A Concise History of the World Read online

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  Foraging and farming families (to 3000 BCE)

  About ten thousand years ago, a group of young people entered a cave in the valley of the Pinturas River in what is now southern Argentina. They held their hands up to a wall of the cave and, using pipes made of bone, blew paint made with different colors of mineral pigments around their hands to create silhouettes. They, or someone else who lived at roughly the same time, also painted hunting scenes with humans, animals, birds, and bolas made of stones on the ends of cords, with which humans captured those birds and animals. Someone also painted geometric and zigzag patterns, and, judging by the dots of paint on the ceiling of the cave, tossed bolas dipped in paint upwards. We know these were young people because the hands are slightly smaller than adult hands, and we know it was a group because they are all different. Most are left hands, which indicates that most of these individuals were right-handed, since they would have held the pipe for blowing in the hand they normally used for tasks. What occasioned this group project in the Cueva de las Manos (Cave of the Hands), as this site has become known, is unknown. It could have been a coming-of-age ceremony for adolescents led with solemnity by adults, or it could have been a less formal coming-of-age ritual conducted by adolescents themselves, akin to graffiti tagging. It could have simply been play. No matter why it was painted, the cave provides powerful evidence for many aspects of early human society: technological inventiveness, symbolic thinking, social cohesion. It, and similar hand prints found all over the world, suggest that the urge to say “I was here” and “we were here” is very old. People would later convey this in writing, and place themselves and their group within larger scales of space and time, but the young people who left their hand prints in the Cueva de las Manos knew these would be seen by those who entered the cave later. They were intentionally creating a record of past events for people in the future, what we would call a history.

  1.1 Hand prints from the Cueva de las Manos, Argentina, made about 8000 BCE, from mineral pigments blown through pipes made of bone to create silhouettes.

  Along with their handprints, the people who painted the Cueva de las Manos also left tools made of bone and stone. Tools made from hard materials are the most common type of evidence that survives from the early human past, and they shape the way we talk (and think) about that past. In the nineteenth century the Danish scholar C.J. Thomsen, studying collections of such tools in Copenhagen, devised a system for dividing human history into eras. Thus the earliest human era became the Stone Age, the next era the Bronze Age, and the next the Iron Age. The Stone/Bronze/Iron progression does not work very well in many parts of world, particularly if it is used as a general measure of technological advance: in some places iron was the first metal to have a major impact, and in many places very complex technologies developed without metals. It also ignores tools made from softer materials (such as plant fibres, sinew, and leather) or from organic materials that generally decayed (such as wood) that were important parts of the human toolkit. And it centers on tools, and not on other material objects or non-material factors. Despite its limitations, however, Thomsen's three-age system has survived. A later scholar further divided the Stone Age into the Old Stone Age, or Paleolithic era, during which food was gained largely by foraging, followed by the New Stone Age, or Neolithic era, which saw the beginning of plant and animal domestication. More recent archaeologists have further divided the Paleolithic into Lower-Middle-Upper (if they work on Europe and Asia), or Early-Middle-Later (if they work on Africa), again based primarily on the tools that have survived, with further subdivisions and geographic variations.

  Along with tools and paintings, other physical evidence also survives in some places, including fossilized bones, teeth, and other body parts; evidence of food preparation, such as fossilized animal bones with cut marks or charring; or holes where corner-posts of houses once stood. Fortunate accidents have preserved materials in a few places when most are long gone: they are deep in the earth in caves, or landslides prevented them from being worn away by wind and water, or the chemical nature of bogs prevented their decay. To all of this evidence, scholars increasingly apply chemical and physical tests along with close observation. These include, among others, analysis of the wear patterns on stone tools (termed microwear analysis), chemical analysis of bones or of fossilized feces to determine food sources and other things (termed stable isotope analysis), genetic testing to examine DNA, and various methods of dating, such as the thermoluminescence dating of sediments, electron spin resonance dating of teeth, and carbon-14 dating of organic materials. To this, they add evidence from comparative linguistics, primatology, ethnography, neurology, and other fields.

  Putting this information together, archaeologists, paleontologists, and other scholars have developed a view of early human history whose basic outline is widely shared, although just as in physics or astronomy, new finds spur rethinking. This chapter traces that history, beginning with the evolution of hominids and the various species in the genus Homo, examining the lifeways, kin structures, art, and rituals of early foragers, and assessing the ways in which plant and animal domestication enabled the creation of larger-scale hierarchical social structures and more elaborate cultural forms.

  Interpreting the partial and scattered remains of the human past involves speculation, and this is particularly true for social and cultural issues. By themselves, tools and other objects generally do not reveal who made or used them (though sometimes this can be determined from the location in which they were found), nor do they indicate what they meant to their creators or users. Because evidence gets rarer and more accidental in its preservation the further back one goes, controversies about how much we can draw from it are especially sharp among those who study the earliest human history.

  Society and culture among other hominids

  Those controversies include a very basic question that seems to be about periodization, but is actually philosophical: when should the story of society and culture start? The eighteenth-century European scientists who invented the system we now use to classify living things placed humans in the animal kingdom, the order of Primates, the family Hominidae, and the genus Homo. The other surviving members of the hominid family are the great apes—chimpanzees, bonobos, gorillas, and orangutans—and some primatologists who study them are quite comfortable talking about, say, chimpanzee society or even chimpanzee culture. All of the great apes—and certain other animals and birds as well—use tools and live in complex social hierarchies, and one bonobo, Kanzi, who now lives with a small group of his relatives at the Iowa Primate Learning Sanctuary in Des Moines, can make sharpened stone tools, gather wood, light a fire, and cook his food after watching the humans who care for him do this. He has been taught to recognize, respond to, and choose symbols on a screen representing objects or ideas, but whether he can recombine symbols to produce new ideas, or recognize that both he and the humans surrounding him are doing this, is hotly debated.

  These two characteristics—combining symbols in new ways, and understanding that both oneself and others have internal lives and consciousness—are currently the core of what most scientists see as the divide between humans and other species. (Other characteristics that have been proposed, such as tool-making, awareness of death, suffering, altruism, and counting, are now known to be shared with other animals.) Symbolic thought involves creating a symbolic or syntactic language, that is, a way of communicating that follows certain rules and that can refer to things or states of being that are not necessarily present. This can be oral or gestural or written or a combination of these, but it must be shared with at least one other being to be a language. Symbolic communication allows better understanding and manipulation of the world, and can be passed from one generation to the next, thus leading to multi-generational collective explanations for that world. A consciousness of consciousness—what philosophers call a “theory of mind”—is also both cognitive and social. It involves not only responding
to what others are doing (which animals clearly do), but also reasoning about what others think or feel, recognizing that they have aims, and making abstractions about why they might be doing something.

  The primatologists who work with Kanzi affirm that he does both of these, but others who observe him think that this is anthropomorphizing. The scholars who study early hominins—the sub-family division within the hominid family that includes us (but excludes the great apes)—are similarly divided. Some think that any discussion of culture among hominins of the past that were not users of symbolic language is also a kind of anthropomorphism, projecting our ways of thinking onto beings that were not like us, or at least not enough like us to have such a thing as “culture.” Clive Gamble and others assert that this is too limited a view, and see symbolic thought expressed through objects and the human body itself millions of years before it was expressed orally, connecting hominins in social webs of shared understanding.

  All sides in these debates about when to start agree about where to start, however: humans evolved in Africa, where between 7 and 6 million years ago some hominids began to walk upright at least some of the time. Initially these hominids combined two-limbed movement on land and four-limbed movement in trees, but over many millennia the skeletal and muscular structures of some of them evolved to make upright walking easier. This included groups that lived in southern and eastern Africa beginning about 4 million years ago, whom paleontologists place in the genus Australopithecus, small hominids with bodies light enough to move easily in trees, but with hind limbs that allowed efficient bipedal motion. About 3.4 million years ago, some australopiths began to use naturally occurring objects as tools to deflesh animals, as evidenced by cutmarks and scrapes on fossilized animal bones. This gave them greater choice about when and where they would eat, as they could cut meat into portable portions. At some point, certain groups in East Africa began to make tools as well as use them; the earliest now identified are 2.6 million years old, but archaeologists suspect that older ones will be found. Hominids struck one stone against another to break off sharp flakes that contemporary archaeologists have found are capable of butchering (though not killing) an elephant, and carried the rocks to make these stone tools from one place to another.

  Like making anything, making these stone flakes required intent, skill, and physical capability, the latter provided by a hand that was able to hold the “hammer” stone precisely, with an opposable thumb and delicate muscles that can manipulate objects. Why austrolopiths developed this hand that was very different from the less flexible (but much stronger) hands of other primates is not clear, but what is clear is that they already had it when they began making tools. The human hand did not evolve to use or make tools, but used tools because it had already evolved. It is thus what paleontologists call an “exaptation”: something that evolved randomly or for a reason that we do not yet understand, but was then used for a specific purpose. Other structures within the body that became essential in later developments—such as the larynx, about which more below—were also exaptations. (Many social structures and cultural forms were exaptations as well—they developed for reasons that are unknown, or perhaps simply as experiments, but then became traditions; explanations for how they originated were invented later that probably have little to do with how they had actually developed.)

  Australopiths seem to have eaten anything available, and fossilized animal bones, fossilized teeth, and other types of evidence indicate that this included meat. Paleontologists think this meat was most likely scavanged; australopiths may have stolen carcasses that leopards had hidden in trees, or engaged in “power scavanging”—throwing rocks with their flexible hands to drive off other predators. This suggests that they lived in larger groups than just a few closely related individuals. Living in larger groups would have also enabled them to avoid predators more effectively—for hominins were prey as well as predators—and may have encouraged more complex communications.

  These new tools and the innovative behaviors that went with them emerged among australopiths, who also branched out into different species in various parts of Africa. Around 2 million years ago, one of these branches developed into a different type of hominin that later paleontologists judged to be the first in the genus Homo. Which of the fossil remains that have been found in East Africa should be categorized as the very first Homo is disputed, because this depends on exactly which anatomical features or behavioral patterns indicated in the scattered bones and stones of the fossil record one sees as making a hominin clearly Homo (and thus the ancestor of us). Among the contenders are Homo habilis (“handy human”) and Homo ergaster (“working human”), names that indicate that the essence of being human to the archaeologists who invented these terms in the 1960s and 1970s was the ability to make things. And make things Homo did: first multipurpose sharpened stone tools generally called hand axes and then slightly specialized versions of these. This suggests greater intelligence, and the skeletal remains support this, for these early members of the genus Homo had a larger brain than did the australopiths. They also had narrow hips, longer legs, and feet that indicate they were fully bipedal, but here there is an irony: the slender upright pelvis made giving birth to a larger-brained infant difficult. Large brains also take more energy to run than other parts of the body, so that large-brained animals have to eat more calories than small-brained ones.

  This disjuncture between brain and pelvis had many consequences, including social ones, which might have begun with Homo ergaster. The pelvis puts a limit on how much the brain can expand before birth, which means that among modern humans much brain expansion occurs after birth; humans are born with brains that are only quarter of the size that they will be at adulthood. Humans thus have a far longer period than do other animals when they are completely dependent on their parents or others around them. Those parents also have a long period during which they must tend an infant or it will die. Judging by brain size, that period was shorter in Homo ergaster than in modern Homo sapiens, but it may still have been long enough that groups developed multi-generational social structures for the care of infants and children. Perhaps Homo ergaster mothers might have even helped one another to give birth, just as they (and the males as well) helped one another gather, hunt, and prepare food, activities that are clearly evident in the fossil record.

  Along with a larger brain and narrower pelvis than austrolopiths, Homo ergaster also had other physiological features with social implications. Their internal organs were small, including those for digestion. Thus, in order to obtain enough energy to survive, they had to eat a diet high in fat and protein, most easily obtainable by eating animals and animal products—insects, reptiles, fish, eggs, and birds along with mammals. Catching some of those animals may have necessitated walking or running significant distances in the hot sun, which is difficult for most mammals because they only lose body heat through panting. Homo ergaster probably had the ability to cool down by sweating, a process made easier by the fact that they were relatively hairless. Studies of human body lice support this idea, for our hairy heads support a type of louse found only in humans and our hairy pubic regions another, which we share with other animals. The former is the descendant of the louse we have been home to since our ancestors had hair everywhere, and the latter we picked up from later contacts with other species.

  This loss of body hair facilitated cooling (and thus hunting), but it also meant that infants could not cling as easily to their mothers as could those of other primate species. How Homo ergaster mothers handled this problem is not evident in the fossil record. Perhaps they did not hunt when they had small children or they left their children briefly, as sites indicate that groups sometimes had a home base to which they returned. Perhaps they devised slings made of plant or animal material to help carry their children, though like any tool made from soft materials these have left no trace.

  Another solution to the problem of a short digestive tract is to transfer some digestion out
side the body, through cooking. Raw meat is hard to chew and digest, as are many raw plant products; other primates spend many hours a day chewing. Cooking allows an outside source of energy—fire—to do much of this work, breaking down complex carbohydrates and proteins to increase the energy yield of food; it also detoxifies many things that would otherwise be dangerous to eat. There are a few shreds of evidence of fire at early Homo ergaster sites, and some scholars, including Richard Wrangham, argue that even without fossil evidence of actual cooking, the larger brains, smaller and less pointed teeth, and shorter guts that developed about 2 million years ago would only have been possible with cooked food. Other scholars see cooking as an invention of hominin species that developed more recently, perhaps beginning around 780,000 BCE, the date of the first widely accepted evidence of controlled fire at a site in Israel. Or perhaps regular use of fire came as late as 400,000 years ago, when hearths become a common part of the archaeological evidence in many areas.

  Wherever and whenever it occurred, cooking had enormous social and cultural consequences. Cooking causes chemical and physical reactions that produce thousands of new compounds and make cooked foods more aromatic and more complex in their flavors than raw foods. As descriptions of roasted coffee or chocolate put it, they develop “overtones” or “flavor notes” of completely different things. Because members of the genus Homo were omnivores, they may have been genetically predisposed to prefer complex flavors, so that cooked food tasted (and smelled, which is essential in taste) better. Thus cooking led to eating together in a group at a specific time and place, which increased sociability. Because it expands the range of possible foodstuffs, cooking encouraged experimentation in other aspects of food preparation. For example, the site in Israel with the earliest hearths also provides evidence of tools used for cracking nuts and seeds, which expanded the ways they could be eaten. Cooking may also have encouraged symbolic thought, as cooked foods often make us think about something that is not there, and both cooking and eating can be highly ritualized activities. Plus cooking involved fire, which itself has deep meaning in later human cultures.