Roughly 9,000 years ago, somewhere around the Tehuacan Valley of present-day Mexico, a common local wildgrass began an extraordinary transformation. It probably started by accident: local foragers favouring those plants with larger, looser seeds, and inadvertently spreading them through their waste. But it wasn’t long before humans made art out of chance and began deliberately selecting the best grasses to sow—and unwittingly became the world’s first genetic engineers.
The crop they invented is known to us as maize corn, and compared to its wild ancestors it is grotesquely malformed. A plant that once reached up to the knees at best now towers over the tallest humans. The cob has swollen from one inch to almost a foot long, and each stalk might produce half a dozen of them. A structure that had evolved for millions of years for the sole purpose of spreading seeds now grips its kernels so strongly you need a sharp kitchen knife to remove them. As a consequence, corn is effectively sterile: without human intervention, the entire species would perish.
Long before labcoats and microscopes, humans became masters of the gene. Today, that power is under scrutiny like never before. The European Union recently resolved to cut red tape on genetically modified crops; nations around the world are debating labelling laws requiring disclosure of GM ingredients; and just last month a UK ethics board provoked outrage when it ruled that the genetic modification of human babies may be permissible.
At the centre of the controversy is an awesome new technology: CRISPR-Cas9. Like artificial selection—humanity’s original gene editing tool—CRISPR-Cas9 is a clever appropriation of nature’s own machinery. When certain bacteria survive an attack by a virus, they take a mugshot of their attacker in the form of snippets of viral DNA. These snippets, stored in a library called CRISPR, can be bundled with some simple molecular machines—the “Cas” part—to create guided missiles that identify viruses by their DNA and slice’n’dice them to death.
About 15 years ago, scientists realised an alternative use for the CRISPR-Cas9 system: as a tool for gene editing, snipping out and even replacing undesirable sequences. Today, one of nature’s most advanced bioweapons is routinely used to shuttle target genes from one organism to another—for example, programming herbicide-resistant genes into crops to make weed control easier and cheaper, or engineering super-nutritious rice to combat the sorts of vitamin deficiencies that kill hundreds of thousands of children every year. Human applications have thus far been stymied by the maze of regulations designed to protect us from dodgy medicine, but with GMO issues no longer capturing the public eye, those laws are beginning to change. Clinical trials targeting HIV, hepatitis C, and sickle cell anaemia are already underway, to name just a few.
Science’s aversion to the genetic modification of humans is a direct legacy of one of the 20th century’s darkest episodes. Though eugenics today is indelibly tied to Nazi ideology, in its heyday it was not only acceptable—it was policy. And its adherents did not need CRISPR-Cas9 to execute their vision: nine thousands years of agricultural history had already shown the way. In the United States, the UK, and even here in Australia, governments forcibly sterilised thousands of disabled, poor, and minority citizens in the name of genetic hygiene. For the old eugenicists, as much as for the earliest farmers, control of reproduction was the key.
The recent UK ruling on “designer” babies is not definitive, but it is suggestive. The long shadow of our shame is beginning to recede, even as our powers over the human genome are set to immeasurably increase. Within reach are remedies to some of nature’s most egregious cruelties—and slippery slopes well-greased with good intentions.
One can dimly imagine a future race of humans: willowy and sexually engorged, muscular and ingenious, cheerful and disposable, and, of course, completely incapable of propagating themselves—except with the permission of their masters. Someone’s idea of perfection, grotesque to our eyes; children, as it were, of the corn.