Prehistoric Populations

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PREHISTORIC POPULATIONS


INTRODUCTION

AFRICA    John Parkington

ASIA    Geoffrey G. Pope

AUSTRALIA AND THE PACIFIC    Peter Hiscock

EUROPE    Jesper L. Boldsen

THE AMERICAS    Robert D. Hoppa

INTRODUCTION

Human prehistory is treated regionally in the series of articles that follow. The discussion mainly pertains to the modern (and only surviving) human species, Homo sapiens, which emerged little more than 100,000 years ago; however, other hominid species–ancestral or cognate lines of the genus Homo–are also referred to. Humans in this generic sense emerged over 2 million years ago. Depending on how human origin is defined, human prehistory thus covers all but a small fraction (95–99.7%) of the duration of human existence.

FIGURE 1

An approximate time line of major hominid species is shown in Figure 1. The dating and in some cases even the species identifications are tentative, subject to revision as research progresses. The associated phylogeny–the relationships among these species–is even less securely founded.

AFRICA

The ancestors of modern human populations separated from those of humankind's nearest primate relatives some 5 million years ago on the African continent and by 2.5 million years ago were making stone artifacts that can be recognized as tools. Slightly less than 1.5 million years ago those kinds of tools appear outside Africa, marking the latitudinal expansion of people from the subtropics to more temperate zones. By 100,000 years ago African descendants of the earliest people were skeletally modern, and soon after that time they were marking stone, bone, and ostrich eggshell in ways that obviously are symbolic, if not artistic, long before such behavior was evident elsewhere.

Less than 50,000 years ago modern people began a further expansion, again emanating from Africa, crossing land bridges, occasionally making sea crossings, and entering arid, cold, and seasonal environments in a wave or waves that would eventually result in a nearly global distribution. Most of the early experiments in the domestication of plants and animals, metallurgy, urban development, and intercontinental trade seem to have originated outside Africa, but starting 500 years ago Africa experienced a return of its progeny in an extended colonial period whose effects have not yet been shaken off.

Several billion stone tools litter the African landscape, but of a billion or more African people who were alive during the period from 5 million to0.5 million years ago there are the fragmentary skeletal remains of about 500 individuals at most. Only from the last 10,000 years is there anything approximating a decent sample, no more than a thousand or two individuals. Palaeoanthropologists refer to up to 15 species of hominids and 5 genera but rarely agree on the correct assignation of most fragments, and only in very rare cases are there nearly complete individuals, let alone useful numbers of contemporary conspecifics.

The discovery of ancient hominid remains in the currently desert environment of Chad, several thousand kilometers away from any other contemporary locality, has underlined the fragility of the current understanding of hominid distribution patterns. Are researchers looking merely at the absence of evidence rather than the evidence of absence? The sampling, dating, and empirical constraints on reconstructing African Pleistocene populations are so severe that anthropologists rarely mention issues such as population sizes, birth or mortality rates, life expectancy, life history patterns, and biogeographical range shifts, except in the most general terms. Demographic research requires much better observations.

Conclusions Drawn from Genetics and Morphology

There are, however, some interesting generalizations that can be made, although some of them depend as much on genetic and linguistic patterns or primate analogues as they do on skeletal or archaeological remains. In different ways genetic and linguistic patterns among current African populations reflect past movements, isolations, and distributions. History is written in the diversity of traces on the physical and social landscape. The application of sophisticated genetic techniques to fossil or subfossil hominid remains, though in its infancy, promises to expand considerably the conclusions that can be drawn from artifact distributions and morphological comparisons.

First, there is nearly universal agreement that through the Pleistocene African populations were becoming increasingly modern and formed the core group from which both archaic and modern people emerged. Although it is possible that early hominids are almost uniquely represented in the dolomite caverns of the south and the rift valley lake beds of the east purely because of good preservational circumstances, stone tool distributions offer an opportunity free of such taxonomic limitations.

African archaeologists now have a good idea of the technological and formal development as well as the approximate dating of artifact assemblages. All the earliest stone tool assemblages come from riverside or lakeside camps in savanna landscapes with moderate to low rainfall, whereas occupations in demonstrably arid, humid, rugged, or forested regions come much later. The savanna hypothesis for the origins of hominid adaptation, however, may have overestimated the terrestrial habit of early hominids at the expense of riverine fringe resource use. Presumably, early populations were expanding into more difficult resource areas, a movement that was facilitated by technological and social innovations and fueled by a growing intellectual capacity. Brain-specific nutrition, such as the fatty acids so abundant in freshwater and marine ecosystems, probably underwrote sustained, and energetically expensive, brain growth. Eventually, certainly by 1.5 million years ago, populations reached the boundaries of the continent in the Mediterranean climates of the north and the south. Only the route to the north led elsewhere.

Movement Out of Africa

The earliest human skeletal remains from outside the African continent date from a little more than 1 million or perhaps 1.5 million years ago in southern Europe and southwestern and southeastern Asia. These sites mark the first out-of-Africa movement, perhaps along productive and nutritionally rich coastal plains, although evidence is scarce. Palaeoanthropologists disagree on whether there were several later movements or a more or less continuous diffusion of population out of Africa after that time, but most support at least one recognizable expansion between 100,000 and 50,000 years ago.

Skeletal remains more or less indistinguishable from the modern form are found around the coastal fringes of southern Africa soon after 100,000 years ago, but their rarity at contemporary sites farther north could as easily be preservational, or even terminological, as evidential. It is possible that modern people evolved throughout Africa. Outside Africa almost all human populations after about 30,000 years ago are described as modern and appear to be ancestral to recent local populations. It appears increasingly likely that whereas African populations were evolving toward the modern condition, the archaic humans already living in Europe and Asia were not, though the significance of genetic separation and the potential for genetic reincorporation are controversial issues.

If these southern African populations really are part of the ancestral stock from which all modern humans evolved, their descendants soon became isolated by extreme aridity in the midlatitudes. By 70,000 years ago both the Saharan and the Kalahari-Namib arid landscapes had expanded under the influence of global glacial expansion, altered atmospheric circulation, and oceanic cooling. This diminished genetic and cultural links between equatorial and Mediterranean African groups at either end of the continent. At the Cape and in the Mediterranean, with similar latitudes and climates, people drifted genetically away from their subtropical relatives until terminal Pleistocene climate changes allowed more substantial connections across shrinking aridity barriers.

The implications of this for Cape populations at the southern tip of the continent are of course profound and quite different from those for their northern relatives living on the fringe of Eurasia. The blood group and other genetic parameters that distinguish broad groups of Africans seem to have been the result of late Pleistocene extreme aridity. As the glaciers melted, previously isolated groups began to reestablish contact, resulting in the complex social, linguistic, genetic, and political landscape that exists in the early twenty-first century.

During the Holocene period population movements within the African continent seem to have been associated with the sub-Saharan spread of farming and metallurgy during the last three millennia. In the early Holocene domesticated plants and animals in Africa were limited to the Mediterranean Basin, where the domestication process began, and to winter rainfall domesticates. Once the idea of domestication had been transferred to subtropical crops, probably in the highlands of Ethiopia, a process of diffusion to the south began. Although the Mediterranean domesticated animals remained the important ones, new plant species, significantly forms of millet and sorghum, were added to the domestic suite.

It was only after the conjunction of domesticated plants, animals, and metallurgy some 2,500 years ago that any kind of rapid population movement can be detected. This is most obviously reflected in the distribution of languages of the Niger-Congo family in western, eastern, and southern Africa. Within this grouping languages spoken by people separated by thousands of kilometers remain linguistically similar, suggesting a recent common ancestry. The most parsimonious explanation is one of recent rapid population movement, bringing Niger-Congospeaking, metal-using farming communities east and then south through the parts of sub-Saharan Africa suited to millet and sorghum farming.

Understandably, many parts of the subcontinent were unattractive to people with domestic stock or crops, leading to the survival of hunting and gathering communities in regions that were too arid, rugged, or forested for some version of agriculture or pastoralism. Farmers moved preferentially into lands that were easily tilled without machinery, naturally watered, and suited to the requirements of both domesticated animals and cultivated crops. The wide distribution of very similar ceramic forms and decorative motifs from the Great Lakes region to the eastern parts of South Africa from about 2,500 to 1,500 years ago mimics the pattern of language similarities and almost certainly supports the notion of a rapid population movement.

Several hundred small, encapsulated groups of hunter-gatherer communities survived across Africa to provide case studies for nineteenth- and twentieth-century ethnographers. The most substantial residual hunting and gathering populations remained in place in the southwestern corner of the continent until very recently in the form of people referred to as bushmen or San. Their nearest geographic, cultural, and genetic relatives, the pastoralist Khoe or Quena (derogatively known as Hottentots), have been the focus of much debate. It appears likely that Khoe pastoralists were former San hunters and gatherers who had gained access to stock through contact with Niger–Congo-speaking mixed farmers who were penetrating the former San regions of southernmost Africa. They were subsequently able to replace or incorporate hunter-gatherer groups in areas where stock, particularly the fat-tailed sheep they herded, could thrive. This process, which essentially was confined to the arid western parts of the subcontinent, was contemporary with the spread of mixed farming in the east, where better rainfall and deeper soils made crop farming viable. These two expansions were complementary and effectively defined the population structure of modern southern Africa.

The Earliest Moderns?

What makes this historically and evolutionarily interesting is the confluence of linguistic, behavioral, and genetic patterns in the geographically well-defined Khoe and San people. Leaving aside earlier theories of the existence of a "Capoid race," it is surely significant that groups formerly dominant south of the Kalahari-Namib arid zone exhibit biological and cultural signs of extreme and long-lasting isolation. Implosive consonants ("clicks"), a highly noticeable feature of Khoesan languages, are unknown in regular speech anywhere else in the world; geneticists have detected ancient mitochondrial DNA lineages among modern Khoe and San people; and the survival of San hunter-gatherers into recent times coincides geographically with the distribution of the best evidence for early modern humans.

It is tempting to write a history of human populations at the Cape that views them as the earliest moderns, subsequently isolated from their relatives elsewhere, allowed by environmental factors and geographic marginality to remain relatively unaffected. It is appropriate that they should have survived to become the best ethnographically studied examples of a formerly pan-human hunting and gathering lifestyle. They are certainly not living fossils, but their study has unlocked the secrets of precolonial rock paintings, provided models for archaeological reconstructions, and graphically illustrated the details of a genocidal colonial era.

See also: Archaeogenetics; Environmental Impact, Human; Evolutionary Demography; Hunter-Gatherers; Indigenous Peoples; Paleodemography; World Population Growth.

bibliography

Klein, Richard. 1999. The Human Career: Human Biological and Cultural Origins. Chicago: University of Chicago Press.

Klein, Richard, and Edgar Blake. 2002. The Dawn of Human Culture. New York: Wiley.

John Parkington

ASIA

The vast majority of the paleoanthropological evidence from Asia, particularly most of the geologically-early evidence, derives from East and Southeast Asia, especially mainland China and Java. Relatively early fossil evidence has also been recovered from Narmada, India. South Asia–including Ceylon, Pakistan, Bangladesh, and especially India–has also played an important role in interpretations of Asian paleolithic archaeology as a whole. West Asia has yielded archaeological and fossil evidence of Neanderthals, early anatomically-modern Homo sapiens, and possibly Homo erectus.

Regional Continuity or Replacement Model Interpretation of Modern Asian Humans

There are two major antithetical theories about the origins of modern Asian populations. One theory, called Replacement Theory or "Out of Africa Theory," maintains that modern Asian populations descended from a geologically recent (ca. 100,000 to 50,000 years ago) migration from Africa that resulted in the total replacement of the indigenous hominids who had occupied Asia from close to or more than one million years ago. The Replacement Theory is based on mtDNA (mitochondrial DNA) studies that purport to show that all modern humans are descended from a single African female, "Eve," as she has been termed in the press. Diametrically opposed to this interpretation is the Regional Continuity Theory, which maintains that Asian Homo erectus evolved into the anatomically modern Asian Homo sapiens. Both theories agree that all hominids originated in Africa; they disagree about when hominids first left Africa and when extant populational distinctions originated.

Replacement proponents have argued that the "crude" nature of the Far East Asian tool kit is the product of the evolutionarily stagnant species Homo erectus. In this scenario, suggested by scholars such as Christopher Stringe and Bernard Wood, Homo erectus left Africa before the development of more sophisticated stone technologies such as the Acheulean "hand axe" and became a genetically-isolated evolutionary dead end, never passing beyond the technological sophistication of the earliest and most crudely made Oldowan artifacts of Africa. But neither the Asian paleontological evidence nor the paleolithic record documents morphological or cultural stagnation. Indeed, there is evident morphological change in the fossil record in the direction of modern Asians. Scholars such as Geoffrey Pope, Mulford Wolpoff and many others assert that both the archaeological and hominid fossil records support evolutionary continuity in Asia.

Culture and Technology

In the 1940s the archaeologist Hallam Movius (1907–1987) pointed out that there is a "line" of demarcation between hand axes of prehistoric South Asia and the crude, so-called "chopping-chopper" tools of the Far East. He believed that places like China and Java were cultural backwaters where human-like technology never evolved beyond the most simplistic levels. His work led to the concept of the "Movius Line," which has been used to demarcate evolving humanity from populations that had somehow become "stuck in time." Very few hand axes have ever been found in China despite long and concerted searches. L. Binford and Nancy Stone (1987) suggest that there is very little reliable evidence for any human-like culture in the artifact assemblages of ancient Asians.

In 1989, Pope countered Movius's resurrected argument with the observation that the "crude" Far Eastern tools coincide with the distribution of bamboo and a wealth of other non-lithic resources. The Pleistocene inhabitants of the region most certainly utilized these resources. Since Homo erectus (i.e., early to middle Pleistocene Homo in East Asia) was the first hominid to colonize both temperate (including seasonally frigid) as well as tropical environments and given its long presence in the region, it seems more reasonable to interpret the simple stone technology of Pleistocene Asia as complementary to sophistication in non-lithic resource utilization. The seemingly unchanging Asian paleolithic record, described (tongue in cheek) by one archeologist as "crude, colorless and unenterprising" (White 1977), is more parsimoniously attributed to an emphasis on non-lithic technology such as bamboo and other organic resources.

Agriculture in Asia seems to have developed independently at about 10,000 years ago in both China and northwest India. Mesopotamian agriculture may also have been of independent origin from the Fertile Crescent in Iraq. Some archaeologists have suggested that rice cultivation and pottery and/or polished stone tools seem to have diffused from China to other circum-Pacific regions. Similar diffusion processes may have existed for other cultigens in South and West Asia.

Hominid Morphology

The history of Far Eastern paleoanthropology begins in 1891 when Eugene Dubois (1858–1940) discovered the first Homo erectus skull cap and femur at Trinil, Java. Subsequent discoveries of other Javanese and Chinese hominids confirmed the hominid status of Homo erectus, as did the many discoveries made at the famous "Peking (Beijing) Man" site of Zhoukoudian Locality 1 in China. These finds are now considered to be representative of Homo erectus.

Anatomically, Homo erectus is defined primarily by its extremely thick cranial bones, a projecting and continuous brow ridge above the eye orbits, a sagittal "keel" of thickened bone running from the top of the skull to the back of the cranium, a thickened and angular occipital region, and a generally robust skeleton. These features are expressed most strongly today among indigenous populations of the southwest Pacific. Homo erectus also displays a muchdebated dental anatomy including what have been called "shovel shaped" incisors, a trait that is most prevalent in modern "Mongoloid" and Mongoloidderived populations. As Pope (1992) pointed out, other facial features also appear to connect this extinct species with modern East Asian and Native American populations.

Such morphological evidence is discounted by proponents of the Replacement Model, who point instead to the biomolecular results of mtDNA studies as an indication that this species and others from East Asia went extinct with the arrival of anatomically-modern Homo sapiens. These DNA interpretations can in turn call into question the many genetic assumptions which the model makes.

A number of anatomically more modernlooking hominids have also been recovered from both Java and China. Only one early hominid specimen has also been recovered from Narmada, India. "Archaic or Pre-modern" hominids all have larger cranial capacities than is typical of Homo erectus, as well as other features reminiscent of fully modern humans. The Solo (Ngandong) crania from Java look very much like scaled-up versions (in terms of cranial capacity) of Homo erectus. Whether these crania should be classified as Homo erectus or Homosapiens is a matter of continuing debate, but they provide strong evidence of continuity between fossil and modern hominids.

By definition, separate species cannot interbreed and produce fertile offspring. Classic reasons for such barriers are geographical separation, anatomical–behavioral incompatibility, temporal separation, genetic incompatibility, or a combination of all or some of these factors. In Asia geographically-widespread hominids give rise to a number of specimens which look anatomically distinct from one another. Whether these differences represent species difference or an increase in variation within a species, is not known. In Pleistocene Asia, variation in appearance seems to increase over time. Since paleoanthropologists have only the bones and stone to study, they cannot tell if the morphological differences in fossils indicate species barriers that would prevent interbreeding or are reproductively unimportant. New forms may have arisen through interbreeding of once far-flung and isolated populations that came into contact again. In short, the relation between morphology and breeding can never be known for certain in fossil paleospecies.

Geography and Climate

The geography and climate that helped shape the anatomical traits and paleoecological adaptations of Homo erectus resulted in a large extent from the continuing tectonic collision of the South Asian Plate with the underbelly of the Asian mainland. This continuing collision produced the vast Himalayan mountain system that, in combination with the equatorial monsoons, has had a strong influence on hominid evolution in Asia. Worldwide climatic fluctuation, while no doubt influential in the formation of climates and topographies, did not, except indirectly, have the profound ecological influence on Asian climates that it had in glacial Europe. However, indirect influence in the form of the development of the loess areas of North China and the rise and fall of sea levels surrounding and alternately isolating and connecting the present islands of the Sunda Shelf certainly affected hominid evolution and dispersal.

The effects of the Himalayan uplift are also responsible for the modern loess plateaus, grabens, and mountains that form the past and present biogeographic regions, barriers, and biogeographic dispersal routes of Asia. Early hominids seem to have been confined to relatively low and thus warmer altitudes, where all of the early hominid finds in Asia have been located. Although the long and repeated occupation of sites such as Zhoukoudian Locality 1 testify to the ability of Homo erectus to endure marked seasonal fluctuations, it seems that cold temperature altitude was a definite limiting factor in the distribution of this species. Over the course of a million years, however, Homo erectus had become adapted to a number of varying environments. It is difficult to imagine that a tool-dependent hominid could have been completely replaced by invaders in all these ecological settings, which it had occupied for approximately one million years.

The influence of the Himalayan uplift also influences researchers' understanding of prehistoric archaeology in Asia. In South Asia and Western Asia, the run-off and resulting detritus from the Himalayan system may be the principal reason that only one early Pleistocene hominid (Narmada) has been recovered from South Asia.

Archaeologists have yet to discover the presence of early (Early Late Pleistocene) hominids in other countries of the Far East, such as the islands of Southeast Asia and Taiwan (and possibly Japan) that were periodically connected by land bridges at times of low sea level. Australia was never connected to Asia, and therefore its first colonization by around 40,000 or more years ago must have been over water.

Gene Flow

As early as 300,000 years ago, hominids that were physically very different from each other were living in the same geographic regions. This also happened in Europe, where Neanderthals lived side by side with modern humans for as much as 60,000 years and also shared (to judge from their artifacts) many of the same cultural attributes. It is rare, if not unknown, for modern hunters and gatherers to exchange only culture and not genes. Furthermore, there is no well-established evidence for one group of hunters and gatherers ever having completely replaced another. It is in this light that the later evolutionary evidence from Asia must be interpreted.

In China, recent finds of pre-modern Homo sapiens (such as Dali and Jinniushan) show a remarkable degree of variation that, on the basis of archaeologists' current knowledge, seems to exceed differences in other geographic areas. One interpretation, strongly supported by Pope and others, is that gene flow across Eurasia became increasingly more common as hominids increased in cultural complexity and technological prowess.

More generally, in the closing phases of the Pleistocene it seems likely that increased gene flow occurred between the eastern and western edges of Eurasia and the continent of Africa. The morphological "sameness" which has often been perceived in Homo erectus culminates in a variety of morphologies that indicate gene flow. Many scholars believe that the much more recent changes in lithic technology may indicate continued and even increased gene flow across the top of Eurasia, primarily proceeding in directions along an East-West axis, but also along a North-South axis.

Conclusion

To explain the origin of modern Asian peoples, one needs to recognize both indigenous development and transcontinental gene flow, and not simple regional continuity or replacement by geologically recent Africans. Physically, Asians are impossible to define as a single group unified by any ubiquitous morphologies. There are clines of differences such as in skin color, facial characteristics, or body type, reflecting regional adaptations. Repeated genetic exchange occurred from both near and far.

From the standpoint of physical anthropology and archaeology, anatomically modern Asian populations are the product of both local indigenous adaptation and extraregional gene flow. From a cultural standpoint, modern Asian groups result from continuing and ancient overlays of culture, religion, and ecological adaptations. Neither the fossil nor the archaeological evidence points to a single geographical or temporal origin of Asians.

See also: Archaeogenetics; Paleodemography; World Population Growth.

bibliography

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Binford, L. R, and Nancy M. Stone. 1987. "On Zhoukoudian. Reply to Comments." Current Anthropology 28(1): 102–105.

Cann, Rebecca L. 1988. "DNA and Human Origins." Annual Review of Anthropology 17: 127–143.

Jia, Lanpo, and Weiwen Huang. 1990. The Story of Peking Man. Beijing: Foreign Language Presses and Oxford University Press.

Keates, Susan. 2000. Early and Middle Pleistocene Hominid Behavior in Asia. Oxford: BAR International Series 863.

Movius, Hallam. 1944. "Early Man and Pleistocene Stratigraphy in Southern and Eastern Asia." Papers of the Peabody Museum of American Archaeology and Ethnology 19(3): 1–125.

Pope, Geoffrey G. 1984. Hominid Evolution in East and Southeast Asia. Ann Arbor: University Microfilms.

——. 1992. "The Craniofacial Evidence for the Origin of Modern Humans in China." The Yearbook of Physical Anthropology 35: 243–298.

——. 1997. "Asian Paleoanthropology." In The History of Physical Anthropology, An Encyclopedia, ed. Frank Spencer. New York and London: Garland Publishing.

——. 1997. "Java." In History of Physical Anthropology, An Encyclopedia, ed. Frank Spencer. New York and London: Garland Publishing.

Pope, Geoffrey, and Susan Keates. 1994. "The Evolution of Human Cognition and Cultural Capacity: A View from the Far East." In Integrative Pathways to the Past, ed. Robert Corrucini and Russel L. Ciochon. Englewood Cliffs, NJ: Prentice Hall.

Stringer, Christopher. 1992. "Replacement, Continuity and the Origin of Homo sapiens." In Continuity or Replacement? Controversies in Homo sapiens Evolution, ed. Günter Brauer and Fred H. Smith. Rotterdam: Balkama.

Swisher III, Carl, et al. 1994. "Age of the Earliest Known Hominids in Java, Indonesia." Science 263: 1,118–1,121.

Tungsheng, Liu, et al. 1985. Loess and the Environment. Beijing: China Ocean Press. Turner, Christy G. 1990. "Major Features of Sundadonty and Sinodonty." American Journal of Physical Anthropology 82(3): 295–317.

von Koenigswald, Gustav H. R. 1962. The Evolution of Man. Ann Arbor: University of Michigan Press.

Wolpoff, Milford. 1999. Paleoanthropology. Boston: McGraw Hill.

Wood, Bernard. 1994. "Taxonomy and Evolutionary Relationships of Homo erectus." Courier Forschunginsitut Senckenberg 171: 159–165.

Geoffrey G. Pope

AUSTRALIA AND THE PACIFIC

Although hominids have been present on Sunda, the continental shelf of what are now islands in Southeast Asia, for more than 800,000 years, they appear to have been unable to regularly cross water barriers. Homo erectus traversed small ocean gaps to reach Flores in Indonesia, but was absent from islands further east. Consequently Australia and the Pacific islands were first colonized by modern humans. This observation has often been used as a measurement of the greater organizational capacity of Homo sapiens during the last 40,000 to 60,000 years, perhaps reflecting enhanced language abilities. Populating the Pacific required human groups to have adequate seacraft, but more importantly to have the means of storing and transmitting information about new environments. In each part of the Australian-Pacific region the first evidence of human occupation not only implies extensive seafaring skills but also includes the archaeological residues of complex social behavior: art and ornaments, burials, and wellorganized settlement structures.

Exploration of the Australian continent and Pacific islands was a prolonged process, taking many millennia to complete. The colonizing process began in the west, and terminated in the remote eastern and southern Pacific Ocean. Australia is the landmass in the region with the earliest dates for human occupation.

Australia

Homo sapiens colonized the Australian continent more than 40,000 years ago, although there is extensive debate as to whether humans arrived as early as about 55,000 to 60,000 years before the present (abbreviated b.p.), or as late as 40,000 to 45,000 This debate hinges on different opinions as to the veracity of alternative dating techniques, as well as uncertainty about the extent of disturbance processes in early archaeological sites. Claims for occupation substantially earlier than 60,000 b.p. have been shown to be spurious. The uncertainty about the date of colonization makes reconstructions of the first settlement systems tenuous. For instance, if colonization took place prior to 40,000 b.p., so few sites are known that discussions of settlement are insubstantial. Furthermore, dating uncertainties make it impossible to evaluate the actual rate of colonization within Australia.

Some scholars have suggested that early settlement may have focused on coastal resources, but this seems unlikely in view of the growing evidence of occupation in arid and semi-arid inland landscapes. Lake Mungo is the most famous example of inland occupation, but hundreds of sites now reveal Pleistocene-era occupation, more than 10,000 years old, in a diverse range of inland landscapes. It is clear that people at least occasionally occupied many environments within Australia, and it is thought that population densities were higher in the zones of higher rainfall around the periphery of the continent. Early models of population change hypothesized fixed patterns of settlement during the Pleistocene, such as continuously low or high numbers of people in the arid core of Australia. These models have more recently been replaced by an image of fluctuating population in response to changing resource availability and discontinuous settlement in at least some landscapes. This is most dramatically illustrated in the glacial uplands of Tasmania, where humans abandoned the region permanently in the terminal Pleistocene, and in some arid landscapes, where some regions were abandoned during the glacial maximum, 14–18,000 b.p., while in other regions with favorable resource bases occupation continued throughout the glacial maximum.

During the late Holocene period (3000 b.p. to present), a larger number of archaeological sites were occupied in many regions of Australia, coastal and inland, islands and mainland. There was also an increase in the number of sites and the number of artifacts in many of those sites. Many archaeologists have interpreted this pattern as a reflection of population increase during the later prehistoric period in Australia. However, the magnitude of any population change has been difficult to evaluate. Calculations of the annual increase in site numbers and the rate of artifact discard show that both measures, in all regions, were well below 0.1 percent per year. It is feasible that this might be the approximate rate of population change, in which case the scale of change would be something like a tripling or quadrupling of population between 4000 and 1000 b.p.. The absolute size of the population during this period cannot be calculated.

Increases of population may have been greater in some regions than in others. For example, in the southeast (particularly in the densely populated Murray River Valley), high levels of anemia, parasitism, and infectious diseases have been inferred from skeletal markers, and perhaps indicate higher densities of people in these lands. This conclusion is consistent with the discovery of many densely-packed cemeteries in this region. Some researchers have therefore suggested that the river valleys of the southeast were more densely populated, but if so these regions also show the same archaeological evidence for increased site and artifact abundance.

If these archaeological patterns indicate minor but sustained population growth, the causes are unclear since this period was one of drier and variable climatic conditions. Some researchers have suggested that intensification of production driven by social competition led to population increase, but there is little support for this theory in the archaeological evidence. However, the cause of population change in this period need not be a dramatic process, since the growth rate discussed here would represent a minor departure from a long-term balance between births and deaths. Moreover, a number of archaeologists have cautioned that the change in the quantities of archaeological material (numbers of sites and artifacts) is probably not a reliable indicator of the magnitude of population change. The quantity of archaeological material preserved from any period is a reflection of many factors in addition to group size, including the destruction of sites and the wastefulness of the production system creating artifacts. Such factors would have exaggerated the observable abundance of material in the recent past. Consequently, while many archaeologists have concluded there were population increases in the late Holocene, the nature and size of those changes remains poorly defined.

Melanesia

Melanesia is that area of the western Pacific that includes New Guinea and a series of large and small islands stretching eastward. Lower sea levels during the Pleistocene meant that New Guinea was connected to northern Australia by an exposed portion of the shared continental shelf, and it is not surprising that the human occupation of New Guinea is thought to be of comparable antiquity to that of Australia. Archaeologists have dated the subsequent colonization of the islands to the east of New Guinea to more than 35,000 years ago, based on a series of archaeological sites in New Britain and New Ireland such as Buang Merabak, Yombon, and Matenkupkum. By about 30,000 b.p. people had reached the Solomon Islands, but here the colonization process halted for 25,000 years. This distribution of archaeological sites in Pleistocene Melanesia is limited to those islands separated by a water barrier of less than 250 kilometers, a distance that perhaps indicates the limits of the maritime journeys of the day. However, within the colonized zone of Melanesia there appears to have been considerable maritime interaction, including possible trade, which implies that longer oceanic journeys may not have been impossible. For whatever reason, more isolated islands were not colonized until much later, with the spread of people archaeologists call Lapita.

Lapita is a distinctive archaeological complex, marked in many sites by elaborate dentate stamped pottery, and by diverse economic practices including but not limited to the use of domesticated plants (yams, taro, banana, etc.) and animals (chicken, pig, dog). This archaeological material first appears in the Bismarck archipelago, east of New Guinea, about 3500 b.p. and spreads eastward throughout Melanesia within a short time. The proliferation of the Lapita Complex is likely to have involved not only the colonization of distant islands of Melanesia but also a region-wide increase in population.

Late Holocene increases in population size in many parts of Melanesia are often thought to reflect the introduction of agriculture that accompanied Lapita. However, the late Holocene population changes in Australia, where agriculture was never established, and the obvious late Holocene growth of populations on Polynesian islands, where agricultural abilities were known to the founding groups, represent parallel demographic trends. These similarities are as yet unexplained but imply processes other than or additional to the introduction of agriculture.

Polynesia

Polynesia is the vast expanse of the central Pacific Ocean covering nearly 30 million square kilometers. Within this area are a number of island groups, from Samoa and Tonga in the west to the Hawaiian Islands in the north, Easter Island in the east, and New Zealand in the southwest. The spread of people across this vast region appears to have taken place in a number of stages. Excavations on many islands suggest humans moved from the Samoa and Tonga island groups eastward into the central Polynesian region about 2200 years ago. After building an economic and demographic base in the Marquesas and Society Islands, people migrated northward to Hawaii and further east to Easter Island approximately 1500 to 1700 years ago. Still later, only within the last 800 years, another migration to the south produced the colonization of New Zealand. These movements of people were sometimes single, one-way voyages, but there is also evidence of return voyaging and secondary migrations, making the colonization process a complex one.

Population change in the Pacific islands has been measured by charting alterations in the abundance of dated habitation sites. For example, on a number of the Hawaiian Islands analysis of this archaeological evidence reveals an S-shaped population curve: there were few habitation sites dated to the period prior to 800 b.p. (1200 c.e.), then a tenfold increase in habitations during the period from 800 to 400 b.p. (1200–1600 c.e.), followed by a stabilizing or even decline in their number. The period of rapid increase is thought to have been caused by the development of intensive forms of food production such as irrigated field systems and fishponds. The cessation of population growth may have been a result of limits to agricultural intensification in some regions and of European contact and diseases. Population growth in the Hawaiian Islands is also entangled with sociopolitical change. In Hawaii's hierarchical political structure, the increased pools of labor could be directed by chiefs to create large-scale infrastructure projects that increased resources for the expanding population. As this process continued, the distinctions of rank and power became exaggerated. Warfare appears to have increased in frequency and severity as struggles over power and resources became more intense. This pattern of increasing warfare, sometimes accompanied by declining populations as human-induced environmental changes occurred, is a common one.

European Contact

In many areas of the Pacific and Australia, the introduction of diseases such as smallpox at the time of European contact led to marked reduction of population and subsequent reorganization of social, political, and economic practices. For this reason it is accepted that many historical observations of population density are poor indicators of precontact demographic conditions. It is likely that population densities in Australia and the Pacific during the late Holocene were substantially higher than observed historically, a pattern that matches well with archaeological evidence.

See also: Archaeogenetics; Hunter-Gatherers; Paleodemography; World Population Growth.

bibliography

Fagan, Brian. 1996. The Oxford Companion to Archaeology. New York: Oxford University Press.

Flood, Josephine. 1995. Archaeology of the Dreamtime, 3rd edition. Sydney: Angus and Robertson.

Kirch, Patrick Vinton. 1985. Feathered Gods and Fishhooks. Honolulu: University of Hawaii Press.

Irwin, Geoffry. 1992. The Prehistoric Exploration and Colonisation of the Pacific. Cambridge, Eng.: Cambridge University Press.

Meehan, Betty, and Neville White, eds. 1991. Hunter-gatherer Demography: Past and Present. Sydney: University of Sydney.

Spriggs, Matthew. 1997. The Island Melanesians. Oxford, Eng.: Blackwell Publishers.

Peter Hiscock

EUROPE

Europe was the last continent of the Old World to be inhabited by modern humans, but the demographic prehistory of Europe is as long, as rich, and a lot better known that that of any other continent. In spite of the short history of human occupation in Europe, some of the most important evolutionary demographic events took place there.

The First Europeans

About 1.7 million years before present (B.P.), Homo ergaster, the earliest hominid species known in Europe, reached the Caucasus. However, it was a descendant of this species, Homo heidelbergensis thatabout 500,000 b.p. became the first true European. These hominids had a lasting influence, as can be seen from the morphological similarity between European Homo heidelbergensis and the Neanderthals who inhabited most of Europe between 250,000 and 30,000 b.p. Anatomically modern humans–Homo sapiens sapiens–only arrived in the region around 40,000 b.p. The Neanderthals adopted some technological skills from the anatomically modern human population, which indicates that the two groups of humans met and exchanged knowledge and probably genes as well.

There were never many Neanderthals in Europe–100,000 individuals at any one time is probably an absolute maximum size of the population. But the few specimens of identified Neanderthal DNA indicate that the size of the breeding population of Neanderthals was as large as that of anatomically modern humans, as shown by John Relethford (2001). The overall number of Neanderthals probably fluctuated along with changes in mean temperature during the glacial cycles. Eric Trinkaus, in his 1995 study, has concluded, based on a small sample, that the pattern of mortality was similar to that found in prehistoric anatomically modern groups, although the Neanderthals experienced a higher level of young adult mortality.

Anatomically modern man and Neanderthals coexisted in Europe for around 10,000 years. Around 30,000 b.p. the Neanderthals ceased to exist as a culturally and biologically distinct group. What happened to them is a source of considerable debate, but the available evidence is slightly in favor of the survival of some Neanderthal genes in the present European population, according to Relethford.

Anatomically modern man appeared in Europe at the beginning of the Upper Palaeolithic period–about 35,000 b.p.–a period marked by many new and well-made stone and bone tools. The rate of cultural innovation increased markedly at that time, making it possible to date archaeological sites more accurately than those of earlier times. Thus it is possible to track fluctuations in population size through the last stages of the last Ice Age. Climatic changes were the main driving force for changes in population size and distribution. The close association between the area occupied and climate indicates that human adaptive strategies remained basically unchanged over the 25,000 or more years (from around 35,000 to 10,000 b.p.) of the Upper Paleolithic. Only at the end of the Upper Paleolithic is there evidence for the use of a broader array of foods and environments, foreshadowing the subsequent early postglacial Mesolithic period.

Economic Transitions

Since the end of the Ice Age (roughly 10,000 years ago) Europe has experienced two fundamental economic transitions. The first transition, the Neolithic Revolution, saw the earlier hunting-and-gathering way of life of the Mesolithic era replaced by subsistence agriculture as the dominant mode of production. In well-dated areas, such as southern Scandinavia, this transition took place over many centuries. Agriculture, which had originated in the Middle East, spread to Europe from east to west along the Mediterranean and southeast to northwest through Central Europe to the plains of Northern Europe. Agricultural communities appeared in Scandinavia some 3000 years after they first were seen in Greece. This peasant agricultural era spans much of the Neolithic and the Bronze and Iron Ages; it can be termed the Peasant Age.

The second transition was from subsistence to market production. This also took several centuries. It was marked by the development and growth of urban centers.

All parts of Europe have gone through Neolithic Revolutions and market transitions, and these transformations, not the absolute dating of various events, define the demographic prehistory of Europe. For example, the Sami of northernmost Europe entered the first transition at a time when the central parts of the Roman Empire were already entering the second transition.

Prehistoric Mortality

All post-glacial periods have yielded extensive cemeteries, the skeletal remains from which allow estimation of age at death distributions. Very rough rates of infant mortality, average late childhood (age 5 to 18 years) mortality rates, and levels of life expectancy can be inferred.

Table 1 summarizes the broad trends in European mortality in terms of the three indicators from the Mesolithic through the Neolithic revolution, the Peasant Age, and the market transitions to contemporary Europe, partly based on skeletal data from

TABLE 1

Richard Paine and Jesper Boldsen published in 2002. Infant mortality is not as high during the Peasant Age as it later becomes. There is a significant increase in late childhood mortality across the Neolithic Revolution, a high plateau during the Peasant Age, and a decline when trade and urban communities became common.

In Scandinavia the change from subsistence to market production took place very late and can therefore be better described. The process seems to have gone through two steps. First there was a sharp increase in late childhood mortality when the market still was peripheral to the local rural communities, followed by a rapid decline as these communities became fully integrated in the network of market towns and trade relations, according to a 1997 study by Boldsen.

The Driving Force of Demographic Evolution

Although much remains to be learned about European population prehistory, it is clear that fluctuations were common. Phases with relatively steady growth were separated by episodes of collapse, when the population had exceeded the carrying capacity of the environment at the existing technological level. Over the millennia, Europe's population grew along with its technology.

When people became settled during the Neolithic Revolution, local environments became much more polluted with human and animal waste, which increased the risk of infection with gastrointestinal diseases. Such infections tend to affect people of all ages, not only infants and the elderly, and are the reason for the initial increase of late childhood mortality. Some infections left definite signs on skeletons but most did not.

With the growth of trade relations and urban centers, new avenues for the spread of infections were opened. Viral infections such as the great killers, measles and smallpox, could spread widely. These are diseases that leave a lasting immunity in survivors, so large human (host) populations are needed to sustain them as endemic or frequently recurrent diseases. However, all segments of the population were not at equal risk of exposure to the relevant pathogens. In small and relatively isolated rural communities, these crowd infections would die out, only to be reintroduced at a later time when the populations no longer had immunological experience with them. Viral infections striking such virgin populations tend to affect people at all ages and cause widespread mortality. Eventually, as contact with the trade network intensified, the reservoir for the pathogens expanded virtually region-wide and what had been the great killer diseases changed to the childhood diseases that affected European populations within living memory.

See also: Climate Change and Population: History; Disease and History; Paleodemography; World Population Growth.

bibliography

Boldsen, Jesper. 1997. "Patterns of Childhood Mortality in Medieval Scandinavia." Revista di Antropologia 74: 147–159.

Paine, Richard, and Jesper L. Boldsen. 2002. "Linking Age-at-Death Distributions and Ancient Population Dynamics: A Case Study." In Paleodemography: Age Distributions from Skeletal Samples, eds. Robert. D. Hoppa and James. W. Vaupel. Cambridge, Eng.: Cambridge University Press.

Relethford, John. 2001. Genetics and the Search for Modern Human Origins. New York: Wiley-Liss.

Trinkaus, Eric. 1995. "Neanderthal Mortality Patterns." Journal of Archaeological Science 22: 121–142.

Jesper L. Boldsen

THE AMERICAS

Unlike the Old World, where modern humans and their ancestors evolved and underwent a variety of demographic processes over a long period of time, the presence of Homo sapiens in the New World is a relatively recent occurrence, with the first migrations having taken place well after the emergence of anatomically-modern humans in the Old World. When these earliest migrations occurred, however, remains the subject of debate, particularly with respect to how and when people migrated to areas south of northwestern North America.

The Peopling of the New World

Researchers generally agree that the first humans in the New World came from Asia. Evidence for this movement comes from the analysis of biological traits such as tooth morphology and blood types as well as from linguistic relationships between contemporary and historical populations. The traditional assumption is that humans traveled from Siberia to Alaska over a land bridge that is now submerged beneath the Bering Strait.

During periods of glaciation, the last of which occurred about 10,000 years ago, this area, called Beringia, would have been dry land. Based on paleo-climatic reconstructions, it is known that Beringia was exposed from about 60,000 years ago to 18,000 years ago. However, that does not indicate when the first human populations migrated into North America or whether current North American aboriginal populations are descended from the early migrants or from subsequent waves of population movement. There is evidence of human occupation on the southern tip of South America from at least 12,500 years ago and perhaps even earlier; this means that the earliest movements into the New World through Alaska must have occurred substantially earlier than this date.

It is possible that humans came to the New World by water, but there is no evidence for this hypothesis. If this occurred, there should be coastal sites, now submerged under higher seas, that show evidence of human occupation.

Early sites of occupation. The evidence for early human migration into the New World comes from a few archaeological sites. On the basis of those clues, most researchers concede that humans were not present south of Alaska until after about 15,000 years ago. Although there may have been an ice-free corridor during the earliest period of migration into the New World, conditions were not suitable for biggame hunting, which would have been necessary for human survival, until after about 14,000 years ago. As a result, researchers have suggested that migrations southward via this ice-free corridor were not likely until that time.

A possible early human occupation site in the Yukon has been dated to between 12,000 and 27,000 years ago; it would be the oldest known human habitation site in the New World. Nearby, the Bluefish Caves site, also in the Yukon Territory, indicates human occupation through the presence of skeletal remains of mammoth, horse, bison, and caribou in association with stone tools. Radiocarbon dating for this site suggests a date between 15,000 and 12,000 years ago.

Linguistic evidence. Linguistic evidence has been used by Joseph Greenberg and Merritt Ruhlen (1992) to argue that there were three successive waves of migration into the New World. By examining and grouping hundreds of contemporary languages from both North America and South America, those researchers determined that there are three distinct language families. The first group is the Amerind family, which is found throughout Central America and South America and much of North America. The second is the Na-Dené family, which today includes Haida on the northwestern coast of Canada as well as Navaho and Apache in the southwestern United States and various Athapaskan languages. The third is the Inuit-Aleut family. These researchers have suggested that since each of these three groups has a closer relationship to an Asian language family than to any language families in the New World, there were three distinct migrations to the New World from Asia, with the Inuit-Aleut language reflecting the last migration, perhaps some 4000 years ago.

Biological and genetic evidence. Biological evidence from teeth has supported Greenberg and Ruhlen's hypothesis. Christy G. Turner (1989) looked at a variety of morphological aspects of teeth from various New World populations. He noted the presence of common Asian traits, such as shovel-shaped incisors–where the lingual side of the central teeth has a scooped-out or shovel-like appearance–in many New World populations. On the basis of population grouping of similarities, Turner suggested that the distribution of traits fell into the same three distinct groupings identified by Greenberg and Ruhlen from the linguistic evidence.

Genetic analyses have been used to shed light on early migrations. Some have suggested that the Inuit-Aleut population group may in fact have split from Na-Dené in the New World. A number of studies of the distribution of mitochondrial DNA groups and of Y-chromosome haplogroups have suggested that there were one or two major migrations to North America from Asia. However, the distribution of genetic patterns in contemporary New World populations is complicated by admixtures with European and other groups in more recent historical times. This can make it difficult to distinguish ancestral but rare traits from recent rare traits without some collaborative evidence (for example, the interactions of indigenous groups with Europeans) from ethnohistorical sources.

Early Peoples of the New World

The first undisputed human populations in North America are referred to as the Palaeo-Arctic tradition. The earliest well-documented Palaeo-Arctic sites have been identified from stone tools and date to between 8000 b.c.e. and 5000 Human populations reflecting the Palaeo-Arctic tradition occur throughout Alaska, the southwestern Yukon, and the Queen Charlotte Islands in British Columbia. Next there is the movement of human populations into the eastern Canadian Arctic and Greenland, sites denoted archaeologically as the Arctic Small Tool tradition. This tradition evolved into the Norton tradition in Alaska and the Dorset culture in the eastern Arctic. The later Thule tradition developed from the Norton tradition in the area around the Bering Strait. It is the Thule tradition that subsequently spread across the entire Arctic region with the exception of the Aleutian Islands.

By 11,000 years ago the evidence that humans were living in North America south of Canada is clear. Archaeological evidence for the Clovis tradition, named after the first site identified near Clovis, New Mexico, can be found in many areas of North America. After that time there is also some evidence from human skeletal remains. One site has been argued to be pre-Clovis: the Meadowcroft Rockshelter in Pennsylvania, where the lower stratum dates between 19,600 and 8,000 years ago. There are clear indications of human occupation at that site that date to about 12,800 years ago.

Archaeological evidence in the form of tools found in association with the remains of butchered animals provides some clues that can help reconstruct these early populations. For example, the Olsen-Chubbuck site in Colorado is a bison kill site that is reflective of a highly organized population. Joe Wheat (1978) has estimated that the nearly 200 bison remains would have produced as much as 25,000 kilograms (55,500 pounds) of meat and may have been recovered from one kill–enough to feed almost 2,000 people for a month. However, these early populations did not continue to subsist on large mammals.

The archaeological evidence for these earliest Paleo-Indian populations in North America before about 8000 b.c.e. remains sparse, and reconstructions point to very small groups of a few adults and children with low population densities. Their survival depended on their dispersal over large territories, with these groups slowly moving into territories farther east. However, it is known through the presence of trade goods and large-scale kill sites that groups would have come together on a regular basis, forming long-term social networks with each other. Sites, such as Debert in Nova Scotia, that date to around 8600 b.c.e. suggest a group size of fifteen to fifty people who probably subsisted on caribou and sea mammals.

In later times, in conjunction with climatic change and perhaps extinctions of many of the larger mammals in the New World, there is evidence of populations exploring new subsistence strategies. Nevertheless, bison remained an important source of food among the plains populations, with archaeological sites such as Head-Smashed-In in Alberta showing that bison drives were used over a 7000-year span. Although the decreasing availability of big game may have been a factor, population growth may have put additional pressure on food sources. Stress on local carrying capacity probably resulted in the frequent fission of groups that dispersed into new territories. This rapid expansion of Paleo-Indian populations is reflected archaeologically by rapidly diversifying cultural assemblages. Survival would have been heavily dependent on game resources for subsistence, and although it fluctuated locally with irregular peaks, overall population growth would have been steady, with regional differences from western to eastern North America.

Mark Nathan Cohen (1989) has argued that the world was increasingly filling up with hunter-gatherer pulations, and this may have forced them to exploit other, less desirable sources of food. Many researchers have argued, however, that the bulk of population growth throughout the world came about after people began to settle down and develop an agricultural subsistence base. Some support for this theory comes from anthropological studies of contemporary groups that show a reduction in the typical birth spacing in sedentary populations compared with nomadic populations.

The Paleo-Indian populations gave way to Archaic populations after about 8000 b.c.e. For many thousand years after that time North American groups continued to develop as regionally distinct populations. Early large-scale settlements in North America are best exemplified by the Mississippian culture after about 200 c.e., which evolved from the earlier Archaic groups in the Midwest and the South. Characteristic of these early chiefdoms are the large earthenworks and burial mounds associated with their permanent, sedentary communities. Although many were networks of smaller communities, a few settlements, such as Cahokia and Moundville, represent large political centers in the region, housing at their peak perhaps as many as 30,000 inhabitants. Within three centuries the area had been abandoned.

Large-scale population centers emerged in Mesoamerica later than they did in the Old World; this probably was related to the later development of agriculture in the New World. About 500 b.c.e. in the Valley of Oaxaca in southern Mexico there was a unification of individual villages to form larger centers. For example, the city of Monte Albán grew to house about 30,000 people. Slightly later the city-state of Teotihuacán in northeastern Mexico emerged, reaching its height around 2000 years ago. Again, this center probably developed from small, scattered farming villages on the slopes south of the Teotihuacán Valley that were inhabited by a few hundred people each.

Around 500 b.c.e. there seems to have been a population shift to settlements on the floor of the valley, with the emergence of distinct centers within the next few centuries. Between about 150 b.c.e. and 500 c.e. the population of the region grew rapidly from several thousand individuals to well over 100,000. Using skeletal samples, Rebecca Storey (1986) has argued that infant and childhood mortality in Teotihuacán was high, with over one-third of infants dying before age one year. This pattern is consistent with large, overcrowded preindustrial urban centers in Europe, where a variety of diseases had become endemic within the population.

Somewhat later the Mayan city of Copán emerged in what is now Honduras, with classic plazas, pyramids, and temples spanning an area of 30 acres. Estimates have suggested that it experienced rapid population growth, doubling in size every hundred years. Reaching its height between 700 and 850 c.e., Copán would have been home to perhaps 20,000 people. Several other Mesoamerican state societies also developed in the highlands and lowlands of what are now Guatemala and the Yucatán Peninsula. Although they once were thought to be less densely populated than Teotihuacán, it is now believed by archaeologists that the extent of Mayan culture has been underestimated, largely because of the dense tropical forest that now covers much of the remains of Mayan civilization.

Between 800 and 1000 c.e. many lowland Mayan cities were abandoned. The reasons for this collapse are unclear; suggestions include population pressure and resource depletion. Others believe that disease played a role, including an increased incidence of yellow fever as a result of deforestation creating larger breeding grounds for mosquitoes.

Large sedentary populations emerged in South America around 8000 years ago along the coast of Peru. Although estimates of population size vary, archaeological evidence points to long periods of high population density in some areas followed by demographic collapse and decline before the arrival of Europeans. Reconstructions of demographic patterns suggest very high infant and childhood mortality, with up to 50 percent of all children dying under 15 years of age. At its height the Incan empire of Peru had a population of some six million to 13 million people. This population was reduced drastically after European contact in the mid-sixteenth century.

Depopulation

Epidemic diseases introduced by Europeans, such as measles and smallpox, probably played a major role in causing a drastically increased level of mortality among New World populations. Estimates of the scale of depopulation depend on estimates of the total population of the New World before European contact, which range from eight million to over 100 million people. The overall distribution of populations throughout the New World varies, but estimates would place a large portion (over half and as much as three quarters) of the total in Mesoamerica.

Although European contact was certainly devastating, many New World populations had already reached a size at which they could support a variety of endemic diseases. Increased population densities and poor sanitation in many large urban centers, such as Cahokia in North America and the Maya city-states in Mesoamerica, would have imposed on them a variety of health burdens, much like their European counterparts. However, rapid colonization and new diseases, in conjunction with warfare, resulted in extremely high mortality and drastic depopulation among many New World peoples.

See also: Archaeogenetics; Climate Change and Population: History; Environmental Impact, Human; Hunter-Gatherers; Paleodemography; World Population Growth.

bibliography

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Steckel Richard H., and Jerry C. Rose, eds. 2002. The Backbone of History: Health and Nutrition in the Western Hemisphere. Cambridge, Eng.: Cambridge University Press.

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Szathmáry, EmoÕke J. E. 1993. "Genetics of Aboriginal North Americans." Evolutionary Anthropology 1: 202–220.

Turner, Christy G., II. 1989. "Teeth and Prehistory in Asia." Scientific American 260(2): 88–91, 94–96.

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Webster, David, and Ann Corinne Freter. 1990. "The Demography of Late Classic Copan." In Precolumbian Population History in the Maya Lowlands, ed. T. P. Culbert and D. Rice. Albuquerque: University of New Mexico Press.

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Robert D. Hoppa