thoughts. There is no single-purpose 'best' language; instead, different languages are better suited for different purposes. For instance, it may not have been an accident that Plato and Aristotle wrote in Greek, while Kant wrote in German. The grammatical particles of those two languages, plus their ease in forming compound words, may have helped make them the pre-eminent languages of Western philosophy. Another example, familiar to all of us who studied Latin, is that highly inflected languages (ones in which word endings suffice to indicate sentence structure) can use variations of word order to convey nuances impossible with English. Our English word order is severely constrained by having to serve as the main clue to sentence structure. If English becomes a world language, that would not be because English was necessarily the best language for diplomacy.
The range of cultural practices in New Guinea also eclipses that within equivalent areas elsewhere in the modern world, because isolated tribes were able to live out social experiments that others would find utterly unacceptable. Forms of self-mutilation and cannibalism varied from tribe to tribe. At the time of first contact, some tribes went naked, others concealed their genitals and practised extreme sexual prudery, and still others (including the Grand Valley Dani) flagrantly advertised the penis and testes with various props. Child-rearing practices ranged from extreme permissiveness (including freedom for Fore babies to grab hot objects and burn themselves), through punishment of misbehaviour by rubbing a Baham child's face with stinging nettles, to extreme repression resulting in Kukukuku child suicide. Barua men pursued institutionalized bisexuality by living in a large, communal, homosexual house with the young boys, while each man had a separate, small, heterosexual house for his wife and daughters and infant sons. Tudawhes instead had two-storey houses in which women, infants, unmarried girls, and pigs lived in the lower storey, while men and unmarried boys lived in the upper storey accessed by a separate ladder from the ground. We would not mourn the shrinking cultural diversity of the modern world if it only meant the end of self-mutilation and child suicide. But the societies whose cultural practices have now become dominant were selected only for economic and military success. Those qualities are not necessarily the ones that foster happiness or promote long-term human survival. Our consumerism and our environmental exploitation serve us well at present but bode ill for the future. Features of American society that already rate as disasters in anyone's book include our treatment of old people, adolescent turmoil, abuse of psychotropic chemicals, and gross inequality. For each of these problem areas, there are (or were before first contact) many New Guinea societies that found far better solutions to the same issues.
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.
FOURTEEN
ACCIDENTAL CONQUERORS
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
