Some 15¸000 years ago¸ the great ice sheets began to retreat at times very rapidly¸ ushered in postglacial times often called the Holocene (Greek Holos¦recent). At the same¸ time world sea levels¸ rose dramatically if irregularly from their previous lows up to 300 feet (90 meters)below modern levels leading to major changes in world geography. The chilly waters of the Bering Sea flooded center Beringia and separated Siberia and Alaska by 11¸000 B.C.E. Sunda in Southeast Asia became an enormous archipelago. Britain became an island and the North Sea and Baltic assumed their modern configurations. The most striking climatic and vegetational transformations took place in northern latitudes¸ in areas like western and vegetational transformations took place in northern latitudes in areas like western and central Europe and in regions of North America contiguous to the great ice sheet. Only 7¸000 years after the Scandinavian ice sheets began retreating¸ forests covered much of Europe. There were major vegetational changes in warmer latitudes too. Rainfall patterns changed at the end of the Ice Age¸ bringing large¸ shallow lakes and short grasslands to the Sahara. As late as 6¸000 B.C.E.¸ forager populations flourished in the desert in areas that are now arid wilderness.
In southwestern Asia¸ warmer conditions saw the immigration of new plant species into highland areas such as the Zagros mountains in Iran¸ among them wild cereal grasses. Their distribution expanded dramatically¸ to the point that wild wheat and barley became important staples for forager groups in the highlands and fertile river valleys like the Euphrates. Far away¸ in Mexico rising temperatures brought a rich forest of cacti and legume trees to mountain valleys of the central highlands. This thorn– scrub– cactus forest included many wild ancestors of domesticated plants among them the maguey¸ squash¸ bean¸ and teosinte¸ the wild grass that was probably the ancestor of wild maize¸ the crop that was to become one of the staples of native American life.
Changes in Forager Societies
These an other Holocene climate changes had profound effects on forager societies throughout the world especially on the intensity of the food quest and the complexity of their societies. So did natural population growth. By 15000 years ago the world forager population was probably approaching about 10 million people. Except in the most favored areas like southwestern France or the Nile valley late Ice Age Age environments were incapable of supporting anything but the sparest of human population densities well under one person per square mile. As a result in early Holocene times after 10000 B.C.E. still rising them human populations began to match the ability of the world's environment to support them as foragers. It was no longer possible to solve a subsistence problem simply by moving elsewhere. People began to exploit a wider range of food resources with greater efficiency both to avert starvation and to protect themselves from food shortages caused by short term droughts and other unpredictable changes. In time forager societies underwent profound changes and in some areas acquired greater complexity.
Nowhere can these changes be seen more clearly than in the Americas settled by Stone Age foragers either during or immediately after the Ice Age. By 11000 B.C.E. then big game that formed a staple part of their diet was extinct. The Paleo–Indians responded to change circumstances by developing ever more marked intensive and specialized ways of exploiting local environments. The change is especially marked in areas of exceptional resource diversity like parts of the west Coast the Peruvian coast and the fertile river valleys of the southern Midwest and southeastern United States. In all these areas forager populations became more sedentary developed specialized technologies for hunting foraging and fishing; and in the process developed some form of social ranking.
The famous Koster site in the Illinois River valley provides a chronicle of this process of intensification taking place over many thousands of years from about 7500 B.C.E. until 1200 C.E. The first visitors were Paleo Indians hunters who camped on the edge of the valley. About 6500 B.C.E. some later inhabitants founded a base camp that covered about ¾ acre (0.1 hectare). An extended family group of about 25 people returned repeatedly to the same locations perhaps to exploit the rich fall hickory nut harvests in the area. Between 5600 and 5000 B.C.E. there were substantial settlements of the permanent mud and brush houses that were occupied for most of the year if not all of it. During spring and summer the inhabitants took thousands of fish gathering mussels and hickory nuts in fall and migratory birds in spring. Even when hunting deer on the nearby uplands the people could find most of their food resources within 3 miles (5 kilometers).
After 2500 B.C.E. Kosters population had risen to the point at which the people were exploiting a much wider range of food resources including acorns which require much more preparation than hickory nuts. Eventually they experimented with the deliberate planting of wild native grasses like goosefoot¸ simply to increase supplies of wild plant foods. The Koster excavations document several long term trends in many Holocene foragers societies tends toward more sedentary settlement intensive exploitation of locally abundant and predictable food resources such as salmon or nuts and carefully organized mass processing and storage of staple foods.
Such intensive exploitation¸ and storage was adaptive in environments where seasonal phenomena such as salmon runs¸ caribou migrations¸ or hickory nut harvests required not only efficient harvesting of quantities of food in a short time¸ but also their processing and storage for later use. By using storage¸ and by careful seasonal exploitation of game¸ plant¸ and aquatic resources¸ like fish and waterfowl¸ Holocene foragers compensated for periodical food shortages caused by short–term climatic change and seasonal fluctuation. For example¸ Native American societies developed a remarkable expertise with wild plant foods. They also evolved an array of simple pestles¸ grinders¸ and other to process seeds¸ and other wild plant foods. Later¸ it was an easy matter to adapt these tool kits to new¸ specialized tasks such as farming.
More restricted territories¸ less mobility¸ rising population densities¸ unpredictable environmental variations¸ and seasonal flood fluctuations were problems common to Holocene foragers throughout the world. A few of these societies¸ especially those in areas with rich and diverse food resources that included fish and sea mammals¸ achieved a greater complexity than Ice Age society¸ with some signs social ranking. Here¸ higher than normal population densities were concentrated in restricted territories circumscribed by geography or neighbors. These populations acquired a more varied diet by using more specialized tool kits and sophisticated food storage systems and preservation techniques. These groups often lived in sedentary¸ large base camps ruled by important kin leaders who monopolized trade with neighboring groups. For example¸ the Chumash Indians of the southern California coast were skilled navigators¸ fishers¸ and sea mammal hunters. Some Chumash communities numbered as many as 1000 people¸ living under hereditary chiefs (wots) There was a small elite of ceremonial officeholders¸ shamans¸ and such experts as canoe builders. Chumash culture was a maritime adaptation made possible by a specialized fishing technology that included planked canoes about 25 feet (7.6 meters). Each community maintained exchanged contracts with other coastal communities and with people living far in the interior.
Chumash culture achieved a degree of social elaboration that represents about the limit of such complexity possible without adopting agriculture. Why did such social complexity develop? Some scholars see the ocean as a kind of Garden of Eden¸ an environment sometimes so productive that foragers could maintain permanent¸ sedentary settlement and maintain high population densities. Perhaps people turned to fish¸ shellfish¸ and sea mammals in a period of rapid environments change¸ like that at the end of the Ice Age. Unfortunately¸ however¸ we do not know decisive marine or riverine resources were in allowing dense populations and sedentary living¸ both essential prerequisties for social complexity.
Away from coasts¸ rivers¸ and lake shores¸ and especially among groups living at the edges of several ecological zones¸ people living in more or less permanent settlements in fish inland environments turned to another strategy. They experimented with the planting of wild plant staples to supplement food resources in short supply. The cultural changes forced upon then by Holocene climate change made it easier for their descendants to adopt radically new economic strategies such as deliberate cultivation of the soil and animal domestication—food production.
Social Complexity among Forager Societies
Complex forager societies did not appear everywhere¸ but they developed in a remarkable variety of environments¸ from fertile river valleys to coastal deserts. Everywhere¸ however¸ certain general conditions were necessary. First¸ population movements had to be limited by either geography or the presence of neighbors. Second¸ resources had to be abundant and predictable in their seasonal appearance. Such resources included fish¸ shellfish¸ nuts¸ and seeds¸ species that are abundant and seldom exhausted. Third¸ population growth might reach a point at which food storage's occur and there is an imbalance between people and their food supply. Again¸ a solution was to intensify the food quest¸ an intensification that might result in a more complex society¸ or¸ as we shall see¸ in food production.
Social complexity was common in areas where freshwater or marine fish¸ shellfish¸or sea mammals were abundant. The potential of marine and freshwater resources was realized only in a relatively few areas like northern Europe¸ Peru¸ and western North America. Here¸ higher than normal population densities were concentrated in restricted territories circumscribed by geography or neighbors. These populations acquired a more varied diet by using more specialized tool kits and sophisticated food storage systems and preservation techniques. These groups often lived in sedentary¶ large base camps ruled by important kin leaders who monopolized trade with neighboring groups. For example¸ the Chumash Indians of the southern Chumash communities numbered as many as 1000 people¸ living under hereditary chiefs (wots). There was a small elite of ceremonial officeholders¸ shamans¸ and such experts as canoe builders. Chumash culture was a maritime adaptation made possible by a specialized fishing technology that included planked canoes about 25 feet long (7.6 meters). Each community maintained exchanged contacts with other coastal communities and with people living far in the interior.
Chumash culture achieved a degree of social elaboration that represents about the limit of such complexity possible without adopting agriculture. Why did such social complexity develop? Some scholars see the ocean as a king of Garden of Eden¸ an environments sometimes so productive that forages could maintain permanent¸ sedentary settlements and maintain high population densities. Perhaps people turned to fish¸ shellfish¸ and sea mammals in a period of rapid environmental change¸ like that at the end of the Ice Age. Unfortunately¸ however¸ we do not know how decisive marine or riverine resources were in allowing dense populations and sedentary living¸ both essential prerequisites for social complexity.
Away from coasts¸ rivers¸ and lake shores¸ and especially among living at the edges of several ecological zones¸ people living in more or less permanent settlements in rich inland environments turned to another strategy. They experimented with the planting of wild plant staples to supplement food resources in short supply. The cultural changes forced upon them by Holocene climate change made it easier for their descendants to adopt radically new economic strategies such as deliberate cultivation of the soil and animal domestication–food production.
