cuts whenever money gets tight. In fact, archaeological research is one of the best bargains available to government planners. All over the world, we are launching developments that have great potential for doing irreversible damage, and that are really just more powerful versions of ideas put into operation by past societies. We cannot afford the experiment of developing five counties in five different ways and seeing which four counties get ruined. Instead, it will cost us much less in the long run if we hire archaeologists to find out what happened the last time, than if we go on making the same mistakes again. Here is just one example. The American Southwest has over 100,000 square miles of pinyon and juniper woodland that we are exploiting more and more for firewood. Unfortunately, the US Forest Service has little data available to help it calculate sustainable yields and recovery rates in that woodland. Yet the Anasazi already tried the experiment and miscalculated, with the result that the woodland still has not recovered in Chaco Canyon after over 800 years. Paying some archaeologists to reconstruct Anasazi firewood consumption would be cheaper than committing the same mistake and ruining 100,000 square miles of the US, as we may now be doing. Finally, let's face the touchiest question. Today, environmentalists view people who exterminate species and destroy habitats as morally bad. Industrial societies have jumped at any excuse to denigrate pre-industrial peoples, in order to justify killing them and appropriating their land. Are the purported new finds about moas and Chaco Canyon vegetation just pseudo-scientific racism that in effect is saying, Maoris and Indians dp not deserve fair treatment because they were bad? What has to be remembered is that it has always been hard for humans to know the rate at which they can safely harvest biological resources indefinitely, without depleting them. A significant decline in resources may not be easy to distinguish from a normal year-to-year fluctuation. It is even harder to assess the rate at which new resources are being produced. By the time that the signs of decline are clear enough to convince everybody, it may be too late to save the species or habitat. Thus, pre-industrial peoples who could not sustain their resources were guilty not of moral sins, but of failures to solve a really difficult ecological problem. Those failures were tragic, because they caused a collapse in lifestyle for the people themselves.
Tragic failures become moral sins only if one should have known better from the outset. In that regard there are two big differences between us and eleventh-century Anasazi Indians—those of scientific understanding, and literacy. We know, and they did not know, how to draw graphs that plot sustainable resource population size as a function of resource harvesting rate. We can read about all the ecological disasters of the past; the Anasazi could not. Yet our generation continues to hunt whales and clear tropical rainforest, as if no one had ever hunted moas or cleared pinyon and juniper woodland. The past was still a Golden Age, of ignorance, while the present is an Iron Age of wilful blindness.
From this point of view it is beyond understanding to see modern societies repeating the past's suicidal ecological mismanagement, with much more powerful tools of destruction in the hands of far more people. It is as if we had not already run that particular film many times before in human history, and as if we did not know the inevitable outcome. Shelley's sonnet 'Ozymandias' evokes Persepolis, Tikal, and Easter Island equally well; perhaps it will some day evoke to others the ruins of our own civilization.
I met a traveller from an antique land Who said: Two vast and trunkless legs of stone Stand in the desert. Near them, on the sand, Half sunk, a shattered visage lies, whose frown, And wrinkled lip, and sneer of cold command, Tell that its sculptor well those passions read Which yet survive, stamped on these lifeless things, The hand that mocked them and the heart that fed; And on the pedestal these words appear: 'My name is Ozymandias, king of kings: Look on my works, ye Mighty, and despair! Nothing beside remains. Round the decay Of that colossal wreck, boundless and bare The lone and level sands stretch far away.
EIGHTEEN
BLITZKRIEG AND THANKSGIVING IN THE NEW WORLD
The United States devote two national holidays, Columbus Day and Thanksgiving Day, to celebrating dramatic moments in the European 'discovery' of the New World. No holidays commemorate the much earlier actual discovery by Indians. Yet archaeological excavations suggest that, in drama, that earlier discovery dwarfs the adventures of Christopher Columbus and of the Plymouth Pilgrims. Within perhaps as little as a thousand years after finding a way through an Arctic ice sheet and crossing the present border between the US and Canada, Indians had swept down to the tip of Patagonia and populated two productive and unexplored continents. The Indians' march southwards was the greatest range expansion in the history
The sweep southwards was marked by another drama. When Indian hunters arrived, they found the Americas teeming with big mammals that are now extinct: elephant-like mammoths and mastodonts, ground sloths weighing up to three tons, armadillo-like glyptodonts weighing up to one ton, bear-sized beavers, and saber-toothed cats, plus American lions, cheetahs, camels, horses, and many others. Had those beasts survived, today's tourists in Yellowstone National Park would be watching mammoths and lions along with the bears and bison. The question of what happened at that moment of hunters-meet-beasts is still highly controversial among archaeologists and paleontologists. According to the interpretation that seems most plausible to me, the outcome was a blitzkrieg in which the beasts were quickly exterminated—possibly within a mere ten years at any given site. If that view is correct, it would have been the most concentrated extinction of big animals since an asteroid collision (it is believed) knocked off the dinosaurs sixty-five million years ago. It would also have been the first of the series of blitzkriegs that marred our supposed Golden Age of environmental innocence (Chapter Seventeen), and that have remained a human hallmark ever since. That dramatic confrontation came as the finale to a long epic in which humans, spreading out of their centre of origin in Africa, occupied all the other habitable continents. Our African ancestors expanded to Asia and Europe around a million years ago, and from Asia to Australia around 50,000 years ago, leaving North and South America as the last habitable continents still without
From Canada to Tierra del Fuego, American Indians today are physically more homogeneous than the inhabitants of any other continent, implying that they arrived too recently to have become very diverse genetically. Even before archaeology uncovered evidence of the first Indians, it was clear that they must have originated from Asia, because modern Indians look similar to Asiatic Mongoloids. Much recent evidence from genetics and anthropology has made that conclusion certain. A glance at a map shows that by far the easiest route from Asia to America is across the Bering Straits separating Siberia from Alaska. The last such land bridge existed (with a few brief interruptions) from about 25,000 to 10,000 years ago.
However, colonization of the New World required more than a land bridge—there had to be people living at the Siberian end of the bridge. Because of its harsh climate the Siberian Arctic, too, was not colonized until late in human history (Chapter Two). Those colonists must have come from the cold temperate zones of Asia or Eastern Europe, as exemplified by stone-age hunters who lived in what is now the Ukraine and who built their houses out of neatly stacked bones of mammoths. By at least 20,000 years ago there were mammoth hunters in the Siberian Arctic as well, and by around 12,000 years ago stone tools similar to those of the Siberian hunters appear in Alaska's archaeological record.
After traversing Siberia and the Bering Straits, the ice-age hunters were still separated by one more barrier from their future hunting grounds in the US: a broad ice cap like that covering
Greenland today, but stretching coast-to-coast across Canada. At intervals during the ice ages a narrow, ice-free, north/south corridor opened through this ice cap, just east of the Rocky Mountains. One such corridor closed around 20,000 years ago, but there had apparently as yet been no human in Alaska waiting to cross it. However, when the corridor next opened around 12,000 years ago, the hunters must have been ready, for their tell-tale stone tools appear soon thereafter not only at the south end of the corridor near Edmonton (Alberta) but also elsewhere south of the ice cap. At that point, hunters met America's elephants and other great beasts, and
