I also want to quickly talk about the other element you mentioned regarding editing permanent changes into the human genome. I spent a lot of time on that in the third part of the book, because I was in the front row in Hong Kong at a conference in 2018 when a Chinese scientist named He Jiankui made the shocking announcement that he had edited the DNA of two babies that had been born a few weeks earlier named Lulu and Nana.

The reason this was so significant and literally headline news around the world is that he had edited the DNA of human embryos. Every edit that he had introduced into that DNA had grown and multiplied and replicated as the embryo grew into the babies that were born nine months later. Those babies, if and when they have children, will pass on that edited gene. That was a red line that 99.9 percent of the world’s citizens and the world’s scientists did not think should be crossed for many reasons: ethical concerns, medical concerns, safety concerns, and technology concerns.

We just don’t know yet enough about CRISPR because the technology is still so young to say hand on heart, that it is 100 percent safe and 100 percent accurate. I think we’ll get there soon, but we’re not there yet. We don’t completely understand how to edit the human embryo’s DNA, even if we really wanted to, even if we felt that we had a couple with a severe genetic disease that had no other options to have a biologically related child. That episode, I spent several chapters discussing it and looking at it at different angles, the politics, the ethics, and where we go from here. I hope people will look at the book for that reason.

I do want to get back to that in just a moment, but you mentioned what we know and don’t know. I’m sitting here looking at an article from June, and it says three new studies show unwanted changes in the human embryo genome after CRISPR editing. Do you have any concern that this will end up being found to be just too dangerous, and technology will stop?

Well, I don’t think it’s going to be stopped. It’s dangerous to apply now, but that’s why scientists are doing these experiments under ethically and regulatory-approved conditions with non-viable human embryos: to understand how embryos develop. These experiments can tell us many things that maybe have nothing to do with gene editing. Remember, we’re using CRISPR as a tool to understand the biology of human development at its earliest stage so that we can, for example, prevent miscarriages or make IVF completely as safe as can possibly be.

The other ramification of the three studies that you just cited are that they give us pause. It tells the scientific community, even if you were thinking about following in the footsteps of the Chinese scientist who did these notorious experiments two years ago (and who incidentally is now in jail in a Chinese prison, serving a three-year prison sentence), “Please stop! Do not pass go!” As those studies from the three leading human embryo genetics labs in the UK and the US showed, when you try to do a gene-editing experiment on a one-day-old human embryo, we can’t predict exactly what is going to happen.

Those studies found a variety of other DNA rearrangements. So no responsible scientists could look somebody in the eye and say, “We know how to do this.” It’s going to take probably several years just to understand the biology and genetics. However, once we reach that point — which I’m sure we will — whether it’s using CRISPR or some other form of gene-editing technology (because they’re always iterating and improving that technology), then I think we’ll be one step closer to deciding whether we, for instance, want to offer gene editing for rare couples who have no other option to have a biologically related child. That’s where we pretty much where we stand at the moment.

We’ve mostly been talking about fixing problems with gene therapy? But what about enhancement? It seems highly unlikely that this is going to stop at therapy. I’m sure when a lot of people heard about that story in China, they figured that this was actually a Chinese government experiment to try to create a new race of hyper-intelligent super people, and that this will lead to a CRISPR arms race that the US will have to join in on. So could you speak to the debates around genetic enhancement?

Yes. Well, let me puncture somebody’s balloon right away. Anybody who thought the Chinese scientist who is now languishing in a Chinese prison was trying to increase the babies’ intelligence is flat out wrong. That doesn’t mean what he was trying to do was appropriate, ethically sound, or even medically sound. Very briefly, he was recruiting couples for his trial where one of the parents had HIV. HIV is still a rampant disease in parts of China, and there’s a huge social stigma to having HIV. So he felt there was a medical need for what he was doing. If he could have engineered those babies to be essentially genetically immune to developing HIV from their father, he would be setting the stage for treatment for hundreds of thousands of other Chinese couples in the same boat.

It was a naive notion. He didn’t talk to enough people, and if he did talk to them, he didn’t listen. He was 34 years old when he did these experiments. He was dreaming of becoming not only the next Nobel Laureate but the next hero, not only for Chinese science but almost for world science. He wanted to be someone who would go down as a hero like a Louie Pastor or Bob Edwards, the British scientist who helped develop IVF. We now have 5 million IVF babies since the birth of Louise Brown in 1978, and that was who He Jiankui was trying to emulate.

Briefly, elements of trying to enhance individuals or huge groups of individuals to enhance intelligence, at least based on our current understanding of science and genetics, are just doomed to fail. There is no on-off switch for intelligence. If you were trying to understand and modulate the human being’s intelligence, and I say this in the most theoretical abstract sense, you would have to potentially tweak the genes of hundreds if not thousands of genes. We just wouldn’t know where to begin to start. I’m really not at all concerned by that, and the reports that just came out from the National Academy of Science has really charted for people who want to explore genome editing in human embryos to engineer changes that would be then inherited and passed on through generations. They have charted a very narrow course, purely for serious medical conditions and really very rare circumstances. The scientific community, I think, has come down pretty hard on that.

Could CRISPR extend lifespans, in some fashion, so that we’re all living to be 150?

At the moment, I would say no. Still, I am aware that many companies and many philanthropists are very interested in understanding and exploring the genetics of extended lifespan. I’m not aware of any magic gene that says, “If you want to extend lifespan, one thing you want to do is to remove the risks of falling off the wagon,” so to speak, because you succumb to Alzheimer’s disease or heart disease or cancer.

One way to answer your question is if gene-editing — not just editing embryos, but the whole repertoire of gene-editing — can provide us ways where that we can tackle genetic diseases, certain types of cancer, and perhaps eventually things like Alzheimer’s disease. In that case, then yes, genome-editing will absolutely help us extend the lifespan.

To add to that, we want not just to live to 150 (and have that last 60 years be racked with illness), but also to make the current lifespan healthier and then add on more healthy years. So I certainly can imagine there being plenty of 60-something billionaires right now thinking about projects they could fund.

We already see that, to some degree, with stem cells. Do you remember, maybe 20 years ago, when scientists made big discoveries in stem cells? And we had the whole debate when George W. Bush took office about whether federal funds should be used to engineer new stem cells, because of the fear that it promoted the destruction of embryos. A lot of stem cell clinics and offshore clinics were set up. I know some philanthropists who’ve funded some of these themselves because, pretty much as you suggested, they want to give themselves the secret of near-everlasting life — and live to 120 playing a couple of sets of tennis every day.

I’m as skeptical about that as I am about genome-editing, providing these sort of magical and fantastical theories. Then again, this book is about a revolution in science technology, and the amazing thing about our field is that you can never predict where the technology is going to go. So I can wax and wane about how this is the greatest technology since sliced bread, and five years from now, somebody may well come up with something that makes CRISPR look quaint and outdated.