Chapter Summary and Key Concepts

Learning Objectives

After reading this chapter, students should be able to:

  • discuss the general origins and spread of anatomically modern humans
  • trace the development of H. neanderthalensis in Eurasia
  • trace the development of H. sapiens in Africa
  • describe the major sites and archaeological cultures providing evidence for this period
  • understand the arguments for and against the replacement vs. the multiregional origin models for the origins of modern humans
  • explain the profound behavioral changes associated with modern humans, such as new technology, and the use of symbolism and art
  • understand the difficulties of dating and interpreting fossils during this transition
  • describe the role of DNA research in the overall picture of Middle and Upper Paleolithic studies
  • discuss the debate over the relationship between modern humans and Neanderthals
  • trace the causes of differing biological and cultural evolution among Neanderthals and modern humans
  • explain current theories about the colonization of Europe, Asia, Australia, and the Americas.

Chapter Summary

THE CLIMATIC BACKGROUND

Modern humans evolved in a context of global climatic fluctuation, reflected in oxygen isotope ratios in ice and deep-sea cores. Over the last 400,000 years, there were at least four interglacials, four severe glacials, and stadials/interstadials within and between these. Geological and faunal indicators are correlated to these.

In the north, plant communities flourished or died back, in Africa, wetter or arid periods alternated, allowing human populations to spread initially, but when desert conditions returned, small groups of humans may have been forced to migrate north or east out of Africa. In eastern Asia, climate was relatively stable, perhaps explaining stasis among Homo erectus.

COMPETING HYPOTHESES FOR THE ORIGIN OF Homo sapiens

In the 1940s, a multi-regional origin model was first proposed which stated that Homo sapiens arose from Homo ergaster populations in different areas after they had moved beyond Africa. Gene flow between populations at the edges of larger regions prevented divergence into more then one species. This “multi-regional evolution hypothesis” has several current proponents. By the 1960s, others suggested that modern humans originated in Africa, and then moved out, having already evolved. This theory has been called Noah’s Ark, Garden of Eden, single origins, and Out of Africa hypotheses.

Proponents of these theories never regarded them as mutually exclusive, but they have had a polarizing effect. Intermediary models have also been debated since the late 1980s. Modern genetics and ancient DNA have provided strong but not unequivocal support for a single African origin.

Thus, the four main hypotheses are: 1) an African replacement hypothesis; 2) an African hybridization and replacement hypothesis; 3) an assimilation hypothesis; and 4) a multi-regional evolution hypothesis.

Scholarly opinion is moving toward a consensus that modern humans evolved biologically in Africa. Even the complex Asian fossil record that is used to support multi-regionalism, no longer refutes African origins. Research now centers on how many dispersal events occurred; how these are reflected in modern human genetics; whether language origin was crucial to the process; and whether modern behavior emerged gradually or suddenly. The subsequent spread of modern humans to Australia and the Americas is still hotly contested, and whether own species exchanged ideas, genes, or violence with archaic Homo species.

THE ANATOMY OF Homo sapiens

Characteristics of modern Homo include cranial capacity greater than 1350 cc; a vertical frontal bone (forehead); a high and parallel-walled cranial vault; a rounded occipital region lacking a prominent occipital torus and with a relatively flat angle of the cranial base; a non-continuous brow ridge expressed more clearly in males; a flat, non-projecting face below the expanded frontal braincase region; and a distinct chin. Postcranially, modern Homo sapiens have long limbs with long distal limb segments, which are less robust than archaic Homo species. A tall, long-limbed, short-trunked body, adapted to hot climates, supports an African origin.

EVOLUTION IN LOW LATITUDES: EVIDENCE FOR THE RISE OF MODERN HUMANS IN AFRICA

Fossils pertinent to an African origin are few. Three chronological groupings are: 1) earlier than 250,000 years ago, in which Homo sapiens traits are evident but retentions from Homo ergaster are also evident; 2) between 250,000 and 125,000 years ago, a transitional group with variable primitive and modern traits; and 3) less than 125,000 years ago, clear anatomically modern humans. A degree of morphological continuity is observable between groups.

GENETIC KEYS TO THE ORIGINS OF MODERN HUMANS

Beginning in the 1980s, different measures of genetic variability were tested, especially in the work of Rebecca Cann, including blood groups, mitochondrial DNA, and the Y chromosome, which support a single origin. Interpretations were debated through the 1990s.

ARCHAEOLOGY AND THE EMERGENCE OF “MODERN” BEHAVIOR IN MIDDLE STONE AGE AFRICA

After 100,000 years ago, the archaeological record reveals new behavioral patterns, related to the biological emergence of anatomically modern Homo sapiens suggesting a new cognitive threshold had been crossed. Previously, most work concentrated on Europe and related to a later period, but now a growing number of African Middle Stone Age sites are showing that people displayed modern behavior by 150,000 years ago: personal ornamentation, use of pigments, and possible mortuary rituals.

EVOLUTION IN HIGH LATITUDES: THE NEANDERTHALS

Anatomical changes in African Homo sapiens were most marked in cranial shape with little facial change, while European Neanderthals retained primitive crania but underwent facial modifications.

Neanderthal traits began to appear 450,000 years ago and coalesced by 250,000 years ago, coinciding with increased glacial cycles, and are most pronounced in northern latitudes, suggesting biological adaptation to cold, dry environments and a physically demanding lifestyle. Neanderthals retained cranial vaults resembling H. heidelbergensis and possessed powerful biting musculature. Wear on front teeth suggests use as a vice-like tool. The nasal aperture and sinuses were large, and probably warmed and moistened cold, dry tundra air to protect the brain and respiration. The brain capacity was generally larger than H. sapiens and postcranially, a large body with robust limbs and pronounced muscular insertions were adaptations to habitual physical stress. Relatively short limbs retained body heat.

Most Neanderthals died by their early 40s, a few lived into their 50s. Mortality peaked in infancy and adolescence, coinciding with weaning, and the onset of adult activities, such as hunting. Charred plant remains at some sites indicate that they were important in the diet when available, although stable isotope analyses of bone suggest a diet of up to 90 percent meat. Large, medium, and small animals were scavenged and hunted with hand-thrust spears of wood or with stone points.

Neanderthals produced a Middle Paleolithic lithic industry called Mousterian (after Le Moustier in France). They used the Levallois flaking technique to produce predictably sized flakes and blades, and the discoidal method, yielding as many variously sized flakes as possible. Some were unmodified, others retouched into scrapers, denticulates, notches, points, and bifacial hand axes.

Neanderthals also worked wood, antler, and bone. They commonly constructed simple hearths for warmth, light, and cooking using wood or coal, and sometimes paved wet floors with stones. They used certain areas for trash disposal, tool-making, eating, resting. Some groups buried some of their. Ocher fragments, pigments, and shells are found at several sites, but there is no convincing art.

EARLY DISPERSALS OF Homo sapiens INTO THE LEVANTINE CORRIDOR

The Levant remained a major corridor for movement between Africa and Eurasia. Data suggest that Neanderthals and modern humans were, on occasion, contemporary in this region. Modern humans appeared by 110,000–90,000 years ago at caves in Israel, with possible “grave goods” indicating mortuary rituals, while Neanderthals buried at nearby caves between 60,000 and 50,000 years ago had no ritual indications. Neanderthal burials occur as late as 45,000 years ago but may be as old as 120,000 years ago.

The first unequivocal modern human burials with Upper Paleolithic artifacts occur around 35,000 years ago, although Aurignacian stone and bone tools and bone jewelry from 45,000 years ago indicate they may have been in the Levant earlier. It may be that several discrete occupations reflect major biogeographic changes, with Neanderthals in the region during the severe cold conditions between about 71,000 and 60,000 years ago, when the earlier modern humans had become locally extinct.

Archaeological evidence indicates that at 50,000 years ago, both populations employed Middle Paleolithic Levalloiso-Mousterian toolkits.

THE COLONIZATION OF EAST ASIA AND AUSTRALIA

By at least 40,000 years ago, modern humans had dispersed into South Asia and Australia, the Caucasus and southeast Siberia, and Europe. New technological and social behaviors in the Upper Paleolithic may be linked to modern human expansion.

By c. 40,000 years ago Homo sapiens were present in Sundaland, which was always separated from Sahul Land (Australia and New Guinea) by deep waters, indicating that ocean crossings were necessary. The actual date of colonization has long been debated.

THE COLONIZATION OF EUROPE, AND THE MIDDLE TO UPPER PALEOLITHIC TRANSITION

The distinctive earliest Upper Paleolithic industry in Europe, the Aurignacian (after Aurignac rockshelter, France), indicates that Homo sapiens reached southern Europe by around 45,000 years ago, and expanded along the coastal Mediterranean as far as Iberia by 40,000 years ago, due to mild climatic conditions. General consensus is that the Aurignacian was produced only by Homo sapiens and not by indigenous Neanderthals but there appears to be no hard and fast break between human and Neanderthal behavior.

Aurignacians were well established in Europe by 35,000 years ago and on the northern European plain by around 30,000 years ago. From this time, jewelry from teeth, ivory and shell circulated over a large, established exchange network. Prismatic blade technology was widely employed, and bone and antler points, awls, and needles are related to sophisticated weaponry and elaborate tailored clothing, aiding expansion into Siberia. Art appeared: engraved ivory and bone, and painted and engraved cave walls. There are no convincing burials or dwelling structures, suggesting that a behavioral revolution was incomplete.

Relations between Neanderthals and Incoming Homo sapiens?

It has proved impossible to prove a direct link between the arrival of modern humans and the extinction of Neanderthals. DNA evidence may point to low levels of interbreeding in the Near East.

DEVELOPMENTS IN MODERN BEHAVIOR: THE EUROPEAN MID- AND LATER UPPER PALEOLITHIC

The Gravettian

The Aurignacian ended around 28,000 years ago across Europe, and was succeeded by the Gravettian technocomplex (after La Gravette, France): more regionally distinct groups sharing general characteristics over a large area, between 29,000 to 21,000 years ago (the middle Upper Paleolithic). A later stage, to c. 14,000 years ago in southern and eastern Europe, is referred to as Epigravettian.

A number of regional centers of occupation are recognized in the middle Upper Paleolithic: southwest France, central Europe, Moravia (Czech Republic), and Slovakia. Central European sites were occupied for many months and much effort was invested in dwellings. Over 40 burials, some double and two triple, with a high degree of ornamentation and grave offerings, attest to the development of mortuary activity, such as at Sungir’ (Russia). Symbolic and artistic behavior is seen in “Venus” figurines and continued cave painting and engraving, with hand prints and stencils, human figures and herbivores depicted on complex, multi-phased panels

The Magdalenian

The climate grew most severe between 21,000 and 19,000 years ago, and northern and high-altitude areas were abandoned. Humans crowded into southern European refuges, undergoing marked regionalization due to isolation. In Italy, the Epigravettian, shows clear continuity, but in France and Iberia, new cultures emerged, such as the Solutrean (after Solutré, France).

From 18,000 years ago, as the climate improved, Europe was rapidly recolonized. Late Upper Paleolithic culture is referred to as the Magdalenian technocomplex (after La Madeleine rockshelter, France). First seen in Iberia and southern France, the culture spread to Russia and southern Europe, reaching Britain by 14,000 years ago, where it is called Creswellian. The exchange of stone and shells over 700 km (435 miles) indicates that social networks were open and covered vast areas. Conical points and harpoons appear for the first time in the Late Magdalenian.

Some sites reach very large sizes, and reflect occupation for several months of the year, perhaps a people congregated seasonally. These often contain mobiliary art, such as exquisitely carved animal heads, engraved tools such as shaft-straighteners and atlatl crooks, notated bones, and stylized female carvings

LATE PLEISTOCENE DISPERSALS: COLONIZATION OF THE AMERICAS

No convincing evidence exists for human colonization of the Americas prior to the last 15,000 years, perhaps because earlier, northern, glacial behavioral adaptations had not yet been invented. These then permitted a last, major dispersal.

During glacial periods, lower sea levels where the Bering Strait now lies created the grassland of “Beringia” connecting Siberia to Alaska. It supported mammoth and Upper Paleolithic hunter-gatherers, who crossed it before 10,500 years ago, when Beringia was submerged for the last time. An ice-free corridor between the Laurentide and Cordilleran ice sheets may have served as a way south. Alternatively, the same people may have crossed the Bering Strait by boat, or along Pacific Rim coasts. A third argument, based on similarities in projectile points in western Europe and the USA states that Solutreans made a trans-Atlantic crossing. This is less plausible, as the Solutrean predates the similar American points by at least 5000 years, and such a crossing would have been difficult given the known technology of the period.

Archaeological, genetic, and linguistic data point to eastern Eurasia, especially northeastern Siberia, as the source population for the Americas, with one or more population waves. The relatively poor archaeology does not provide direct evidence of Paleoindian forebears, but artifacts, lifeways, and human skeletons at some sites suggest connections.

Linguistic and genetic evidence point to Asian sources with a complex colonization sequence. Three Native American languages groups, Na Dene, Eskimo-Aleut, and Amerind, may represent a “three wave” colonization. Others argue for one event before 20,000 years ago, after which proto-Paleoindian diverged into the three groups. Genetically, Amerindians fall into five haplotypes or clades that cluster in Siberia. However, there is often little correspondence between linguistic and genetic diversity.

Mitochondrial DNA from living Native Americans is rooted in Siberia or Mongolia, where shovel-shaped incisors are found. Surprising genetic similarity is found among people from Alaska to Brazil, indicating that one dispersal event was primary. Migration from Siberia to Chile occurred by 13,000 years ago, thus some believe that initial dispersal must have been at least 20,000 years ago. The Y chromosome data suggest colonization did not precede 18,000 years ago.

Archaeological visibility improves with the Clovis phenomenon, suggesting either that more humans arrived or that their behavioral strategies became more likely to leave traces in the archaeological record.

Box Features

Key Controversy: The Complex Fossil Record in Asia and Modern Human Emergence

Key Controversy: The Initial Upper Paleolithic and the Emergence of Modern Behavior

Key Controversy: The Evolution Of Language

Key Controversy: The Meaning Of “Venus” Figurines

Key Controversy: Big-Game Extinctions in North America

Key Discovery: The Neanderthal Genome

Key Method: Radiocarbon Dating

Key Site: Klasies River Mouth: Middle Stone Age Hunters?

Key Site: Blombos Cave and the Origins of Symbolism

Key Sites: Four Sites with Upper Paleolithic Art

Key Site: Monte Verde, Chile

Key words and terms

Climate, geography, environment

  • glacial periods
  • deep-sea cores
  • ice cores
  • saw-tooth curves
  • geological and faunal indicators of environmental zones
  • glacial/interglacial
  • stadial/interstadial
  • Eurasia: warm/cold
  • Africa: cycles of arid or wetter periods

Dating methods

  • biostratigraphy
  • electron spin resonance (ESR)
  • uranium series dating
  • thermoluminescence (TL)
  • optically stimulated luminescence (OSL)

Species

  • Homo sapiens
  • Homo ergaster
  • Homo erectus
  • Homo heidelbergensis
  • Homo neanderthalensis

Sites

  • Neander Valley
  • Bodo, Ethiopia
  • Broken Hill (Kabwe), Zambia
  • Elandsfontein (Saldanha), South Africa
  • Ndutu, Tanzania
  • Salé, Morocco
  • Florisbad, South Africa
  • Omo (Kibish), Ethiopia
  • Jebel Irhoud, Morocco
  • Ngaloba (Laetoli), Tanzania
  • Herto, Ethiopia
  • Die Kelders Cave, South Africa
  • Equus Cave, South Africa
  • Makapansgat, South Africa
  • Border Cave, South Africa
  • Klasies River Mouth, South Africa
  • Dar-es-Soltan, Morocco
  • Skhul, Israel
  • Qafzeh, Israel
  • Vindija Cave, Croatia
  • Blombos Cave, South Africa
  • Katanda, Democratic Republic of Congo
  • Howieson’s Poort, South Africa
  • Swanscombe, England
  • Mauer, Germany
  • Atapuerca, Spain
  • Krapina, Croatia
  • Kebara Cave, Israel
  • Dederiyeh Cave, Syria
  • Gorham’s Cave, Gibraltar
  • Umm el Tlel, Syria
  • La Cotte de St. Brelade, Jersey
  • Il’skaya, Russia
  • Salzgitter-Lebenstedt, Germany
  • Shanidar Cave, Iraq
  • Kebara Cave, Israel
  • Vanguard Cave, Gibraltar
  • Le Moustier, France
  • Buran-Kaya III, Ukraine
  • Abric Romaní, Spain
  • Lehringen, Germany
  • La Ferrassie, France
  • Grotta dei Fumane, Italy
  • Tata, Hungary
  • Amud, Israel
  • Tabun, Israel
  • Ksar Akil, Lebanon
  • Niah Cave, Sarawak
  • Willandra Lakes, Australia
  • Kow Swamp, Australia
  • Malakunanja, Australia
  • Lake Mungo, Australia
  • El Castillo, Spain
  • Goyet, Belgium
  • Hohle Fels, Germany
  • Vogelherd Cave, Germany
  • Lagar Velho, Portugal
  • Arcy-sur-Cure, France
  • La Gravette, France
  • Dolni Vestonice, Moravia
  • Pavlov, Moravia
  • Kostenki, Russia
  • Predmosti, Moravia
  • Sungir’, Russia
  • Pech Merle, France
  • Stellmoor, Germany
  • La Madeleine, France
  • Laugerie Haute, France
  • Altamira, Spain
  • Lascaux, France
  • Mezhirich, Russa
  • Brillenhöhle, Germany
  • Uptar, Siberia
  • Folsom, USA
  • Meadowcroft, USA
  • Cactus Hill, USA
  • Taima-Taima, Venezuela
  • Guitarrero, Peru
  • Pikimachay, Peru
  • Monte Verde, Chile
  • Cueva del Medio, Chile
  • Pedra Furada, Brazil
  • Buttermilk Creek, USA
  • Shawnee Minisink, USA
  • Blackwater Draw, USA
  • Debert, Canada

Hypotheses, theories

  • multi-regional evolution hypothesis
  • single origin evolution hypothesis
  • hybridization and replacement model
  • assimilation hypothesis
  • Out of Africa model

People

  • Franz Weidenreich
  • Alan Thorne
  • Milford Wolpoff
  • Louis Leakey
  • W. W. Howells
  • Chris Stringer
  • Peter Andrews
  • Gunter Bräuer
  • Fred Smith
  • Marta Mirazón Lahr
  • Robert Foley
  • Leslie Aiello
  • Richard Klein
  • Philip Rightmire
  • T.F. Dreyer
  • Karl Butzer
  • Rebecca Cann
  • John Relethford
  • Henry Harpending
  • Lewis Binford
  • William King
  • Jean-Jacques Hublin
  • Mary Stiner
  • Sabine Gaudzinski
  • Steven Kuhn
  • François Bordes
  • Paul Mellars
  • Daniel Lieberman and John Shea
  • Joseph Greenberg
  • Christy Turner
  • Stephen Zegura
  • Ryk Ward
  • Thomas Dillehay

Fossils, proposed species

  • the Bodo cranium
  • Homo rhodesiensis
  • Homo helmei
  • Omo 1 and 2
  • Homo sapiens idaltu
  • LH18
  • Irhoud 1 and 2
  • Skhul V cranium
  • Deep Skull
  • Pestera cu Oase mandible
  • Lagar Velho Boy

Genetic evidence

  • nuclear DNA
  • blood groups
  • mitochondrial DNA (mtDNA)
  • Y chromosome
  • mutation rate
  • molecular clock
  • coalescence
  • population bottleneck
  • “Mitochondrial Eve”
  • rate of mutation problems
  • microsatellite DNA
  • population genetics
  • mtDNA diversity

Tools, artifacts, cultures

  • Mousterian
  • Levallois flaking techniques
  • discoidal method
  • edge retouch
  • scrapers, denticulates, notches, points, bifaces (hand axes)
  • Clovis points
  • Aurignacian
  • Gravettian
  • Epigravettian
  • Solutrean
  • Magdalenian technocomplex
  • Creswellian
  • Molodovan
  • Azilian industry