The Third Chimpanzee for Young People

by Jared Diamond

  We know that there has been much convergent evolution among species on Earth. There should be some convergence between earth’s species and those elsewhere. Radio communication has evolved here only once, but convergent evolution leads us to expect that it will have emerged on some other planets as well. The group of birds called woodpeckers shows us, however, that convergence is not universal.

  Woodpecking is a terrific lifestyle based on digging holes in live wood and prying off pieces of bark to eat tree sap and insects. It means dependable food sources all year round, and sheltered nest cavities in the holes. Not surprisingly, woodpeckers are very successful birds, widespread over most of the world, with nearly two hundred species, many of them common.

  How hard is it to evolve to become a woodpecker? Not very. Woodpeckers are related to several other bird groups. The woodpeckers do have special adaptations for drilling and prying wood. These adaptations include chisellike bills, nostrils protected with feathers to keep out sawdust, thick skulls, strong neck muscles, and short, stiff tails to press against tree trunks as a brace.

  None of the woodpeckers’ adaptations is remotely as complicated as building a radio, and all of them are based on features shared by other birds. You might expect the whole package of woodpecking to have evolved repeatedly, with many large groups of animals that drill into live wood for food or nest sites. But nothing else has evolved to enjoy the splendid opportunities of the woodpecker lifestyle. Not all splendid opportunities are seized. if woodpecking evolved only once in the history of life on earth, should we expect radio building to have evolved more than once in the universe?

  Biology and the Evolution of Radios

  If radio building were like woodpecking, some species might have evolved certain elements of the package, even if we were the only species to evolve the complete package. We might have found turkeys building transmitters but no receivers, or kangaroos building receivers but no transmitters. The fossil record might reveal five-watt transmitters in the beds of ancient seas, two-hundred-watt transmitters among the bones of the last dinosaurs, and five-hundred-watt transmitters used by sabertoothed cats, until finally humans boosted the power enough to send radio signals into space.

  None of that happened. Two centuries ago, modern humans didn’t even have the ideas that would lead to radios. The first practical experiments didn’t begin until 1888. Only one of the billions of species that have existed on earth showed any tendency toward radio building, and even that species failed to build a radio for the first 69,999/70,000ths of its 7-million-year history. A visitor from outer space who came to Earth as recently as 1800 would have written off any hope of radios being invented here.

  Radios are pretty specific. What about more general qualities necessary to make radios? Chief among those qualities are intelligence and dexterity, which is the ability to control the fine manipulations of objects. Very few animals on Earth have had much of either. No animal has acquired as much of them as humans have.

  The only other species that have acquired a little intelligence and dexterity are bonobos and common chimpanzees. In terms of species survival, those two have been rather unsuccessful. Earth’s really successful species have been rats and beetles, which are present everywhere in great numbers. But rats and beetles owe their worldwide presence and huge population sizes to things other than intelligence and dexterity.

  The Silence Is Deafening—Thank Goodness

  The last variable in the Green Bank formula has to do with how long advanced technological civilizations last. The intelligence and dexterity needed to build radios are useful for other purposes, including making devices for destroying the environment and for killing. Here on earth, we are now stewing in our civilization’s juices. Half a dozen countries have the means for bringing us all to a quick end, and other countries are eagerly seeking to get their hands on those means.

  It was pure chance that we developed radios at all, and even more of a fluke that we developed radios before we invented the technology that could end us all. Our history suggests that any civilizations that might arise elsewhere are short-lived. They could have reversed their progress overnight, just as we now risk doing.

  We’re very lucky that that’s so. i find it mind-boggling that astronomers who want to spend hundreds of millions of dollars on the search for extraterrestrial life have never thought seriously about what would happen if we found it—or it found us. Would we and the aliens sit down together for fascinating discussions? Would they share their advanced technology with us?

  Here, again, our experience on Earth offers useful guidance. We’ve already found two species that are very intelligent but less technologically advanced than we are: the bonobo and the common chimpanzee. Has our response been to sit down and try to communicate with them? In a few cases, yes, but mostly it has been to shoot them, dissect them, cut off their hands for trophies, put them in cages, infect them with diseases as medical experiments, and destroy or take over their habitats. Throughout history, human explorers who discovered technically less advanced humans responded by shooting them, devastating their populations with new diseases, and destroying or seizing their territory.

  Any advanced terrestrials who found us would surely treat us the same way. If there really are any radio civilizations within listening distance of us, let’s turn off our own transmitters and try to escape being found, or we’re doomed.

  Fortunately for us, the silence from outer space is deafening. Out there, in the billions of galaxies with billions of stars, there must be some transmitters, but not many, and they won’t last long. What woodpeckers teach us about flying saucers is that we’re unlikely ever to see one. For all practical purposes, we’re alone in a crowded universe. Thank goodness!

  PART FOUR

  WORLD CONQUERORS

  Members of the Archbold Expedition atop their seaplane on a New Guinea lake. This 1938 expedition broke the long isolation of the Dani people, who had lived in the Grand Valley of western New Guinea, unknown to the outside world, for centuries.

  LANGUAGE, AGRICULTURE, AND ADVANCED technology are among the cultural hallmarks that make humans unique. They’ve allowed us to spread over the globe and become world conquerors. In the process ofworld conquest, our species underwent a basic change in the way different populations of people related to one another. This part of the book explores how and why that change happened—and what it might mean for our future.

  Most animal species live across only a small part ofthe earth’s surface. Hamilton’s frog, for example, is limited to one forest patch of 37 acres plus one rock pile covering 720 square yards in New Zealand. Humans used to occupy just warm, nonforested areas of Africa. By 50,000 years ago our range— that is, the part ofthe planet we occupied—was still limited to tropical and warm parts of Africa and Eurasia. Then we expanded to Australia and New Guinea (around 50,000 years ago), cold parts of Europe (by 30,000 years ago), Siberia (by 20,000 years ago), North and South America (around 11,000 years ago), and Polynesia (between 3,600 and 1,000 years ago). Today we occupy or at least visit all lands and the surface of all the oceans, and we are starting to probe into space and the ocean’s depths.

  Our expansion didn’t just mean moving into unoccupied areas. It also involved human populations conquering, driving out, or killing other human populations. Some groups colonized the territory of others, settling on the land and taking military or political control of it. We became conquerors of one another as well as of the world. Our expansion reveals another human hallmark: our tendency to kill members of our own species in large numbers. This grew out of traits found in the animal world, but we’ve taken it far beyond its animal limits. Our tendency to kill one another is one ofthe possible reasons that our species might fall.

  In the next three chapters we’ll see how the expansion of our range led to a flowering of languages and cultures. We’ll explore the question of why some people gained advantages that let them conquer other people, and we’ll examine one of the largest s
hifts in recent history: the expansion of modern Europeans into the Americas and Australia.

  Finally, we’ll look at one of humanity’s darker traits, xenophobia, which is fear of people who are different from us. Xenophobia has roots in the competition that occurs everywhere in the animal world, but only humans have developed weapons that can kill large numbers of our own species at a distance. A look at the history of human genocide shows the ugly tradition that gave rise to the horrors of modern war.

  CHAPTER 11

  THE LAST FIRST CONTACTS

  A LONG STAGE OF HUMAN HISTORY DREW CLOSER to its end on August 4, 1938. On that date a scientific expedition from the American Museum of Natural History became the first outsiders to enter the western part of the Grand Valley in New Guinea, a long, lush valley hidden from the island’s coasts by steep walls of knife-edged, jungle-covered mountain ridges. The area was long thought to be uninhabited, but to everyone’s astonishment, the valley proved to be densely populated by fifty thousand people living in the Stone Age. No one had known they existed, and they had no idea that there were other people and an outside world.

  The scientific expedition had traveled into the interior of New Guinea to search for unknown birds and mammals. It found an unknown human society, now known as the Dani people. The 1938 entry into the Grand Valley was one of the last first contacts between an advanced culture and a large population with no knowledge of the outside world. It was a landmark in the process by which humanity changed from thousands of tiny societies to world conquerors with world knowledge. To see the significance of that 1938 meeting, we need to understand what “first contact” means—and how it has changed human societies.

  The World before First Contact

  Most animal species occupy a geographic range that is limited to a small fraction of the earth’s surface. When animals do occur on several continents, individuals from the different continents do not visit each other. Instead, each continent, and usually each small part of a continent, has its own distinctive population. That population has contacts with its close neighbors but not with distant members of the same species.

  The fact that populations have limited geographic ranges is reflected in geographic variations within species. Populations of the same species in different geographic areas tend to evolve into different-looking subspecies, because most breeding remains within the same population. For example, there are two subspecies of lowland gorillas in Africa: eastern and western. No east African lowland gorilla has ever turned up in West Africa, and no West African lowland gorilla has been seen in east Africa. Although they belong to the same species, the two subspecies look different enough for biologists to be able to identify them on sight.

  Humans have been typical animals throughout most of our evolutionary history, meaning that populations of people have tended to remain inside distinct geographical areas. each human population became genetically molded to its area’s climate and diseases. in addition, differences in language and culture kept humans from freely mixing.

  We think of ourselves as travelers, but we were just the opposite for several million years. every human group was ignorant of the world beyond its own lands and those of its immediate neighbors. While most peoples had trade relations with their neighbors, some groups thought they were the only humans in existence. Perhaps the smoke of fires on the horizon, or an empty canoe floating down the river, proved the existence of other people. But to venture out of one’s own territory to meet those strangers, even if they lived only a few miles away, seemed suicidal. Groups had a no-trespassing mentality. The notion of accepting unrelated strangers was as unthinkable as the idea that such a stranger might show up on your doorstep.

  Only in the past few thousand years have changes in political systems and technology allowed some people to travel far, to meet people of other cultures, and to learn about places and peoples they had not personally visited. This process speeded up with Christopher Columbus’s arrival in the Americas in 1492. Today there remain only a few tribes, in New Guinea and South America, that still await their first contact with remote outsiders. Yet the world before first contact—a world that is finally ending within our generation—holds the key to the great diversity in human cultures.

  Isolation and Diversity

  Today, thanks to the Internet, movies, and TV, we can picture parts of the world we haven’t visited. We can read about them in books. Language barriers no longer block the flow of information. Most villages that still speak minor languages contain at least one person who speaks one of the world’s major languages, such as english. Almost every village in the world has received fairly direct accounts of the outside world, and has given the outside world accounts of itself.

  Precontact peoples had no way to picture the outside world or learn about it directly. information arrived, if it arrived at all, by way of long chains of accounts passed along by many people, translated into various languages along the way, with accuracy lost at each step. The highlanders of New Guinea, for example, knew nothing of the ocean a hundred miles away, or of the white men who had been prowling their coasts for several centuries. First contact had a powerful effect on the highlanders—one that is hard for those of us living in the modern world to imagine.

  First contact revolutionized the highlanders’ material culture by bringing such items as steel axes, which were immediately recognized as better than stone axes. Later came missionaries and government administrators, who changed the highlanders’ culture by ending long-standing practices such as cannibalism, tribal war, and marriage of one man to multiple wives. Tribespeople sometimes voluntarily gave up their old ways in favor of the new goods and practices they saw. But there was also a deeper revolution in the highlanders’ view of the universe. They and their neighbors were no longer the only humans, with the only way of life.

  The scientists’ entry into the Grand Valley in 1938 was a turning point for the Dani. It was also part of a turning point in human history. What difference did it make that all human groups used to live in relative isolation, waiting for first contact, while only a few such groups remain today? To glimpse the answer to that question, we can compare places whose isolation ended long ago with areas where groups remained isolated into modern times. We can also study the rapid changes that have followed first contacts throughout history. These comparisons suggest that contact between distant peoples gradually wiped out much of the cultural diversity that had developed during thousands of years of isolation.

  ART IN FLAMES

  FOR A GOOD EXAMPLE OF HOW ISOLATION increases cultural diversity, while contact means less cultural diversity, we can look at the range of art in New Guinea before and after contact with the rest of the world.

  Styles of sculpture, music, and dance used to vary greatly from village to village. Some villagers along the Sepik River and in the Asmat swamps produced wood carvings that are now world-famous because of their quality. But New Guinea villagers have been increasingly pressured or lured into abandoning their artistic traditions. When I visited an isolated small tribe of 578 people in 1965, for example, the missionary who controlled the only store had just manipulated the people into burning all their art—which he called “heathen artifacts.”

  Artworks such as this carving (made in New Guinea in the late nineteenth or early twentieth century) are prized by collectors and museums—but many have been destroyed, and the art of making them lost, as the diversity of cultures around the world shrinks.

  On my first visit to remote New Guinea villages in 1964, I heard log drums and traditional songs. On my visits in the 1980s, I heard guitars, rock music, and battery-operated boom boxes. Anyone who has seen the Asmat carvings at New York’s Metropolitan Museum of Art, or who has heard a duet played on log drums at breathtaking speed, can appreciate the enormous tragedy of art lost after first contact.

  The Extinction of Languages

  Cultural diversity is represented in diversity of languages—and there has been a massive loss of lan
guages. europe today has about fifty languages. Most of them belong to a single family of languages, called indo-european. in contrast, New Guinea, with less than one-tenth of europe’s area and less than one-hundredth of its population, has hundreds of languages. Many of them are unrelated to any other known language in New Guinea or elsewhere! The average New Guinea language is spoken by a few thousand people who live within ten miles of each other.

  That’s what the world used to be like, with each isolated tribe having its own language, until the rise of agriculture allowed a few groups to expand and spread their language over large areas. it was only about six thousand years ago that the indo-european language family began to expand, leading to the end of almost all earlier languages in western europe. The same thing happened in Africa within the last few thousand years, when the Bantu language family exterminated most other languages of Africa south of the Sahara Desert. in North and South America, hundreds of Indian languages have become extinct in recent centuries.

  Isn’t language loss a good thing, because fewer languages make it easier for the world’s people to communicate? Maybe, but it’s a bad thing in other ways. Languages differ in structure and vocabulary. They also differ in how they express feelings, relationships among events, and personal responsibility. They differ in how they shape our thoughts. There’s no single “best” language. Instead, different languages are better suited for different purposes. When a language goes extinct, we lose a window into the unique worldview of the people who once spoke it.