The Last Ice AgeEdit
Perhaps it would be better to call it the most recent Ice Age, because in fact, the Earth has had many Ice Ages. In fact, climatologists, people who study long-term weather conditions, have found at least four earlier ice ages, and an older age for the Earth.
Ice Ages tend to be similar every time they occur. The whole planet becomes significantly cooler, and a vast majority of the planet's water becomes locked in ice at high altitudes and at the North and South Poles. Sea levels drop precipitously, and a sheet of ice extends outwards from the poles and from high mountains like the Alps in Europe and the Rockies in North America to cover huge swaths of the planet's land area. The ice sheet can be more than a mile thick in places, and the ice is so heavy, and moves so forcefully in places, that the underlying soil is ripped up, and the bedrock below the soil is pummeled, cracked and ground into huge boulders and tiny pebbles. Everywhere else, sea levels drop about fifty feet -- shorelines in some places stretch outwards more than a mile beyond the present shores, and numerous small islands and shoals appear even beyond that.
The last Ice Age, which geologists call the Würm III Ice Age, lasted from about 20,000 years ago until about 15,000 years ago. All of Canada and much of the United States were swaddled in ice sheets as far south as Oregon, Wyoming, Illinois and Pennsylvania. Europe north of the Alps was almost totally covered, as was much of central Russia. Tibet, western China and northern India vanished under the ice buildup on the Himalayas. World temperatures dropped an average of 12° F, enough to make even Florida or India unpleasantly cool.
Hunting and GatheringEdit
Anthropologists believe that at the start of the last Ice Age, the human population of Earth was less than a million people. Their existence revolved around a style of living which still exists today, although it is gradually being wiped out everywhere, by a combination of economic, political and social pressures, as well as outright violence. People who practice this way of life are called hunter-gatherers.
Hunter-gatherers do not grow plants or raise animals for food. Instead, they practice a lifestyle in which the men go out to hunt wild animals every few days, while the women gather wild but edible plants and wild but useful medicinal plants every few days. There is usually a very strong division of labor between the sexes in hunter-gatherer cultures; though men may gather some plants, and women may do some hunting, the expectation is usually strong that women will stay close to a family's camp while the men go far afield in search of food.
Every few months, as these resources become scarce in one region, the people pack up their few belongings and move to a new location within their territory. Each family may have a territory of hundreds of square miles over which they may range quite broadly in the course of a year, living off of what the land produces. A hunter-gatherer family might have a dozen favorite campsites, with one on the seashore, one by a lake, one in the hills and one in the woods. Fish and shellfish form their seashore diet while they make baskets from marsh reeds; by the lake they may eat deer and make arrows and spears from nearby trees; in the hills they eat mountain goats and make stone tools from a deposit of obsidian; in the forest they eat birds and fill their baskets with nuts and fruits for the winter.
Hunter-gathering is a remarkably simple life, and it was the way of life practiced by humans and hominids back into the Paleolithic age's earliest years, as near as modern scientists can agree. People tend to have very few possessions, because they are very mobile, and they have no animals to help them carry their gear from one place to another. A tent may be the most elaborate piece of equipment the whole family owns. Modern hunter-gatherer clans tend to have fairly long life expectancies, usually around 70 years of age; some modern developing societies do not have such long life spans as hunter-gatherers do.
Today we can only guess at the lifestyles of ancient hunter-gatherers, based on modern examples. Most hunter-gatherers live and travel in extended families of at least three generations -- grandparents, parents, aunts and uncles, as well as children. Older children take care of the youngest and the oldest. The family has to take care of all the needs of all its members, because there is no larger society to take on the work of caring for the elderly or educating the littlest ones. Aunts help mothers watch the youngest children, and collect the necessary plants to keep the family fed and healthy; uncles help train young boys to hunt smaller animals, and to help on the hunts for larger game. The same was probably true of ancient hunter-gatherers, as well.
Additionally, anthropologists and historians speculate that hunter-gatherer families 20,000 years ago belonged to larger groups called tribes. Tribes are clusters of families bound together by common taboos and beliefs for social advantage. While families lived on their own most of the time, such an existence in an otherwise empty landscape would have been difficult, especially if every other family was potentially an enemy. Thus, some families that spoke the same or similar languages would form alliances with one another, by marrying their children into one another's bloodlines, and by trading luxury goods, and feasting together. As families became too large to live together, they would bud off into new extended families that remained attached to the old relationships with other families. Strangers who proved their usefulness and loyalty could also marry into these arrangements, giving them both protection and responsibility.
In this way, different families and peoples experimented with the most useful prohibitions, prescriptions and modalities for living in a complex world. The tribes formed a social network which made it possible for individuals to travel great distances in relative safety. However, tribes may have also led to conflict, as different tribes began competing for water, food and other resources. Tribes may have also become so large that they subdivided, with clans existing as groups of families within the larger tribes.
Clans and tribes also offered opportunities for leadership. Within an extended family, the oldest adult usually has tremendous influence and receives the respect of his or her descendants, simply for living so long. However, within a tribe issues other than age may be a factor in choosing a leader. Some tribes may have chosen the biggest and bravest as their leaders, while others may have chosen the wisest or the most clever. Many modern hunter-gatherer tribes, and presumably ancient tribes as well, gradually developed four types of leader: the big man, who was usually the most important hunter; the chief, who was usually an older man or woman who was respected because of years of experience; the medicine man or woman, or shaman, who worked with plants and minerals to cure the illnesses and injuries of the tribe; and the artisan, who was particularly skilled at manufacturing goods necessary to the tribe's survival such as spears, baskets or clothing.
The beginning of the Ice Age must have startled and surprised these leaders and their dependents and followers a great deal. Colder temperatures and ice probably killed some tribes completely. Others moved toward the equator, seeking warmer temperatures and easier living conditions. Some must have stayed near the ice and weathered the cold, changing their habits and patterns of living to accommodate the change in environment.
However, the end of the most recent Ice Age around 12,000 years ago, put even greater pressures on the tribes that survived than the beginning had. As temperatures and sea levels rose, the Earth experienced a substantial die-off of plant and animal types. Some historians blame this pattern of extinction on our earliest ancestors; others attribute it to rapid climate change unrelated to human activity. Neither side has a total lock on the truth at this point. There is no solid evidence to prove the debate either way.
Through a process called domestication, early humans began controlling the development of a number of plant and animal species. They probably began by planting the seeds of their favorite foods in gardens, in order to harvest luxury or high-status foods like fruit, berries, nuts or grains. By cultivating small plots of land, human families would gain substantial riches, both in terms of surplus food and status. The plants that produced the most food would be bred with each other, in order to produce a more reliable crop with greater substance useful to humans. A similar process developed fiber plants like cotton, flax and hemp. In like manner, other human tribes took the effort to capture live samples of their favorite food animals, from cattle and camels to reindeer and sheep. By killing off the most aggressive males in a herd, and breeding animals according to traits which humans found desirable, these early pastoralists created modern farm animals.
Domestication of AnimalsEdit
Domestication of animals began earlier, at least as far as modern historians know. Because bones fossilize over time, and because they can remain intact in dry and pH-neutral soil longer, they appear in the fossil record much earlier than any sign of domesticated plants. Dogs appear to be the oldest domesticated species, and they may have been domesticated by the late Paleolithic age, around 20,000 years ago. Dogs made the crossing to the Americas with Siberian Ice Age hunter-gatherers, but no other domestic species made the transition. However, dogs did not cross into Australia with the people who became the Australian Aboriginals 40,000 years ago. The date of canine domestication is thus a little confusing.
However, the real appearance of domesticated animals begins much later. Sheep and Goat (Capra aegagrus hircus) appearing in 8000 BCE. The domestic cat (Felis domesticus), thought to descent from a few as five self-domesticating African Wildcats (Felis silvestris lybica) c. 8000 BCE, in the Near East, was found in the form in a kitten that was buried alongside a human in Cyprus, dating 7500 BCE. The Chicken (Gallus gallus domesticus) in 6000 BCE. The Dromedary Camel (Camelus dromedarius) appear to have been domesticated by about 4000 BCE and the Bactrian camel (Camelus bactrianus) around 2500 BCE. The Horse (Equus ferus caballus) also join them around 4000 BCE, as well as Cattle (Bos primigenius taurus) and the Duck (Anas platyrhynchos domesticus).
The example of horned goats is instructive. At sites dated between 7000 and 6000 BCE, goat horns appear in the middens of ancient peoples living in the Near East. All of these goat horns have a slightly curved profile, like a scimitar or other curving sword blade, suitable for ramming and goring another goat, or a predator, or a human who got too close. At sites dated between 6000 and 5000 BCE, a new type of goat horn appears, representing maybe 10% of the total. These horns, instead of being wicked tools for battle, have become curled and twisted. Between 5000 and 3000 BCE, the number of twisted goat horns remains fairly steady. However, by 2500 BCE, twisted and curled goat horns have become the norm, and represent 80% of the finds. By 1500 BCE, they represent 100% of the finds; the wild goat with its sharp and vicious horns had been replaced by a domesticated goat with twisted horns. Where the wild goat's horns could kill a man with a single strike, the twisted horns might batter someone but leave him alive.
From this, modern historians deduced that horn shape was not the only characteristic which early human breeding programs sought to preserve and pass on to future generations. Early humans must have also been concerned with things like meat, milk, and wool — all useful products derived from both goats and sheep, as well as other animals. Additionally, for most of the period covered by this book, most parts of the Near East were not typically well-settled, and the goat-herders must have preferred that their animals had some ability to defend themselves against predators such as wolves and lions. Historians call people who herd animals for their living, and who derive only minimal benefit from farming, pastoralists. All types of animal-rearing, taking into account both pastoralism and farming, is called animal husbandry. Animal husbandry lends itself well to a variation on the hunter-gatherer lifestyle, in which nomads, or people who travel widely seeking food for their herds or flocks, roam between several areas which provide food and water for both themselves and the animals they tend.
Domestication of PlantsEdit
Domestication of plants followed a similar but later process to the domestication of animals. Historians term all sorts of deliberate human growth of plants, cultivation. Cultivation is a process by which humans plant seeds, care for the seedlings, harvest the mature plants and store some seeds for future use even while eating the majority of the harvest.
Most wild plants do not produce many seeds. They do not flood the ground around them with seeds, because any such seeds will quite naturally compete with the mother plant that created the seeds in the first place. Birds and animals may carry a number of seeds away in their feces, but the majority of new plants wind up competing for the same ground in the same ecological niche. Humans changed the balance of nature by first identifying plants that were good to eat, and then establishing seeds from those plants under favorable growing conditions.
The first type of cultivation, then, was probably horticulture. Horticulture is the care and tending of gardens — small plots of land yielding a variety of plant products for the use of an extended family or tribe. Many tribal peoples, including nomads, found horticulture to be a highly successful strategy for feeding themselves. In many areas, horticulturalists employed a technique called the slash-and-burn technique to prepare their garden areas. The largest and least useful trees in a proposed garden were de-barked in a broad ring at the base of the tree; the gardeners cut down smaller trees and shrubs with knives and axes. The whole area was then burned, creating a bed of ashes from the dead plant material. The garden would thrive for several years in the ashes, before the soil nutrients became exhausted; then the gardeners would move on.
A second, later type of cultivation is called agriculture. Where horticulturalists establish small gardens supporting a variety of useful plants, agriculture involves converting large stretches of territory to a single plant, in essence creating fields. Evidence of agriculture, as opposed to horticulture, does not appear in the archaeological record until about 4500 BCE, when it made rapid inroads in five areas world-wide. These five areas are sometimes called cultural hearths, for their role in helping establish both culture and civilization in their regions of the world. Each area developed a particular group of food and fiber plants for cultivation in fields, and these plants remain the core of the modern world's diet today.
Four of these areas came into existence in the Old World: Africa, Asia, and Europe. Because these areas were located in river valleys, the archaeological record notes different types of agriculture being domesticated in different locations. Several areas invented agriculture independently of one another. The Jordan valley and the area known as the Levantine corridor show evidence of some of the earliest domesticated wheat at Jericho and Tell Aswad by 8800 BCE. Domestication spread to the Tigris and Euphrates river valleys, and around a region of Mesopotamia commonly called the fertile crescent. Domestication in Mesopotamia involved in the cultivation of wheat, barley and other founder crops; peas, lentils, chickpeas, bitter vetch and flax. Another area is Egypt, whose Nile River became a garden country quite early, involved in the production of domesticated cotton, wheat and barley. The Indus River valley in India was the third region, involved in cultivating rice, barley, beans and other crops. The fourth region of the Old World was China, which produced rice, wheat and lentils. The fifth region followed a substantially different pattern. Mesoamerica, or southern Mexico and the nations of Guatemala, Honduras, Belize, Costa Rica, Nicaragua and El Salvador, had no vast river systems in which to build elaborate agricultural systems. Here, agriculture grew out of horticulture, as the gardens needed to sustain the local populations became larger and larger. In about 5200 BCE, a local grain called teosinte became the focus of an intense breeding program. By 2500 BCE, its seed stalks had doubled in size, and the seeds themselves had also doubled. By 1 CE, these seed stalks had increased in size by another third. This plant is today known as maize or corn, and it formed the basis of the diet of the Americas from around 2000 BCE even to the present day. Mesoamerica also domesticated a whole host of other plants, including cotton, chili peppers, gourds, squash, melons and potatoes. All of these modern-day agricultural crops originally came from Mesoamerican gardens.
Early humans may have seeded gardens at one campsite, and then gone on to visit other campsites for several months before returning to check on their plants. They would have found at least some of their efforts trampled or eaten by wild animals, stripped of their leaves by ravenous insects, or eaten by other hunter-gatherer family groups. Although the earliest tribes to practice horticulturalism may not have had strong senses of ownership over their gardens, later generations might have felt seriously inconvenienced, or perhaps even robbed. They would make plans to stay at campsites with gardens over longer periods of time, and harvested the results of their efforts. If they had planned on using the produce from their gardens for the purposes of holding a celebratory feast, they may have been even more irritated than usual with the thieves.
These humans usually developed their gardening campsites a little more thoroughly than they might at hunting or gathering grounds. Occasionally buildings of rough stones and roofed with branches and straw replaced tents. People dug wells or cisterns to provide local water sources for animals and people; they also dug irrigation ditches to provide water to their gardens in dry seasons. As people invested more time and energy into their camps and gardens, packing up and moving to a new campsite became less and less desirable. Eventually, people may have just decided to stick by their gardens year by year. The hunter-gatherers, once nomadic, now became sedentary.
"Ancient History/Human Evolution/Neolithic Age" (Wikibooks) en.wikibooks.org/wiki/Ancient_History/Human_Evolution/Neolithic_Age