CRISPR allows scientists to edit DNA, eliminating undesirable genes and potentially swapping in preferable alternatives.
- Bill Gates is advocating for the use of genetic editing tools like CRISPR.
- CRISPR allows scientists to edit DNA, eliminating undesirable genes and potentially swapping in preferable alternatives.
- Gates thinks we could use genetic editing to make livestock and crops more sustainable and to eliminate malaria-causing mosquitoes.
The ability to rewrite the genetic code for life is a powerful one.
In the past few years, scientists have revolutionized our ability to do so with the discovery and refinement of a molecular tool called CRISPR that allows us to edit sections of DNA. This tool can snip specific parts of genetic code out and replace them with new segments, eliminating diseases or giving creatures whole new traits.
While it was possible to edit DNA before CRISPR's discovery, this tool allows us to do so far more accurately and cheaply than ever before.
In a recent essay published in Foreign Affairs, Bill Gates described some of the ways genetic editing technologies have the potential to transform the world. Since the 1990s, he wrote, the world has made significant progress toward ending child mortality, fighting disease and hunger, and raising people out of poverty.
But there's still a long way to go.
"[I]f the world is to continue the remarkable progress of the past few decades, it is vital that scientists, subject to safety and ethics guidelines, be encouraged to continue taking advantage of such promising tools as CRISPR," Gates wrote.
Gates has long been supportive of using genetic editing tools. He was one of the early investors in Editas Medicine, one of the first companies to start trying to use CRISPR to eliminate human diseases. Gates Foundation researchers have worked for nearly a decade on ways to use genetic editing to improve crops and to wipe out malaria-carrying mosquitoes.
In this latest essay, Gates lays out exactly where he thinks gene editing could have the biggest impact right now.
Feeding the world
One of the first places that many experts think people will encounter life forms with edited DNA is in the world of agriculture.
Editing the genes of a plant or animal doesn't involve adding in genes from other creatures, like some forms of genetic modification. (Genetically modified organisms are still considered safe by most scientists — and Gates supports those, too.) But it's possible to change organisms in powerful ways using genetic editing.
As Gates explained, researchers are studying ways to modify the genes of livestock animals like tropical cows, which normally don't produce much milk, to make them produce milk more like dairy cows. Scientists also trying to see if they can make dairy cattle more resilient in hot weather, something essential in a warming world. Researchers have already figured out how to edit the genetic code of cows to remove their horns using a similar sort of modification.
Editing the genes of crops could also make it easier for them to survive hot or arid conditions, provide more nutrients, and require less water to thrive. These are the sorts of modifications that could be essential to feed the world — as Gates wrote, the population of Africa is expected to more than double by 2050. And the world will only continue to get warmer.
Wiping out disease
But Gates points out the the same genetic editing tool might be able to make enormous progress in the fight against malaria, a disease that his Gates Foundation has been trying to eradicate for years. The mosquito-borne illness kills about 450,000 people every year and infects hundreds of millions.
Out of 3,500 species of mosquito around the world, only the females from about 40 Anopheles species can transmit malaria. Using CRISPR, researchers think they could fundamentally alter the DNA of some members those species in a way that would spread a gene that would make the population infertile or only able to produce male offspring
Making a genetic change designed to spread to the rest of the population is an effort known as a gene drive, a process Gates said could potentially wipe out or drastically reduce the populations of Anopheles mosquitoes.
But spreading a deadly gene through a species is not something to take lightly. As Dan Strickman, a medical entomologist and Senior Program Officer for Vector Control at the Gates Foundation, told me on a visit to their offices in 2016, the potential that these genes could somehow transfer to another species is a serious concern.
"Nobody signed up for that," he said.
But so far, tests have shown that gene drives can be conducted safely in lab settings. In a 2016 report (co-funded by the Gates Foundation), the National Academies of Sciences, Engineering, and Medicine endorsed continued research into gene drives.
The ability to easily modify DNA is a wildly powerful tool that could do a world of good as long as it's done carefully.
As Gates wrote, "It would be a tragedy to pass up the opportunity."