Time is an essential part of archaeology, serving as a focal point of archaeological inquiry and an important component of archaeological analyses. Archaeology, likewise, is integral to the understanding of time and its effects, not just in the uncovering of dates to significant events in the history of humanity, but by providing evidence regarding changes and developments in humanity, including its biological makeup, technology, and traditions. By virtue of its intimate alliance with time, archaeology provides not only a greater understanding of what humanity has endured through history but also a means to learn about what humanity will possibly see in the future.
Early Conceptions of Time and Humanity’s Existence
How old is the universe? When was the earth created? When did humans first walk on the earth? When was the first writing system created? How long did it take for humanity to develop from earlier primate species? When were the bow and arrow first utilized? When did writing first surface?
Today, archaeologists, in conjunction with scholars from multiple fields, have a variety of methodologies at their disposal to determine answers to these questions. However, with the field of archaeology not attaining any cohesive structure until the 19th century, individuals from other occupations provided the initial research that dictated our understanding of humanity through time, and their conceptualizations were often supported by unique sources. One of the more prominent such conceptualizations in history was based on the Judeo-Christian Bible.
An Irish clergyman, Archbishop James Ussher, looked to the Hebrew Bible for clarification of the earth’s creation. Ussher’s estimate, which he generated based on an interpretation of chapters in the Bible, indicated the earth came into existence circa 4004 BCE. In effect, humanity’s developments and accomplishments, which include the spread of humanity throughout the world as well as humankind’s domestication of animals, cultivation of plants, and generation of multiple writing and language systems, were achieved during a period of less than 6 millennia. Today, such a time interval is difficult to accept given our more thorough understanding of geological processes and our ability to date natural materials directly, but 400 years ago when Ussher unveiled his estimate, many accepted this as the age of the planet and the duration of humanity’s appearance and development. Yet, like most theories, Ussher’s estimate was challenged by new thoughts about time and the antiquity of both the planet and our species.
Ussher, one among many who looked to religious documentation and beliefs to date the earth and humanity, preceded other noted scholars who sought the planet’s age, although the next wave of researchers looked elsewhere for answers. Of particular importance among them were the uniformi- tarianists. These scholars, including James Hutton and Charles Lyell, spent considerable amounts of time observing the geology of the earth and natural processes like erosion. Noticing the length of time needed for the natural landscape to change, whether through water action, wind damage, or other act of erosion, the uniformitarianists argued that it would have taken considerably longer than 6,000 years for the earth to form mountain ranges, lakes, rivers, and canyons. Such observations ultimately led to questions about humanity’s development alongside the planet’s landscape. Enter the evolutionists.
The impact of uniformitarianism was profound in that it promulgated the idea that the earth and humanity had existed for a great deal of time and that changes were continually occurring. It was in this atmosphere that Charles Darwin, Alfred Wallace, and other scientists developed their ideas of humanity and other species evolving over millennia. Looking at biological organisms as opposed to rocks, strata, and natural processes, supporters of evolution reasoned that changes to species, like the formation and disintegration of rock, took time. With the discovery of remains relegated to earlier hominid species during the late 19th century, the idea that humanity had been around for a significant number of years became embedded in the minds of numerous scholars and accepted by many in society as well. Collectively, these early concepts of time and the duration during which the earth formed and humanity and other organisms emerged provided a framework of understanding. Today, archaeologists ask many of the same questions, although their tools for answering such questions provide more accurate answers.
Modern Measures of Time in Archaeological Analysis
Archaeologists today have a broad range of tools at their disposal to determine the age of artifacts, sites, and human remains. The exactness of each of these methods varies considerably, but for the most part, they provide a substantial benefit to the understanding of time. In a general sense, the technologies referenced here are divided into two categories, the first of which is absolute dating methods.
Absolute Dating Methods
Absolute or chronometric dating methods are the most recent dating methods developed; they are utilized to date artifacts and sites alike. Although the name implies these methods of dating can obtain an exact date for the object analyzed, the reality is that archaeologists actually obtain a range of dates during which the object was created. Still, absolute dating techniques are a world apart from relative techniques and are of special importance to our understanding of human history, particularly in the evolution of humanity through time. Of the absolute dating methods most often used by archaeologists, radiocarbon dating, or carbon-14 dating, is undoubtedly the most prominent and widely utilized. Radiocarbon dating can be used to date organic material such as bone or wood that is from 500 years old to 40,000 years old. The principle behind this method is that after a living being dies, whether plant or animal, the radiocarbon within the specimen begins to decay. Because the decay rate of radiocarbon is known, it is possible to determine the age of organic material based on how much radiocarbon is remaining. The actual process of determining dates based on the radiocarbon method is rather complex, especially with regard to the care required in the collection and containment of samples. Yet, the reward of utilizing this technology is a more precise date for an artifact or archaeological site than a researcher would receive from relative dating techniques (discussed in the next section).
A second absolute dating method utilized by archaeologists is potassium-argon dating. Used to date rocks from 50,000 years old to 2 billion years old, the potassium-argon procedure involves the observance of potassium-40, or rather the argon created by decaying potassium-40 particles, that collects within rock over time. The actual procedure allows archaeologists to date sites and artifacts based on their association with dated rock material.
Dendrochronology, establishing a timeline based on tree ring sequences, is another example of an absolute dating method that has provided archaeologists with a means of determining the age of artifacts and sites. Profiles of tree limbs and trunks reveal a series of rings indicative of the tree’s growth patterns. Knowing that thick rings denote good growing seasons and thin rings denote poor growing seasons, researchers can establish environmental patterns that trees endured through time. Once environmental seasons are developed for a region, and for an extended period of time, future tree ring samples discovered can be compared to established sequences providing indications of the age of the tree specimen. In this way, a tree fragment used to construct a building, wagon, or fence can be dated.
A final method of absolute dating is the use of historical documentation. Newspapers, diaries, and photographs provide a significant amount of information with which to date events, places, and people. Additionally, coins, stamps, and other objects with dates inscribed on their surface can also provide estimates for artifact assemblages in which they are recovered. Such direct historical links are arguably one of the most accurate methods for measuring time.
These absolute measures of time, while not 100% effective in establishing periods, reflect the advances archaeologists and other scholars have achieved in dating sites and objects. They are very different from earlier methods that only provide a basic or relative measure of time.
Relative Dating Methods
Christian Thomsen, a Danish 19th-century curator, initiated a sorting of artifacts based on the ideas of a three-age system reminiscent of earlier classifications separating artifacts into materials made from stone, bronze, and iron, although his system showed remarkable improvements and analysis of archeological finds. However, although Thomsen’s dating and classification system provided a significant improvement in the understanding of the past and dating of archaeological material, such methods of ascribing dates or measuring time fail to provide anything more than a general idea of when an artifact was used in relation to a fixed or already determined point in time. This includes dates of when a person died or when a site was occupied. Of the variety of relative dating techniques used by archaeologists, there are two that are commonly used. The first and most fundamental of these is stratigraphy.
Stratigraphy is straightforward in its conception, but it is far from being uncomplicated in its implementation. From a basic standpoint, stratigraphy is a careful observance by archaeologists of the layers of earth as they excavate. By noticing and acknowledging the placement of artifacts and soil features, it is possible to gauge the date of an object by its provenience and relative position to other artifacts. Essentially speaking, the deeper an artifact is within the soil, the older it is relative to the objects that lay above it. This system of observation and analysis becomes significantly more complicated by the disturbance of archaeological sites by human interaction with the ground or by natural occurrences such as earthquakes, flooding, and glacial activity. However, from a basic level, this is a manner of gauging the age of an assemblage whether it be an artifact, burial, or collection of artifacts. A second method of relative dating often utilized by archaeologists is seriation.
Although not as simple in explanation and implementation as stratigraphy, seriation is nevertheless a rather straightforward approach to determining the relative age of an artifact and associated assemblages. The approach of seriation as employed by archaeologists centers on the collection of artifact types and the observance of styles or varieties of artifacts produced by a society. Whether the types of artifacts collected and observed are pottery or projectile points, ornamentation or clothing, the principle behind this dating method is the same. After collecting artifacts of a specific type, such as a stone spear point, from a number of sites, the percentage of each variety of spear point is calculated. Given that every variety has a period of time during which it is popular, sites can be aligned or placed in order of occupation based on the presence of each variety. Limitations of this technique include the fact that excavation may fail to uncover all specimens of a variety found at a site. However, when used in conjunction with other dating methods, whether absolute or relative in nature, seriation can be an extremely effective means for determining the age of a site.
Archaeological Knowledge and Time
Archaeological reconnaissance, often conducted by researchers from other fields of study, has brought an awareness of major achievements made by humanity in the past. In that way, archaeology has provided knowledge of the past that otherwise would have remained lost. Of particular importance to such discoveries are sites and artifact assemblages related to human origins, early innovations, instances of human migration, and effects of contact on culture change.
Researchers have discovered much about humanity’s development over time through archaeology. With major discoveries of early hominid remains surfacing in the late 19th century, archaeologists have had sufficient time with which to decode much of the past, although many answers to our questions about human origins remain elusive. As for some of the more significant discoveries in this area of research, a few stand out among the most critical. At Laetoli, in Tanzania, Africa, for example, Mary Leakey, in the late 1970s, uncovered a trail of footprints preserved by volcanic ash. The footprints, created by three australo- pithecines (Australopithecus afarensis), provided evidence that human ancestors were walking erect (bipedalism) by around 3.6 million years before the present (BP), a major discovery about humanity’s development in time that archaeological efforts recovered.
Not far from Laetoli, and also in Tanzania, archaeologists uncovered more evidence regarding human origins and development. In the Olduvai Gorge, the Leakey family spent decades searching through the multiple layers of the canyon, which dated as far back as approximately 2 million years BP. The reward for their painstaking efforts included the remains of early hominids Australopithecus boisei and Homo habilis, both dated to nearly 1.8 million years BP. Additionally, among the remains of giraffes, antelopes, and elephants, the Leakeys uncovered lithic tools. Collectively, the hominid remains and tools found at Olduvai Gorge provided a clearer understanding of the emergence of the Homo line from earlier hominids and the initial tool tradition created by humankind, namely, the Oldowan tradition. A final discovery connected to archaeological excavations and humanity’s development through time revolves around caves in Europe whose walls were decorated by paintings created during Paleolithic times.
Lascaux, Chauvet, and Altamira are among the many caves discovered since the 19th century with wall paintings scattered throughout multiple chambers. Often discovered by chance, these caves are adorned with paintings and engravings depicting human beings and an array of animal species, many of which are now extinct. Early on, these caves were often thought of as hoaxes, because many people found it hard to believe that Paleolithic peoples could have created such impressive renderings. Yet, as absolute dating techniques were created and improved and as more analysis was done on artifacts and remains recovered from the caves, it became clear that by nearly 30,000 years ago, human populations were able to create art depicting great detail and often abstract in nature, which indicated an advancement in human mental capacity.
Humanity’s continual adaptation to everchanging environments still provides the impetus for technological innovation. Through archaeo- logically based examinations of the past, the innovations created by humanity have been unearthed along with the knowledge of when such technologies first surfaced. In the Mesopotamia region along the shores of the Euphrates River, for example, excavations of the ancient city of Uruk uncovered the earliest forms of writing, which date to roughly 5,400 BP. Although they were little more than clay tablets with tabulations made of merchandise in the form of depictions of ore, tools, food, and livestock, this discovery helped determine the earliest mode of writing. In a similar vein, researchers have uncovered evidence of when specific plants were domesticated in the New and Old Worlds.
Maize provided a main staple for many societies in South, Central, and North America, serving as a major contributor to the rise of large, nucleated villages and cities. The question is, where did it originate? Despite continued debates over maize’s domestication, excavations throughout areas near and in the Tehuacan Valley indicated that maize was cultivated as long as 5,000 years ago. As for Old World domesticates, excavations in the Near East, near present-day Syria, Jordan, and other Middle Eastern nations, recovered plant remains that showed changes to barley and wheat composition, which followed the increased use of tools for processing food. The appearance of these plant alterations and technologies indicates that barley and wheat were cultivated roughly over 10,000 years ago. Once again, archaeological analysis provided insight into the time frame during which human activity occurred.
When did human populations first reach North America and the rest of the New World? When did the first New World culture emerge? To this day, multiple interested parties debate this question. From among scientists, estimates of when humankind first reached North, South, and Central America ran from 2,000 years to upward of 30,000 years ago. Native Americans, meanwhile, look toward their oral traditions for guidance on this issue with many arguing that they always have lived on the New World continents. Archaeological analysis has provided insight into this inquiry and has since the early 1900s when Paleoindian- related artifacts were uncovered near Clovis, New Mexico. Consequently, archaeology has proven effective in discovery information about when migrations occurred in time.
As for migration into North America, having already established that projectile points found near Folsom, New Mexico, were dated to roughly 10,000 years ago, researchers argued that the earliest peoples to enter North America had to have preceded the Folsom-using populations because the Clovis points were found in a layer of soil below Folsom points. Thus archaeological research provided an idea as to when the first culture (Clovis) surfaced and when humans first reached the New World (c. 12,000 BP). Excavations in Pennsylvania at the Meadowcroft site have uncovered evidence going back even farther, with assemblages dated beyond 15,000 BP. Collectively, these findings give ample evidence that human populations entered North America not long after 20,000 BP. Excavations in South America indicate that people reached the New World relatively early as well. At Monte Verde in Chile, evidence of stone tools and wood supports for structures has been unearthed after having been preserved in bog conditions for millennia. The radiocarbon dates acquired from the site date to roughly 13,000 BP. Today, debates regarding dates obtained from Monte Verde and Meadowcroft remain. However, from the combined evidence, archaeological research has provided some understanding of when in time humans first reached the New World, setting a window of likelihood from tens of thousands of years down to a few thousand.
The effectiveness of archaeology, although questioned by some, is tremendous in that the analysis of material culture recovered from the archaeological record continues to provide clues as to when various hominid forms surfaced, when innovations occurred, and when humans migrated to different parts of the globe. Archaeology also has assisted in determining when contact and culture change occurred between two or more human populations.
Contact and Culture Change
The initial arrival of European explorers, missionaries, and emigrants to North America occurred at a time when record keeping was not standardized or thorough. Many of the Europeans who arrived were illiterate; others recorded nothing more than lists of supplies. All told, records of the effect of contact between Europeans and Native Americans were void of great detail, leaving questions as to when contact occurred in many instances and how long it took for both populations to integrate styles or commodities utilized by the other. Archaeology fills this void. With excavations ranging in size from a few test units to entire sites being uncovered, archaeologists have amassed large collections from Native American village sites dating to the contact period. Iroquoian village site assemblages dating to the early 1600s, for example, contain European products ranging from glass beads, copper pots, and components from firearms. From an analysis of material recovered, it is clear that Iroquoian peoples soon learned to rework the European objects and materials, copper and iron kettles for instance, into utilitarian objects such as weaponry and hunting implements (spear points, arrowheads, knives, etc.). What is the importance of archaeology to the understanding of contact between two populations? It assists in discovering roughly when contact occurred when no written record exists and how long it takes for the technologies and resources of two peoples to be shared.
Important Archaeological Sites and Their Temporal Significance
The mere mention of the word archaeology usually generates images of broken stonework, pottery sherds, stone projectile points, and monoliths strewn across a field. On a larger scale, people equate the study of human material culture with a few sites throughout the world that hold special temporal significance.
Located along the Mississippi River near St. Louis, Illinois, Cahokia was once one of the largest municipalities in North America. With extensive settlement of the area beginning roughly 1,300 years ago, dependent upon maize production and eventually reaching a size of approximately 40,000 people, Cahokia eventually developed into a series of populated sectors positioned around large, earthen mounds used for multiple purposes, including burial and public interaction. The largest of these mounds was the multileveled Monk’s Mound, which reached a height of approximately 30 meters, covered an area greater than 5 hectares, and served as the center of Cahokia itself. Extensive analysis of Cahokia determined that the inhabitants traded extensively, lived in a stratified society, and utilized the wealth of natural resources available in addition to cultivating a variety of plants. In view of time, Cahokia’s mounds are of particular significance, because the size, shape, and use of public space varied considerably, including areas where wooden beams were placed in order to plot and record astronomical events such as equinoxes. Cahokia additionally served as a prime example of a tradition known as Mississippian, which archaeologists equate with societies that shared multiple cultural characteristics, including the erection of earthen mounds and the dependence on maize cultivation between 1,300 BP and 500 BP.
The site of Cuzco, located in the Peruvian hinterland, was the capital of the Inca Empire. Supported by extensive canal and road systems and a repository for precious commodities from throughout South America, Cuzco served as the axis for the empire. Clergy, aristocracy, military commanders, and craftspeople lived within the immediate municipality while the general populace occupied the outlying regions. Cuzco exemplified the complexity of Inca architecture with buildings and temples made of fitted stone blocks, many of which serve as foundations for modern buildings to this day. Likewise, the Inca system of roads, which stretched thousands of kilometers throughout the empire and included depots and quarters to shelter and resupply travelers, were centered around the capital, making Cuzco the focal point for trade and control.
Much of Cuzco’s history was recorded in documentation provided by Spanish explorers who first traveled throughout South America approximately 500 years ago. Ultimately, the Spanish and Incas clashed. The confrontation led to the Incas destroying Cuzco and the Spanish gaining considerable control of the region. In time, the Spanish forces rebuilt the city, preserving much of Cuzco’s outline. Today, it is possible to see how Cuzco was organized by the Incas and what importance its structures served to the empire overall by the distribution of building types throughout the site. Additionally, the site—specifically its origins, development, and eventual reconstruction on the part of Spanish forces—reflects the metamorphosis that Inca civilization went through after contact with European entities.
The Pyramids of Giza
The pyramids at Giza often form the heart of people’s image of the ancient civilization that populated the banks of the Nile. For many, pyramids were constructed and utilized by every Egyptian ruler during the ancient civilization’s millennia of existence. As for the design of their pyramids, Egyptians erected step and flat-sided varieties with the larger structures reaching over 150 meters high and covering over 4 hectares in area. Yet, the larger pyramids at Giza, which include the Great Pyramid of King Khufu and are larger and more complex in their internal designs than later pyramids, are not typical of every dynasty that ruled Egypt. These early pyramids date to the Old Kingdom, approximately 4,200 to 4,700 years ago. Later Egyptian rulers constructed less elaborate burial chambers, with pyramids even being abandoned for tombs cut out of rock in later centuries.
Europe is home to multiple caverns whose walls are decorated with paintings and engravings depicting abstract and realistic images of humans and of animals, many species of which are now extinct. Lascaux, located in southern France, is one of the more renowned of these sites. Spanning over 200 meters in total length, this cavern includes hundreds of engravings and paintings of humans, bison, horses, and other assorted animals. As for the techniques for applying the renderings to the cavern walls, the artists generated colors using charcoal, iron oxides, and manganese oxides, while engravings were created likely through the use of an assortment of flint tools. Since the initial discovery of such cave renderings over a century ago, a variety of arguments have surfaced as to the purpose of these art forms. Yet, whether these ancient paintings and engravings were believed to serve as magic or just art for art’s sake is not the most crucial question.
With the advancement of dating techniques making it possible to directly date the cavern’s renderings, researchers were able to determine that Lascaux was decorated approximately 17,000 years BP. This discovery, along with the complex nature of the mediums and painting/engraving techniques utilized by the artists, indicated that Paleolithic populations were more capable than researchers originally thought possible, both in their conceptualization of their world and their place within it.
Located in the county of Wiltshire in southern England, Stonehenge remains one of the most noted archaeological sites to both enthusiasts and archaeologists alike. With initial construction beginning approximately 5,000 years ago, Stonehenge underwent multiple stages of construction over a span of roughly 1,500 years. The result of these stages was the erection of the monoliths for which the site is known. Additionally, the site’s engineers established embankments, ditches, and other components, which have been partially damaged, rearranged, and destroyed by subsequent visitation to the site. Today, speculation as to the purpose of the site has included the belief that it serves as a calendar for predicting celestial events such as equinoxes and eclipses. However, the only calculation that appears credible is the timing of the summer solstice and its alignment to Stonehenge’s Heel Stone and Avenue. However, the loss and movement of Stonehenge’s monoliths and earthworks makes even this assertion questionable.
The ancient city of Teotihuacan has long augmented the landscape near present-day Mexico City. With occupation of the area beginning approximately 2,100 BP and continuing until roughly 1,000 BP, Teotihuacan developed into one of the largest cities in the world with a maximum population of over 100,000 people at times. As for total area of occupation, Teotihuacan expanded quickly through the centuries, ultimately covering approximately 20 square kilometers. The structures that were erected by the site’s inhabitants were stone and plaster buildings, particularly living quarters and temples. Teotihuacan’s occupants lived in various sized apartment compounds capable of sheltering multiple families, with total populations of over 100 persons in some instances. The temples were equally diverse in size and were positioned among the apartment compounds. All told, over 4,000 structures were erected at Teotihuacan, with the Pyramid of the Sun, which stood over 60 meters high, standing above everything else. Interspaced among all of these structures were marketplaces, courtyards, and roadways that connected all of Teotihucan’s living spaces and helped forge the footprint of this mammoth city.
Today, Teotihuacan is a favorite destination and research topic for both archaeologists and tourists alike, and every year, continued excavation and analysis of artifacts reveal more about the site’s residents and their contact with neighboring peoples. Such investigation of the ruins of Teotihuacan is far from being a recent development, however. Throughout time, later populations, including the Aztecs, visited the site and utilized its space for their own purposes. The significance of this reality is that archaeological sites are often multicomponent in nature, playing host to several occupations. While each occupation will vary in its duration of stay and area of activity, the importance of each occupation is nevertheless an equal contributor to the site’s history and time itself.
The Zhoukoudian caverns, located near Beijing, have yielded Homo erectus remains since the early decades of the 20th century along with an assortment of lithic tools and evidence of early fire use. While many specimens recovered were subsequently lost during World War II, the impact of the remains is still intense. Temporally speaking, the range in Homo erectus remains discovered in the Zhoukoudian region reflects the continual evolution of the species over the course of nearly 300,000 years (550,000 BP to 250,000 BP), particularly with regard to brain size.
Humanity’s cultures are ever changing through time. Equipped with the technologies and theories of multiple fields, archaeologists continually seek to understand these changes through the careful collection and analysis of the material culture human populations have left in their civilization’s wake. Although the interests and theoretical foundations among archaeologists vary considerably, and even as newer avenues of research such as paradigms based on critical thought and gender theory have taken center stage, an emphasis on time remains of central importance to most archaeological research.
See also Altamira Cave; Anthropology; Boucher de Perthes, Jacques; Chaco Canyon; Chauvet Cave; Dating Techniques; Egypt, Ancient; Evolution, Cultural; Lascaux Cave; Olduvai Gorge; Pompeii; Rapa Nui (Easter Island); Rome, Ancient; Rosetta Stone; Seven Wonders of the Ancient World; Stonehenge; Time, Measurements of
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