Because diseases have been the biggest killers of people, they have also been decisive shapers of history. Until World War II, more victims of war died of war-borne microbes than of battle wounds.
Societies with effective conflict resolution, sound decision making, and harmonious economic redistribution can develop better technology, concentrate their military power, seize larger and more productive territories, and crush autonomous smaller societies one by one.
By comparison with high population densities in Japan and Java and China, Australia looked empty and attractive to Asian invasion – so thought the prime minister, but Asians themselves did not think that way.
That was part of the reason why my 1959 crisis was so traumatic to me: it was my first acute life crisis. By comparison, my 1980 and 2000 professional crises were un-traumatic. I did eventually switch career directions from membrane physiology to evolutionary physiology around 1980, and from physiology to geography after 2000. But those decisions weren’t painful, because I had come to assume from my previous experience that things would probably turn out OK.
Australia stands out from all the other continents: the differences between Eurasia, Africa, North America, and South America fade into insignificance compared with the differences between Australia and any of those other landmasses. Australia is by far the driest, smallest, flattest, most infertile, climatically most unpredictable, and biologically most impoverished continent.
The histories of the Fertile Crescent and China also hold a salutary lesson for the modern world: circumstances change, and past primacy is no guarantee of future primacy. One might even wonder whether the geographical reasoning employed throughout this book has at last become wholly irrelevant in the modern world, now that ideas diffuse everywhere instantly on the Internet and cargo is routinely airfreighted overnight between continents.
In Africa as elsewhere in the world, some peoples were much “luckier” than others, in the suites of domesticable wild plant and animal species that they inherited from their environment.
Traditionally, the sole animal raised on a large scale for food in Japan has been the pig; sheep and goats have never been significant, and cattle were raised for pulling plows and carts but not for food. Japanese-raised beef remains a luxury food of the wealthy few, selling for up to $100 per pound.
As the Bitterroot’s water commissioner, Vern Woolsey, explained it succinctly to me, “Whenever you have a source of water and more than two people using it, there will be a problem. But why fight about water? Fighting won’t make more water!
In short, the explanation of why Iceland became the European country with the most serious ecological damage is not that cautious Norwegian and British immigrants suddenly threw caution to the winds when they landed in Iceland, but that they found themselves in an apparently lush but actually fragile environment for which their Norwegian and British experience had failed to prepare them.
Eurasia’s east–west major axis, unlike the Americas’ north–south major axis, permitted diffusion without change in latitude and associated environmental variables. In contrast to Eurasia’s consistent east–west breadth, the New World was constricted over the whole length of Central America and especially at Panama.
Those historical inequalities have cast long shadows on the modern world, because the literate societies with metal tools have conquered or exterminated the other societies.
The UCLA historian Christopher Ehret has applied this linguistic approach to determining the sequence in which domestic plants and animals became utilized by the people of each African language family. By a method termed glotto-chronology, based on calculations of how rapidly words tend to change over historical time, comparative linguistics can even yield estimated dates for domestications or crop arrivals.
The Anasazi collapse and other southwestern collapses offer us not only a gripping story but also an instructive one for the purposes of this book, illustrating well our themes of human environmental impact and climate change intersecting, environmental and population problems spilling over into warfare, the strengths but also the dangers of complex non-self-sufficient societies dependent on imports and exports, and societies collapsing swiftly after attaining peak population numbers and power.
Flexibility can come from the freedom of having been allowed to make one’s own choices as one was growing up.
The overall picture for Easter is the most extreme example of forest destruction in the Pacific, and among the most extreme in the world: the whole forest gone, and all of its tree species extinct. Immediate consequences for the islanders were losses of raw materials, losses of wild-caught foods, and decreased crop yields.
That might have led to an Easter-Island–like catastrophe. Instead, over the course of the next two centuries Japan gradually achieved a stable population and much more nearly sustainable resource consumption rates. The shift was led from the top by successive shoguns, who invoked Confucian principles to promulgate an official ideology that encouraged limiting consumption and accumulating reserve supplies in order to protect the country against disaster.
Those protohumans are generally known as Australopithecus africanus, Homo habilis, and Homo erectus, which apparently evolved into each other in that sequence.
We are increasingly seeing a similar phenomenon on a global scale today, as illegal immigrants from poor countries pour into the overcrowded lifeboats represented by rich countries, and as our border controls prove no more able to stop that influx than were Gardar’s chiefs and Los Angeles’s yellow tape.
THE DISCIPLINE OF history is generally not considered to be a science, but something closer to the humanities. At best, history is classified among the social sciences, of which it rates as the least scientific.
My own impression, from having divided my life between United States cities and New Guinea villages, is that the so-called blessings of civilization are mixed. For example, compared with hunter-gatherers, citizens of modern industrialized states enjoy better medical care, lower risk of death by homicide, and a longer life span, but receive much less social support from friendships and extended families.