Jared Diamond - The rise and fall of the third chimpanzee

Unfortunately, alternative models of human society are rapidly disappearing, and the tiiiie has passed when humans could try out new models in isolation. Surely there are no remaining uncontacted populations anywhere as large as the one encountered by Archbold's patrol on that August day of 1938. When I worked on New Guinea's Rouffaer River in 1979, missionaries nearby had just found a tribe of a few hundred nomads, who reported another uncontacted band five days' travel upstream. Small bands have also been turning up in remote parts of Peru and Brazil. However, at some point within this last decade of the Twentieth Century, we can expect the last first contact, and the end of the last separate experiment at designing human society. While that last first contact will not mean the end of human cultural diversity, much of which is proving capable of surviving television and travel, it certainly does mean a drastic reduction. That loss is to be mourned, for the reasons that I have just been discussing. But our xenophobia was tolerable only as long as our means to kill each other were too limited to bring about our fall as a species. When I try to think of reasons why nuclear weapons will not inexorably combine with our genocidal tendencies to break the records we have already set for genocide in the first half of the Twentieth Century, our accelerating cultural homogenization is one of the chief grounds for hope that I can identify. Loss of cultural diversity may be the price that we have to pay for survival.

The largest-scale human population shift of the past millenium has been the European conquest of the Americas and of Australia, formerly settled by other peoples. Why did conquest go in that direction rather than in the reverse direction? It was largely an accident of biogeography: Europeans inherited the most useful suite of wild plant and animal species suitable for. domestication, on which subsequent technological and political development depended.

Some of the most obvious features of our daily lives pose the hardest questions for scientists. If you look around you at most locations in the US or Australia, most of the people you see will be of European ancestry. At the same locations 500 years ago, everyone without exception would have been an American Indian in the US, or a native (aboriginal) Australian in Australia. Why is it that Europeans came to replace most of the native population of North America and Australia, instead of Indians or native Australians coming to replace most of the original population of Europe?

This question can be rephrased to ask: why was the ancient rate of technological and political development fastest in Eurasia, slower in the Americas (and in Africa south of the Sahara), and slowest in Australia? For example, in 1492 much of the population of Eurasia used iron tools, had writing and agriculture, had large centralized states with ocean-going ships, and was on the verge of industrialization. The Americas had agriculture, only a few large centralized states, writing in only one area, no ocean-going ships or iron tools, and were technologically and politically a few thousand years behind Eurasia. Australia lacked agriculture, writing, states, and ships, was still in a pre-first-contact condition, and used stone tools comparable to ones made over ten thousand years earlier in Eurasia. It was those technological and political differences—not the biological differences determining the outcome of competition among animal populations—that permitted Europeans to expand to other continents.

Nineteenth-century Europeans had a simple, racist answer to such questions. They concluded that they acquired their cultural head start through being inherently more intelligent, and that they therefore had a manifest destiny to conquer, displace, or kill 'inferior' peoples. The trouble with this answer is that it was not just loathsome and arrogant, but also wrong. It is obvious that people differ enormously in the knowledge they acquire, depending on their circumstances as they grow up. But no convincing evidence of genetic differences in mental ability among peoples has been found, despite much effort.

Because of this legacy of racist explanations, the whole subject of human differences in level of civilization still reeks of racism. Yet there are obvious reasons why the subject begs to be properly explained. Those technological differences led to great tragedies in the past 500 years, and their legacies of colonialism and conquest still powerfully shape our world today. Until we can come up with a convincing alternative explanation, the suspicion that racist genetic theories might be true will linger.

In this chapter I shall argue that continental differences in level of civilization arose from geography's effect on the development of our cultural hallmarks, not from human genetics. Continents differed in the resources on which civilization depended—especially, in the wild animal and plant species that proved useful for domestication. Continents also differed in the ease with which domesticated species could spread fr<&m one area to another. Even today, Americans and Europeans are painfully aware how distant geographical features, like the Persian Gulf or the Isthmus of Panama, affect our lives. But geography and biogeography have been moulding human lives even more profoundly, for hundreds of thousands of years. Why do I emphasize plant and animal species? As the biologist J. B. S. Haldane remarked, 'Civilization is based, not only on men, but on plants and animals. Agriculture and herding, though they also brought the disadvantages discussed in Chapter Ten, still made it possible to feed far more people per square mile of land than could live on the wild foods available in that same area. Storable food surpluses grown by some individuals permitted other individuals to devote themselves to metallurgy, manufacturing, writing—and to serving in full-time professional armies. Domestic animals provided not only meat and milk to feed people, but also wool and hides to clothe people, and power to transport people and goods. Animals also provided power to pull ploughs and carts, and thus to increase agricultural productivity greatly over that previously attainable by human muscle power alone.

As a result, the world's human population rose from about ten million around 10,000 BC, when we were all still hunter-gatherers, to over five billion today. Dense populations were prerequisite to the rise of centralized states. Dense populations also promoted the evolution of infectious diseases, to which exposed populations then evolved some resistance but other populations did not. All these factors determined who colonized and conquered whom. Europeans' conquest of America and Australia was due not to their better genes but to their worse germs (especially smallpox), more advanced technology (including weapons and ships), information storage through writing, and political organization—all stemming ultimately from continental differences in geography.

Let's start with the differences in domestic animals. By around 4000 BC western Eurasia already had its 'Big Five' domestic livestock that continue to dominate today: sheep, goats, pigs, cows, and horses. Eastern Asians domesticated four other cattle species that locally replace cows: yaks, water buffalo, gaur, and banteng. As already mentioned, these animals provided food, power, and clothing, while the horse was also of incalculable military value. (It was both the tank, the truck, and the jeep of warfare until the Nineteenth Century.) Why did American Indians not reap similar benefits by domesticating the corresponding native American mammal species, such as mountain sheep, mountain goats, peccaries, bison, and tapirs? Why did Indians mounted on tapirs, and native Australians mounted on kangaroos, not invade and terrorize Eurasia? The answer is that, even today, it has proved possible to domesticate only a tiny fraction of the world's wild mammal species. This becomes clear when one considers all the attempts that failed. Innumerable species reached the necessary first step of being kept captive as tame pets. In New Guinea villages I routinely find tamed possums and kangaroos, while I saw tamed monkeys and weasels in Amazonian Indian villages. Ancient Egyptians had tamed gazelles, antelopes, cranes, and even hyenas and possibly giraffes. Romans were terrorized by the tamed African elephants with which Hannibal crossed the Alps (not Asian elephants, the tame elephant species in circuses today).