Carl Zimmer writes books, articles, essays, and blog posts in which he reports from the frontiers of biology, where scientists are expanding our understanding of life. Since 2013 he has been a columnist at the New York Times, where his column “Matter” appears each week. He agreed to answer some of our questions before taking the stage at Aspen Ideas Festival to discuss genetics and the future of babymaking.
What is CRISPR and why is it important for the average American to know about it?
CRISPR is a technology for rewriting DNA. Scientists discovered a natural version of CRISPR in bacteria, which use it to attack viruses by garbling their genes. They then tinkered with the molecules until they could make changes to the DNA in just about any organism, be it a fly, a tomato, or a human. Genetic engineering is nothing new — scientists started making controlled changes to DNA in the 1970s — but until now, the technology has been crude. CRISPR, on the other hand, is quick, versatile, fairly precise, and cheap.
Right now CRISPR is a scientific tool, allowing scientists to learn new things about how genes work. But before long, CRISPR is going to make its way into everyday life. Researchers are making new kinds of changes to crops with CRISPR. Editing the DNA that controls the flowering of tomatoes could create new varieties that can grow well in Canada, for example. CRISPR will also probably be applied to medicine in the next decade. Doctors may be able to edit the DNA of immune cells to make them better at killing cancer cells. It may also be possible to cure genetic disorders like muscular dystrophy by erasing disease-causing mutations — but that sort of treatment will probably take many more years to get through testing for safety and efficacy.
Do you have any advice for those researching genetic modification? What are the moral and ethical implications of such procedures?
It is very easy to go overboard when thinking about the future of genetic modification. Some people will promise the moon and the stars. Other people will promise an dystopian apocalypse. I think everyone — scientists, reporters, politicians, and curious citizens alike — needs to dig deep into these scenarios to separate the real potential benefits and risks from the hype. We are far too prone to fixate on technological solutions and threats while ignoring the messy reality of politics and policy.
Using CRISPR to make corn with a higher yield will not fix famines caused by bad economic systems or civil wars. If someone figures out how to use CRISPR to cure muscular dystrophy, they probably won’t give the treatment away for free. In fact, judging from current medical pricing, they may very well charge a million dollars for it. It’s presumptuous to assume that gene editing will wipe away disease when we do such a bad job of delivering medicine today.
Scientists generally abide by a 14-day rule when it comes to how long embryos are allowed to develop. Do you believe this should be adjusted for the sake of further research?
The 14-day rule was crucial to science. It created an agreement under which scientists could move forward and discover important facts about how embryos develop. But from the start, it was an arbitrary line. It seemed early enough to avoid any controversies over whether embryos had consciousness or could feel pain. After all, they didn’t even have a nervous system at 14-days. But no one had any idea how to grow a human embryo for even a week in a lab, and so no one could break the rule even if they tried.
That’s changing now. Scientists have found the right chemicals to keep human embryos viable for close to 14 days. With more research, they could probably go beyond that limit soon. Scientists are also learning how to assemble stem cells together in miniature molds. The cells then start communicating with each other and start developing in embryo-like ways. These cells, given the right chemicals, might develop into different organs — a liver, for example, or a muscle. The 14-day rule will be useless for making ethical decisions in these studies. These embryo-like structures may reveal new clues about diseases that we can’t find out any other way. But we have to decide which ones are acceptable to grow, and which cross a moral line.
Has the rise of artificial intelligence changed the way you think about genetics?
Artificial intelligence is a good lesson in the mystery of complexity. Scientists are mimicking some properties of the brain to develop machine learning. Computers now have the capacity to train themselves to recognize patterns and learn how to do things — to listen to what we say to them, to identify clusters of symptoms that reveal the early stages of a disease, and so on. But if you look under the hood and see how computers are processing the information, it’s hard to make sense of what’s going on. The computers create complex networks of their own to solve problems that aren’t based on clear, logical principles. Our own intelligence is an emergent property, produced by thousands of genes interacting inside cells that are nestled in a brain, which is in turn nestled in a complicated environment. You can’t simply look at a list of our genes and see how intelligence works.
How should policymakers be preparing for populations with lengthened lifespans?
We’re in an awkward stage of human history right now. Clean drinking water, antibiotics, vaccines, and other advances starting in the late nineteenth century have drastically reduced the rate of childhood mortality around the world. People are far more likely to survive to middle age and beyond. People are also more likely now to avoid dying of many diseases of adulthood thanks to medical advances in the treatment of cancer and other conditions. Unfortunately, many people are not living into their eighties or nineties in good health. Alzheimer’s disease, diabetes, and other chronic disorders are becoming increasingly common, thanks in part to people’s longer lives. These disorders are already putting a big strain on our health systems, and things are only going to get worse as populations get grayer. Rather than seeking immortality, we would be better off finding ways to live well while we’re here.
In your long career as a science writer, what is the one thing that excites you the most? What is the one thing that frightens you the most?
My excitement about scientific research is continually renewed. Researchers are doing things today that I wouldn’t have dreamed possible when I first started writing about science. What scares me is the ease with which people can ignore scientific research when they feel that it threatens their world view — and the cynicism of those who mislead the public.
The views and opinions of the author are his own and do not necessarily reflect those of the Aspen Institute.
