Guns, Germs & Steel

explanations. Why didn't capitalism flourish in Native Mexico, mercantil-

WHY ISWORLDHISTORY LIKE AN ONION? • I I
ism in sub-Saharan Africa, scientific inquiry in China, advanced technology in Native North America, and nasty germs in Aboriginal Australia? If one responds by invoking idiosyncratic cultural factors—e.g., scientific inquiry supposedly stifled in China by Confucianism but stimulated in western Eurasia by Greek of Judaeo-Christian traditions—then one is continuing to ignore the need for ultimate explanations: why didn't traditions like Confucianism and the Judaeo-Christian ethic instead develop in western Eurasia and China respectively? In addition, one is ignoring the fact that Confucian China was technologically more advanced that western Eurasia until about a.d. 1400.
It is impossible to understand even just western Eurasian societies themselves, if one focuses on them. The interesting questions concern the distinctions between them and other societies. Answering those questions requires us to understand all those other societies as well, so that western Eurasian societies can be fitted into the broader context.
Some readers may feel that I am going to the opposite extreme from conventional histories, by devoting too little space to western Eurasia at the expense of other parts of the world. I would answer that some other parts of the world are very instructive, because they encompass so many societies and such diverese societies within a small geographical area. Other readers may find themselves agreeing with one reviewer of this book. With mildly critical tongue in cheek, the reviewer wrote that I seem to view world history as an onion, of which the modern world constitutes only the surface, and whose layers are to be peeled back in the search for historical understanding. Yes, world history is indeed such an onion! But that peeling back of the onion's layers is fascinating, challenging—and of overwhelming importance to us today, as we seek to grasp our past's lessons for our future.

Chapter One: Up To The Starting Line
A suitable starting point from which to compare historical developments on the different continents is around 11,000 B.C.(*) This date corresponds approximately to the beginnings of village life in a few parts of the world, the first undisputed peopling of the Americas, the end of the Pleistocene Era and last Ice Age, and the start of what geologists term the Recent Era. Plant and animal domestication began in at least one part of the world within a few thousand years of that date. As of then, did the people of some continents already have a head start or a clear advantage over peoples of other continents?
If so, perhaps that head start, amplified over the last 13,000 years, provides the answer to Yali's question. Hence this chapter will offer a whirlwind tour of human history on all the continents, for millions of years, from our origins as a species until 13,000 years ago. All that will now be summarized in less than 20 pages. Naturally, I shall gloss over details and mention only what seem to me the trends most relevant to this book.
Our closest living relatives are three surviving species of great ape: the gorilla, the common chimpanzee, and the pygmy chimpanzee (also known as bonobo). Their confinement to Africa, along with abundant fossil evidence, indicates that the earliest stages of human evolution were also played out in Africa. Human history, as something separate from the history of animals, began there about 7 million years ago (estimates range from 5 to 9 million years ago). Around that time, a population of African apes broke up into several populations, of which one proceeded to evolve into modern gorillas, asecond into the two modern chimps, and the third into humans. The gorilla line apparently split off slightly before the split between the chimp and the human lines.
Fossils indicate that the evolutionary line leading to us had achieved a substantially upright posture by around 4 million years ago, then began to increase in body size and in relative brain size around 2.5 million years ago. Those protohumans are generally known as Australopithecus africanus, Homo habilis, and Homo erectus, which apparently evolved into each other in that sequence. Although Homo erectus, the stage reached around 1.7 million years ago, was close to us modern humans in body size, its brain size was still barely half of ours. Stone tools became common around 2.5 million years ago, but they were merely the crudest of flaked or battered stones. In zoological significance and distinctiveness, Homo erectus was more than an ape, but still much less than a modern human.
All of that human history, for the first 5 or 6 million years after our origins about 7 million years ago, remained confined to Africa. The first human ancestor to spread beyond Africa was Homo erectus, as is attested by fossils discovered on the Southeast Asian island of Java and conventionally known as Java man (see Figure 1.1).

The oldest Java 'man' fossils-of course, they may actually have belonged to a Java woman-have usually been assumed to date from about a million years ago. However, it has recently been argued that they actually date from 1.8 million years ago. (Strictly speaking, the name Homo erectus belongs to these Javan fossils, and the African fossils classified as Homo erectus may warrant a different name.) At present, the earliest unquestioned evidence for humans in Europe stems from around half a million years ago, but there are claims of an earlier presence. One would certainly assume that the colonization of Asia also permitted the simultaneous colonization of Europe, since Eurasia is a single landmass not bisected by major barriers.
That illustrates an issue that will recur throughout this book. Whenever some scientist claims to have discovered 'the earliest X'-whether X is the earliest human fossil in Europe, the earliest evidence of domesticated corn in Mexico, or the earliest anything anywhere-that announcement challenges other scientists to beat the claim by finding something still earlier. In reality, there must be some truly 'earliest X,' with all claims of earlier X's being false. However, as we shall see, for virtually any X, every year brings forth new discoveries and claims of a purported still earlier X, along with refutations of some or all of previous years' claims of earlier X. It often takes decades of searching before archaeologists reach a consensus on such questions.
By about half a million years ago, human fossils had diverged from older Homo erectus skeletons in their enlarged, rounder, and less angular skulls. African and European skulls of half a million years ago were sufficiently similar to skulls of us moderns that they are classified in our species, Homo sapiens, instead of in Homo erectus. This distinction is necessarily arbitrary, since Homo erectus evolved into Homo sapiens. However, these early Homo sapiens still differed from us in skeletal details, had brains significantly smaller than ours, and were grossly different from us in their artifacts and behavior. Modern stone-tool-making peoples, such as Yali's great-grandparents, would have scorned the stone tools of half a million years ago as very crude. The only other significant addition to our ancestors' cultural repertoire that can be documented with confidence around that time was the use of fire.
No art, bone tool, or anything else has come down to us from early Homo sapiens except for their skeletal remains, plus those crude stone tools. There were still no humans in Australia, for the obvious reason that it would have taken boats to get there from Southeast Asia. There were also no humans anywhere in the Americas, because that would have required the occupation of the nearest part of the Eurasian continent (Siberia), and possibly boat-building skills as well. (The present, shallow Bering Strait, separating Siberia from Alaska, alternated between a strait and a broad intercontinental bridge of dry land, as sea level repeatedly rose and fell during the Ice Ages.) However, boat building and survival in cold Siberia were both still far beyond the capabilities of early Homo sapiens.
After half a million years ago, the human populations of Africa and western Eurasia proceeded to diverge from each other and from East Asian populations in skeletal details. The population of Europe and western Asia between 130,000 and 40,000 years ago is represented by especially many skeletons, known as Neanderthals and sometimes classified as a separate species, Homo neanderthalensis. Despite being depicted in innumerable cartoons as apelike brutes living in caves, Neanderthals had brains slightly larger