Ancient History/Human Evolution/Paleolithic Age

From Wikibooks, open books for an open world
< Ancient History‎ | Human Evolution
Jump to: navigation, search

The Paleolithic Era

The Paleolithic (or Palæolithic) Era, is the name historians give to the time period between 2.6 million years ago, and approximately 12,000 years ago. Historians categorize the Paleolithic Era as prehistory because there was no written language to record events, names, dates or places. Everything we know today about prehistory, including the Paleolithic age, is as a result of the investigations of paleo-anthropologists, archaeologists, physical and cultural anthropologists, zoologists, chemists, botanists, physicists, historians and dedicated amateurs. It is difficult and under-appreciated work, but it is necessary if our understanding of the past is to advance.

Hominids

Homo erectus

Four useful developments came about during this time. These developments were very important to the Homo habilis they helped with everyday doings including hunting and cooking. Tools, the ideas of tools, fire and shelter are the four developments that were introduced to the Homo habilis. A fifth development was language, it acted both as a cultural artifact and mental change.

Homo neanderthalensis

Neanderthal humans were a prehistoric, stone-tool using species of human, the last of which are thought to have lived 28,000 years ago. First published in 1863 from a cave in Germany's Neander Valley, Neanderthal remains and associated tools have since been found across Eurasia from Gibraltar to Uzbekistan. The average adult Neanderthal was much more powerfully built than a modern adult human, with distinct facial features including low, thick brow ridges. Neanderthals inhabited Europe during Ice Age periods, surviving extremely harsh climatic conditions which may have prompted the evolution of their stout, muscular frames.

Neanderthals buried their dead, and even included flowers with some burials. When Homo sapiens arrived in Europe 40,000 - 50,000 years ago, Neanderthals were present. There has been much speculation about contact and even interbreeding between the two types of human, but genetic surveys have never found modern humans with DNA that could be matched to DNA recovered from Neanderthal remains. It is possible that modern humans, using more refined tools and techniques for hunting, out-competed Neanderthals for food resources and brought about their extinction.

Homo sapiens

Anthropologists believe that modern man, or Homo sapiens, emerged as a distinct species by about 100,000 years ago. Extensive studies of ancient human remains and shelters seem to show that groups of Homo sapiens left Africa and entered Asia via the Middle East around 65,000 years ago.

The first modern humans to evolve in Africa lived mainly on meat. By 70,000 years ago, they had switched to a marine diet consisting largely of shellfish. This new research suggests they moved along the coasts of the Arabian peninsula into India, Indonesia and Australia about 65,000 years ago. An offshoot later settled the Middle East and Asia about 30,000 to 40,000 years ago. (Ref: BBC News 13 May 2005 "Early humans followed Coast" )

By 35,000 to 40,000 years ago, modern humans were living across the Old World from Europe to Australia. About 12,000 to 15,000 years ago, humans crossed into North America from Asia via Beringia, a now submerged land bridge that existed during the Pleistocene Ice Age when sea levels were lower. They rapidly spread across North and South America after the climate became warmer and the ice sheets retreated.

Around 10,000 years ago agriculture began at sites such as Jericho and Catal Huyuk in the Fertile Crescent, an area in the Middle East between the eastern Mediterranean Sea and the Persian Gulf. These early towns and villages were generally located near sources of water for growing crops. It was not until millennia later that humans developed irrigation techniques and could grow crops using the rising and falling waters of The Fertile Crescent's twin rivers, the Tigris and the Euphrates. This period is generally accepted as the birth of modern civilization and the beginning of the nation-state.

Hominids to Humans

Physical Changes

As hominids developed into humans (Homo sapiens), they underwent various physical changes. Most obviously, our ancestors learned to walk upright on two legs, rather than alternating between two legs and four legs. This straightened the spine, and moved the foramen magnum from the back of the skull to the underside. Hominin faces flattened, and the space between the eyes narrowed, so that they could look forward and see from side to side.

Our ancestors also developed a taste for a broad variety of foods. Early hominids, like Australopithicus robustus, were clearly vegetarian plant-eaters, based on their teeth and jaw structure. But later hominids, including Australopithicus afarensis and Homo erectus, clearly used their incisors to tear meat and their molars to chew it.

Mental Changes

Mental changes in early hominins were substantial. From Australopithicus afarensis, who had barely 300 cubic centimeters of brain size, hominin heads eventually expanded to Homo neanderthalensis's impressive 1950 cubic centimeters. At least some of this expanded brain power was shifted from processing scents to processing sights and sound. Another substantial portion went to controlling the auditory and language functions. Smell diminished in importance as more brain power was reserved for looking, listening and talking.

The modern Homo sapiens brain is actually smaller than neandethalensis, but paleoanthropologists theorize that once the brain reached an optimum size for certain kinds of work, it began specializing, miniaturizing, and integrating. The result is that the modern human brain may be smaller, but its critical functions are much more closely packed into a narrower space, for more efficient functioning. In this way, the process of evolution continued in early humans.

Technological Changes

The Paleolithic Era accounts for millions of years of human experience, a period many times longer than the mere ten thousand years that something resembling civilization can be said to have existed. This first primitive era saw few changes in how humans lived. Yet four great developments did occur which represent some of the most momentous changes in human lifestyles. These four changes may be summarized: the idea of a tool, a range of tools, fire, and shelter. A fifth "tool", language, acts as both a cultural artifact and a mental change.

Tools

Tools seem like such a basic part of everyday life that it is hard to imagine a world without them. The computer you are using to read this book is a tool, though, and so is the desk or table on which the computer rests. Your chair is a tool, and the electricity which powers your computer is provided by another tool, a power plant which converts other forms of energy into electrical power. Tools, in a very real sense, are all artifacts -- objects made by human hands to serve some purpose.

In the early Paleolithic period, from about 3 million years ago until 1 million years ago, the hominids from which we arose lived much like other animals: they hunted and gathered food from natural sources, and ate only the food that was immediately edible to a human digestive system. No one appears to have had any tools at all. Some early hominids were vegetarian; others were meat-eaters. Yet neither group cooked their food, consuming it raw instead. This placed significant limitations on their diets — a number of plants and animals cannot be consumed and digested raw.

About two million years ago, our predecessor, a hominid known as Homo habilis used his hands with opposable thumbs to construct a crude tool from stone. This tool, called a hand axe was about the size of a modern adult male's fist, bi-faced, with a sharp point. The hand axe was used for breaking open bones to scoop out the rich marrow inside, a popular food item among hominids. No doubt, the same tool served as a weapon as well.

The hand axe was formed by taking a nodule of flint, and gradually breaking away all the pieces of flint which did not match the shape of the ideal hand-axe. This process is called core-formed flint-knapping, because it takes a lump of flint and gradually disposes of all of the flint which does not match the desired shape.

Homo habilis and his relatives made core-formed hand axes for a million years before a new group of hominids, Homo erectus, hit upon a new technology which reverberates to the present day. Before Homo erectus, there was only one tool in the world, and it was a hand axe. However, Homo erectus hit upon a new method for producing hand axes. Instead of chopping away at a flint nodule until it looked like a hand axe, the new tool-makers would knock a piece of flint off a core, and then shape the splinter, or flake to the desired shape. This process created numerous microliths, or sharp pieces of flint or chert, which could be used as small knives or as scrapers on hides or bone.

The development of flaking, or using smaller chips from a flint nodule rather than the main core of the nodule, spread rapidly. Within 100,000 years, nearly all peoples in the world were using the new technique for making hand axes. Something else interesting happened as well. As the technique of flaking spread, new forms of flaking appeared as well. No longer were hominids making only hand axes. They began creating a whole series of new tools out of flint and quartzite and chert and obsidian: burins, or drills, for putting holes in wood; awls for punching holes in leather; scrapers for cleaning the meat off of hides and bones; knives for cutting meat or vegetables; points for spears (and later still, arrows); and chisels for working stone, wood and bone.

Tool Specialization

Archaeologists would say that the denizens of the late Paleolithic had begun to specialize. Specialization in a historical context means the development of new forms to accommodate new activities. The hand axe had been a sufficient tool when everyone in the world was interested in collecting marrow from the insides of bones. However, around one million years ago, there was an explosion of new tool types, ranging from needles to drills to knives.

The increasing number of tool types suggests to archaeologists that there was also an explosion in the number and types of human activity. Why make a needle, if there is no thread to use with it? Why make a needle, if you have no cloth or leather to sew together? The presence of so many tools shows that hominids were opening oysters with finesse, instead of simply smashing the shells. They were sewing leather or plant material together, to make baskets and bags and clothing. They were drilling holes in wood, to make houses or boats. They were scraping hides because they wished to make leather. They were making knives to use in their kitchen areas because they were making more complex types of food. They were making spears because they were hunting large animals -- and defending themselves against human predators as well.

Perishable Tools

Other types of tools show up in the late Paleolithic age. It is hard to tell what they are, however, because many of these tools are made of perishable materials such as wood, bone, leather and cloth. We can guess at their existence today only by hints. If a bone fishing hook appears at an archaeological site, we can presume they had fishing line, perhaps made out of vegetable fibers. If a stone with a specific shape and a hole in it is found, scientists can guess at the existence of a spinning spindle, to make thread. The presence of beads in patterns in a grave suggests thread for the beads to be strung upon, or even clothing for the beads to be sewn on. It is hard to make generalizations about the existence of baskets in the Paleolithic period, but people must have made nets, baskets and bags for carrying food and fruit, and catching fish, at many places around the world.

Fire

Sometime between 300,000 and 1.5 million years ago, humans also tamed fire. Taming fire may not be the same as controlling it. Some scientists believe that the hominid Homo erectus stumbled upon a lightning-struck tree or a forest fire, and captured a few coals in a basket, a bag or an animal horn. It may not have been able to put out the fire and re-start it, but it at least had some coals from which it could keep a hearth fire alive.

Homo erectus used fire in a number of interesting ways. First, their overnight stops now included a warm and welcoming light at the center and a fire that kept animals at bay. Second, that warm and welcoming light also provided enough heat to cook food. New plants and animal foods became open to humans for the first time as a result of this tamed fire. Third, the heat and light on a torch could be used to start large fires, and drive animal prey towards a trap or ambush site. Homo habilis could now catch a lot more food on the hoof. Fourth, the same fire could be used to drive away predators. It made camps safer, and it gave hominids a new tool for defeating rivals who ate the same animals. Finally, fire probably stimulated the creation of language. As early peoples sat around the fire, they would have enacted stories from their family history, and discussed new tool types. At first, these conversations may have been mere gestures accompanied by grunts, perhaps boastful males re-enacting their daring deeds of the day. However, over dozens or hundreds of generations, hominids would have developed strong speech centers in the brain, which would make word banks and grammars possible. The existence of many language families in the world today is one strong argument for the independent development of language. Language seems inherently human, a process linked to thinking and the development of reason.

Yet all of these many benefits of fire would be canceled if the people failed to keep their fire fed. The coals would go out, and all the benefits of having fire would be lost, for the hominids had no way to restart the flame once it was extinguished and the coals turned to ash.

Controlling Fire

Sometime between 500,000 and 1 million years ago, one of the hominids (probably Homo erectus) discovered that some stones gave off sparks when they were struck together. They also discovered that friction can produce heat, and heat can produce sparks which then generate flame. Four techniques developed for mastering friction and sparks. The first of these simply involved jamming one stick into a groove in another stick, and rubbing back and forth until the friction produced a spark or a flame. The second method, the drill method, involves twirling one stick against another until the heat produced generates a spark or a flame. Bow-drilling, the third method, involves using a bow with a cord strung around the vertical stick, to speed the friction and increase the likelihood of flame. The fourth method requires a naturally occurring ferrous metal and a piece of flint; when the two are struck together, the resulting sparks can start a fire.

With four methods for generating fire, hominids no longer needed to fear the loss of their coals. Bowdrilling or stick rubbing were slow and inefficient ways of starting a fire, but they worked reliably and well. Now hominids really controlled fire, because they could let it go out, and start it again, whenever they needed and wherever they wanted. It was likely considered an almost magical process. The Greek myth of Prometheus attributes almost mystical power to the ability to control fire, and declared that the wrath of the gods must surely fall on one who knew such secrets. More: Karlo Sostaric, Book Isis and Osiris

Clothing

The third technological shift represents the development of shelter and clothing. Most clothing is made out of perishable materials like leather and cloth, which readily decay in the ground after only short periods of time. Modern scientists can only postulate the existence of clothing in the Paleolithic Age from the existence of needles and other tools for sewing and preparing hides. Archaeologists find one possible sign of clothing in the Paleolithic era, though: in some very ancient grave sites, a thin layer or halo of colored earth surrounds the skeleton. Most scholars believe this red ocher residue to be the remnants of paint smeared on the body. However, some believe this colored earth to be the remains of clothing at burial.

Certainly, later Neanderthal man (Homo neanderthalensis) started burying their dead. The graves tend to be very simple. Often the dead person is buried in a fetal position, suggesting the same shape in death as the infant at birth. Flowers are often scattered in the grave, along with strands of beads and a few simple tools. The custom of burying someone with grave goods remains a consistent part of human life in many places even today.

Shelter

Most early hominids probably lived in the open air, near to sources of food and water. They chose locations that could be defended against predators and rivals and that were shielded from the worst weather. Many such locations could be found near rivers, lakes and streams, perhaps with low hilltops nearby that could serve as refuges in troubled times. Since water can erode and change landscapes quite drastically, both in the course of ordinary motion and catastrophe, many of these campsites are utterly destroyed, and not even skilled archaeologists can find them, much less reconstruct them. Our understanding of Paleolithic dwellings is thus necessarily limited.

Even so, a few examples of Paleolithic houses exist, although they only come to light very recently in the Paleolithic era, no more than 200,000 years ago. These "houses" are more frequently campsites within caves or in the open air, with little in the way of formal structures for living in. However, as the Paleolithic era progressed, dwellings became more sophisticated, more elaborate, and more house-like. The oldest examples are shelters within caves, followed by houses of wood, straw and rock; a few examples exist of houses built out of bones.

Caves

Caves are the most famous example of Paleolithic shelter, though the number of caves used by Paleolithic peoples is drastically small compared with the number of hominids thought to have lived on earth 500,000 years ago. Most hominids probably never entered a cave in their lives, much less lived in one. Nonetheless, the remains of hominid settlement show interesting patterns. In one cave, a tribe of Homo neanderthalensis kept a hearth fire burning for a thousand years, leaving behind an accumulation of coals and ash. In another cave, post holes in the dirt floor reveal that the residents built some sort of shelter or enclosure with a roof to protect themselves from water dripping on them from the cave ceiling. They often used the rear portions of the cave as middens, depositing their garbage in the back of the cave.

In the later, more recent Paleolithic period, about 125,000 years ago, caves ceased to act as houses. Instead, they became religious or magical places for early peoples to gather for ritual purposes. Caves, such as Lascaux in France and Altamira in Spain, became art galleries filled with elaborate images of horse, bison, buffalo, mammoths and other animals. Lit by flickering firelight, these images appeared to move and come alive. Archaeologists do not know whether ancient peoples worshiped these images or used them for the purpose of working magical spells on the animals they hunted. Modern visitors to such caves are awed by the beauty of these ancient artworks, even so.

Some scholars today believe that these caves were the work of Homo sapiens sapiens -- our own direct ancestor. As of this writing, no artwork has yet been found at any Homo erectus or Homo neanderthalensis archaeological site, anywhere in the world. The creation of art, and the symbolic thinking that goes with creating sculptures or paintings, may truly be the mental process that separates human beings from other types of animals. Other scholars contest this claim.

Tents and Huts

Other than caves, modern archaeologists know few other types of shelter available to ancient peoples. Some examples exist, but they are quite rare. In Siberia, a group of Russian scientists uncovered a house or tent with a frame constructed of mammoth bones. The great tusks supported the roof, while the skulls and thigh bones formed the walls of the tent. Several families could live inside, where three small hearths, little more than rings of stones, kept people warm during the winter. Archaeologists presume that the roof was made of mammoth hides in several layers. Similar houses existed in France and Germany; all date to about 90,000 years ago.

Much more recently than that, around 50,000 years ago, a group of Paleolithic Homo sapiens camped on a lake shore in southern France. At Terra Amata, these hunter-gatherers built a long and narrow house. The foundation was a ring of stones, with a flat threshold stone for a door at either end. Vertical posts down the middle of the house supported roofs and walls of sticks and twigs, probably covered over with a layer of straw. A hearth outside served as the kitchen, while a smaller hearth inside kept people warm.

Both dwellings could be easily abandoned by their residents. This is why they are not considered true houses, which was a development of the Neolithic period rather than the Paleolithic period. However, they give us brief looks at the lives of our most distant ancestors.

Language and Culture

In modern eyes, perhaps the most significant technology of the Paleolithic Age was the development of language. Language is not strictly speaking a technology—you cannot hold it or touch it. Instead, it relies upon changes in the human brain—the development of speech centers to govern the tongue and lips to produce precise sounds, the development of memory to hold lists of words, the development of rules to govern how those words are used in different circumstances, and the development of hearing centers in the brain to process foreign sounds as words within a set of rules. These functions did not come overnight. Fire may have stimulated some of them: ancient peoples sat or danced around fires, and they must have had stories to tell each other of their discoveries. Hunting stimulated others: needing to catch food that ran away required co-ordination among different hunters. People also created language while searching for edible plants, and plants with medical properties to cure or lessen the hurts of themselves and their families.

With the development of language came the development of culture. Having a name for a thing -- be it a plant, an animal, a stone, a tool, or an event -- meant that early humans carried ideas about how the world worked. They taught those ideas to their children, and to their children after them. Young people not only learned what plants to eat and what not to eat, they learned about the dead and the living within their family and beyond; they learned how to make tools, and what those tools were for. By extension, children learned what they should do and what they should not -- a series of prescriptions and taboos that governed behavior. As different groups of humanity spread across the globe, some of these prescriptions and taboos were forgotten, and new ones were learned. Different places, with different animals and plants, and different dangers, developed different lists of forbidden and acceptable activities. In this way, the many peoples and tribes and cultures of the world originated.

By 20,000 years before the present, with the exception of some islands off the beaten track of human exploration, humans had settled in virtually every place in the world. Then came the Ice.