World

History of the World: Human beings have probably lived on the earth about 2 million years. But the story of world history begins only about 5,500 years ago with the invention of writing. The period before people began to write is usually called prehistory.

 

Archaeologists have pieced together the story of prehistory by studying what the people left behind, including artwork, tools, ruins of buildings, fossils, and even their own skeletons. Such objects provide the main evidence of what prehistoric people were like and how they lived.

PREHISTORIC PEOPLE

 

Prehistoric people are human beings who lived before writing was invented about 5,500 years ago. Writing enabled people to record information they wished to save, including descriptions of events in their lives. In this way, the invention of writing marked the beginning of history. The period before human beings learned to write is called prehistory, and people who lived during this period are known as prehistoric people.

Most scientists believe the first human beings lived about 2 million years ago. But early humans probably arose from ancestors who first lived more than 4 million years ago. These pre-human ancestors were small, humanlike creatures who walked erect. This article will discuss both prehistoric people and their near ancestors.

Scientists first discovered evidence of prehistoric people during the mid-1800's. Most of this evidence consisted of ancient, sharp-edged tools that prehistoric people had made of stone. The first fossilized bones of prehistoric people were also found during this time.

As scientists collected more fossils of prehistoric people, they began to form a clearer picture of what these early people looked like. For example, fossil evidence showed that early human beings had smaller brains than most modern people have. This indicated to many scientists that humans had evolved--that is, modified their physical structure over time. Scientists developed a set of ideas about human origins called the theory of human evolution. This theory states that as the environment of the world changed, the pre-human ancestors of prehistoric people went through a series of changes that resulted in the first human beings. They, in turn, evolved into modern human beings.

Today, many kinds of scientists work together to learn about prehistoric people. Archaeologists search for and examine such physical evidence as pottery and tools to help explain how prehistoric people lived. Botanists study the remains of prehistoric plants, and zoologists analyses fossils of prehistoric animals that lived during the time of prehistoric people. Geologists study the layers of rock in which fossils are found. All these scientists are called anthropologists if their chief concern is the study of human physical and cultural development.

 

Evidence of prehistoric people--such as fossils, tools, and other remains--is rare and often fragmented. Evidence of the earliest types of prehistoric people is the most difficult to find. Anthropologists must base their theories about prehistoric people's way of life on this extremely limited evidence. As a result, scientists cannot yet present a detailed picture of early human life. In addition, new discoveries sometimes disprove theories that scientists already hold.

Pre-human ancestors: Most scientists believe that human beings and apes--such as chimpanzees and gorillas--share a common ancestor. To support this theory, scientists point out that the fossilized remains of ancient humanlike beings and apes reveal many similarities, including similar brain sizes. In addition, studies comparing the physical structure, blood, and genetic material of modern humans with those of apes show that people are more similar to apes than to any other living animal.

The ancestors of human beings probably began evolving separately from the ancestors of apes between about 10 million and 5 million years ago. This evolutionary split marks the beginning of the development of hominids. Hominids are members of the scientific family made up of human beings and early humanlike ancestors. Most anthropologists believe the first hominids were humanlike creatures called australopithecines.

Where and when they lived: The australopithecines first appeared more than 4 million years ago in Africa. Fossil evidence suggests that these creatures became extinct between 2 million and 1 million years ago, about when the first human beings appeared.

Scientists have discovered australopithecine fossils at sites in eastern and southern Africa. Because these are the oldest examples of hominid fossils, most scientists generally believe that the hominid family originated in Africa and prehistoric people later spread out into other parts of the world.

What they looked like: The australopithecines looked very different from modern human beings. In some ways, such as in their facial features, they may have resembled chimpanzees. However, many, if not all, australopithecine species could stand upright and walk on two legs, and their canine teeth were much smaller and less pointed than those of apes. These features identify australopithecines as members of the hominid family and separate them from the ape family.

The australopithecines had large faces that jutted out. Their brains were about one-third the size of modern human brains. Their molars were large, flat, and suitable for grinding food. Anthropologists believe from the shape of these creatures' teeth that they ate such foods as fruit, vegetables, nuts, seeds, and insects.

Types of australopithecines: The australopithecines were members of the genus Australopithecus (southern ape). According to differences in the shape of the creatures' jaws and teeth and the size of their brains, scientists have divided the genus Australopithecus into five species: (1) A. anamensis, (2) A. afarensis, (3) A. africanus, (4) A. robustus, and (5) A. boisei.

The earliest known species of Australopithecus was A. anamensis, which appeared in eastern Africa around 4 million years ago. This species seems to have evolved by about 3,700,000 years ago into another Australopithecus species, A. Afarensis. The most complete australopithecine fossil scientists have found is a partial skeleton of a female A. afarensis. It was found at Hadar, Ethiopia. Scientists estimate that this creature, nicknamed "Lucy," was more than 107 centimetres tall and weighed about 27 kilograms. A. afarensis had about the same size brain as that of a chimpanzee.

By about 3 million years ago, A. africanus had replaced A. afarensis. Scientists have found fossils of A. africanus at several sites in South Africa. These creatures had rounder skulls and slightly larger brains than those of A. afarensis, but in other features they were not much different.

Many scientists believe that an evolutionary split occurred among the australopithecines during the time of A. africanus. This split resulted in the appearance of an additional evolutionary line, separate from A. africanus, that led to A. robustus and A. boisei. Scientists refer to these two species as the robust australopithecines. They had larger molars and more powerful jaws than the other two species of Australopithecus. But their brain size was about the same as that of A. africanus. The earlier two species are called gracile (slender) australopithecines. The robust australopithecines probably became extinct between 1,500,000 and 1,000,000 years ago. The Australopithecus species were closely related to the first known hominids, Ardipithecus ramidus, which lived in what is now Ethiopia about 4,400,000 years ago.

The first human beings: Most anthropologists believe that the first human beings evolved from a gracile australopithecine about 2 million years ago. The oldest tools that scientists have found date from about 21/2 million years ago. But be-cause no hominid fossils were found with these tools, scientists do not know whether an australopithecine or an early human made them.

Most prehistoric tools that have been found and studied are made of stone. As a result, this period of time is called the Stone Age. Early toolmakers may also have used wood and other materials, but none of those tools have survived. The Stone Age lasted from the first use of stone tools until bronze replaced stone as the chief tool making material. In some areas, this occurred about 3000 B.C. The first part of the Stone Age is called the Palaeolithic Period. This period lasted until about 8000 B.C., after people had started farming. Even after some people learned to provide food by farming, many others continued to live by gathering wild plants and by hunting. These Stone Age hunters and gatherers who lived after 8000 B.C. are called Mesolithic people. Farmers from this period are called Neolithic people.

Homo habilis is considered by anthropologists to be the oldest human species. These prehistoric people lived in Africa about 2 million years ago. The Latin word homo means human being. Habilis means handy or skilful. Anthropologists have found important fossils of Homo habilis at sites east of Lake Turkana in northern Kenya and in Olduvai Gorge in Tanzania.

Homo habilis' brain was much larger than that of an australopithecine, but only about half the size of a modern human brain. Homo habilis also had smaller molars and a less protruding face than the australopithecines had. Some fossil evidence indicates that Homo habilis males were much larger than Homo habilis females. This difference, known as sexual dimorphism, appears among many modern primates. Scientists have also detected such a difference among the australopithecines. Among modern human beings, however, sexual dimorphism is less extreme.

Many anthropologists believe Homo habilis made the first tools. Some of the earliest known tools have been found with Homo habilis fossils. These devices were sharp-edged stones used for cutting, scraping, and chopping. Prehistoric people made them by striking one piece of stone with another, chipping pieces away to produce a cutting edge. These first tools were extremely crude, but over time early human beings began to craft tools of a finer quality. Later toolmakers started using mallets of wood or bone to tap away small chips of stone, producing a straight, sharp cutting edge.

Scientists believe Homo habilis ate meat in addition to fruit, insects, and plants. Archaeologists have found animal bones buried with stone tools from the time of Homo habilis. Many of the bones show scratch marks that were probably made by the cutting action of stone tools. These marks indicate that Homo habilis used tools to butcher game and to scrape meat off bones. But scientists do not know whether these early humans killed large animals themselves or merely ate the meat after the animals had been killed by predators.

Homo erectus: Fossil evidence indicates that by about 11/2 million years ago, Homo habilis had evolved into a more advanced human species. Scientists call this species Homo erectus. The term Homo erectus refers to the upright posture of these creatures. One of the best examples of Homo erectus that scientists have found is a nearly complete fossil skeleton of a boy who was probably about 12 years old. The skeleton, which is more than 11/2 million years old, was found west of Lake Turkana in northern Kenya.

Homo erectus probably stood slightly more than 150 centimetres tall. These creatures had thick skulls, sloping foreheads, and large, chinless jaws. Their skulls had a browridge, a raised strip of bone across the lower forehead. Homo erectus also had smaller molars, a smaller face, and a less protruding face than Homo habilis had. The brain size of early Homo erectus was only slightly larger than that of Homo habilis. During the course of Homo erectus evolution, however, brain size increased considerably. It eventually reached a size just slightly smaller than that of a modern human brain. Fossil evidence indicates that Homo erectus males were larger than Homo erectus females.

The earliest Homo erectus fossils have been found in Africa, where these prehistoric people probably remained until about 1 million years ago. Many scientists believe that prehistoric people had begun to migrate out of Africa by that time. Anthropologists have found fossil bones of Homo erectus that date from about 1 million years ago on the island of Java, in Indonesia. Homo erectus tools from the same time have been discovered in southern Europe and Asia. By about 500,000 years ago, Homo erectus had spread into northern Asia.

 

Homo erectus was probably the first human being to master the use of fire. These people may also have been the first to wear clothing. Scientists believe that as Homo erectus moved into northern areas and faced cold winters, fire and clothing became necessary. Archaeologists have not found any traces of early clothing, but it was probably made from animal hides. The oldest evidence of the use of fire was found in a cave that Homo erectus occupied about 500,000 years ago near what is now Beijing, in northern China. Stone tools and the remains of more than 40 Homo erectus individuals were found in the cave, along with burnt animal bones surrounded by thin layers of ash.

 

Homo erectus was a more skilful toolmaker than Homo habilis. For example, Homo erectus created double-edged cutting tools called hand axes out of stone. These early human beings probably used hand axes for many tasks, such as shaping wood or bone and cutting up meat. The bones of large animals, including mammoths, have been found at Homo erectus sites. But scientists do not know if these people actually hunted big game. They may have collected the remains of animals that had been killed by predators. The main foods in the Homo erectus diet were probably fruit, vegetables, nuts, seeds, insects, and small animals.

 

Early Homo sapiens: Between about 400,000 and 300,000 years ago, Homo erectus evolved into a new human species called Homo sapiens. Because evolution took place gradually during this time, anthropologists have found it difficult to say precisely when Homo sapiens first appeared. Anthropologists disagree on whether certain fossil specimens from this period are Homo sapiens or Homo erectus.

 

The term Homo sapiens means wise human being. All people living today belong to this species. But early Homo sapiens differed greatly from modern people.

 

The first Homo sapiens strongly resembled Homo erectus. The main difference between the two was that Homo sapiens had a higher and more rounded skull. However, like Homo erectus, the first Homo sapiens individuals had large faces that protruded around the mouth and nose. They also had big browridges and low, sloping foreheads. These people lacked a chin, a feature found only in the modern type of human beings.

 

The brain size of early Homo sapiens varied over a wide range. Some of these people had brains that were similar in size to those of late Homo erectus. Others had brains nearly as large as modern human brains.

 

Early Homo sapiens were about as tall as modern human beings. They were solidly built with powerful muscles and were probably much stronger than modern people. The difference in size between males and females that is so well marked in earlier hominids appears to be reduced in Homo sapiens.

 

Homo sapiens were the first prehistoric people to inhabit large areas of Europe. Anthropologists have found important Homo sapiens fossils in England, France, Germany, Greece, and Italy. Homo sapiens fossils have also been discovered in many parts of Asia and Africa.

 

Some of the most important evidence of Homo sapiens' way of life comes from a site called Terra Amata, which lies near Nice, France, along the coast of the Mediterranean Sea. Terra Amata was a settlement occupied by what some anthropologists believe was a group of Homo sapiens about 250,000 years ago or earlier.

 

At Terra Amata, scientists found evidence of tentlike structures that a group of Homo sapiens probably built for shelter. Further evidence indicates that this group stayed for periods of time at Terra Amata to hunt and gather food during a yearly round of various campsites. Prehistoric people did not form permanent settlements until farming began about 11,000 years ago. But the studies at Terra Amata suggest that earlier people created temporary settlements at specific locations based on their knowledge of food sources.

 

Neanderthals were a type of early Homo sapiens who lived in parts of Europe and the Middle East from about 130,000 to 35,000 years ago. Different types of early Homo sapiens occupied other parts of Africa, Europe, and Asia during this period. Neanderthals have become the most widely known of the early Homo sapiens mainly because they were the first prehistoric people to be discovered. The term Neanderthal, also spelled Neandertal, comes from the Neander Valley near Dusseldorf, Germany. The first Neanderthal fossils that scientists identified as prehistoric people were found there in 1856.

 

The Neanderthals were large and muscular. Like other early Homo sapiens, they had protruding faces, large browridges, and low foreheads. Most of them also lacked a chin. However, the Neanderthals had large brains. Their average brain size was larger than that of modern human beings.

 

Some Neanderthals lived in Europe during the Ice Age, when sheets of ice covered many northern parts of the world. These Neanderthals developed qualities that enabled them to cope with harsh winter conditions. Archaeologists have found most evidence of Neanderthals in caves, where many of these people lived to escape the extreme cold. But archaeologists have also discovered sites where Neanderthals camped in the open. These sites provide evidence that the Neanderthals pitched large circular tents around a central hearth area. The tent covering probably consisted of hides, leaves, or bark supported by wooden posts and secured to the ground by stakes made from animal bones.

 

The Neanderthals were more skilled hunters and toolmakers than earlier prehistoric people. The bones of many animals have been found at Neanderthal sites. Some of the bones indicate these people sometimes hunted such large animals as horses, reindeer, and mammoths. But they were more successful in capturing hares and other small animals. The Neanderthals made a variety of stone tools. They used these tools to butcher animals, prepare vegetable foods, scrape animal hides, and carve wood. They also made sharp, pointed tools that may have been spearheads.

 

The Neanderthals were the first human beings known to have buried their dead. In Neanderthal sites throughout Europe and the Middle East, archaeologists have uncovered the carefully buried skeletons of women, men, and children. Anthropologists do not understand why the Neanderthals adopted this custom.

 

The rise of modern human beings: The first prehistoric people with modern human features appeared about 100,000 years ago in either the Middle East or Africa. These people had a chin, a high forehead, and a smaller, less-protruding face than earlier Homo sapiens had. The first physically modern human beings also lacked the large brow ridge of earlier people and had a higher and more rounded skull. Scientists classify modern human beings as Homo sapiens sapiens, a subspecies of Homo sapiens.

 

Anthropologists are fairly certain that the first modern human beings evolved from earlier types of Homo sapiens. But scientists have had difficulty understanding the precise evolutionary relationship between modern humans and early Homo sapiens. For example, fossil evidence shows that Neanderthals lived in Europe and the Middle East after the modern type of human beings appeared. This evidence makes it difficult for scientists to determine whether Neanderthals were the ancestors of modern Europeans or were a related type of early human being that became extinct.

 

The question of human races is related to the origin of modern human beings. Most anthropologists today reject the idea that the human population can be divided into biologically defined races. Physical features of modern human beings change gradually from one region to another, making it difficult to draw a dividing line between them. However, anthropologists have observed that groups of people who have lived in certain parts of the world for many thousands of years tend to differ in appearance from groups in other parts of the world. These differences are probably adaptations to local environments. For example, people whose ancestors have lived for generations in sunny climates tend to have dark skin. Dark pigment helps protect the skin from sunburn and reduces the risk of skin cancer.

 

Anthropologists have developed two main theories to explain the origin of modern human beings and the development of what are sometimes called "races"--that is, the physical differences among populations in different regions. These theories may be referred to as (1) the multiple origins theory and (2) the single origin theory.

 

The multiple origins theory: Some anthropologists believe that the spread of separate human populations began with the migration of Homo erectus out of Africa about 1 3/4 million years ago. According to this theory, Homo erectus split into separate populations in Africa, Asia, and Europe. These groups evolved according to their different environments and developed different physical characteristics. Eventually, Homo erectus in each geographic area evolved into a form of Homo sapiens unique to the area. These multiple types of Homo sapiens, in turn, became the ancestors of the so-called modern human races.

 

The best evidence supporting this theory comes from a series of skulls found in Indonesia and Australia. In age, these skulls span a period beginning about 1 million years ago and lasting until the appearance of physically modern human beings. All the skulls show similar features that are characteristic of that part of the world. These fossils appear to represent a population that continuously evolved over time and resulted in modern Southeast Asian people.

 

The single origin theory: Other anthropologists disagree with the multiple origins theory and claim that separate modern human populations had a common ancestor much more recently. According to this single origin theory, modern human beings--Homo sapiens sapiens--first appeared in either Africa or the Middle East between 200,000 and 100,000 years ago. This modern type of human being then spread to other parts of Africa, Asia, and Europe, replacing the older populations of Homo sapiens who were living there. All other populations of early human beings, such as Neanderthals, became extinct. According to this theory, the development of different physical characteristics in today's so-called racial groups began with the spread of Homo sapiens sapiens from Africa or the Middle East.

 

Some of the best fossil evidence that supports this theory comes from cave sites in Israel. At two of these sites, called Qafzeh and Skhul, archaeologists excavated fossil skeletons of modern-looking human beings that date from about 100,000 years ago. But at a nearby site called Kebara, a Neanderthal skeleton that dates from about 60,000 years ago was found. Supporters of the single origin theory point out that it is difficult to place the Neanderthals as ancestors of modern human beings if they were known to have lived after modern human beings first appeared. Therefore, another group--the first modern humans from either Africa or the Middle East--must have replaced the Neanderthals.

 

Some scientists also support this theory through use of genetic evidence from living people. Molecular biologists have gained a greater understanding of human evolution by studying the rate of change of human genetic material. By calculating this rate of change, some scientists have concluded that all living human beings must have evolved from one physically modern human ancestor who lived about 200,000 years ago. In one version of this theory, the common ancestor--who has become known as African Eve--was a Stone Age woman in Africa. Although most scientists accept the conclusion of genetic studies that modern human beings originated in Africa, many of them believe this common ancestor appeared earlier than supporters of the single origin theory claim.

 

Cultural development of modern human beings: Fossil evidence indicates that the cultural activities of the first physically modern humans were similar to those of other Homo sapiens who lived during that time. For example, the modern-looking human beings from the 100,000-year-old sites of Qafzeh and Skhul were found with the same kinds of stone tools that Neanderthals used at sites nearby. Thus, the appearance of modern human beings did not represent a sudden change in life style or culture from the earlier populations.

 

Throughout the early stages of human evolution, the rate of cultural change among prehistoric people was extremely slow. Stone tools and other products of human skill remained unchanged for many thousands of years. However, about 35,000 years ago, the rate of cultural change began to accelerate rapidly. This later period is generally referred to as the Upper Palaeolithic.

 

During the Upper Palaeolithic, prehistoric people made an extraordinary number of advances in their way of life. The best-known type of human beings from this period is the Cro-Magnons. The Cro-Magnons lived in Europe, the Middle East, and North Africa from about 40,000 to 10,000 years ago. Scientists believe they resembled modern Europeans.

 

The improvement of tools was one of the major accomplishments of the Cro-Magnons and other Upper Palaeolithic people. After 35,000 years ago, new tool types and methods of manufacture appeared at a rapid pace. Stone tools made during this time were much more refined and complex in design. Toolmakers invented many new devices to serve specialized carving, cutting, and drilling functions. Tools made from bone, ivory, and animal horns also became widely used. Archaeologists have found harpoons, fish spears, and needles made from bone that date from this period. These tools suggest the introduction of many new activities, such as sewing close-fitting clothes and fishing with improved equipment.

 

Upper Palaeolithic fossil sites also indicate that these people had become skilful hunters. Some sites hold the remains of thousands of animals. In addition, the bones of mammoths, horses, and reindeer are common, suggesting these people hunted large animals successfully.

 

The appearance of art was one of the most spectacular developments of the Upper Palaeolithic. The oldest works of art that archaeologists have found date from this period. Furthermore, the practice of creating art seems to have spread rapidly--especially in Europe.

 

Some of the oldest artworks from the Upper Palaeolithic were ornaments, such as beads made from polished shells. After about 20,000 years ago, prehistoric people began to produce a variety of artwork. They excelled at carving--creating beautiful sculptures of animals and people, usually from ivory or bone. They also made engravings of people, fish, birds, and other animals on bone, ivory, and stone. The Upper Palaeolithic people also sculpted clay, ivory, and stone figurines of women, which may have represented fertility.

 

A number of caves in Europe are covered with paintings, drawings, and engravings from the Upper Palaeolithic. Most distinctive of these are the paintings, which appear on the cave walls and ceilings. Most of the paintings are of the animals early people probably hunted, including bison, mammoths, and horses. Some of the paintings show animals that have been speared.

 

Many of the paintings are of a high artistic quality. Palaeolithic artists used three basic colours: black, red, and yellow. They obtained these pigments from natural sources including charcoal, clay, and such minerals as iron. Often, the artists painted animals on a part of the cave wall where there was a natural swelling, which created a three-dimensional effect.

 

The development of speech: No one knows when or how spoken language developed. However, many anthropologists think that human beings may have first begun to speak sometime during the Upper Palaeolithic. These scientists believe that the many cultural developments which occurred at this time--especially the appearance of art--may be related to the development of speech. The beginnings of speech, the creation of artwork, and the making of complex tools all required advancements in human intelligence and cooperation.

 

The spread of settlement: Prehistoric people spread into new areas during the Upper Palaeolithic. Cultural and technological advances enabled them to migrate to such places as Australia, the Pacific Islands, and North and South America.

 

Perhaps as early as 50,000 years ago, people used boats to reach Australia. About 20,000 years ago, people from Australia and Asia began to colonize the Pacific Islands. These people employed sophisticated navigational systems that involved knowledge of the stars, water currents, and wind direction. They also used simple navigational instruments.

 

By 30,000 years ago, human beings had spread to the cold, harsh tundra of northeast Asia. At that time, the Bering Strait was a land bridge that connected Asia and North America. Most scientists believe that prehistoric people crossed this land bridge and were living in North America by 15,000 years ago. Eventually, early modern human beings populated all of North and South America.

 

The most recent ice age ended about 11,500 years ago. As the vast sheets of ice receded, the environment of many prehistoric people changed and greatly affected their way of life. In some areas, such as Europe, forests began to spread across the land. The people of these areas learned to hunt new species of animals and gather new varieties of plants from these forests. In other parts of the world, people began to experiment with methods of controlling their supply of food. This led to the beginning of farming.

 

The rise of agriculture, according to most scientists, began in the Middle East about 11,000 years ago, or 9000 B.C. The first farmers lived in a region called the Fertile Crescent, which covers what is now Lebanon and parts of Iran, Iraq, Israel, Jordan, Syria, and Turkey. At first, these people probably did not depend entirely on the crops they grew. But as they improved their methods, farming became their most important source of food. The earliest plants grown in the Middle East were probably barley and wheat. Early farmers in the Middle East eventually reared cattle, goats, pigs, and sheep.

 

The first farmers originated in areas where there were enough wild plants and animals to provide food for large populations. As a result, people often settled in permanent villages for years at a time. At the end of the Ice Age, the climate became warmer and affected the food supply. New plants, such as grains, replaced older plants. Scientists believe that Upper Palaeolithic people were able to remain in permanent settlements because they discovered how to control these new plants and increase the amount of food in their area. They learned that they could plant seeds from the plants that they ate. They also learned that they could domesticate animals, perhaps by capturing young ones from the wild and rearing them. In time, people began to depend on these planted crops and domestic animals for a steady supply of food.

 

By about 7000 B.C., agriculture had developed independently in Asia and southern North America. In what are now Thailand and southern China, farmers grew breadfruit, bananas, and rice, while people in what became Mexico grew beans, maize, and vegetable marrows.

 

People were herding cattle and growing grain in northern Africa by 6000 B.C. By that time, people had also begun to farm in the Indus River Valley of what is now Pakistan. By 4000 B.C., farming had begun in the Huang He Valley of China. Farming spread throughout most of Europe by 3000 B.C. Farming in most parts of North and South America began after prehistoric times. Food was probably more plentiful in these areas, so farming did not become necessary until later.

 

Changes in life style: Prehistoric farmers, called Neolithic people, had a way of life that differed greatly from that of Upper Palaeolithic people. In some ways, farming made life easier. It provided a steady supply of food and enabled people to stay in one place for a long time. However, farmers also had to work longer and harder than did hunters and gatherers.

 

Prehistoric farmers set up villages near their fields and lived there as long as their crops grew well. Most fields produced good crops for only a few years. The land then became unproductive because continuous planting used up nutrients in the soil. The early farmers did not know about fertilizers that could replace these nutrients. They shifted their crops to new fields until none of the land near their village was fertile. Then they moved to a new area and built another village. In this way, farmers settled many new areas.

 

Prehistoric farmers built larger, longer-lasting settlements than the camps that Palaeolithic people had built. In the Middle East, for example, early farmers constructed their houses of solid, sun-dried mud. Dried mud was much more resistant to weather than the materials earlier people used, such as skins and bark. The early farmers also learned to build fences to confine and protect their livestock.

 

The end of prehistoric times: Neolithic people made inventions and discoveries at an even faster rate than did the people of the Upper Palaeolithic. Early farmers developed a number of useful tools. These implements included sickles to cut grain, millstones to grind flour, and polished stone axeheads.

 

By about 11,000 B.C., people had discovered how to make pottery. Before that time, they used animal skins or bark containers to hold water. To boil water, early cooks had to drop hot stones into the water, because they could not hang animal skins or bark over a fire. Pottery containers enabled people to hold and boil water easily. After the rise of agriculture, people used pottery to store grain and other food.

 

No one knows when people made the first objects out of metal. But metals became important only after metalworkers learned to make bronze, a substance hard and durable enough to make lasting tools. People of the Middle East made bronze as early as 3500 B.C. The Bronze Age began when bronze replaced stone as the chief tool making material. In some areas, such as the Near East, the Bronze Age began about 3000 B.C.

 

The development of farming was an important step toward the rise of civilization. As farming methods improved and food became more plentiful, many people were freed from the jobs of food production. These people developed new skills and trades. In addition, the abundant food supply enabled more people to live in each community. In time, some farming villages became cities. The first cities appeared by about 3500 B.C. These cities were the birthplaces of modern civilization.

 

Archaeologists believe writing was invented about 3500 B.C. in cities in the Tigris-Euphrates Valley in what is now Iraq. People then learned to record their history, and prehistoric times came to an end.

 

The first traces of writing date from about 3500 B.C. From then on, people could record their own history. By writing down their experiences, they could tell future generations what they were like and how they lived. From these documents, we can learn firsthand about the rise and fall of civilizations and the course of other important events. The history of the world--from the first civilizations to the present--is based largely on what has been written down by peoples through the ages.

 

The beginnings of agriculture about 9,000 B.C. brought about a great revolution in human life. Prehistoric people who learned to farm no longer had to roam in search of food. Instead, they could settle in one place. Some of their settlements grew to become the world's first cities. People in the cities learned new skills and developed specialized occupations. Some became builders and craft workers. Others became merchants and priests. Eventually, systems of writing were invented. These developments gave rise to the first civilizations.

 

For hundreds of years, the earliest civilizations had little contact with one another and so developed independently. The progress each civilization made depended on the natural resources available to it and on the inventiveness of its people. As time passed, civilizations advanced and spread and the world's population rose steadily. The peoples of various civilizations began to exchange ideas and skills. Within each civilization, groups of people with distinctive customs and languages emerged. In time, some peoples, such as the Romans, gained power over others and built huge empires. Some of these empires flourished for centuries before collapsing. Great religions and later science and scholarship developed as people wondered about the meaning of human life and the mysteries of nature.

 

About 500 years ago, one civilization--that of Western Europe--started to exert a powerful influence throughout the world. The Europeans began to make great advances in learning and the arts, and they came to surpass the rest of the world in scientific and technological achievements. The nations of Europe sent explorers and military forces to distant lands. They set up overseas colonies, first in the Americas and then on other continents, and conquered other regions. As a result, Western customs, skills, political ideas, and religious beliefs spread across much of the world.

 

Today, the many peoples of the world continue to be separated by different cultural traditions. But they also have more in common than ever before. Worldwide systems of communications and transportation have broken down barriers of time and distance and rapidly increased the exchange of ideas and information between peoples. However far apart people may live from one another, they are affected more and more by the same political and economic changes. In some way, almost everyone can now be affected by a war or a political crisis in a faraway land or by a rise in petroleum prices in distant oil-producing countries. The separate cultures of the world seem to be blending into a common world culture. Much of world history is the story of the way different civilizations have come closer together.

 

World, History of the Early Centers of Civilization

 

For hundreds of thousands of years, prehistoric people lived by hunting, fishing, and gathering wild plants. Even small groups of people had to roam over large areas of land to find enough food. A group usually stayed in one place only a few days. The discovery of agriculture gradually ended the nomadic way of life for many people. After prehistoric men and women learned to raise crops and domesticate animals, they no longer had to wander about in search of food. They could thus begin to settle in villages.

 

Agriculture was developed at different times in different regions of the world. People in the Middle East began to grow cereal grasses and other plants about 9000 B.C. They also domesticated goats and sheep at about that time, and they later tamed cattle. In southeastern Asia, people had begun raising crops by about 7000 B.C. People who lived in what is now Mexico probably learned to grow crops about 7000 B.C.

 

 

 

The invention of farming paved the way for the development of civilization. As prehistoric people became better farmers, they began to produce enough food to support larger villages. In time, some farming villages developed into the first cities. The plentiful food supplies enabled more and more people to give up farming for other jobs. These people began to develop the arts, crafts, trades, and other activities of civilized life.

 

Agriculture also stimulated technological and social changes. Farmers invented the hoe, sickle, and other tools to make their work easier. The hair of domestic animals and fibres from such plants as cotton and flax were used to make the first textiles. People built ovens to bake the bread they made from cultivated grain and learned to use hotter ovens to harden pottery. The practice of agriculture required many people to work together to prepare the fields for planting and to harvest the crops. New systems of government were developed to direct such group activities.

 

The changes brought about by agriculture took thousands of years to spread widely across the earth. By about 3500 B.C., civilization began. It started first in Southwest Asia. Three other early civilizations developed in Africa and in south and east Asia. All these early civilizations arose in river valleys, where fertile soil and a readily available water supply made agriculture easier than elsewhere. The valleys were (1) the Tigris-Euphrates Valley in the Middle East, (2) the Nile Valley in Egypt, (3) the Indus Valley in what is now Pakistan, and (4) the Huang He Valley in northern China.

 

While civilization was developing in the four valleys, people in most other parts of the world were still following their old ways of life. Little cultural progress was being made in such regions as northern and central Europe, central and southern Africa, northern and southeastern Asia, and most of North America. In parts of Central and South America, the people were developing some new ways of life. But advanced civilizations did not appear there until hundreds of years later.

 

The Tigris-Euphrates Valley: One of the most fertile regions of the ancient world lay between the Tigris and Euphrates rivers in southern Mesopotamia (now Iraq). Silt deposited by the rivers formed a rich topsoil ideal for growing crops. By the 5000's B.C., many people had settled in villages in the lower part of the Tigris-Euphrates Valley, an area later called Summer.

 

The Sumerians lived by farming, fishing, and hunting the wild fowl of the river marshes. They built dykes to control the flooding of the Tigris and Euphrates rivers and irrigation canals to carry water to their fields. By about 3500 B.C., some Sumerian farm villages had grown into small cities, which marked the beginning of the world's first civilization. A number of these cities developed into powerful city-states by about 3200 B.C.

 

The Sumerians produced one of the greatest achievements in world history. By about 3500 B.C., they had invented the first form of writing. It consisted of picturelike symbols scratched into clay. The symbols were later simplified to produce cuneiform, a system of writing that used wedge-shaped characters. Archaeologists have found thousands of clay tablets with Sumerian writings. These tablets show the high level of development of the Sumerian culture. They include historical and legal documents; letters; economic records; literary and religious texts; and studies in mathematics, astronomy, and medicine.

 

The Sumerians used baked bricks to build great palaces and towering temples called ziggurats in their cities. They believed that their gods lived on the tops of the ziggurats. Sumerian craft workers produced board games, beautifully designed jewellery, metal ware, musical instruments, decorative pottery, and stone seals engraved with pictures and inscriptions. The Sumerians invented the potter's wheel and were among the first people to brew beer and make glass. Their system of counting in units of 60 is the basis of the 360-degree circle and the 60-minute hour.

The Sumerian city-states had no central government or unified army and continually struggled among themselves for power. As time passed, they were increasingly threatened by neighboring Semitic peoples, who were attracted by the growing wealth of the Tigris-Euphrates Valley. During the 2300's B.C., a Semitic king, Sargon of Akkad, conquered Sumer. Sargon united all Mesopotamia under his rule, creating the world's first empire. The Akkadians combined Sumerian civilization with their own culture. Their rule lasted more than 60 years. Then invaders from the northeast overran the empire. These invaders soon left Mesopotamia, and Sumer was once again divided into separate city-states. One city-state, Ur, briefly controlled all the others.

 

By about 2000 B.C., the Sumerians had completely lost all political power to invading Semites. Mesopotamia then broke up into a number of small kingdoms under various Semitic rulers. The city of Babylon became the centre of one kingdom. The Babylonian rulers gradually extended their authority over all Mesopotamian peoples. The greatest Babylonian king was Hammurabi, who ruled from about 1792 to 1750 B.C. Hammurabi developed one of the first law codes in history. The famous Code of Hammurabi contained nearly 300 legal provisions, including many Sumerian and Akkadian laws. It covered such matters as divorce, false accusation, land and business regulations, and military service.

 

In Syria in the 2000's B.C., a powerful Semitic kingdom called Ebla grew up in northern Syria. Its economy was based upon the making of metal products and textiles and it traded with many states. Other states paid tribute (taxes) to Ebla. Ebla was destroyed before 2000 B.C.

 

The Nile Valley: The civilization of ancient Egypt began to develop in the valley of the Nile River about 3100 B.C. Agriculture flourished in the valley, where the floodwaters of the Nile deposited rich soil year after year. Beyond the Nile Valley lay an uninhabited region of desert and rock. Egyptian culture thus developed with little threat of invasions by neighboring peoples.

 

During the 3000's B.C., Egypt consisted of two large kingdoms. Lower Egypt covered the Nile Delta. Upper Egypt lay south of the delta on the two banks of the river. About 3100 B.C., according to legend, King Menes of Upper Egypt conquered Lower Egypt and united the two kingdoms. Menes also founded the first Egyptian dynasty (series of rulers in the same family). The rulers of ancient Egypt were believed to be divine.

 

The ancient Egyptians borrowed little from other cultures. They invented their own form of writing--an elaborate system of symbols known as hieroglyphics. They also invented papyrus, a paper like material made from the stems of reeds. The Egyptians developed one of the first religions to emphasize life after death. They tried to make sure their dead enjoyed a good life in the next world. The Egyptians built great tombs and mummified (embalmed and dried) corpses to preserve them. They filled the tombs with clothing, food, furnishings, and jewellery for use in the next world. The most famous Egyptian tombs are gigantic pyramids in which the kings were buried. The pyramids display the outstanding engineering and surveying skills of the Egyptians. The government organized thousands of workers to construct the pyramids, as well as temples and palaces, in the Egyptian cities. The cities served chiefly as religious and governmental centers for the surrounding countryside. Most of the people lived in villages near the cities.

 

Over the years, huge armies of conquering Egyptians expanded the kingdom's boundaries far beyond the Nile Valley. At its height in the 1400's B.C., Egypt ruled Syria, Lebanon, Palestine, and part of the Sudan. As a powerful state at the junction of Asia and Africa, Egypt played an important role in the growth of long-distance trade. Egyptian caravans carried goods throughout the vast desert regions surrounding the kingdom. Egyptian ships sailed to all the major ports of the ancient world. From other lands, the Egyptians acquired gems, gold, ivory, leopard skins, fine woods, and other rich materials, which they used to create some of the most magnificent art of ancient times.

 

Although the ancient Egyptians had contacts with other cultures, their way of life changed little over thousands of years. Their civilization gradually declined, and the Egyptians found it harder and harder to resist invaders who had greater vigour and better weapons. Egyptian records from the 1200's and 1100's B.C. describe constant attacks by "sea peoples." These peoples may have come from islands in the Aegean Sea or from lands along the east coast of the Mediterranean Sea. After 1000 B.C., power struggles between rival Egyptian dynasties further weakened the kingdom.

 

The Indus Valley: Historians have only partly translated the writings left behind by the ancient civilization that arose in the valley of the Indus River and its tributaries. As a result, they have had to rely almost entirely on archaeological findings for information about the Indus culture. The ruins of two large cities--Mohenjo-Daro and Harappa--tell much about the Indus Valley civilization. The remains of hundreds of small settlements have also been discovered in the valley. Some of these settlements were farming villages, and others were seaports and trading posts.

 

Mohenjo-Daro and Harappa probably had more than 35,000 inhabitants each by about 2500 B.C. The people of the Indus Valley had a well-developed system of agriculture that provided food for the large population. They dug ditches and canals to irrigate their farms. The Indus cities had brick buildings and well-planned streets laid out in rectangular patterns. Elaborate brick-lined drainage systems provided sanitation for the towns. Craft workers made decorated furniture, fine jewellery, metal utensils, toys, and stone seals that were engraved with animal and human forms. Inscriptions on these seals as well as on some pottery and a few other objects, provide the only traces of Indus writing that have been discovered so far.

 

Archaeologists have discovered that standardized sizes of bricks and uniform weights and measures were used throughout the Indus Valley. The Indus settlements traded with one another and with foreign cul