“There are more things in heaven and earth…than are dreamt of in your philosophy.”
WILLIAM SHAKESPEARE, HAMLET
The idea of writing this book came to me in the middle of the Amazon. My wife was there as a medical anthropologist. I was baggage. We flew on a small plane to a faraway place where we did not speak the local language, did not know the customs, and more often than not, did not entirely recognize the food. We were often the only ones fully clothed. We were the only ones who did not sleep in a handmade hammock. We were the only ones who complained about the bugs. We could not have felt more foreign.
We were Westerners raised on books and computers, highways and cell phones, living in a village without running water or electricity. There was also the small matter, parenthetically, that everyone in town believed that we were a “commission” sent to lead an indigenous revolution against the navy. It was easy to go to sleep at the end of the day feeling a little misunderstood.
Then one perfect Amazonian evening, with macaws hanging in midair and monkeys calling from beyond the village green, we played soccer. I am not good at soccer, but that evening it was wonderful. Everyone knew the rules. We all spoke the same language of passes and shots. We understood one another perfectly. It seemed like a transcendent moment. I was, as the photos show, smiling widely. As darkness came over the field and the match ended, the goalie, Juan, walked over to me and, leaning in, said in a matter-of-fact way, “In your home, do you have a moon too?” So much for transcendence.
After I explained to Juan that yes, we did have a moon and yes, it was remarkably similar to his, I felt a sort of awe at the possibilities that existed in his world. In Juan’s world, each village could have its own moon. In Juan’s world, the unknown and undiscovered was immense and marvelous. The known was a small field in the jungle, the local trees, some bugs, and a livelihood. Juan knew his daily life, and all the rest was conjecture. He had never seen the Andes Mountains, which begin their rise into the clouds just twenty miles south of Juan’s home, just beyond the distance Juan could run. Anything was possible.
In Western society, we know that Earth has only one moon. We have looked at our planet from every angle and found all of the wildest things left to find. I can, from my computer at home, pull up satellite images of Juan’s village. There are no more continents and no more moons to search for, little left to discover. At least it seems that way. Yet, as I thought about Juan’s question, I was not sure how much more we could really rule out. I am, in part, an ant biologist, so my thoughts turned to what we know about insect life and I knew that much in the world of insects remains unknown. How much, though? How ignorant are we? The question of what we know and do not know clung to me.
The next step in my nascent obsession with what we know about the world was simple. I began collecting newspaper articles about new species. Articles would, it seemed, come out almost every week. New monkey discovered. New phylum discovered. New spider, new rat, new porcupine, new whale, new relative of the giraffe, and on and on they appear. My drawer quickly filled, and this was just with big things. My own specialty is ants, but “new ant” never makes it into the paper. I have an ant named after me and no one has ever called me from the New York Times to talk about it. I have never even seen it again after I first collected it. No one has.
I began a second drawer for more general discoveries: new cave system discovered with dozens of nameless species, new mountain of life discovered in Papua New Guinea, new lineage of microbes, four hundred species of bacteria found in the human gut. The second drawer began to fill and as it did, I wondered whether there were bigger discoveries out there, not just species or lineages, but entire basic kinds of life that are all around us but invisible, life on other planets, life that lives off substances thought to be useless, life even without DNA. I started a third drawer for these big discoveries. It fills more slowly, but all the same, it fills.
In looking into the stories of biological discovery, I also began to find something else, a collection of scientists, often obsessive, usually brilliant, occasionally half-mad, who made the discoveries. It is easy to imagine that most new discoveries come from global collaborations and expensive research programs in which progress is incremental and dependent on many individuals. Yet to a surprising extent the biggest recent discoveries in biological science appear to still depend on the observations and insights of just one or a few people. Those individuals very often see the same things that other scientists see, but they pay more attention to them, and they focus on them to the point of exhaustion, and at the risk of the ridicule of their peers. In looking for the stories of discovery and what is left to discover I found the stories of these people and the ways in which their lives, little known to me before I began writing this book and probably little known to you, have changed how we see the world.
I began to see similarities not only among the scientists who made big discoveries, but also in how Western scientists and society responded to those discoveries. For one, we are, before these discoveries, always more ignorant than we imagine ourselves to be. Unlike Juan, we are repeatedly willing to imagine we have found most of what is left to discover. Before microbes were discovered, scientists were confident that insects were the smallest organisms. Before life was discovered at the bottom of the ocean, many scientists were confident that nothing lived deeper than three hundred fathoms. Once we made a tree of life that included four kingdoms (animals, plants, fungi, and prokaryotes), we were confident that there would be no more major branches to reveal.
Here I tell the stories of some of the biologists whose discoveries have shaped what we know about the dimensions of the living world. I focus on those discoverers who found entirely new realms of life whether at the bottom of the ocean or in our own cells. We are again at a stage when we believe we have found most of what might be found, but we are wrong. The more I have acquainted myself with the stories of the biological discoveries, the more I have been convinced that whole realms of life remain to be found.
I began by thinking that Juan, in asking if we too had a moon, was the naive one, not me. But my view of the world has changed. While I sat talking to scientists for this book, none of them asked if I too had a moon, but one admitted that he was looking for a fourth domain of life. Another believes he has discovered the cause of more than half of all diseases on Earth. Yet another believes that more than half of all life on Earth can be found in the crust and subsurface beneath the ocean and our feet. We will not find another moon, but what these scientists imagine is just as surprising. And even before a new realm or kind of life is found, we still have to explore the realms we have already discovered. Most species on Earth are not yet named. Most named species have not yet been studied. When we lived in small communities, hunting and gathering, we knew only the animals and plants around us, particularly those that were useful or dangerous. Living on the thin green surface of our small planet in a universe full of stars, we are not so different today. The wild leaps up and more often than not we do not even know its name.