we exterminate some prey species when we colonize a new environment or acquire new destructive power. Like some animal populations that suddenly escaped their former limits on growth, we risk destroying ourselves by destroying our resource base. What about the view that we were in a state of relative ecological equilibrium until the Industrial Revolution, and that only since then have we begun seriously to exterminate species and overexploit our environment? That Rousseau-esque fantasy will be taken up in the three chapters of Part Five. Chapter Seventeen examines the widespread belief in a former Golden Age, when we supposedly lived as noble savages practising a conservation ethic and in harmony with Nature. In reality, mass extinctions have coincided with each major extension of human lebensraum during the last ten thousand years and possibly much longer. Our direct responsibility for the extinctions is clearest in the case of the most recent expansions, where the evidence is still fresh—Europeans' expansion over the globe since 1492, and the earlier colonization of oceanic islands by Polynesians and the Malagasy. Older expansions such as the first human occupation of the Americas and Australia were also accompanied by mass extinctions, though the trail of evidence has had much more time to fade and so conclusions about cause and effect are necessarily weaker. It is not just the case that the Golden Age was blackened by mass extinctions. While no large human population has eaten itself out of existence, some populations on small islands have done so, and many large populations have damaged their resources to the point of economic collapse. The clearest examples come from isolated cultures, such as the collapses of Easter Island and Anasazi civilizations. But environmental factors also drove the major shifts in Western civilization, including the successive collapses of the Middle Eastern, then Greek, then Roman hegemonies. Self-destructive abuse of our environment, far from being a modern invention, has long been a prime mover of human history. Chapter Eighteen looks more closely at the biggest, most dramatic, and most controversial of these
'Golden Age mass extinctions'. Around 11,000 years ago most of the large mammals of two entire continents, North America and South America, became extinct. Around the same time appears the first unequivocal evidence for human occupation of the Americas, by the ancestors of American Indians. It was the biggest expansion of human territory since Homo erectus spread out of Africa to colonize Europe and Asia a million years ago. The temporal coincidence between the first Americans and the last big American mammals, the lack of mass extinctions elsewhere in the world at that same time, and proofs that some of the now-extinct beasts were hunted have suggested what is termed the New World blitzkrieg hypothesis. According to this interpretation, as the first wave of human hunters multiplied and spread from Canada to Patagonia, they encountered big animals that had never seen humans before, and they exterminated as they marched. However this theory's critics are at least as numerous as its backers; Chapter Eighteen 'will try to make sense of the debate.
The concluding chapter will seek to put approximate numbers on the count of species that we have already driven into extinction. We shall start with the firmest numbers: the species whose extinctions occurred in modern times and were well documented, and for which the search for survivors has been so thorough as to leave no doubt that there are no survivors. Next come estimates of three less certain numbers: the modern species that have not been seen alive for some time and that became extinct before anyone was aware of it; the modern species that have not even been 'discovered' and received a name; and the species that humans exterminated before the rise of modern science. That background will let us appraise the main mechanisms by which we exterminate, and the number of species that we are likely to exterminate within my sons' lifetime—if we proceed at our current rate.
SEVENTEEN
THE GOLDEN AGE THAT NEVER WAS
We cling to belief in a Rousseau-esque fantasy that the past was a Golden Age of environmentalism, when people lived in harmony with Nature. In reality, human societies, including those of stone-age farmers and possibly of hunter-gatherers as well, have been undermining their own subsistence by exterminating species and damaging environments for thousands of years. We differ from our supposedly conservationist forebears only in our greater numbers, more potent technology for inflicting damage, and access to written histories from which we refuse to learn.
Every part of the earth is sacred to my people. Every shining pine needle, every sandy shore, every mist in the dark woods, every clearing and humming insect is holy in the memory and experience of my people. . The white man… is a stranger who conies in the night and takes from the land whatever he needs. The earth is not his brother but his enemy. . Continue to contaminate your bed, and you will one night suffocate in your own waste. [From a letter written in 1855 to President Franklin Pierce, by Chief Seattle of the Duwanish tribe of American Indians.]
Environmentalists sickened by the damage that industrial societies are wreaking on the world often look to the past as a Golden Age. When Europeans began to settle America, the air and rivers were pure, the landscape green, the Great Plains teeming with bison. Today we breathe smog, worry about toxic chemicals in our drinking water, pave over the landscape, and rarely see any large wild animal. Worse is surely to come. By the time that my young sons reach retirement age, half of the world's species will be extinct, the air radioactive, and the seas polluted with oil. Undoubtedly, two simple reasons go a long way towards explaining our worsening mess: modern technology has far more power to cause havoc than did the stone axes of the past, and far more people are alive now than ever before. But a third factor may also have contributed, a change in attitudes. Unlike modern city- dwellers, at least some pre-industrial peoples—like the Duwanish, whose chief I quoted—depend on and revere their local environment. Stories abound of how such peoples are in effect practising conservationists. As a New Guinea tribesman once explained to me, 'It's our custom that if a hunter one day kills a pigeon in one direction from the village, he waits a week before hunting for pigeons again, and then goes in the opposite direction. We are only beginning to realize how sophisticated are the conservationist policies of so-called 'primitive' peoples. For instance, well-intentioned foreign experts have made deserts out of large areas of Africa. In those same areas, local herders had thrived for uncounted millennia, by making annual nomadic migrations which ensured that land never became overgrazed.
The nostalgic outlook shared until recently by most of my environmentalist colleagues and myself is part of a human tendency to view the past as a Golden Age in many other respects. A famous exponent of this outlook was the eighteenth-century French philosopher Jean-Jacques Rousseau, whose Discourse on the Origin of Inequality traced our degeneration from the Golden Age to the human misery that Rousseau saw around him. When eighteenth-century European explorers encountered pre-industrial peoples like Polynesians and American Indians, those peoples became idealized in European salons as 'noble savages' living in a continued Golden Age, untouched by-such curses of civilization as religious intolerance, political tyranny, and social inequality. Even now, the days of classical Greece and Rome are widely considered to be the Golden Age of western civilization. Ironically, the Greeks and Romans also saw themselves as degenerates from a past Golden Age. I can still recite half-consciously those lines of the Roman poet Ovid that I memorized in tenth-grade Latin, 'Aurea prima sata est aetas, quae viydice nullo. . ('First came the Golden Age, when men were honest and righteous of their own free will. . ) Ovid went on to contrast those virtues with the rampant treachery and warfare of his own times. I have no doubt that any humans still alive in the radioactive soup of the Twenty-second Century will write equally nostalgically about our own era, which will then seem untroubled by comparison. Given this widespread belief in a Golden Age, some recent discoveries by archaeologists and paleontologists have come as a shock. It is now clear that pre-industrial societies have been exterminating species, destroying habitats, and undermining their own existence for thousands of years. Some of the best documented examples involve Polynesians and American Indians, the very peoples most often cited as exemplars of environmentalism. Needless to say, this revisionist view is hotly contested, not only in the halls of academia but also among lay people in Hawaii, New Zealand, and other areas with large Polynesian or Indian minorities. Are the new 'discoveries' just one more piece of racist pseudo-science by which white settlers seek to justify dispossessing indigenous peoples? How could the discoveries be reconciled with all the evidence for conservationist practices by modern pre-industrial peoples? If the discoveries were true, could we use them as case histories to help us predict the fate that our own environmental policies may bring upon us? Could the recent findings explain some otherwise
