During my work as a geneticist and anthropologist I’ve been lucky enough to work with people around the world, ranging from senior politicians and the heads of major corporations to hunter-gatherer tribesmen eking out a precarious existence in remote wilderness locations. What has struck me over and over again is the huge amount of change taking place in the world today, regardless of where one lives. Some of this change is good, such as the overall decrease in poverty during the course of my lifetime, or the drop in the birthrate in developing countries. Other things, though, like 9/11 and the 2008 terrorist attacks in Mumbai, have not been so welcome though.
Everywhere there is a feeling that the world is in flux, that we are on the brink of a historic transition, and that the world will be fundamentally changed somehow in the next few generations. The pace of technological change is accelerating, and we are all swept up in it. Think of all of the indispensable things in your daily life you have only learned to use in the past decade or so. Email, Google, instant messaging and mobile phones spring to mind immediately, but there’s also hybrid car technology, curbside recycling and social networking sites like Facebook. All have found widespread application only since the mid-1990s, and yet today we can’t imagine living without them. Trying to imagine what the world will be like at the close of the 21st century is nearly impossible.
With all of these amazing technological advances, though, has come a great deal of ancillary baggage. The unprecedented rise in chronic disease in westernized societies is perhaps the most obvious example. I say westernized, rather than western, because we are now well aware of the growing incidence of heart disease, diabetes and plain-old obesity in the developing world, particularly in places such as India and China. As they become more like us, they are taking on many of our worst attributes as well. Psychological disorders such as depression and anxiety are also on the rise, and drugs to treat these disorders are now the most widely prescribed in the United States. This seemingly inexorable march toward western unhealthiness made me wonder why it happened in the first place. Is there some sort of fatal mismatch between western culture and our biology that is making us ill? And if there is such a mismatch, how did our present culture come to dominate? Surely we are the masters of our own fate, and we created the culture that is best suited to us, rather than the other way around?
The answer to this was a long time in coming. It took me on a global quest to discover the similarities between what happened thousands of years ago and what is happening now, as we face what promises to be another turning apparent point in our evolution. During the course of researching of my first book, The Journey of Man, I was struck by the effects of the agricultural lifestyle on humans living 10,000 years ago in the Middle East. It turns out that early farmers were actually less healthy than the surrounding hunter-gatherer populations. So why did the farmers ‘win’ so resoundingly, to the extent that virtually no one on Earth today lives as a hunter-gatherer? The answer, like most insights into major historical events, is somewhat complicated, but reveals a simple pattern in human history that seems to repeat itself again and again: necessity is the mother of invention.
The changes as we settled down into villages and then cities wrought havoc on our biology, adapted as it was to millions of years of leading a semi-nomadic existence as hunter-gatherers. Instead of modifying the culture to suit our physiology, though, we seem to have adapted biologically to the prevailing culture. The signals of this are still visible in our DNA, and we are still in the process of adapting to it. It is likely that we have changed more at the DNA level in the past 10,000 years than we did in the previous 100,000. This acceleration in the rate of evolutionary change is unprecedented in the history of our species.
Of course, such enormous cultural changes have effects on far more than simply our biology. As we settled down into farming villages, and then towns and cities, society became more complicated. Hunter-gatherers, having fewer people in their groups, tend to have fairly simple and egalitarian social structures. A chief perhaps, but certainly not a specialized bureaucracy, a professional army, a priesthood and other trappings of what we call civilization. The existence of these things is a direct outcome of the decision to settle down and start growing food. As more food is planted, you can have more children, and they are actually useful to help tend the fields. Over time this iterative cycle leads to a literal explosion in population, and as a result the human population rose from a few million at the dawn of the Neolithic, 10,000 years ago, to over six and a half billion today. Modern society is so complex that it’s amazing that the whole system doesn’t seize up, or that terrorist acts aren’t more common.
So, how can a species that spent almost all of its evolutionary history adapting to hunting and gathering in small, fairly dispersed groups learn to cope with the challenges posed by this relatively new culture? In short, it’s time for us to grow up. Stewart Brand, paraphrasing Edmund Leach in the opening sentence of the first Whole Earth Catalog in 1969, said it well: we are as gods, it’s time we got good at it. The final section of the book deals with three critical challenges facing us in the next century – challenges that have come about through our actions over the past 10,000 years, and that threaten to be our undoing unless we address them.
The first is the growing power of genetic engineering. Over the past two decades our knowledge of human genetics has exploded. I still remember debating with fellow geneticists the summer before I started graduate school, in 1989, whether it was possible or even advisable to sequence an entire human genome. The costs/benefit ratio was unclear, and many felt that it was simply too expensive and would take too long to complete to yield anything of real value. That all changed in the late 1990s, when Craig Venter’s private company Celera and the publicly funded Human Genome Project competed to see who could finish the first complete genome sequence. It was declared a tie in March of 2000, and the race was then on to figure out what the billions of nucleotide bases actually meant. The rate at which this knowledge has accumulated in the past decade has been nothing short of breathtaking, and as a geneticist I feel lucky to have been able to practice my trade at this point in history. We now know so much more about how tiny variations in the genetic code can lead to the phenotypes that define us – physical appearance, personality, diseases – than we did only a few short years ago.
With this knowledge, of course, has come the desire to use the information to improve the human condition. Generating such knowledge is not simply an academic exercise for the benefit of the genetics community, after all – huge promises were made in order to obtain the billions of dollars of funding it took to sequence the first genome. Health would be improved, we would be better able to predict our abilities and predilections, and overall humanity would be better off. However, unlike other technologies that have witnessed explosive growth over the past couple of decades, from computers to nanotechnology, the applications of genetics have the potential to affect the biological identity of future generations, through our ability to choose the traits our children – and all subsequent generations – will carry. While Gattaca-like scenarios are still a long way off, the potential is there. How will we know if we are making genetic decisions that are best in the long run, for our children’s great, great, great-grandchildren? And what is at risk long-term as we make decisions based on proximal desires or threats?
The second enormous challenge that we need to face as a result of the events set in motion 10,000 years ago with the development of agriculture is climate change. It’s now commonplace to talk about global warming and carbon footprints, so much so that it’s easy to forget that until quite recently few thought it was even possible that the actions of our species could have a potentially catastrophic effect on the Earth’s climate. We’re just along for the ride, we seemed to be telling ourselves as we consumed ever more hydrocarbons, releasing the noxious cocktail of exhaust fumes into the atmosphere. Now we appear to have set in motion a series of events that, even if we can manage to bring our greenhouse gas production under control, threatens to change the very nature of the planet we live on. How we learn to deal with this will be an enormous technical and social challenge over the next century, and beyond. While it will likely spur us into action on the technologies required to reduce emissions, the effects of global warming will nonetheless still be felt by us, and by our descendants, for decades to come.
The final significant challenge, unlike the other two, is not fundamentally technological in nature, though some of the solutions will likely involve the application of technology. We have now evolved culturally to the point where the entire world is connected in a way it has never been before. Not only is it possible to jet off to Mumbai for a lecture over the course of a weekend, as I did in the aftermath of the 2008 attacks, but we use telecommunications technology to talk, email, SMS, instant message, videoconference and otherwise connect with each other in ways that were inconceivable only a century ago. Recall that when Alexander Graham Bell invented the telephone, the New York World (then a major US newspaper) famously asked ‘of what use is such an invention?’ In the past century our world has become ever more connected, to the extent that today what happens in Kansas or Calcutta is immediately transmitted via streams of electrons to people around the world. The effect of this connectivity has been the globalization of culture, and as the West is the in the hegemony at the moment, this means that more and more people are becoming ever more western. While to those of us in living in the West there are many good aspects to this, to many others our way of life is not all it’s meant to be. For secular rationality, read loss of faith and certainty. For improving living standards, read increased consumption. For increased social mobility, read loss of traditional roles and threats to vested interests. The rise of fundamentalism in the latter half of the 20th century reflects the very real loss of the traditions that guided much of humanity over the past several thousand years. What to replace those traditions with, especially for those not privy to the largesse of the modern world, is a difficult question. If you believe that you have a stake in the future, you are likely to embrace it; if you feel left out, this is much less likely. Providing an inclusive mythos for the modern age will be a significant challenge of the next century.
While all of these issues have their proximal causes in the modern world, ultimately the forces that created them were set in motion by the enormous changes that took place long before. The biggest revolution of the past 50,000 years was not the advent of the Internet, the growth of the industrial age out of the seeds of the Enlightenment, or the development of modern methods of long-distance navigation. Rather, it was a seemingly trivial event that happened rather quickly around 10,000 years ago – the dawn of the age of agriculture, when a few people living in several locations around the world decided to stop gathering their food from the land, abiding by limits set in place by nature, and grow their food. This desire has had more far-reaching consequences for our species than any other. With this change though, and the power we developed, we must also learn some humility. In today’s world, where small groups of terrorists can inflict such lasting damage on the psyche of nations, where simple decisions can affect the biological inheritance of generations far in the future, and more species are likely to go extinct as a result of our actions than at any point in the past 60 million years, it is necessary to take stock and realize that with great desires come great consequences.
About the author
Spencer Wells is an Explorer-in-Residence at the National Geographic Society and Frank H. T. Rhodes Class of ’56 Professor at Cornell University. He leads the Genographic Project, which is collecting and analyzing hundreds of thousands of DNA samples from people around the world in order to decipher how our ancestors populated the planet. Wells received his Ph.D. from Harvard University and conducted postdoctoral work at Stanford and Oxford. He has written two books, The Journey of Man and Deep Ancestry.
Originally published June 7, 2010