Genetic evidence has already shown that human evolution is not the story of steady and inevitable progress that the developments related above might make it appear to be. About 70,000 BCE, so about the time oral symbolic language seems to have been initially developing, the total population of the ancestors of all people living today shrank to about 10,000 people, and perhaps to only a few thousand. One proposed explanation for this genetic bottleneck was a volcanic mega-explosion near today's Lake Toba in Indonesia, which led, according to some scholars, to a multi-year volcanic winter that drastically reduced food sources and thus the hominin (and animal) population. Another explanation is more cultural and social: perhaps the Homo sapiens that were beginning to use symbolic language were increasingly picky about mates, choosing them from only among other language users rather than from among all Homo sapiens in an early example of the endogamy that would become such a common feature of later human groups. Or these two could have operated together, with both climate change and intentional endogamy reducing the genetic stock.
However and whenever behaviorally modern humans emerged, at just about the time of the Toba explosion Homo sapiens were doing what Homo ergaster did before them and what they have done ever since: moving. First across Africa, and then into Eurasia, initially sporadically and then more regularly. They used rafts or boats to reach what is now Australia by at least 50,000 years ago and perhaps earlier, which required traveling across nearly 40 miles of ocean even when sea levels were at their lowest during the last ice age. By 20,000 years ago humans were living in northern Siberia above the Arctic Circle, and by at least 15,000 years ago they had walked across the land bridges then linking Siberia and North America at the Bering Strait and had crossed into the Americas. Because by 14,000 years ago humans were already in southern South America, 10,000 miles from the land bridges, many scholars now think that people came to the Americas much earlier, perhaps 20,000 or even 30,000 years ago, using rafts or boats along the coasts when water prevented walking.
Homo sapiens moved into areas where there were already other types of hominins. This included Neanderthals, who appear to have lived side by side with the immigrants in Europe and western Asia for millennia, hunting the same types of animals and gathering the same types of plants. Eventually the Neanderthals may have all been killed, or they may simply have lost the competition for food as the climate worsened in a period of increasing glaciation that began around 40,000 years ago. So far no evidence of interactions between Homo sapiens and any other hominin group has been discovered (other than DNA), but we know the outcome: Homo sapiens survived, others did not. The rest of this book is thus the story of these thinking humans.
Map 1.2 DNA evidence of global Homo sapiens migration
Foraging lifeways
The final retreat of the glaciers occurred between 15,000 and 10,000 years ago, and with the melting of glaciers sea levels rose. Parts of the world that had been linked by land bridges, including North America and Asia as well as many parts of Southeast Asia, became separated by water. This cut off migratory paths, but also spurred innovation. Humans designed and built ever more sophisticated boats and learned how to navigate by studying wind and current patterns, bird flights, and the position of the stars. They sailed to increasingly remote islands, including those in the Pacific, the last parts of the globe to be settled. The western Pacific islands were inhabited by about 2000 bce, and other island groups long after this; the traditional dating of the first settlements of Hawai‘i, Rapa Nui (Easter Island), and New Zealand put these in the last half of the first millennium CE, but more recent studies suggest that these may have been as late as the thirteenth century CE. In areas where food resources were rich, such as along seacoasts, people built structures and lived relatively permanently in one place.
Eventually human cultures became widely diverse, but in the Paleolithic period people throughout the world lived in ways that were similar to one another, in small groups of related individuals—what anthropologists often refer to as “bands” —who moved through the landscape in search of food. Paleolithic peoples have often been called hunter-gatherers, but recent archaeological and anthropological research indicates that both historical and contemporary hunter-gatherers have depended much more on gathered foods than on hunted meat. Thus it would be more accurate to call them “gatherer-hunters,” and most scholars now call them foragers, a term that highlights the flexibility and adaptability in their search for food. Most of what foragers ate was plants, and much of the animal protein in their diet came from foods gathered or scavenged rather than hunted directly: insects, shellfish, small animals caught in traps, fish and other sea creatures caught in weirs and nets, and animals killed by other predators. Gathering and hunting probably varied in importance seasonally or from year to year depending on environmental factors and the decisions of the group.
Paleolithic peoples did hunt large game. Groups working together forced animals over cliffs, threw spears, and, beginning about 17,000 bce, used bows and atlatls—notched throwing sticks made of bone, wood, or antler—to launch arrows and barbs with flint points bound to wooden shafts so that they could stand farther away from their prey while hunting. The warming climate that accompanied the final retreat of the glaciers was less favorable to the very large mammals that had roamed the open spaces of many parts of the world. Wooly mammoths, mastodons, and wooly rhinos all died out in Eurasia in this megafaunal extinction, as did camels, horses, and sloths in the Americas and giant kangaroos and wombats in Australia. In many places, these extinctions occurred just about the time that modern humans appeared, and increasing numbers of scientists think that they were at least in part caused by human hunting.
Most foraging societies that exist today or did so until recently have some type of division of labor by sex, and also by age, with children and older people responsible for different tasks than adult men and women. Men are more often responsible for hunting, through which they gain prestige as well as meat, and women for gathering plant and animal products. This has led scholars to assume that in Paleolithic society men were also responsible for hunting, and women for gathering. Human remains provide some evidence for this, as skeletons and teeth indicate the type of tasks the person did while they were alive. At Chinchorro on the north coast of Chile, for example, male skeletons from the period 7000–2000 BCE often show bone growths in the ears, the result of diving in the cold coastal waters for seals and shellfish (today this condition is called “surfer's ear”), while female skeletons show changes in the ankle bones resulting from prolonged squatting, perhaps to process the marine products or gather and process terrestrial foods. Such a division of labor is not universal, however: in some of the world's foraging peoples, such as the Agta of the Philippines, women hunt large game, and in numerous others women are involved in certain types of hunting, such as driving herds of animals toward a cliff or compound or throwing nets over them. Where women hunt, they either carry their children in slings or leave them with other family members, suggesting that cultural norms, rather than the biology of lactation, is the basis for male hunting. In many Paleolithic sites male and female skeletons show little evidence of sexually differentiated work, and the stone and bone tools that remain from the Paleolithic period give no clear evidence of who used them. The division of labor was most likely flexible, particularly during periods of scarcity, and also changed over time.
Both hunted and gathered foods were cooked, generally by roasting them directly over or near a fire or placing them in a pit-oven along with heated stones or smoldering wood. Grains and nuts were ground, mixed with water, and baked on stones into flat breads, the earliest direct evidence of which comes from about 30,000 years ago; later grinding became a women's task in almost all of the world's societies, but there is less evidence for this in the Paleolithic. Cooking stones, which have been found at some Paleolithic sites and continued to be used into recent times by some groups, may have also been put in bags made from animal skins along
with liquids and other ingredients, thus introducing a new method of cooking—boiling. That new method was made easier with the invention of clay pots, themselves “roasted” in a fire at a temperature high enough to make them watertight. The earliest surviving example of a fired clay object is a figurine of a woman from today's Czech Republic that dates from about 29,000 BCE (about which more below), but fired clay pots have been found in Japan that date from about 15,000 BCE, and China and eastern Russia from somewhat after that. These were made either in an open fire or more likely in a pit that was filled with combustible materials, somewhat covered, and set on fire. Cooking in bags with heated stones (and later with fired clay balls that served the same function) or in pots expanded the repertoire of possible foodstuffs to those that were too hard to process or eat otherwise, including legumes and certain kinds of grains and shellfish. It also provided those who did not have good (or any) teeth, such as infants and the elderly, with softer foods.
Because organic materials from the Paleolithic survive only very rarely, it is difficult to speculate about clothing and other soft material goods, although bone needles for sewing and awls for punching holes in leather can give us some indications. Clothing and headgear were often decorated with beads made from shells, ivory, teeth, and other hard materials, and from the placement of these in undisturbed burials archaeologists can see that the clothing of men and women was often different, as was clothing in some places at different stages of life. Thus gender and age had a social meaning.
The oldest direct evidence of weaving comes from the same area of the Czech Republic that has yielded the earliest fired clay, and is itself clay: fragments with impressions of knotted cordage and woven basketry or cloth made of plant fibre, dating from around 30,000 years ago. (Some scholars suggest that the 75,000-year-old cross-hatched pattern in pieces of ochre found in South Africa mentioned above also represents netting, though it is not an impression made by an actual net.) Along with clothing and bags, weaving, plaiting, and cording (twisting plant fibres together to make string and rope) may have been used to make nets and snares that were more delicate than those that could be made out of leather or sinew, and to make slings to carry infants. Weaving, plaiting, and cording were developed independently in many parts of the world, as objects made of materials that have survived demonstrate: ivory objects show textile motifs; clay figurines wear clothing and headgear; the placement of beads and ornaments found in burials shows they were originally strung on corded necklaces or sewn onto clothing.
1.3 The Venus of Brassempouy, a small head carved from mammoth ivory carved about 25,000 years ago in what is now southern France. The decoration on the head is usually interpreted as a patterned hood, or perhaps a representation of netting or woven cloth.
Obtaining and processing food was a constant preoccupation, but it was not a constant job. Studies of recent foragers indicate that, other than in times of environmental disasters such as prolonged droughts, people need only about ten to twenty hours a week to gather food and carry out the other tasks needed to survive, such as processing food, locating water, and building shelters. The diet of foragers is varied and—especially compared to today's diet of highly processed foods loaded with fat, sugar, and salt—nutritious: low in fat and salt, high in fiber, and rich in vitamins and minerals. The slow pace of life and healthy diet did not mean that Paleolithic life spans approached those of the modern world, however. People avoided such contemporary killers as heart disease and diabetes, but studies of skeletal remains indicate that they often died at young ages from injuries, infections, animal attacks, and interpersonal violence. Mothers and infants died in childbirth, and many children died before they reached adulthood.
Total human population thus grew slowly during the Paleolithic, to perhaps half a million about 30,000 years ago. By about 10,000 years ago this number had grown to 5 million — ten times as many people. This was a significant increase, but it took 20,000 years. (By contrast, the earth's population today is more than 7 billion; it was slightly under one billion a mere three hundred years ago.) The low population density meant that human impact on the environment was relatively small, although still significant.
Family, kinship, and ethnicity
Small bands of humans — twenty or thirty people was a standard size for foragers in harsh environments — were scattered across broad areas, but this did not mean that each group lived in isolation. Their travels in search of food brought them into contact with one another, not simply for talking, celebrating, and feasting, but also for providing opportunities for the exchange of sexual partners, which was essential to group survival. Today we understand that having sexual relations with close relatives is disadvantageous because it creates greater risk of genetic disorders. Earlier societies did not have knowledge of genetics, but most of them developed rules against sexual relations among immediate family members, and sometimes very complex rules about allowable partners among more distant relatives. Some natural scientists argue that incest taboos have a biological or instinctual basis, while most anthropologists see them as cultural, arising from desires to lessen intergroup rivalries or increase opportunities for alliances with other lineages. Whatever the reasons, people sought mates outside their own band, and bands became linked by bonds of kinship, which in a few places has been traced through the study of bone chemistry. Mating arrangements varied in their permanence, but many groups seem to have developed a somewhat permanent arrangement whereby a person—more often a woman than a man—left her or his original group and joined the group of a mate, what would later be termed marriage. Judging by later ethnographic parallels, how kin groups were defined and understood varied tremendously, but they remained significant power structures for millennia, and in some areas still have influence over major aspects of life, such as an individual's job or marital partner.
Stereotypical representations of Paleolithic people often portray a powerful fur-clad man holding a club and dragging off a (usually attractive) fur-clad woman by her hair, or men going off to hunt while women and children crouch around a fire, waiting for the men to bring back great slabs of meat. Studies of the relative importance of gathering to hunting, women's participation in hunting, and gender relations among contemporary foraging peoples have led some analysts to turn these stereotypes on their heads. They see Paleolithic bands as egalitarian groups in which the contributions of men and women to survival were recognized and valued, and in which both men and women had equal access to the limited amount of resources held by the group. This may also be a stereotype, overly romanticizing Paleolithic society as a sort of vegetarian commune. Social relations among foragers were not as hierarchical as they were in other types of societies, but many foraging groups from more recent periods had one person who held more power than others, and that person was almost always a man. In fact, anthropologists who study such groups call them “Big Man” societies. This debate about gender relations is often part of larger discussions about whether Paleolithic society — and by implication “human nature” — was primarily peaceful and nurturing or violent and brutal, and whether these qualities are gender-related. Like much else about the Paleolithic, sources about gender and about violence are fragmentary and difficult to interpret; there may simply have been a diversity of patterns, as there is among more modern foragers.
Whether peaceful and egalitarian, violent and hierarchical, or somewhere in between, heterosexual relations produced children, who were fed as infants by their mothers or by another woman who had recently given birth. Breast milk was the only food available that infants could easily digest, so mothers nursed their children for several years. Along with providing food for infants, extended nursing brings a side benefit: it suppresses ovulation and thus acts as a contraceptive. Foraging groups needed children to survive, but too many could tax scarce food resources. Many groups may have practiced selective infanticide or abandonment. They may also have exchanged children of different ages with other groups, which further deep
ened kinship connections between groups. Other than for feeding, children were most likely cared for by other male and female members of the group as well as by their mothers, as they are in modern foraging cultures.
Within each band, and within the larger kin group, individuals had a variety of identities; they were simultaneously fathers, sons, husbands, and brothers, or mothers, daughters, wives, and sisters. Each of these identities was relational (parent to child, sibling to sibling, spouse to spouse), and some of them, especially parent to child, gave one power over others. Along with age, gender, and position in a family, people were also no doubt differentiated by personal qualities such as intelligence, courage, and charisma. Burials provide evidence of social differentiation and social connections. The people who buried a young adult woman near Bordeaux in southern France about 19,000 years ago, for example, dressed her in clothing, covered her with ochre pigment, and placed her in a container made of stone slabs, along with a few perforated shells, a bead, some tools made of bone and stone, bones of antelope and reindeer, and 71 red deer canine teeth that had holes drilled in them for stringing and may have been on a necklace. Red deer did not live near Bordeaux at this time of worsening climate, so the teeth had most likely been brought there over many years through networks of exchange, perhaps given as gifts in marriages or in trade for other goods. Something about this young woman or her death led those who buried her to decide to include so many valuable grave goods; through this they referenced both her individual identity (and perhaps high social position) and her links to a social network that ranged across time and space.
Bands of foragers may have been exogamous, but as humans spread out over much of the globe, kin groups and larger networks of interrelated people often became isolated from one another, and people mated only within this larger group. Thus local exogamy was accompanied by endogamy at a larger scale, and over many generations humans came to develop differences in physical features, including skin and hair color, eye and body shape, and amount of body hair, although genetically there is less variety among them than among chimpanzees. Language also changed over generations, so that thousands of different languages were eventually spoken; more than eight hundred have been identified, for example, in contemporary Papua New Guinea alone. Groups created widely varying cultures and passed them on to their children, further increasing diversity among humans.
A Concise History of the World (Cambridge Concise Histories) Page 5