Hacking Darwin

Scientists and theologians can debate whether the first spark of life on our planet sprang from thermal vents on the ocean floor or divine inspiration (or both), but most everyone who believes in science recognizes that around 3.8 billion years ago the first single-cell organisms emerged. These microorganisms would have died after one generation if they couldn’t find a way to reproduce. But life found a way, and the microbes that started dividing were the ones able to keep their little microbial families going. If each division of these early cells had been an exact copy of the parent, our world would still be occupied solely by these single-cell creatures.

But that’s not what happened.

The history of our species is the story of little errors and other changes that kept popping up in the reproduction process.

Cover for the book, Hacking Darwin, by Jaime Metzl
Excerpted from Hacking Darwin: Genetic Engineering and the Future of Humanity by Jamie Metzl. © 2019 by Jamie Metzl.
Used with permission of the publisher, Sourcebooks, Inc. All rights reserved.

After a billion years of these small variations created a vast number of slightly different models, one or more of them transformed into simple, multicellular organisms. Still not much by today’s standards, these organisms had the potential to introduce even more differences as they reproduced. Some of these variations gave one type of organism or another a small advantage in acquiring food or fending off enemies, providing them the opportunity to live on and mutate more. After two and a half billion years of this, the mutation and competition driving life forward took another miraculous leap with the advent of sexual ­reproduction.

Sexual reproduction introduced a radical new way of generating diversity when the genetic information of mothers and fathers recombined in novel ways. This incredible process supercharged some of these simple organisms to begin mutating wildly, particularly by around 540 million years ago, into a previously unimaginable diversity of life, including fish. About 200 million years ago, some fish crawled out of the water and evolved into mammals. Around 300,000 years ago, some of those mammals morphed into Homo sapiens, a.k.a. us.

That’s basically our evolutionary history. Every one of us is a single-cell organism gone wild through nearly four billion years of random mutation whose ancestors have continually out-competed their competitors in a never-ending cage match for survival. If your ancestors survived and procreated, you are here. If not, you are not. The shorthand name for this is Darwinian evolution. It got us to this point. But now the principles of Darwinian evolution are themselves mutating.

If we traveled a thousand years into the past, kidnapped a baby, and brought that baby into our world today, that child would grow up into an adult indistinguishable from everyone else. But if we jumped back into the time machine and went a thousand years from today into the future to do the same, the baby we brought back would be a genetic superhuman by our current standards. He or she would be stronger and smarter than the other children, resistant to many diseases, longer-lived, and have genetic traits today associated with outlier humans, like particular forms of genius, or with animals, like super-keen sensory perceptions. He or she might even carry new traits not yet known in the human or animal worlds but made from the same biological building blocks that have given rise to the great diversity of all life.

Illustration of woman reaching into a strand of DNA.

In the second term of the Clinton administration, I was working on the White House National Security Council. My then-boss Richard Clarke was telling anyone who would listen that terrorism was a major threat and that the United States needed to much more aggressively go after an obscure terrorist named Osama bin Laden. When the 9/11 planes crashed into the Twin Towers, Dick’s prophetic and now famous memo on Al-Qaeda was stuck, disregarded, in President Bush’s inbox.

Dick always used to say that if everyone in Washington was focusing on one thing, you could be sure there was something far more important being missed. The lesson stuck with me. After leaving the White House, I kept thinking about the then-nascent revolution in genetics and biotechnology. I became consumed with reading everything I could find and tracking down some of the smartest scientists and thinkers in the world to learn more. I became increasingly convinced we as a society weren’t doing nearly enough to prepare for the coming genetic revolution.

Not everyone has heard of Moore’s Law, the observation that computer-processing power roughly doubles about every two years, but we’ve all internalized its implications. That’s why we expect each new version of our iPhones and laptops to be lighter and do more. But it’s becoming increasingly clear there is a Moore’s Law equivalent for understanding and altering all biology, including our own.

We are coming to realize our biology is yet another system of information technology. Our heredity is not magic, we have learned, but code that is increasingly understandable, readable, writable, and hackable. Because of this, we will soon have many of the same expectations for ourselves as we do for our other information technology. We will increasingly see ourselves in many ways as I.T.

This idea frightens many people, and it should. It should also excite us based on its incredible life-affirming possibilities. Regardless of how we feel, the genetic future will arrive far sooner than we are prepared for, building on technologies that already exist.

Will the benefits of this science go to the privileged few, or will we use these advances to reduce suffering, respect diversity, and promote global health and well-being for everyone?

As a start, we will use the existing technologies of in vitro fertilization (IVF) and informed embryo selection not just to screen out the simplest genetic diseases and select gender, but also to choose and then alter the genetics of our future children more broadly.

A second, overlapping phase of the human genetic revolution will go a step further, bumping up the number of eggs available for IVF by inducing large numbers of adult cells like blood or skin cells into stem cells, turning those stem cells into egg cells, and then growing those egg cells into actual eggs.

If and when this process becomes safe for humans, women undergoing IVF will be able to have not just 10 or 15 of their eggs fertilized, but hundreds. Instead of screening the smaller number of their own embryos, these prospective parents would be able to review screens for hundreds or more, supercharging the embryo selection process with big-data analytics.

Many parents will also consider the possibility of not just selecting but of genetically altering their future children. Gene-editing technologies have been around for years, but the recent development of new tools like CRISPR-Cas9 is making it possible to edit the genes of all species, including ours, with far greater precision, speed, flexibility, and affordability than ever before. With CRISPR and tools like it, it will ultimately be scientifically possible to give embryos new traits and capabilities by inserting DNA from other humans, animals, or someday even synthetic sources.

Once parents realize they can use IVF and embryo selection to screen out the risk of many genetic diseases and potentially select for perceived positive traits like higher IQ and even greater extroversion and empathy, more parents will want their children conceived outside the mother. Many will come to see conception through sex as a dangerous and unnecessary risk. Governments and insurance companies will want prospective parents to use IVF and embryo selection to avoid having to pay for lifetimes of care for avoidable and expensive genetic diseases.

With whatever mix of catalysts and first movers, it is almost impossible to believe that our species will forgo chasing advances in technologies that have the potential to eradicate terrible diseases, improve our health, and increase our life spans. We have embraced every new technology — from explosives to nuclear energy to anabolic steroids to plastic surgery — that promises to improve our lives despite their potential downsides, and this will be no exception. The very idea of altering our genetics calls for an enormous dose of humility, but we would be a different species if humility, not hubristic aspiration, had been our guiding principle.

With these tools, we will want to eliminate genetic diseases in the near term, alter and enhance other capabilities in the medium term, and, perhaps, prepare ourselves to live on a hotter Earth, in space, or on other planets in the longer term. Over time, mastering the tools of genetically manipulating ourselves will come to be seen as perhaps the greatest innovation in the history of our species, the key to unlocking an almost unimaginable potential and in many ways an entirely new future.

But that doesn’t make all of this any less jarring.

As this revolution unfolds, not everyone will be comfortable with genetic enhancement, based on their ideological or religious beliefs or due to real or perceived safety concerns. Life is not just about science and code. It involves mystery and chance and, for some, spirit.

If ours was an ideologically uniform species, this transformation would be challenging. In a world where differences of opinion and belief are so vast and levels of ­development so disparate, it has the potential, at least if we’re not careful, to be cataclysmic.

We’ll have to ask, and answer, some truly fundamental questions. Will we use these powerful technologies to expand or limit our humanity? Will the benefits of this science go to the privileged few, or will we use these advances to reduce suffering, respect diversity, and promote global health and well-being for everyone? Who has the right to make individual or collective decisions that could ultimately impact the entire human gene pool? And what kind of process, if any, do we need to make the best collective decisions possible about our future evolutionary trajectory as one or possibly more than one species?

There are no easy answers to any of these questions, but every human being needs to be part of the process of grappling with them. Our collective responses, laundered by our conversations, organizations, civil movements, political structures, and global institutions, will determine in many ways who we are, what we value, and how we move forward. But to be part of that process, we all have an urgent need to educate ourselves on the issues.

The door is open for all of us. Whether we like it or not, we are all marching toward it. Our future awaits.

Excerpted from Hacking Darwin: Genetic Engineering and the Future of Humanity by Jamie Metzl. © 2019 by Jamie Metzl.  Used with permission of the publisher, Sourcebooks, Inc. All rights reserved.

Featured image: Shutterstock

Your Health Checkup: The Science of Epigenetics or Why I Behave Like Uncle Harry

“Your Health Checkup” is our online column by Dr. Douglas Zipes, an internationally acclaimed cardiologist, professor, author, inventor, and authority on pacing and electrophysiology. Dr. Zipes is also a contributor to The Saturday Evening Post print magazine. Subscribe to receive thoughtful articles, new fiction, health and wellness advice, and gems from our archive. 

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As is sometimes the case, “old wives’ tales” may contain a whisper of truth.

Many families have curious notions. Growing up, when I behaved in a certain way, my mother would say, “You inherited that from your Uncle Harry,” or whoever’s behavior I was mirroring. My grandmother often repeated the belief that a mother’s fright during pregnancy could affect the baby.

My college genetics course convinced me that my mother and grandmother were wrong. I learned I could not inherit acquired behavior. I inherited genes from my mother and father in which the DNA was permanent, unchanging, and could not be influenced by external environmental events, such as Uncle Harry’s behavior. Similarly, a baby, already conceived, could not be impacted by an event that frightened the mother.

It turns out my mother and grandmother may have been right after all. Acquired behavior can be inherited.

This involves the science of epigenetics, the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself. For example, an environmental event like trauma can leave its mark, not on the DNA directly, but on regulatory processes that modulate how the gene works and how it assembles various proteins that can alter health and behavior.

A recent study found that male children of abused Civil War prisoners were about ten percent more likely to die after middle age than children of parents who were not POWs. Individuals exposed in the womb to famine during the Dutch Hunger Winter in 1944-1945 had a particular chemical alteration, or epigenetic change, noted on one of their genes six decades later that affected their health.

Thus, it may be that parental stress prior to, or even after, conception can impact the sperm, egg, or a developing fetus to influence. If the impact of such traumatic events can be inherited, it might be operative in children and grandchildren of survivors of traumatic events such as the Holocaust, 9/11, fire, poverty, earthquakes, and tsunamis.

Scientists have questioned the validity of some of these conclusions, particularly those relying on epidemiologic interpretations. However, data from well controlled studies are hard to challenge.

For example, in one such study, scientists exposed male mice to the smell of cherry blossoms while delivering mild electric shocks to their feet. Predictably, the mice exhibited fear whenever they subsequently smelled cherry blossoms. Two weeks later, the mice were bred, and their offspring were raised to adulthood never smelling cherry blossoms. When the offspring smelled cherry blossoms for the first time as adults, they became anxious and fearful. They could even detect lesser amounts of the cherry blossom odor in the air than their parents. When the first-generation mice bred, their offspring exhibited a similar reaction, establishing that fear from a single acquired traumatic experience could be transmitted across at least two generations. Artificially inseminated females using the sperm from the original fear-conditioned mice to eliminate any socially transmitted effects between the parents resulted in the same responses.

In another series of experiments, male rat offspring of fathers exposed to cocaine ingested less drug than did rats whose fathers were never exposed to cocaine, again establishing that environmental perturbations can impact the behavior of descendants, perhaps in this example as a protective mechanism.

These observations have convinced me that the impact of an acquired experience can be inherited. Maybe I was genetically programmed to act like Uncle Harry.