who crosses the line first, all of humanity wins.
We could all use something big to cheer about, something that reminds us that this planet is our home, not just a launching pad to the Moon or Mars. It’s been nearly 25 years since the world last united around a biology-based trip to the moon. The first Human Genome Project inspired an entire generation to see life as a code that can be read and understood. Writing the human genome could inspire the next generation to see DNA as something that can be synthesized, opening up possibilities that evolution has never explored before.
The question is no longer whether we can write the human genome, but whether we can do so wisely – and for the good of everyone.
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